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root / drupal7 / includes / bootstrap.inc @ b0dc3a2e

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<?php
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3
/**
4
 * @file
5
 * Functions that need to be loaded on every Drupal request.
6
 */
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8
/**
9
 * The current system version.
10
 */
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define('VERSION', '7.52');
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/**
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 * Core API compatibility.
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 */
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define('DRUPAL_CORE_COMPATIBILITY', '7.x');
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/**
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 * Minimum supported version of PHP.
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 */
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define('DRUPAL_MINIMUM_PHP', '5.2.4');
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23
/**
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 * Minimum recommended value of PHP memory_limit.
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 */
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define('DRUPAL_MINIMUM_PHP_MEMORY_LIMIT', '32M');
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28
/**
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 * Error reporting level: display no errors.
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 */
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define('ERROR_REPORTING_HIDE', 0);
32

    
33
/**
34
 * Error reporting level: display errors and warnings.
35
 */
36
define('ERROR_REPORTING_DISPLAY_SOME', 1);
37

    
38
/**
39
 * Error reporting level: display all messages.
40
 */
41
define('ERROR_REPORTING_DISPLAY_ALL', 2);
42

    
43
/**
44
 * Indicates that the item should never be removed unless explicitly selected.
45
 *
46
 * The item may be removed using cache_clear_all() with a cache ID.
47
 */
48
define('CACHE_PERMANENT', 0);
49

    
50
/**
51
 * Indicates that the item should be removed at the next general cache wipe.
52
 */
53
define('CACHE_TEMPORARY', -1);
54

    
55
/**
56
 * @defgroup logging_severity_levels Logging severity levels
57
 * @{
58
 * Logging severity levels as defined in RFC 3164.
59
 *
60
 * The WATCHDOG_* constant definitions correspond to the logging severity levels
61
 * defined in RFC 3164, section 4.1.1. PHP supplies predefined LOG_* constants
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 * for use in the syslog() function, but their values on Windows builds do not
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 * correspond to RFC 3164. The associated PHP bug report was closed with the
64
 * comment, "And it's also not a bug, as Windows just have less log levels,"
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 * and "So the behavior you're seeing is perfectly normal."
66
 *
67
 * @see http://www.faqs.org/rfcs/rfc3164.html
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 * @see http://bugs.php.net/bug.php?id=18090
69
 * @see http://php.net/manual/function.syslog.php
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 * @see http://php.net/manual/network.constants.php
71
 * @see watchdog()
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 * @see watchdog_severity_levels()
73
 */
74

    
75
/**
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 * Log message severity -- Emergency: system is unusable.
77
 */
78
define('WATCHDOG_EMERGENCY', 0);
79

    
80
/**
81
 * Log message severity -- Alert: action must be taken immediately.
82
 */
83
define('WATCHDOG_ALERT', 1);
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85
/**
86
 * Log message severity -- Critical conditions.
87
 */
88
define('WATCHDOG_CRITICAL', 2);
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90
/**
91
 * Log message severity -- Error conditions.
92
 */
93
define('WATCHDOG_ERROR', 3);
94

    
95
/**
96
 * Log message severity -- Warning conditions.
97
 */
98
define('WATCHDOG_WARNING', 4);
99

    
100
/**
101
 * Log message severity -- Normal but significant conditions.
102
 */
103
define('WATCHDOG_NOTICE', 5);
104

    
105
/**
106
 * Log message severity -- Informational messages.
107
 */
108
define('WATCHDOG_INFO', 6);
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110
/**
111
 * Log message severity -- Debug-level messages.
112
 */
113
define('WATCHDOG_DEBUG', 7);
114

    
115
/**
116
 * @} End of "defgroup logging_severity_levels".
117
 */
118

    
119
/**
120
 * First bootstrap phase: initialize configuration.
121
 */
122
define('DRUPAL_BOOTSTRAP_CONFIGURATION', 0);
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124
/**
125
 * Second bootstrap phase: try to serve a cached page.
126
 */
127
define('DRUPAL_BOOTSTRAP_PAGE_CACHE', 1);
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129
/**
130
 * Third bootstrap phase: initialize database layer.
131
 */
132
define('DRUPAL_BOOTSTRAP_DATABASE', 2);
133

    
134
/**
135
 * Fourth bootstrap phase: initialize the variable system.
136
 */
137
define('DRUPAL_BOOTSTRAP_VARIABLES', 3);
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139
/**
140
 * Fifth bootstrap phase: initialize session handling.
141
 */
142
define('DRUPAL_BOOTSTRAP_SESSION', 4);
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144
/**
145
 * Sixth bootstrap phase: set up the page header.
146
 */
147
define('DRUPAL_BOOTSTRAP_PAGE_HEADER', 5);
148

    
149
/**
150
 * Seventh bootstrap phase: find out language of the page.
151
 */
152
define('DRUPAL_BOOTSTRAP_LANGUAGE', 6);
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154
/**
155
 * Final bootstrap phase: Drupal is fully loaded; validate and fix input data.
156
 */
157
define('DRUPAL_BOOTSTRAP_FULL', 7);
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159
/**
160
 * Role ID for anonymous users; should match what's in the "role" table.
161
 */
162
define('DRUPAL_ANONYMOUS_RID', 1);
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164
/**
165
 * Role ID for authenticated users; should match what's in the "role" table.
166
 */
167
define('DRUPAL_AUTHENTICATED_RID', 2);
168

    
169
/**
170
 * The number of bytes in a kilobyte.
171
 *
172
 * For more information, visit http://en.wikipedia.org/wiki/Kilobyte.
173
 */
174
define('DRUPAL_KILOBYTE', 1024);
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176
/**
177
 * The language code used when no language is explicitly assigned.
178
 *
179
 * Defined by ISO639-2 for "Undetermined".
180
 */
181
define('LANGUAGE_NONE', 'und');
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183
/**
184
 * The type of language used to define the content language.
185
 */
186
define('LANGUAGE_TYPE_CONTENT', 'language_content');
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188
/**
189
 * The type of language used to select the user interface.
190
 */
191
define('LANGUAGE_TYPE_INTERFACE', 'language');
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193
/**
194
 * The type of language used for URLs.
195
 */
196
define('LANGUAGE_TYPE_URL', 'language_url');
197

    
198
/**
199
 * Language written left to right. Possible value of $language->direction.
200
 */
201
define('LANGUAGE_LTR', 0);
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203
/**
204
 * Language written right to left. Possible value of $language->direction.
205
 */
206
define('LANGUAGE_RTL', 1);
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208
/**
209
 * Time of the current request in seconds elapsed since the Unix Epoch.
210
 *
211
 * This differs from $_SERVER['REQUEST_TIME'], which is stored as a float
212
 * since PHP 5.4.0. Float timestamps confuse most PHP functions
213
 * (including date_create()).
214
 *
215
 * @see http://php.net/manual/reserved.variables.server.php
216
 * @see http://php.net/manual/function.time.php
217
 */
218
define('REQUEST_TIME', (int) $_SERVER['REQUEST_TIME']);
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220
/**
221
 * Flag used to indicate that text is not sanitized, so run check_plain().
222
 *
223
 * @see drupal_set_title()
224
 */
225
define('CHECK_PLAIN', 0);
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227
/**
228
 * Flag used to indicate that text has already been sanitized.
229
 *
230
 * @see drupal_set_title()
231
 */
232
define('PASS_THROUGH', -1);
233

    
234
/**
235
 * Signals that the registry lookup cache should be reset.
236
 */
237
define('REGISTRY_RESET_LOOKUP_CACHE', 1);
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239
/**
240
 * Signals that the registry lookup cache should be written to storage.
241
 */
242
define('REGISTRY_WRITE_LOOKUP_CACHE', 2);
243

    
244
/**
245
 * Regular expression to match PHP function names.
246
 *
247
 * @see http://php.net/manual/language.functions.php
248
 */
249
define('DRUPAL_PHP_FUNCTION_PATTERN', '[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*');
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251
/**
252
 * A RFC7231 Compliant date.
253
 *
254
 * http://tools.ietf.org/html/rfc7231#section-7.1.1.1
255
 *
256
 * Example: Sun, 06 Nov 1994 08:49:37 GMT
257
 */
258
define('DATE_RFC7231', 'D, d M Y H:i:s \G\M\T');
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260
/**
261
 * Provides a caching wrapper to be used in place of large array structures.
262
 *
263
 * This class should be extended by systems that need to cache large amounts
264
 * of data and have it represented as an array to calling functions. These
265
 * arrays can become very large, so ArrayAccess is used to allow different
266
 * strategies to be used for caching internally (lazy loading, building caches
267
 * over time etc.). This can dramatically reduce the amount of data that needs
268
 * to be loaded from cache backends on each request, and memory usage from
269
 * static caches of that same data.
270
 *
271
 * Note that array_* functions do not work with ArrayAccess. Systems using
272
 * DrupalCacheArray should use this only internally. If providing API functions
273
 * that return the full array, this can be cached separately or returned
274
 * directly. However since DrupalCacheArray holds partial content by design, it
275
 * should be a normal PHP array or otherwise contain the full structure.
276
 *
277
 * Note also that due to limitations in PHP prior to 5.3.4, it is impossible to
278
 * write directly to the contents of nested arrays contained in this object.
279
 * Only writes to the top-level array elements are possible. So if you
280
 * previously had set $object['foo'] = array(1, 2, 'bar' => 'baz'), but later
281
 * want to change the value of 'bar' from 'baz' to 'foobar', you cannot do so
282
 * a targeted write like $object['foo']['bar'] = 'foobar'. Instead, you must
283
 * overwrite the entire top-level 'foo' array with the entire set of new
284
 * values: $object['foo'] = array(1, 2, 'bar' => 'foobar'). Due to this same
285
 * limitation, attempts to create references to any contained data, nested or
286
 * otherwise, will fail silently. So $var = &$object['foo'] will not throw an
287
 * error, and $var will be populated with the contents of $object['foo'], but
288
 * that data will be passed by value, not reference. For more information on
289
 * the PHP limitation, see the note in the official PHP documentation at·
290
 * http://php.net/manual/arrayaccess.offsetget.php on
291
 * ArrayAccess::offsetGet().
292
 *
293
 * By default, the class accounts for caches where calling functions might
294
 * request keys in the array that won't exist even after a cache rebuild. This
295
 * prevents situations where a cache rebuild would be triggered over and over
296
 * due to a 'missing' item. These cases are stored internally as a value of
297
 * NULL. This means that the offsetGet() and offsetExists() methods
298
 * must be overridden if caching an array where the top level values can
299
 * legitimately be NULL, and where $object->offsetExists() needs to correctly
300
 * return (equivalent to array_key_exists() vs. isset()). This should not
301
 * be necessary in the majority of cases.
302
 *
303
 * Classes extending this class must override at least the
304
 * resolveCacheMiss() method to have a working implementation.
305
 *
306
 * offsetSet() is not overridden by this class by default. In practice this
307
 * means that assigning an offset via arrayAccess will only apply while the
308
 * object is in scope and will not be written back to the persistent cache.
309
 * This follows a similar pattern to static vs. persistent caching in
310
 * procedural code. Extending classes may wish to alter this behavior, for
311
 * example by overriding offsetSet() and adding an automatic call to persist().
312
 *
313
 * @see SchemaCache
314
 */
315
abstract class DrupalCacheArray implements ArrayAccess {
316

    
317
  /**
318
   * A cid to pass to cache_set() and cache_get().
319
   */
320
  protected $cid;
321

    
322
  /**
323
   * A bin to pass to cache_set() and cache_get().
324
   */
325
  protected $bin;
326

    
327
  /**
328
   * An array of keys to add to the cache at the end of the request.
329
   */
330
  protected $keysToPersist = array();
331

    
332
  /**
333
   * Storage for the data itself.
334
   */
335
  protected $storage = array();
336

    
337
  /**
338
   * Constructs a DrupalCacheArray object.
339
   *
340
   * @param $cid
341
   *   The cid for the array being cached.
342
   * @param $bin
343
   *   The bin to cache the array.
344
   */
345
  public function __construct($cid, $bin) {
346
    $this->cid = $cid;
347
    $this->bin = $bin;
348

    
349
    if ($cached = cache_get($this->cid, $this->bin)) {
350
     $this->storage = $cached->data;
351
    }
352
  }
353

    
354
  /**
355
   * Implements ArrayAccess::offsetExists().
356
   */
357
  public function offsetExists($offset) {
358
    return $this->offsetGet($offset) !== NULL;
359
  }
360

    
361
  /**
362
   * Implements ArrayAccess::offsetGet().
363
   */
364
  public function offsetGet($offset) {
365
    if (isset($this->storage[$offset]) || array_key_exists($offset, $this->storage)) {
366
      return $this->storage[$offset];
367
    }
368
    else {
369
      return $this->resolveCacheMiss($offset);
370
    }
371
  }
372

    
373
  /**
374
   * Implements ArrayAccess::offsetSet().
375
   */
376
  public function offsetSet($offset, $value) {
377
    $this->storage[$offset] = $value;
378
  }
379

    
380
  /**
381
   * Implements ArrayAccess::offsetUnset().
382
   */
383
  public function offsetUnset($offset) {
384
    unset($this->storage[$offset]);
385
  }
386

    
387
  /**
388
   * Flags an offset value to be written to the persistent cache.
389
   *
390
   * If a value is assigned to a cache object with offsetSet(), by default it
391
   * will not be written to the persistent cache unless it is flagged with this
392
   * method. This allows items to be cached for the duration of a request,
393
   * without necessarily writing back to the persistent cache at the end.
394
   *
395
   * @param $offset
396
   *   The array offset that was requested.
397
   * @param $persist
398
   *   Optional boolean to specify whether the offset should be persisted or
399
   *   not, defaults to TRUE. When called with $persist = FALSE the offset will
400
   *   be unflagged so that it will not be written at the end of the request.
401
   */
402
  protected function persist($offset, $persist = TRUE) {
403
    $this->keysToPersist[$offset] = $persist;
404
  }
405

    
406
  /**
407
   * Resolves a cache miss.
408
   *
409
   * When an offset is not found in the object, this is treated as a cache
410
   * miss. This method allows classes implementing the interface to look up
411
   * the actual value and allow it to be cached.
412
   *
413
   * @param $offset
414
   *   The offset that was requested.
415
   *
416
   * @return
417
   *   The value of the offset, or NULL if no value was found.
418
   */
419
  abstract protected function resolveCacheMiss($offset);
420

    
421
  /**
422
   * Writes a value to the persistent cache immediately.
423
   *
424
   * @param $data
425
   *   The data to write to the persistent cache.
426
   * @param $lock
427
   *   Whether to acquire a lock before writing to cache.
428
   */
429
  protected function set($data, $lock = TRUE) {
430
    // Lock cache writes to help avoid stampedes.
431
    // To implement locking for cache misses, override __construct().
432
    $lock_name = $this->cid . ':' . $this->bin;
433
    if (!$lock || lock_acquire($lock_name)) {
434
      if ($cached = cache_get($this->cid, $this->bin)) {
435
        $data = $cached->data + $data;
436
      }
437
      cache_set($this->cid, $data, $this->bin);
438
      if ($lock) {
439
        lock_release($lock_name);
440
      }
441
    }
442
  }
443

    
444
  /**
445
   * Destructs the DrupalCacheArray object.
446
   */
447
  public function __destruct() {
448
    $data = array();
449
    foreach ($this->keysToPersist as $offset => $persist) {
450
      if ($persist) {
451
        $data[$offset] = $this->storage[$offset];
452
      }
453
    }
454
    if (!empty($data)) {
455
      $this->set($data);
456
    }
457
  }
458
}
459

    
460
/**
461
 * Starts the timer with the specified name.
462
 *
463
 * If you start and stop the same timer multiple times, the measured intervals
464
 * will be accumulated.
465
 *
466
 * @param $name
467
 *   The name of the timer.
468
 */
469
function timer_start($name) {
470
  global $timers;
471

    
472
  $timers[$name]['start'] = microtime(TRUE);
473
  $timers[$name]['count'] = isset($timers[$name]['count']) ? ++$timers[$name]['count'] : 1;
474
}
475

    
476
/**
477
 * Reads the current timer value without stopping the timer.
478
 *
479
 * @param $name
480
 *   The name of the timer.
481
 *
482
 * @return
483
 *   The current timer value in ms.
484
 */
485
function timer_read($name) {
486
  global $timers;
487

    
488
  if (isset($timers[$name]['start'])) {
489
    $stop = microtime(TRUE);
490
    $diff = round(($stop - $timers[$name]['start']) * 1000, 2);
491

    
492
    if (isset($timers[$name]['time'])) {
493
      $diff += $timers[$name]['time'];
494
    }
495
    return $diff;
496
  }
497
  return $timers[$name]['time'];
498
}
499

    
500
/**
501
 * Stops the timer with the specified name.
502
 *
503
 * @param $name
504
 *   The name of the timer.
505
 *
506
 * @return
507
 *   A timer array. The array contains the number of times the timer has been
508
 *   started and stopped (count) and the accumulated timer value in ms (time).
509
 */
510
function timer_stop($name) {
511
  global $timers;
512

    
513
  if (isset($timers[$name]['start'])) {
514
    $stop = microtime(TRUE);
515
    $diff = round(($stop - $timers[$name]['start']) * 1000, 2);
516
    if (isset($timers[$name]['time'])) {
517
      $timers[$name]['time'] += $diff;
518
    }
519
    else {
520
      $timers[$name]['time'] = $diff;
521
    }
522
    unset($timers[$name]['start']);
523
  }
524

    
525
  return $timers[$name];
526
}
527

    
528
/**
529
 * Returns the appropriate configuration directory.
530
 *
531
 * Returns the configuration path based on the site's hostname, port, and
532
 * pathname. See default.settings.php for examples on how the URL is converted
533
 * to a directory.
534
 *
535
 * @param bool $require_settings
536
 *   Only configuration directories with an existing settings.php file
537
 *   will be recognized. Defaults to TRUE. During initial installation,
538
 *   this is set to FALSE so that Drupal can detect a matching directory,
539
 *   then create a new settings.php file in it.
540
 * @param bool $reset
541
 *   Force a full search for matching directories even if one had been
542
 *   found previously. Defaults to FALSE.
543
 *
544
 * @return
545
 *   The path of the matching directory.
546
 *
547
 * @see default.settings.php
548
 */
549
function conf_path($require_settings = TRUE, $reset = FALSE) {
550
  $conf = &drupal_static(__FUNCTION__, '');
551

    
552
  if ($conf && !$reset) {
553
    return $conf;
554
  }
555

    
556
  $confdir = 'sites';
557

    
558
  $sites = array();
559
  if (file_exists(DRUPAL_ROOT . '/' . $confdir . '/sites.php')) {
560
    // This will overwrite $sites with the desired mappings.
561
    include(DRUPAL_ROOT . '/' . $confdir . '/sites.php');
562
  }
563

    
564
  $uri = explode('/', $_SERVER['SCRIPT_NAME'] ? $_SERVER['SCRIPT_NAME'] : $_SERVER['SCRIPT_FILENAME']);
565
  $server = explode('.', implode('.', array_reverse(explode(':', rtrim($_SERVER['HTTP_HOST'], '.')))));
566
  for ($i = count($uri) - 1; $i > 0; $i--) {
567
    for ($j = count($server); $j > 0; $j--) {
568
      $dir = implode('.', array_slice($server, -$j)) . implode('.', array_slice($uri, 0, $i));
569
      if (isset($sites[$dir]) && file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $sites[$dir])) {
570
        $dir = $sites[$dir];
571
      }
572
      if (file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $dir . '/settings.php') || (!$require_settings && file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $dir))) {
573
        $conf = "$confdir/$dir";
574
        return $conf;
575
      }
576
    }
577
  }
578
  $conf = "$confdir/default";
579
  return $conf;
580
}
581

    
582
/**
583
 * Sets appropriate server variables needed for command line scripts to work.
584
 *
585
 * This function can be called by command line scripts before bootstrapping
586
 * Drupal, to ensure that the page loads with the desired server parameters.
587
 * This is because many parts of Drupal assume that they are running in a web
588
 * browser and therefore use information from the global PHP $_SERVER variable
589
 * that does not get set when Drupal is run from the command line.
590
 *
591
 * In many cases, the default way in which this function populates the $_SERVER
592
 * variable is sufficient, and it can therefore be called without passing in
593
 * any input. However, command line scripts running on a multisite installation
594
 * (or on any installation that has settings.php stored somewhere other than
595
 * the sites/default folder) need to pass in the URL of the site to allow
596
 * Drupal to detect the correct location of the settings.php file. Passing in
597
 * the 'url' parameter is also required for functions like request_uri() to
598
 * return the expected values.
599
 *
600
 * Most other parameters do not need to be passed in, but may be necessary in
601
 * some cases; for example, if Drupal's ip_address() function needs to return
602
 * anything but the standard localhost value ('127.0.0.1'), the command line
603
 * script should pass in the desired value via the 'REMOTE_ADDR' key.
604
 *
605
 * @param $variables
606
 *   (optional) An associative array of variables within $_SERVER that should
607
 *   be replaced. If the special element 'url' is provided in this array, it
608
 *   will be used to populate some of the server defaults; it should be set to
609
 *   the URL of the current page request, excluding any $_GET request but
610
 *   including the script name (e.g., http://www.example.com/mysite/index.php).
611
 *
612
 * @see conf_path()
613
 * @see request_uri()
614
 * @see ip_address()
615
 */
616
function drupal_override_server_variables($variables = array()) {
617
  // Allow the provided URL to override any existing values in $_SERVER.
618
  if (isset($variables['url'])) {
619
    $url = parse_url($variables['url']);
620
    if (isset($url['host'])) {
621
      $_SERVER['HTTP_HOST'] = $url['host'];
622
    }
623
    if (isset($url['path'])) {
624
      $_SERVER['SCRIPT_NAME'] = $url['path'];
625
    }
626
    unset($variables['url']);
627
  }
628
  // Define default values for $_SERVER keys. These will be used if $_SERVER
629
  // does not already define them and no other values are passed in to this
630
  // function.
631
  $defaults = array(
632
    'HTTP_HOST' => 'localhost',
633
    'SCRIPT_NAME' => NULL,
634
    'REMOTE_ADDR' => '127.0.0.1',
635
    'REQUEST_METHOD' => 'GET',
636
    'SERVER_NAME' => NULL,
637
    'SERVER_SOFTWARE' => NULL,
638
    'HTTP_USER_AGENT' => NULL,
639
  );
640
  // Replace elements of the $_SERVER array, as appropriate.
641
  $_SERVER = $variables + $_SERVER + $defaults;
642
}
643

    
644
/**
645
 * Initializes the PHP environment.
646
 */
647
function drupal_environment_initialize() {
648
  if (!isset($_SERVER['HTTP_REFERER'])) {
649
    $_SERVER['HTTP_REFERER'] = '';
650
  }
651
  if (!isset($_SERVER['SERVER_PROTOCOL']) || ($_SERVER['SERVER_PROTOCOL'] != 'HTTP/1.0' && $_SERVER['SERVER_PROTOCOL'] != 'HTTP/1.1')) {
652
    $_SERVER['SERVER_PROTOCOL'] = 'HTTP/1.0';
653
  }
654

    
655
  if (isset($_SERVER['HTTP_HOST'])) {
656
    // As HTTP_HOST is user input, ensure it only contains characters allowed
657
    // in hostnames. See RFC 952 (and RFC 2181).
658
    // $_SERVER['HTTP_HOST'] is lowercased here per specifications.
659
    $_SERVER['HTTP_HOST'] = strtolower($_SERVER['HTTP_HOST']);
660
    if (!drupal_valid_http_host($_SERVER['HTTP_HOST'])) {
661
      // HTTP_HOST is invalid, e.g. if containing slashes it may be an attack.
662
      header($_SERVER['SERVER_PROTOCOL'] . ' 400 Bad Request');
663
      exit;
664
    }
665
  }
666
  else {
667
    // Some pre-HTTP/1.1 clients will not send a Host header. Ensure the key is
668
    // defined for E_ALL compliance.
669
    $_SERVER['HTTP_HOST'] = '';
670
  }
671

    
672
  // When clean URLs are enabled, emulate ?q=foo/bar using REQUEST_URI. It is
673
  // not possible to append the query string using mod_rewrite without the B
674
  // flag (this was added in Apache 2.2.8), because mod_rewrite unescapes the
675
  // path before passing it on to PHP. This is a problem when the path contains
676
  // e.g. "&" or "%" that have special meanings in URLs and must be encoded.
677
  $_GET['q'] = request_path();
678

    
679
  // Enforce E_ALL, but allow users to set levels not part of E_ALL.
680
  error_reporting(E_ALL | error_reporting());
681

    
682
  // Override PHP settings required for Drupal to work properly.
683
  // sites/default/default.settings.php contains more runtime settings.
684
  // The .htaccess file contains settings that cannot be changed at runtime.
685

    
686
  // Don't escape quotes when reading files from the database, disk, etc.
687
  ini_set('magic_quotes_runtime', '0');
688
  // Use session cookies, not transparent sessions that puts the session id in
689
  // the query string.
690
  ini_set('session.use_cookies', '1');
691
  ini_set('session.use_only_cookies', '1');
692
  ini_set('session.use_trans_sid', '0');
693
  // Don't send HTTP headers using PHP's session handler.
694
  // An empty string is used here to disable the cache limiter.
695
  ini_set('session.cache_limiter', '');
696
  // Use httponly session cookies.
697
  ini_set('session.cookie_httponly', '1');
698

    
699
  // Set sane locale settings, to ensure consistent string, dates, times and
700
  // numbers handling.
701
  setlocale(LC_ALL, 'C');
702
}
703

    
704
/**
705
 * Validates that a hostname (for example $_SERVER['HTTP_HOST']) is safe.
706
 *
707
 * @return
708
 *  TRUE if only containing valid characters, or FALSE otherwise.
709
 */
710
function drupal_valid_http_host($host) {
711
  // Limit the length of the host name to 1000 bytes to prevent DoS attacks with
712
  // long host names.
713
  return strlen($host) <= 1000
714
    // Limit the number of subdomains and port separators to prevent DoS attacks
715
    // in conf_path().
716
    && substr_count($host, '.') <= 100
717
    && substr_count($host, ':') <= 100
718
    && preg_match('/^\[?(?:[a-zA-Z0-9-:\]_]+\.?)+$/', $host);
719
}
720

    
721
/**
722
 * Sets the base URL, cookie domain, and session name from configuration.
723
 */
724
function drupal_settings_initialize() {
725
  global $base_url, $base_path, $base_root;
726

    
727
  // Export these settings.php variables to the global namespace.
728
  global $databases, $cookie_domain, $conf, $installed_profile, $update_free_access, $db_url, $db_prefix, $drupal_hash_salt, $is_https, $base_secure_url, $base_insecure_url;
729
  $conf = array();
730

    
731
  if (file_exists(DRUPAL_ROOT . '/' . conf_path() . '/settings.php')) {
732
    include_once DRUPAL_ROOT . '/' . conf_path() . '/settings.php';
733
  }
734
  $is_https = isset($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) == 'on';
735

    
736
  if (isset($base_url)) {
737
    // Parse fixed base URL from settings.php.
738
    $parts = parse_url($base_url);
739
    if (!isset($parts['path'])) {
740
      $parts['path'] = '';
741
    }
742
    $base_path = $parts['path'] . '/';
743
    // Build $base_root (everything until first slash after "scheme://").
744
    $base_root = substr($base_url, 0, strlen($base_url) - strlen($parts['path']));
745
  }
746
  else {
747
    // Create base URL.
748
    $http_protocol = $is_https ? 'https' : 'http';
749
    $base_root = $http_protocol . '://' . $_SERVER['HTTP_HOST'];
750

    
751
    $base_url = $base_root;
752

    
753
    // $_SERVER['SCRIPT_NAME'] can, in contrast to $_SERVER['PHP_SELF'], not
754
    // be modified by a visitor.
755
    if ($dir = rtrim(dirname($_SERVER['SCRIPT_NAME']), '\/')) {
756
      $base_path = $dir;
757
      $base_url .= $base_path;
758
      $base_path .= '/';
759
    }
760
    else {
761
      $base_path = '/';
762
    }
763
  }
764
  $base_secure_url = str_replace('http://', 'https://', $base_url);
765
  $base_insecure_url = str_replace('https://', 'http://', $base_url);
766

    
767
  if ($cookie_domain) {
768
    // If the user specifies the cookie domain, also use it for session name.
769
    $session_name = $cookie_domain;
770
  }
771
  else {
772
    // Otherwise use $base_url as session name, without the protocol
773
    // to use the same session identifiers across HTTP and HTTPS.
774
    list( , $session_name) = explode('://', $base_url, 2);
775
    // HTTP_HOST can be modified by a visitor, but we already sanitized it
776
    // in drupal_settings_initialize().
777
    if (!empty($_SERVER['HTTP_HOST'])) {
778
      $cookie_domain = $_SERVER['HTTP_HOST'];
779
      // Strip leading periods, www., and port numbers from cookie domain.
780
      $cookie_domain = ltrim($cookie_domain, '.');
781
      if (strpos($cookie_domain, 'www.') === 0) {
782
        $cookie_domain = substr($cookie_domain, 4);
783
      }
784
      $cookie_domain = explode(':', $cookie_domain);
785
      $cookie_domain = '.' . $cookie_domain[0];
786
    }
787
  }
788
  // Per RFC 2109, cookie domains must contain at least one dot other than the
789
  // first. For hosts such as 'localhost' or IP Addresses we don't set a cookie domain.
790
  if (count(explode('.', $cookie_domain)) > 2 && !is_numeric(str_replace('.', '', $cookie_domain))) {
791
    ini_set('session.cookie_domain', $cookie_domain);
792
  }
793
  // To prevent session cookies from being hijacked, a user can configure the
794
  // SSL version of their website to only transfer session cookies via SSL by
795
  // using PHP's session.cookie_secure setting. The browser will then use two
796
  // separate session cookies for the HTTPS and HTTP versions of the site. So we
797
  // must use different session identifiers for HTTPS and HTTP to prevent a
798
  // cookie collision.
799
  if ($is_https) {
800
    ini_set('session.cookie_secure', TRUE);
801
  }
802
  $prefix = ini_get('session.cookie_secure') ? 'SSESS' : 'SESS';
803
  session_name($prefix . substr(hash('sha256', $session_name), 0, 32));
804
}
805

    
806
/**
807
 * Returns and optionally sets the filename for a system resource.
808
 *
809
 * The filename, whether provided, cached, or retrieved from the database, is
810
 * only returned if the file exists.
811
 *
812
 * This function plays a key role in allowing Drupal's resources (modules
813
 * and themes) to be located in different places depending on a site's
814
 * configuration. For example, a module 'foo' may legally be located
815
 * in any of these three places:
816
 *
817
 * modules/foo/foo.module
818
 * sites/all/modules/foo/foo.module
819
 * sites/example.com/modules/foo/foo.module
820
 *
821
 * Calling drupal_get_filename('module', 'foo') will give you one of
822
 * the above, depending on where the module is located.
823
 *
824
 * @param $type
825
 *   The type of the item (theme, theme_engine, module, profile).
826
 * @param $name
827
 *   The name of the item for which the filename is requested.
828
 * @param $filename
829
 *   The filename of the item if it is to be set explicitly rather
830
 *   than by consulting the database.
831
 * @param bool $trigger_error
832
 *   Whether to trigger an error when a file is missing or has unexpectedly
833
 *   moved. This defaults to TRUE, but can be set to FALSE by calling code that
834
 *   merely wants to check whether an item exists in the filesystem.
835
 *
836
 * @return
837
 *   The filename of the requested item or NULL if the item is not found.
838
 */
839
function drupal_get_filename($type, $name, $filename = NULL, $trigger_error = TRUE) {
840
  // The $files static variable will hold the locations of all requested files.
841
  // We can be sure that any file listed in this static variable actually
842
  // exists as all additions have gone through a file_exists() check.
843
  // The location of files will not change during the request, so do not use
844
  // drupal_static().
845
  static $files = array();
846

    
847
  // Profiles are a special case: they have a fixed location and naming.
848
  if ($type == 'profile') {
849
    $profile_filename = "profiles/$name/$name.profile";
850
    $files[$type][$name] = file_exists($profile_filename) ? $profile_filename : FALSE;
851
  }
852
  if (!isset($files[$type])) {
853
    $files[$type] = array();
854
  }
855

    
856
  if (!empty($filename) && file_exists($filename)) {
857
    // Prime the static cache with the provided filename.
858
    $files[$type][$name] = $filename;
859
  }
860
  elseif (isset($files[$type][$name])) {
861
    // This item had already been found earlier in the request, either through
862
    // priming of the static cache (for example, in system_list()), through a
863
    // lookup in the {system} table, or through a file scan (cached or not). Do
864
    // nothing.
865
  }
866
  else {
867
    // Look for the filename listed in the {system} table. Verify that we have
868
    // an active database connection before doing so, since this function is
869
    // called both before we have a database connection (i.e. during
870
    // installation) and when a database connection fails.
871
    $database_unavailable = TRUE;
872
    try {
873
      if (function_exists('db_query')) {
874
        $file = db_query("SELECT filename FROM {system} WHERE name = :name AND type = :type", array(':name' => $name, ':type' => $type))->fetchField();
875
        if ($file !== FALSE && file_exists(DRUPAL_ROOT . '/' . $file)) {
876
          $files[$type][$name] = $file;
877
        }
878
        $database_unavailable = FALSE;
879
      }
880
    }
881
    catch (Exception $e) {
882
      // The database table may not exist because Drupal is not yet installed,
883
      // the database might be down, or we may have done a non-database cache
884
      // flush while $conf['page_cache_without_database'] = TRUE and
885
      // $conf['page_cache_invoke_hooks'] = TRUE. We have a fallback for these
886
      // cases so we hide the error completely.
887
    }
888
    // Fall back to searching the filesystem if the database could not find the
889
    // file or the file does not exist at the path returned by the database.
890
    if (!isset($files[$type][$name])) {
891
      $files[$type][$name] = _drupal_get_filename_fallback($type, $name, $trigger_error, $database_unavailable);
892
    }
893
  }
894

    
895
  if (isset($files[$type][$name])) {
896
    return $files[$type][$name];
897
  }
898
}
899

    
900
/**
901
 * Performs a cached file system scan as a fallback when searching for a file.
902
 *
903
 * This function looks for the requested file by triggering a file scan,
904
 * caching the new location if the file has moved and caching the miss
905
 * if the file is missing. If a file had been marked as missing in a previous
906
 * file scan, or if it has been marked as moved and is still in the last known
907
 * location, no new file scan will be performed.
908
 *
909
 * @param string $type
910
 *   The type of the item (theme, theme_engine, module, profile).
911
 * @param string $name
912
 *   The name of the item for which the filename is requested.
913
 * @param bool $trigger_error
914
 *   Whether to trigger an error when a file is missing or has unexpectedly
915
 *   moved.
916
 * @param bool $database_unavailable
917
 *   Whether this function is being called because the Drupal database could
918
 *   not be queried for the file's location.
919
 *
920
 * @return
921
 *   The filename of the requested item or NULL if the item is not found.
922
 *
923
 * @see drupal_get_filename()
924
 */
925
function _drupal_get_filename_fallback($type, $name, $trigger_error, $database_unavailable) {
926
  $file_scans = &_drupal_file_scan_cache();
927
  $filename = NULL;
928

    
929
  // If the cache indicates that the item is missing, or we can verify that the
930
  // item exists in the location the cache says it exists in, use that.
931
  if (isset($file_scans[$type][$name]) && ($file_scans[$type][$name] === FALSE || file_exists($file_scans[$type][$name]))) {
932
    $filename = $file_scans[$type][$name];
933
  }
934
  // Otherwise, perform a new file scan to find the item.
935
  else {
936
    $filename = _drupal_get_filename_perform_file_scan($type, $name);
937
    // Update the static cache, and mark the persistent cache for updating at
938
    // the end of the page request. See drupal_file_scan_write_cache().
939
    $file_scans[$type][$name] = $filename;
940
    $file_scans['#write_cache'] = TRUE;
941
  }
942

    
943
  // If requested, trigger a user-level warning about the missing or
944
  // unexpectedly moved file. If the database was unavailable, do not trigger a
945
  // warning in the latter case, though, since if the {system} table could not
946
  // be queried there is no way to know if the location found here was
947
  // "unexpected" or not.
948
  if ($trigger_error) {
949
    $error_type = $filename === FALSE ? 'missing' : 'moved';
950
    if ($error_type == 'missing' || !$database_unavailable) {
951
      _drupal_get_filename_fallback_trigger_error($type, $name, $error_type);
952
    }
953
  }
954

    
955
  // The cache stores FALSE for files that aren't found (to be able to
956
  // distinguish them from files that have not yet been searched for), but
957
  // drupal_get_filename() expects NULL for these instead, so convert to NULL
958
  // before returning.
959
  if ($filename === FALSE) {
960
    $filename = NULL;
961
  }
962
  return $filename;
963
}
964

    
965
/**
966
 * Returns the current list of cached file system scan results.
967
 *
968
 * @return
969
 *   An associative array tracking the most recent file scan results for all
970
 *   files that have had scans performed. The keys are the type and name of the
971
 *   item that was searched for, and the values can be either:
972
 *   - Boolean FALSE if the item was not found in the file system.
973
 *   - A string pointing to the location where the item was found.
974
 */
975
function &_drupal_file_scan_cache() {
976
  $file_scans = &drupal_static(__FUNCTION__, array());
977

    
978
  // The file scan results are stored in a persistent cache (in addition to the
979
  // static cache) but because this function can be called before the
980
  // persistent cache is available, we must merge any items that were found
981
  // earlier in the page request into the results from the persistent cache.
982
  if (!isset($file_scans['#cache_merge_done'])) {
983
    try {
984
      if (function_exists('cache_get')) {
985
        $cache = cache_get('_drupal_file_scan_cache', 'cache_bootstrap');
986
        if (!empty($cache->data)) {
987
          // File scan results from the current request should take precedence
988
          // over the results from the persistent cache, since they are newer.
989
          $file_scans = drupal_array_merge_deep($cache->data, $file_scans);
990
        }
991
        // Set a flag to indicate that the persistent cache does not need to be
992
        // merged again.
993
        $file_scans['#cache_merge_done'] = TRUE;
994
      }
995
    }
996
    catch (Exception $e) {
997
      // Hide the error.
998
    }
999
  }
1000

    
1001
  return $file_scans;
1002
}
1003

    
1004
/**
1005
 * Performs a file system scan to search for a system resource.
1006
 *
1007
 * @param $type
1008
 *   The type of the item (theme, theme_engine, module, profile).
1009
 * @param $name
1010
 *   The name of the item for which the filename is requested.
1011
 *
1012
 * @return
1013
 *   The filename of the requested item or FALSE if the item is not found.
1014
 *
1015
 * @see drupal_get_filename()
1016
 * @see _drupal_get_filename_fallback()
1017
 */
1018
function _drupal_get_filename_perform_file_scan($type, $name) {
1019
  // The location of files will not change during the request, so do not use
1020
  // drupal_static().
1021
  static $dirs = array(), $files = array();
1022

    
1023
  // We have a consistent directory naming: modules, themes...
1024
  $dir = $type . 's';
1025
  if ($type == 'theme_engine') {
1026
    $dir = 'themes/engines';
1027
    $extension = 'engine';
1028
  }
1029
  elseif ($type == 'theme') {
1030
    $extension = 'info';
1031
  }
1032
  else {
1033
    $extension = $type;
1034
  }
1035

    
1036
  // Check if we had already scanned this directory/extension combination.
1037
  if (!isset($dirs[$dir][$extension])) {
1038
    // Log that we have now scanned this directory/extension combination
1039
    // into a static variable so as to prevent unnecessary file scans.
1040
    $dirs[$dir][$extension] = TRUE;
1041
    if (!function_exists('drupal_system_listing')) {
1042
      require_once DRUPAL_ROOT . '/includes/common.inc';
1043
    }
1044
    // Scan the appropriate directories for all files with the requested
1045
    // extension, not just the file we are currently looking for. This
1046
    // prevents unnecessary scans from being repeated when this function is
1047
    // called more than once in the same page request.
1048
    $matches = drupal_system_listing("/^" . DRUPAL_PHP_FUNCTION_PATTERN . "\.$extension$/", $dir, 'name', 0);
1049
    foreach ($matches as $matched_name => $file) {
1050
      // Log the locations found in the file scan into a static variable.
1051
      $files[$type][$matched_name] = $file->uri;
1052
    }
1053
  }
1054

    
1055
  // Return the results of the file system scan, or FALSE to indicate the file
1056
  // was not found.
1057
  return isset($files[$type][$name]) ? $files[$type][$name] : FALSE;
1058
}
1059

    
1060
/**
1061
 * Triggers a user-level warning for missing or unexpectedly moved files.
1062
 *
1063
 * @param $type
1064
 *   The type of the item (theme, theme_engine, module, profile).
1065
 * @param $name
1066
 *   The name of the item for which the filename is requested.
1067
 * @param $error_type
1068
 *   The type of the error ('missing' or 'moved').
1069
 *
1070
 * @see drupal_get_filename()
1071
 * @see _drupal_get_filename_fallback()
1072
 */
1073
function _drupal_get_filename_fallback_trigger_error($type, $name, $error_type) {
1074
  // Hide messages due to known bugs that will appear on a lot of sites.
1075
  // @todo Remove this in https://www.drupal.org/node/2383823
1076
  if (empty($name)) {
1077
    return;
1078
  }
1079

    
1080
  // Make sure we only show any missing or moved file errors only once per
1081
  // request.
1082
  static $errors_triggered = array();
1083
  if (empty($errors_triggered[$type][$name][$error_type])) {
1084
    // Use _drupal_trigger_error_with_delayed_logging() here since these are
1085
    // triggered during low-level operations that cannot necessarily be
1086
    // interrupted by a watchdog() call.
1087
    if ($error_type == 'missing') {
1088
      _drupal_trigger_error_with_delayed_logging(format_string('The following @type is missing from the file system: %name. For information about how to fix this, see <a href="@documentation">the documentation page</a>.', array('@type' => $type, '%name' => $name, '@documentation' => 'https://www.drupal.org/node/2487215')), E_USER_WARNING);
1089
    }
1090
    elseif ($error_type == 'moved') {
1091
      _drupal_trigger_error_with_delayed_logging(format_string('The following @type has moved within the file system: %name. In order to fix this, clear caches or put the @type back in its original location. For more information, see <a href="@documentation">the documentation page</a>.', array('@type' => $type, '%name' => $name, '@documentation' => 'https://www.drupal.org/node/2487215')), E_USER_WARNING);
1092
    }
1093
    $errors_triggered[$type][$name][$error_type] = TRUE;
1094
  }
1095
}
1096

    
1097
/**
1098
 * Invokes trigger_error() with logging delayed until the end of the request.
1099
 *
1100
 * This is an alternative to PHP's trigger_error() function which can be used
1101
 * during low-level Drupal core operations that need to avoid being interrupted
1102
 * by a watchdog() call.
1103
 *
1104
 * Normally, Drupal's error handler calls watchdog() in response to a
1105
 * trigger_error() call. However, this invokes hook_watchdog() which can run
1106
 * arbitrary code. If the trigger_error() happens in the middle of an
1107
 * operation such as a rebuild operation which should not be interrupted by
1108
 * arbitrary code, that could potentially break or trigger the rebuild again.
1109
 * This function protects against that by delaying the watchdog() call until
1110
 * the end of the current page request.
1111
 *
1112
 * This is an internal function which should only be called by low-level Drupal
1113
 * core functions. It may be removed in a future Drupal 7 release.
1114
 *
1115
 * @param string $error_msg
1116
 *   The error message to trigger. As with trigger_error() itself, this is
1117
 *   limited to 1024 bytes; additional characters beyond that will be removed.
1118
 * @param int $error_type
1119
 *   (optional) The type of error. This should be one of the E_USER family of
1120
 *   constants. As with trigger_error() itself, this defaults to E_USER_NOTICE
1121
 *   if not provided.
1122
 *
1123
 * @see _drupal_log_error()
1124
 */
1125
function _drupal_trigger_error_with_delayed_logging($error_msg, $error_type = E_USER_NOTICE) {
1126
  $delay_logging = &drupal_static(__FUNCTION__, FALSE);
1127
  $delay_logging = TRUE;
1128
  trigger_error($error_msg, $error_type);
1129
  $delay_logging = FALSE;
1130
}
1131

    
1132
/**
1133
 * Writes the file scan cache to the persistent cache.
1134
 *
1135
 * This cache stores all files marked as missing or moved after a file scan
1136
 * to prevent unnecessary file scans in subsequent requests. This cache is
1137
 * cleared in system_list_reset() (i.e. after a module/theme rebuild).
1138
 */
1139
function drupal_file_scan_write_cache() {
1140
  // Only write to the persistent cache if requested, and if we know that any
1141
  // data previously in the cache was successfully loaded and merged in by
1142
  // _drupal_file_scan_cache().
1143
  $file_scans = &_drupal_file_scan_cache();
1144
  if (isset($file_scans['#write_cache']) && isset($file_scans['#cache_merge_done'])) {
1145
    unset($file_scans['#write_cache']);
1146
    cache_set('_drupal_file_scan_cache', $file_scans, 'cache_bootstrap');
1147
  }
1148
}
1149

    
1150
/**
1151
 * Loads the persistent variable table.
1152
 *
1153
 * The variable table is composed of values that have been saved in the table
1154
 * with variable_set() as well as those explicitly specified in the
1155
 * configuration file.
1156
 */
1157
function variable_initialize($conf = array()) {
1158
  // NOTE: caching the variables improves performance by 20% when serving
1159
  // cached pages.
1160
  if ($cached = cache_get('variables', 'cache_bootstrap')) {
1161
    $variables = $cached->data;
1162
  }
1163
  else {
1164
    // Cache miss. Avoid a stampede.
1165
    $name = 'variable_init';
1166
    if (!lock_acquire($name, 1)) {
1167
      // Another request is building the variable cache.
1168
      // Wait, then re-run this function.
1169
      lock_wait($name);
1170
      return variable_initialize($conf);
1171
    }
1172
    else {
1173
      // Proceed with variable rebuild.
1174
      $variables = array_map('unserialize', db_query('SELECT name, value FROM {variable}')->fetchAllKeyed());
1175
      cache_set('variables', $variables, 'cache_bootstrap');
1176
      lock_release($name);
1177
    }
1178
  }
1179

    
1180
  foreach ($conf as $name => $value) {
1181
    $variables[$name] = $value;
1182
  }
1183

    
1184
  return $variables;
1185
}
1186

    
1187
/**
1188
 * Returns a persistent variable.
1189
 *
1190
 * Case-sensitivity of the variable_* functions depends on the database
1191
 * collation used. To avoid problems, always use lower case for persistent
1192
 * variable names.
1193
 *
1194
 * @param $name
1195
 *   The name of the variable to return.
1196
 * @param $default
1197
 *   The default value to use if this variable has never been set.
1198
 *
1199
 * @return
1200
 *   The value of the variable. Unserialization is taken care of as necessary.
1201
 *
1202
 * @see variable_del()
1203
 * @see variable_set()
1204
 */
1205
function variable_get($name, $default = NULL) {
1206
  global $conf;
1207

    
1208
  return isset($conf[$name]) ? $conf[$name] : $default;
1209
}
1210

    
1211
/**
1212
 * Sets a persistent variable.
1213
 *
1214
 * Case-sensitivity of the variable_* functions depends on the database
1215
 * collation used. To avoid problems, always use lower case for persistent
1216
 * variable names.
1217
 *
1218
 * @param $name
1219
 *   The name of the variable to set.
1220
 * @param $value
1221
 *   The value to set. This can be any PHP data type; these functions take care
1222
 *   of serialization as necessary.
1223
 *
1224
 * @see variable_del()
1225
 * @see variable_get()
1226
 */
1227
function variable_set($name, $value) {
1228
  global $conf;
1229

    
1230
  db_merge('variable')->key(array('name' => $name))->fields(array('value' => serialize($value)))->execute();
1231

    
1232
  cache_clear_all('variables', 'cache_bootstrap');
1233

    
1234
  $conf[$name] = $value;
1235
}
1236

    
1237
/**
1238
 * Unsets a persistent variable.
1239
 *
1240
 * Case-sensitivity of the variable_* functions depends on the database
1241
 * collation used. To avoid problems, always use lower case for persistent
1242
 * variable names.
1243
 *
1244
 * @param $name
1245
 *   The name of the variable to undefine.
1246
 *
1247
 * @see variable_get()
1248
 * @see variable_set()
1249
 */
1250
function variable_del($name) {
1251
  global $conf;
1252

    
1253
  db_delete('variable')
1254
    ->condition('name', $name)
1255
    ->execute();
1256
  cache_clear_all('variables', 'cache_bootstrap');
1257

    
1258
  unset($conf[$name]);
1259
}
1260

    
1261
/**
1262
 * Retrieves the current page from the cache.
1263
 *
1264
 * Note: we do not serve cached pages to authenticated users, or to anonymous
1265
 * users when $_SESSION is non-empty. $_SESSION may contain status messages
1266
 * from a form submission, the contents of a shopping cart, or other user-
1267
 * specific content that should not be cached and displayed to other users.
1268
 *
1269
 * @param $check_only
1270
 *   (optional) Set to TRUE to only return whether a previous call found a
1271
 *   cache entry.
1272
 *
1273
 * @return
1274
 *   The cache object, if the page was found in the cache, NULL otherwise.
1275
 */
1276
function drupal_page_get_cache($check_only = FALSE) {
1277
  global $base_root;
1278
  static $cache_hit = FALSE;
1279

    
1280
  if ($check_only) {
1281
    return $cache_hit;
1282
  }
1283

    
1284
  if (drupal_page_is_cacheable()) {
1285
    $cache = cache_get($base_root . request_uri(), 'cache_page');
1286
    if ($cache !== FALSE) {
1287
      $cache_hit = TRUE;
1288
    }
1289
    return $cache;
1290
  }
1291
}
1292

    
1293
/**
1294
 * Determines the cacheability of the current page.
1295
 *
1296
 * @param $allow_caching
1297
 *   Set to FALSE if you want to prevent this page from being cached.
1298
 *
1299
 * @return
1300
 *   TRUE if the current page can be cached, FALSE otherwise.
1301
 */
1302
function drupal_page_is_cacheable($allow_caching = NULL) {
1303
  $allow_caching_static = &drupal_static(__FUNCTION__, TRUE);
1304
  if (isset($allow_caching)) {
1305
    $allow_caching_static = $allow_caching;
1306
  }
1307

    
1308
  return $allow_caching_static && ($_SERVER['REQUEST_METHOD'] == 'GET' || $_SERVER['REQUEST_METHOD'] == 'HEAD')
1309
    && !drupal_is_cli();
1310
}
1311

    
1312
/**
1313
 * Invokes a bootstrap hook in all bootstrap modules that implement it.
1314
 *
1315
 * @param $hook
1316
 *   The name of the bootstrap hook to invoke.
1317
 *
1318
 * @see bootstrap_hooks()
1319
 */
1320
function bootstrap_invoke_all($hook) {
1321
  // Bootstrap modules should have been loaded when this function is called, so
1322
  // we don't need to tell module_list() to reset its internal list (and we
1323
  // therefore leave the first parameter at its default value of FALSE). We
1324
  // still pass in TRUE for the second parameter, though; in case this is the
1325
  // first time during the bootstrap that module_list() is called, we want to
1326
  // make sure that its internal cache is primed with the bootstrap modules
1327
  // only.
1328
  foreach (module_list(FALSE, TRUE) as $module) {
1329
    drupal_load('module', $module);
1330
    module_invoke($module, $hook);
1331
  }
1332
}
1333

    
1334
/**
1335
 * Includes a file with the provided type and name.
1336
 *
1337
 * This prevents including a theme, engine, module, etc., more than once.
1338
 *
1339
 * @param $type
1340
 *   The type of item to load (i.e. theme, theme_engine, module).
1341
 * @param $name
1342
 *   The name of the item to load.
1343
 *
1344
 * @return
1345
 *   TRUE if the item is loaded or has already been loaded.
1346
 */
1347
function drupal_load($type, $name) {
1348
  // Once a file is included this can't be reversed during a request so do not
1349
  // use drupal_static() here.
1350
  static $files = array();
1351

    
1352
  if (isset($files[$type][$name])) {
1353
    return TRUE;
1354
  }
1355

    
1356
  $filename = drupal_get_filename($type, $name);
1357

    
1358
  if ($filename) {
1359
    include_once DRUPAL_ROOT . '/' . $filename;
1360
    $files[$type][$name] = TRUE;
1361

    
1362
    return TRUE;
1363
  }
1364

    
1365
  return FALSE;
1366
}
1367

    
1368
/**
1369
 * Sets an HTTP response header for the current page.
1370
 *
1371
 * Note: When sending a Content-Type header, always include a 'charset' type,
1372
 * too. This is necessary to avoid security bugs (e.g. UTF-7 XSS).
1373
 *
1374
 * @param $name
1375
 *   The HTTP header name, or the special 'Status' header name.
1376
 * @param $value
1377
 *   The HTTP header value; if equal to FALSE, the specified header is unset.
1378
 *   If $name is 'Status', this is expected to be a status code followed by a
1379
 *   reason phrase, e.g. "404 Not Found".
1380
 * @param $append
1381
 *   Whether to append the value to an existing header or to replace it.
1382
 */
1383
function drupal_add_http_header($name, $value, $append = FALSE) {
1384
  // The headers as name/value pairs.
1385
  $headers = &drupal_static('drupal_http_headers', array());
1386

    
1387
  $name_lower = strtolower($name);
1388
  _drupal_set_preferred_header_name($name);
1389

    
1390
  if ($value === FALSE) {
1391
    $headers[$name_lower] = FALSE;
1392
  }
1393
  elseif (isset($headers[$name_lower]) && $append) {
1394
    // Multiple headers with identical names may be combined using comma (RFC
1395
    // 2616, section 4.2).
1396
    $headers[$name_lower] .= ',' . $value;
1397
  }
1398
  else {
1399
    $headers[$name_lower] = $value;
1400
  }
1401
  drupal_send_headers(array($name => $headers[$name_lower]), TRUE);
1402
}
1403

    
1404
/**
1405
 * Gets the HTTP response headers for the current page.
1406
 *
1407
 * @param $name
1408
 *   An HTTP header name. If omitted, all headers are returned as name/value
1409
 *   pairs. If an array value is FALSE, the header has been unset.
1410
 *
1411
 * @return
1412
 *   A string containing the header value, or FALSE if the header has been set,
1413
 *   or NULL if the header has not been set.
1414
 */
1415
function drupal_get_http_header($name = NULL) {
1416
  $headers = &drupal_static('drupal_http_headers', array());
1417
  if (isset($name)) {
1418
    $name = strtolower($name);
1419
    return isset($headers[$name]) ? $headers[$name] : NULL;
1420
  }
1421
  else {
1422
    return $headers;
1423
  }
1424
}
1425

    
1426
/**
1427
 * Sets the preferred name for the HTTP header.
1428
 *
1429
 * Header names are case-insensitive, but for maximum compatibility they should
1430
 * follow "common form" (see RFC 2617, section 4.2).
1431
 */
1432
function _drupal_set_preferred_header_name($name = NULL) {
1433
  static $header_names = array();
1434

    
1435
  if (!isset($name)) {
1436
    return $header_names;
1437
  }
1438
  $header_names[strtolower($name)] = $name;
1439
}
1440

    
1441
/**
1442
 * Sends the HTTP response headers that were previously set, adding defaults.
1443
 *
1444
 * Headers are set in drupal_add_http_header(). Default headers are not set
1445
 * if they have been replaced or unset using drupal_add_http_header().
1446
 *
1447
 * @param array $default_headers
1448
 *   (optional) An array of headers as name/value pairs.
1449
 * @param bool $only_default
1450
 *   (optional) If TRUE and headers have already been sent, send only the
1451
 *   specified headers.
1452
 */
1453
function drupal_send_headers($default_headers = array(), $only_default = FALSE) {
1454
  $headers_sent = &drupal_static(__FUNCTION__, FALSE);
1455
  $headers = drupal_get_http_header();
1456
  if ($only_default && $headers_sent) {
1457
    $headers = array();
1458
  }
1459
  $headers_sent = TRUE;
1460

    
1461
  $header_names = _drupal_set_preferred_header_name();
1462
  foreach ($default_headers as $name => $value) {
1463
    $name_lower = strtolower($name);
1464
    if (!isset($headers[$name_lower])) {
1465
      $headers[$name_lower] = $value;
1466
      $header_names[$name_lower] = $name;
1467
    }
1468
  }
1469
  foreach ($headers as $name_lower => $value) {
1470
    if ($name_lower == 'status') {
1471
      header($_SERVER['SERVER_PROTOCOL'] . ' ' . $value);
1472
    }
1473
    // Skip headers that have been unset.
1474
    elseif ($value !== FALSE) {
1475
      header($header_names[$name_lower] . ': ' . $value);
1476
    }
1477
  }
1478
}
1479

    
1480
/**
1481
 * Sets HTTP headers in preparation for a page response.
1482
 *
1483
 * Authenticated users are always given a 'no-cache' header, and will fetch a
1484
 * fresh page on every request. This prevents authenticated users from seeing
1485
 * locally cached pages.
1486
 *
1487
 * ETag and Last-Modified headers are not set per default for authenticated
1488
 * users so that browsers do not send If-Modified-Since headers from
1489
 * authenticated user pages. drupal_serve_page_from_cache() will set appropriate
1490
 * ETag and Last-Modified headers for cached pages.
1491
 *
1492
 * @see drupal_page_set_cache()
1493
 */
1494
function drupal_page_header() {
1495
  $headers_sent = &drupal_static(__FUNCTION__, FALSE);
1496
  if ($headers_sent) {
1497
    return TRUE;
1498
  }
1499
  $headers_sent = TRUE;
1500

    
1501
  $default_headers = array(
1502
    'Expires' => 'Sun, 19 Nov 1978 05:00:00 GMT',
1503
    'Cache-Control' => 'no-cache, must-revalidate',
1504
    // Prevent browsers from sniffing a response and picking a MIME type
1505
    // different from the declared content-type, since that can lead to
1506
    // XSS and other vulnerabilities.
1507
    'X-Content-Type-Options' => 'nosniff',
1508
  );
1509
  drupal_send_headers($default_headers);
1510
}
1511

    
1512
/**
1513
 * Sets HTTP headers in preparation for a cached page response.
1514
 *
1515
 * The headers allow as much as possible in proxies and browsers without any
1516
 * particular knowledge about the pages. Modules can override these headers
1517
 * using drupal_add_http_header().
1518
 *
1519
 * If the request is conditional (using If-Modified-Since and If-None-Match),
1520
 * and the conditions match those currently in the cache, a 304 Not Modified
1521
 * response is sent.
1522
 */
1523
function drupal_serve_page_from_cache(stdClass $cache) {
1524
  // Negotiate whether to use compression.
1525
  $page_compression = !empty($cache->data['page_compressed']);
1526
  $return_compressed = $page_compression && isset($_SERVER['HTTP_ACCEPT_ENCODING']) && strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE;
1527

    
1528
  // Get headers set in hook_boot(). Keys are lower-case.
1529
  $hook_boot_headers = drupal_get_http_header();
1530

    
1531
  // Headers generated in this function, that may be replaced or unset using
1532
  // drupal_add_http_headers(). Keys are mixed-case.
1533
  $default_headers = array();
1534

    
1535
  foreach ($cache->data['headers'] as $name => $value) {
1536
    // In the case of a 304 response, certain headers must be sent, and the
1537
    // remaining may not (see RFC 2616, section 10.3.5). Do not override
1538
    // headers set in hook_boot().
1539
    $name_lower = strtolower($name);
1540
    if (in_array($name_lower, array('content-location', 'expires', 'cache-control', 'vary')) && !isset($hook_boot_headers[$name_lower])) {
1541
      drupal_add_http_header($name, $value);
1542
      unset($cache->data['headers'][$name]);
1543
    }
1544
  }
1545

    
1546
  // If the client sent a session cookie, a cached copy will only be served
1547
  // to that one particular client due to Vary: Cookie. Thus, do not set
1548
  // max-age > 0, allowing the page to be cached by external proxies, when a
1549
  // session cookie is present unless the Vary header has been replaced or
1550
  // unset in hook_boot().
1551
  $max_age = !isset($_COOKIE[session_name()]) || isset($hook_boot_headers['vary']) ? variable_get('page_cache_maximum_age', 0) : 0;
1552
  $default_headers['Cache-Control'] = 'public, max-age=' . $max_age;
1553

    
1554
  // Entity tag should change if the output changes.
1555
  $etag = '"' . $cache->created . '-' . intval($return_compressed) . '"';
1556
  header('Etag: ' . $etag);
1557

    
1558
  // See if the client has provided the required HTTP headers.
1559
  $if_modified_since = isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) ? strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) : FALSE;
1560
  $if_none_match = isset($_SERVER['HTTP_IF_NONE_MATCH']) ? stripslashes($_SERVER['HTTP_IF_NONE_MATCH']) : FALSE;
1561

    
1562
  if ($if_modified_since && $if_none_match
1563
      && $if_none_match == $etag // etag must match
1564
      && $if_modified_since == $cache->created) {  // if-modified-since must match
1565
    header($_SERVER['SERVER_PROTOCOL'] . ' 304 Not Modified');
1566
    drupal_send_headers($default_headers);
1567
    return;
1568
  }
1569

    
1570
  // Send the remaining headers.
1571
  foreach ($cache->data['headers'] as $name => $value) {
1572
    drupal_add_http_header($name, $value);
1573
  }
1574

    
1575
  $default_headers['Last-Modified'] = gmdate(DATE_RFC7231, $cache->created);
1576

    
1577
  // HTTP/1.0 proxies does not support the Vary header, so prevent any caching
1578
  // by sending an Expires date in the past. HTTP/1.1 clients ignores the
1579
  // Expires header if a Cache-Control: max-age= directive is specified (see RFC
1580
  // 2616, section 14.9.3).
1581
  $default_headers['Expires'] = 'Sun, 19 Nov 1978 05:00:00 GMT';
1582

    
1583
  drupal_send_headers($default_headers);
1584

    
1585
  // Allow HTTP proxies to cache pages for anonymous users without a session
1586
  // cookie. The Vary header is used to indicates the set of request-header
1587
  // fields that fully determines whether a cache is permitted to use the
1588
  // response to reply to a subsequent request for a given URL without
1589
  // revalidation. If a Vary header has been set in hook_boot(), it is assumed
1590
  // that the module knows how to cache the page.
1591
  if (!isset($hook_boot_headers['vary']) && !variable_get('omit_vary_cookie')) {
1592
    header('Vary: Cookie');
1593
  }
1594

    
1595
  if ($page_compression) {
1596
    header('Vary: Accept-Encoding', FALSE);
1597
    // If page_compression is enabled, the cache contains gzipped data.
1598
    if ($return_compressed) {
1599
      // $cache->data['body'] is already gzip'ed, so make sure
1600
      // zlib.output_compression does not compress it once more.
1601
      ini_set('zlib.output_compression', '0');
1602
      header('Content-Encoding: gzip');
1603
    }
1604
    else {
1605
      // The client does not support compression, so unzip the data in the
1606
      // cache. Strip the gzip header and run uncompress.
1607
      $cache->data['body'] = gzinflate(substr(substr($cache->data['body'], 10), 0, -8));
1608
    }
1609
  }
1610

    
1611
  // Print the page.
1612
  print $cache->data['body'];
1613
}
1614

    
1615
/**
1616
 * Defines the critical hooks that force modules to always be loaded.
1617
 */
1618
function bootstrap_hooks() {
1619
  return array('boot', 'exit', 'watchdog', 'language_init');
1620
}
1621

    
1622
/**
1623
 * Unserializes and appends elements from a serialized string.
1624
 *
1625
 * @param $obj
1626
 *   The object to which the elements are appended.
1627
 * @param $field
1628
 *   The attribute of $obj whose value should be unserialized.
1629
 */
1630
function drupal_unpack($obj, $field = 'data') {
1631
  if ($obj->$field && $data = unserialize($obj->$field)) {
1632
    foreach ($data as $key => $value) {
1633
      if (!empty($key) && !isset($obj->$key)) {
1634
        $obj->$key = $value;
1635
      }
1636
    }
1637
  }
1638
  return $obj;
1639
}
1640

    
1641
/**
1642
 * Translates a string to the current language or to a given language.
1643
 *
1644
 * The t() function serves two purposes. First, at run-time it translates
1645
 * user-visible text into the appropriate language. Second, various mechanisms
1646
 * that figure out what text needs to be translated work off t() -- the text
1647
 * inside t() calls is added to the database of strings to be translated.
1648
 * These strings are expected to be in English, so the first argument should
1649
 * always be in English. To enable a fully-translatable site, it is important
1650
 * that all human-readable text that will be displayed on the site or sent to
1651
 * a user is passed through the t() function, or a related function. See the
1652
 * @link http://drupal.org/node/322729 Localization API @endlink pages for
1653
 * more information, including recommendations on how to break up or not
1654
 * break up strings for translation.
1655
 *
1656
 * @section sec_translating_vars Translating Variables
1657
 * You should never use t() to translate variables, such as calling
1658
 * @code t($text); @endcode, unless the text that the variable holds has been
1659
 * passed through t() elsewhere (e.g., $text is one of several translated
1660
 * literal strings in an array). It is especially important never to call
1661
 * @code t($user_text); @endcode, where $user_text is some text that a user
1662
 * entered - doing that can lead to cross-site scripting and other security
1663
 * problems. However, you can use variable substitution in your string, to put
1664
 * variable text such as user names or link URLs into translated text. Variable
1665
 * substitution looks like this:
1666
 * @code
1667
 * $text = t("@name's blog", array('@name' => format_username($account)));
1668
 * @endcode
1669
 * Basically, you can put variables like @name into your string, and t() will
1670
 * substitute their sanitized values at translation time. (See the
1671
 * Localization API pages referenced above and the documentation of
1672
 * format_string() for details about how to define variables in your string.)
1673
 * Translators can then rearrange the string as necessary for the language
1674
 * (e.g., in Spanish, it might be "blog de @name").
1675
 *
1676
 * @section sec_alt_funcs_install Use During Installation Phase
1677
 * During the Drupal installation phase, some resources used by t() wil not be
1678
 * available to code that needs localization. See st() and get_t() for
1679
 * alternatives.
1680
 *
1681
 * @section sec_context String context
1682
 * Matching source strings are normally only translated once, and the same
1683
 * translation is used everywhere that has a matching string. However, in some
1684
 * cases, a certain English source string needs to have multiple translations.
1685
 * One example of this is the string "May", which could be used as either a
1686
 * full month name or a 3-letter abbreviated month. In other languages where
1687
 * the month name for May has more than 3 letters, you would need to provide
1688
 * two different translations (one for the full name and one abbreviated), and
1689
 * the correct form would need to be chosen, depending on how "May" is being
1690
 * used. To facilitate this, the "May" string should be provided with two
1691
 * different contexts in the $options parameter when calling t(). For example:
1692
 * @code
1693
 * t('May', array(), array('context' => 'Long month name')
1694
 * t('May', array(), array('context' => 'Abbreviated month name')
1695
 * @endcode
1696
 * See https://localize.drupal.org/node/2109 for more information.
1697
 *
1698
 * @param $string
1699
 *   A string containing the English string to translate.
1700
 * @param $args
1701
 *   An associative array of replacements to make after translation. Based
1702
 *   on the first character of the key, the value is escaped and/or themed.
1703
 *   See format_string() for details.
1704
 * @param $options
1705
 *   An associative array of additional options, with the following elements:
1706
 *   - 'langcode' (defaults to the current language): The language code to
1707
 *     translate to a language other than what is used to display the page.
1708
 *   - 'context' (defaults to the empty context): A string giving the context
1709
 *     that the source string belongs to. See @ref sec_context above for more
1710
 *     information.
1711
 *
1712
 * @return
1713
 *   The translated string.
1714
 *
1715
 * @see st()
1716
 * @see get_t()
1717
 * @see format_string()
1718
 * @ingroup sanitization
1719
 */
1720
function t($string, array $args = array(), array $options = array()) {
1721
  global $language;
1722
  static $custom_strings;
1723

    
1724
  // Merge in default.
1725
  if (empty($options['langcode'])) {
1726
    $options['langcode'] = isset($language->language) ? $language->language : 'en';
1727
  }
1728
  if (empty($options['context'])) {
1729
    $options['context'] = '';
1730
  }
1731

    
1732
  // First, check for an array of customized strings. If present, use the array
1733
  // *instead of* database lookups. This is a high performance way to provide a
1734
  // handful of string replacements. See settings.php for examples.
1735
  // Cache the $custom_strings variable to improve performance.
1736
  if (!isset($custom_strings[$options['langcode']])) {
1737
    $custom_strings[$options['langcode']] = variable_get('locale_custom_strings_' . $options['langcode'], array());
1738
  }
1739
  // Custom strings work for English too, even if locale module is disabled.
1740
  if (isset($custom_strings[$options['langcode']][$options['context']][$string])) {
1741
    $string = $custom_strings[$options['langcode']][$options['context']][$string];
1742
  }
1743
  // Translate with locale module if enabled.
1744
  elseif ($options['langcode'] != 'en' && function_exists('locale')) {
1745
    $string = locale($string, $options['context'], $options['langcode']);
1746
  }
1747
  if (empty($args)) {
1748
    return $string;
1749
  }
1750
  else {
1751
    return format_string($string, $args);
1752
  }
1753
}
1754

    
1755
/**
1756
 * Formats a string for HTML display by replacing variable placeholders.
1757
 *
1758
 * This function replaces variable placeholders in a string with the requested
1759
 * values and escapes the values so they can be safely displayed as HTML. It
1760
 * should be used on any unknown text that is intended to be printed to an HTML
1761
 * page (especially text that may have come from untrusted users, since in that
1762
 * case it prevents cross-site scripting and other security problems).
1763
 *
1764
 * In most cases, you should use t() rather than calling this function
1765
 * directly, since it will translate the text (on non-English-only sites) in
1766
 * addition to formatting it.
1767
 *
1768
 * @param $string
1769
 *   A string containing placeholders.
1770
 * @param $args
1771
 *   An associative array of replacements to make. Occurrences in $string of
1772
 *   any key in $args are replaced with the corresponding value, after optional
1773
 *   sanitization and formatting. The type of sanitization and formatting
1774
 *   depends on the first character of the key:
1775
 *   - @variable: Escaped to HTML using check_plain(). Use this as the default
1776
 *     choice for anything displayed on a page on the site.
1777
 *   - %variable: Escaped to HTML and formatted using drupal_placeholder(),
1778
 *     which makes it display as <em>emphasized</em> text.
1779
 *   - !variable: Inserted as is, with no sanitization or formatting. Only use
1780
 *     this for text that has already been prepared for HTML display (for
1781
 *     example, user-supplied text that has already been run through
1782
 *     check_plain() previously, or is expected to contain some limited HTML
1783
 *     tags and has already been run through filter_xss() previously).
1784
 *
1785
 * @see t()
1786
 * @ingroup sanitization
1787
 */
1788
function format_string($string, array $args = array()) {
1789
  // Transform arguments before inserting them.
1790
  foreach ($args as $key => $value) {
1791
    switch ($key[0]) {
1792
      case '@':
1793
        // Escaped only.
1794
        $args[$key] = check_plain($value);
1795
        break;
1796

    
1797
      case '%':
1798
      default:
1799
        // Escaped and placeholder.
1800
        $args[$key] = drupal_placeholder($value);
1801
        break;
1802

    
1803
      case '!':
1804
        // Pass-through.
1805
    }
1806
  }
1807
  return strtr($string, $args);
1808
}
1809

    
1810
/**
1811
 * Encodes special characters in a plain-text string for display as HTML.
1812
 *
1813
 * Also validates strings as UTF-8 to prevent cross site scripting attacks on
1814
 * Internet Explorer 6.
1815
 *
1816
 * @param string $text
1817
 *   The text to be checked or processed.
1818
 *
1819
 * @return string
1820
 *   An HTML safe version of $text. If $text is not valid UTF-8, an empty string
1821
 *   is returned and, on PHP < 5.4, a warning may be issued depending on server
1822
 *   configuration (see @link https://bugs.php.net/bug.php?id=47494 @endlink).
1823
 *
1824
 * @see drupal_validate_utf8()
1825
 * @ingroup sanitization
1826
 */
1827
function check_plain($text) {
1828
  return htmlspecialchars($text, ENT_QUOTES, 'UTF-8');
1829
}
1830

    
1831
/**
1832
 * Checks whether a string is valid UTF-8.
1833
 *
1834
 * All functions designed to filter input should use drupal_validate_utf8
1835
 * to ensure they operate on valid UTF-8 strings to prevent bypass of the
1836
 * filter.
1837
 *
1838
 * When text containing an invalid UTF-8 lead byte (0xC0 - 0xFF) is presented
1839
 * as UTF-8 to Internet Explorer 6, the program may misinterpret subsequent
1840
 * bytes. When these subsequent bytes are HTML control characters such as
1841
 * quotes or angle brackets, parts of the text that were deemed safe by filters
1842
 * end up in locations that are potentially unsafe; An onerror attribute that
1843
 * is outside of a tag, and thus deemed safe by a filter, can be interpreted
1844
 * by the browser as if it were inside the tag.
1845
 *
1846
 * The function does not return FALSE for strings containing character codes
1847
 * above U+10FFFF, even though these are prohibited by RFC 3629.
1848
 *
1849
 * @param $text
1850
 *   The text to check.
1851
 *
1852
 * @return
1853
 *   TRUE if the text is valid UTF-8, FALSE if not.
1854
 */
1855
function drupal_validate_utf8($text) {
1856
  if (strlen($text) == 0) {
1857
    return TRUE;
1858
  }
1859
  // With the PCRE_UTF8 modifier 'u', preg_match() fails silently on strings
1860
  // containing invalid UTF-8 byte sequences. It does not reject character
1861
  // codes above U+10FFFF (represented by 4 or more octets), though.
1862
  return (preg_match('/^./us', $text) == 1);
1863
}
1864

    
1865
/**
1866
 * Returns the equivalent of Apache's $_SERVER['REQUEST_URI'] variable.
1867
 *
1868
 * Because $_SERVER['REQUEST_URI'] is only available on Apache, we generate an
1869
 * equivalent using other environment variables.
1870
 */
1871
function request_uri() {
1872
  if (isset($_SERVER['REQUEST_URI'])) {
1873
    $uri = $_SERVER['REQUEST_URI'];
1874
  }
1875
  else {
1876
    if (isset($_SERVER['argv'])) {
1877
      $uri = $_SERVER['SCRIPT_NAME'] . '?' . $_SERVER['argv'][0];
1878
    }
1879
    elseif (isset($_SERVER['QUERY_STRING'])) {
1880
      $uri = $_SERVER['SCRIPT_NAME'] . '?' . $_SERVER['QUERY_STRING'];
1881
    }
1882
    else {
1883
      $uri = $_SERVER['SCRIPT_NAME'];
1884
    }
1885
  }
1886
  // Prevent multiple slashes to avoid cross site requests via the Form API.
1887
  $uri = '/' . ltrim($uri, '/');
1888

    
1889
  return $uri;
1890
}
1891

    
1892
/**
1893
 * Logs an exception.
1894
 *
1895
 * This is a wrapper function for watchdog() which automatically decodes an
1896
 * exception.
1897
 *
1898
 * @param $type
1899
 *   The category to which this message belongs.
1900
 * @param $exception
1901
 *   The exception that is going to be logged.
1902
 * @param $message
1903
 *   The message to store in the log. If empty, a text that contains all useful
1904
 *   information about the passed-in exception is used.
1905
 * @param $variables
1906
 *   Array of variables to replace in the message on display. Defaults to the
1907
 *   return value of _drupal_decode_exception().
1908
 * @param $severity
1909
 *   The severity of the message, as per RFC 3164.
1910
 * @param $link
1911
 *   A link to associate with the message.
1912
 *
1913
 * @see watchdog()
1914
 * @see _drupal_decode_exception()
1915
 */
1916
function watchdog_exception($type, Exception $exception, $message = NULL, $variables = array(), $severity = WATCHDOG_ERROR, $link = NULL) {
1917

    
1918
   // Use a default value if $message is not set.
1919
   if (empty($message)) {
1920
     // The exception message is run through check_plain() by _drupal_decode_exception().
1921
     $message = '%type: !message in %function (line %line of %file).';
1922
   }
1923
   // $variables must be an array so that we can add the exception information.
1924
   if (!is_array($variables)) {
1925
     $variables = array();
1926
   }
1927

    
1928
   require_once DRUPAL_ROOT . '/includes/errors.inc';
1929
   $variables += _drupal_decode_exception($exception);
1930
   watchdog($type, $message, $variables, $severity, $link);
1931
}
1932

    
1933
/**
1934
 * Logs a system message.
1935
 *
1936
 * @param $type
1937
 *   The category to which this message belongs. Can be any string, but the
1938
 *   general practice is to use the name of the module calling watchdog().
1939
 * @param $message
1940
 *   The message to store in the log. Keep $message translatable
1941
 *   by not concatenating dynamic values into it! Variables in the
1942
 *   message should be added by using placeholder strings alongside
1943
 *   the variables argument to declare the value of the placeholders.
1944
 *   See t() for documentation on how $message and $variables interact.
1945
 * @param $variables
1946
 *   Array of variables to replace in the message on display or
1947
 *   NULL if message is already translated or not possible to
1948
 *   translate.
1949
 * @param $severity
1950
 *   The severity of the message; one of the following values as defined in
1951
 *   @link http://www.faqs.org/rfcs/rfc3164.html RFC 3164: @endlink
1952
 *   - WATCHDOG_EMERGENCY: Emergency, system is unusable.
1953
 *   - WATCHDOG_ALERT: Alert, action must be taken immediately.
1954
 *   - WATCHDOG_CRITICAL: Critical conditions.
1955
 *   - WATCHDOG_ERROR: Error conditions.
1956
 *   - WATCHDOG_WARNING: Warning conditions.
1957
 *   - WATCHDOG_NOTICE: (default) Normal but significant conditions.
1958
 *   - WATCHDOG_INFO: Informational messages.
1959
 *   - WATCHDOG_DEBUG: Debug-level messages.
1960
 * @param $link
1961
 *   A link to associate with the message.
1962
 *
1963
 * @see watchdog_severity_levels()
1964
 * @see hook_watchdog()
1965
 */
1966
function watchdog($type, $message, $variables = array(), $severity = WATCHDOG_NOTICE, $link = NULL) {
1967
  global $user, $base_root;
1968

    
1969
  static $in_error_state = FALSE;
1970

    
1971
  // It is possible that the error handling will itself trigger an error. In that case, we could
1972
  // end up in an infinite loop. To avoid that, we implement a simple static semaphore.
1973
  if (!$in_error_state && function_exists('module_implements')) {
1974
    $in_error_state = TRUE;
1975

    
1976
    // The user object may not exist in all conditions, so 0 is substituted if needed.
1977
    $user_uid = isset($user->uid) ? $user->uid : 0;
1978

    
1979
    // Prepare the fields to be logged
1980
    $log_entry = array(
1981
      'type'        => $type,
1982
      'message'     => $message,
1983
      'variables'   => $variables,
1984
      'severity'    => $severity,
1985
      'link'        => $link,
1986
      'user'        => $user,
1987
      'uid'         => $user_uid,
1988
      'request_uri' => $base_root . request_uri(),
1989
      'referer'     => isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : '',
1990
      'ip'          => ip_address(),
1991
      // Request time isn't accurate for long processes, use time() instead.
1992
      'timestamp'   => time(),
1993
    );
1994

    
1995
    // Call the logging hooks to log/process the message
1996
    foreach (module_implements('watchdog') as $module) {
1997
      module_invoke($module, 'watchdog', $log_entry);
1998
    }
1999

    
2000
    // It is critical that the semaphore is only cleared here, in the parent
2001
    // watchdog() call (not outside the loop), to prevent recursive execution.
2002
    $in_error_state = FALSE;
2003
  }
2004
}
2005

    
2006
/**
2007
 * Sets a message to display to the user.
2008
 *
2009
 * Messages are stored in a session variable and displayed in page.tpl.php via
2010
 * the $messages theme variable.
2011
 *
2012
 * Example usage:
2013
 * @code
2014
 * drupal_set_message(t('An error occurred and processing did not complete.'), 'error');
2015
 * @endcode
2016
 *
2017
 * @param string $message
2018
 *   (optional) The translated message to be displayed to the user. For
2019
 *   consistency with other messages, it should begin with a capital letter and
2020
 *   end with a period.
2021
 * @param string $type
2022
 *   (optional) The message's type. Defaults to 'status'. These values are
2023
 *   supported:
2024
 *   - 'status'
2025
 *   - 'warning'
2026
 *   - 'error'
2027
 * @param bool $repeat
2028
 *   (optional) If this is FALSE and the message is already set, then the
2029
 *   message won't be repeated. Defaults to TRUE.
2030
 *
2031
 * @return array|null
2032
 *   A multidimensional array with keys corresponding to the set message types.
2033
 *   The indexed array values of each contain the set messages for that type.
2034
 *   Or, if there are no messages set, the function returns NULL.
2035
 *
2036
 * @see drupal_get_messages()
2037
 * @see theme_status_messages()
2038
 */
2039
function drupal_set_message($message = NULL, $type = 'status', $repeat = TRUE) {
2040
  if ($message || $message === '0' || $message === 0) {
2041
    if (!isset($_SESSION['messages'][$type])) {
2042
      $_SESSION['messages'][$type] = array();
2043
    }
2044

    
2045
    if ($repeat || !in_array($message, $_SESSION['messages'][$type])) {
2046
      $_SESSION['messages'][$type][] = $message;
2047
    }
2048

    
2049
    // Mark this page as being uncacheable.
2050
    drupal_page_is_cacheable(FALSE);
2051
  }
2052

    
2053
  // Messages not set when DB connection fails.
2054
  return isset($_SESSION['messages']) ? $_SESSION['messages'] : NULL;
2055
}
2056

    
2057
/**
2058
 * Returns all messages that have been set with drupal_set_message().
2059
 *
2060
 * @param string $type
2061
 *   (optional) Limit the messages returned by type. Defaults to NULL, meaning
2062
 *   all types. These values are supported:
2063
 *   - NULL
2064
 *   - 'status'
2065
 *   - 'warning'
2066
 *   - 'error'
2067
 * @param bool $clear_queue
2068
 *   (optional) If this is TRUE, the queue will be cleared of messages of the
2069
 *   type specified in the $type parameter. Otherwise the queue will be left
2070
 *   intact. Defaults to TRUE.
2071
 *
2072
 * @return array
2073
 *   A multidimensional array with keys corresponding to the set message types.
2074
 *   The indexed array values of each contain the set messages for that type.
2075
 *   The messages returned are limited to the type specified in the $type
2076
 *   parameter. If there are no messages of the specified type, an empty array
2077
 *   is returned.
2078
 *
2079
 * @see drupal_set_message()
2080
 * @see theme_status_messages()
2081
 */
2082
function drupal_get_messages($type = NULL, $clear_queue = TRUE) {
2083
  if ($messages = drupal_set_message()) {
2084
    if ($type) {
2085
      if ($clear_queue) {
2086
        unset($_SESSION['messages'][$type]);
2087
      }
2088
      if (isset($messages[$type])) {
2089
        return array($type => $messages[$type]);
2090
      }
2091
    }
2092
    else {
2093
      if ($clear_queue) {
2094
        unset($_SESSION['messages']);
2095
      }
2096
      return $messages;
2097
    }
2098
  }
2099
  return array();
2100
}
2101

    
2102
/**
2103
 * Gets the title of the current page.
2104
 *
2105
 * The title is displayed on the page and in the title bar.
2106
 *
2107
 * @return
2108
 *   The current page's title.
2109
 */
2110
function drupal_get_title() {
2111
  $title = drupal_set_title();
2112

    
2113
  // During a bootstrap, menu.inc is not included and thus we cannot provide a title.
2114
  if (!isset($title) && function_exists('menu_get_active_title')) {
2115
    $title = check_plain(menu_get_active_title());
2116
  }
2117

    
2118
  return $title;
2119
}
2120

    
2121
/**
2122
 * Sets the title of the current page.
2123
 *
2124
 * The title is displayed on the page and in the title bar.
2125
 *
2126
 * @param $title
2127
 *   Optional string value to assign to the page title; or if set to NULL
2128
 *   (default), leaves the current title unchanged.
2129
 * @param $output
2130
 *   Optional flag - normally should be left as CHECK_PLAIN. Only set to
2131
 *   PASS_THROUGH if you have already removed any possibly dangerous code
2132
 *   from $title using a function like check_plain() or filter_xss(). With this
2133
 *   flag the string will be passed through unchanged.
2134
 *
2135
 * @return
2136
 *   The updated title of the current page.
2137
 */
2138
function drupal_set_title($title = NULL, $output = CHECK_PLAIN) {
2139
  $stored_title = &drupal_static(__FUNCTION__);
2140

    
2141
  if (isset($title)) {
2142
    $stored_title = ($output == PASS_THROUGH) ? $title : check_plain($title);
2143
  }
2144

    
2145
  return $stored_title;
2146
}
2147

    
2148
/**
2149
 * Checks to see if an IP address has been blocked.
2150
 *
2151
 * Blocked IP addresses are stored in the database by default. However for
2152
 * performance reasons we allow an override in settings.php. This allows us
2153
 * to avoid querying the database at this critical stage of the bootstrap if
2154
 * an administrative interface for IP address blocking is not required.
2155
 *
2156
 * @param $ip
2157
 *   IP address to check.
2158
 *
2159
 * @return bool
2160
 *   TRUE if access is denied, FALSE if access is allowed.
2161
 */
2162
function drupal_is_denied($ip) {
2163
  // Because this function is called on every page request, we first check
2164
  // for an array of IP addresses in settings.php before querying the
2165
  // database.
2166
  $blocked_ips = variable_get('blocked_ips');
2167
  $denied = FALSE;
2168
  if (isset($blocked_ips) && is_array($blocked_ips)) {
2169
    $denied = in_array($ip, $blocked_ips);
2170
  }
2171
  // Only check if database.inc is loaded already. If
2172
  // $conf['page_cache_without_database'] = TRUE; is set in settings.php,
2173
  // then the database won't be loaded here so the IPs in the database
2174
  // won't be denied. However the user asked explicitly not to use the
2175
  // database and also in this case it's quite likely that the user relies
2176
  // on higher performance solutions like a firewall.
2177
  elseif (class_exists('Database', FALSE)) {
2178
    $denied = (bool)db_query("SELECT 1 FROM {blocked_ips} WHERE ip = :ip", array(':ip' => $ip))->fetchField();
2179
  }
2180
  return $denied;
2181
}
2182

    
2183
/**
2184
 * Handles denied users.
2185
 *
2186
 * @param $ip
2187
 *   IP address to check. Prints a message and exits if access is denied.
2188
 */
2189
function drupal_block_denied($ip) {
2190
  // Deny access to blocked IP addresses - t() is not yet available.
2191
  if (drupal_is_denied($ip)) {
2192
    header($_SERVER['SERVER_PROTOCOL'] . ' 403 Forbidden');
2193
    print 'Sorry, ' . check_plain(ip_address()) . ' has been banned.';
2194
    exit();
2195
  }
2196
}
2197

    
2198
/**
2199
 * Returns a URL-safe, base64 encoded string of highly randomized bytes (over the full 8-bit range).
2200
 *
2201
 * @param $byte_count
2202
 *   The number of random bytes to fetch and base64 encode.
2203
 *
2204
 * @return string
2205
 *   The base64 encoded result will have a length of up to 4 * $byte_count.
2206
 */
2207
function drupal_random_key($byte_count = 32) {
2208
  return drupal_base64_encode(drupal_random_bytes($byte_count));
2209
}
2210

    
2211
/**
2212
 * Returns a URL-safe, base64 encoded version of the supplied string.
2213
 *
2214
 * @param $string
2215
 *   The string to convert to base64.
2216
 *
2217
 * @return string
2218
 */
2219
function drupal_base64_encode($string) {
2220
  $data = base64_encode($string);
2221
  // Modify the output so it's safe to use in URLs.
2222
  return strtr($data, array('+' => '-', '/' => '_', '=' => ''));
2223
}
2224

    
2225
/**
2226
 * Returns a string of highly randomized bytes (over the full 8-bit range).
2227
 *
2228
 * This function is better than simply calling mt_rand() or any other built-in
2229
 * PHP function because it can return a long string of bytes (compared to < 4
2230
 * bytes normally from mt_rand()) and uses the best available pseudo-random
2231
 * source.
2232
 *
2233
 * @param $count
2234
 *   The number of characters (bytes) to return in the string.
2235
 */
2236
function drupal_random_bytes($count)  {
2237
  // $random_state does not use drupal_static as it stores random bytes.
2238
  static $random_state, $bytes, $has_openssl;
2239

    
2240
  $missing_bytes = $count - strlen($bytes);
2241

    
2242
  if ($missing_bytes > 0) {
2243
    // PHP versions prior 5.3.4 experienced openssl_random_pseudo_bytes()
2244
    // locking on Windows and rendered it unusable.
2245
    if (!isset($has_openssl)) {
2246
      $has_openssl = version_compare(PHP_VERSION, '5.3.4', '>=') && function_exists('openssl_random_pseudo_bytes');
2247
    }
2248

    
2249
    // openssl_random_pseudo_bytes() will find entropy in a system-dependent
2250
    // way.
2251
    if ($has_openssl) {
2252
      $bytes .= openssl_random_pseudo_bytes($missing_bytes);
2253
    }
2254

    
2255
    // Else, read directly from /dev/urandom, which is available on many *nix
2256
    // systems and is considered cryptographically secure.
2257
    elseif ($fh = @fopen('/dev/urandom', 'rb')) {
2258
      // PHP only performs buffered reads, so in reality it will always read
2259
      // at least 4096 bytes. Thus, it costs nothing extra to read and store
2260
      // that much so as to speed any additional invocations.
2261
      $bytes .= fread($fh, max(4096, $missing_bytes));
2262
      fclose($fh);
2263
    }
2264

    
2265
    // If we couldn't get enough entropy, this simple hash-based PRNG will
2266
    // generate a good set of pseudo-random bytes on any system.
2267
    // Note that it may be important that our $random_state is passed
2268
    // through hash() prior to being rolled into $output, that the two hash()
2269
    // invocations are different, and that the extra input into the first one -
2270
    // the microtime() - is prepended rather than appended. This is to avoid
2271
    // directly leaking $random_state via the $output stream, which could
2272
    // allow for trivial prediction of further "random" numbers.
2273
    if (strlen($bytes) < $count) {
2274
      // Initialize on the first call. The contents of $_SERVER includes a mix of
2275
      // user-specific and system information that varies a little with each page.
2276
      if (!isset($random_state)) {
2277
        $random_state = print_r($_SERVER, TRUE);
2278
        if (function_exists('getmypid')) {
2279
          // Further initialize with the somewhat random PHP process ID.
2280
          $random_state .= getmypid();
2281
        }
2282
        $bytes = '';
2283
      }
2284

    
2285
      do {
2286
        $random_state = hash('sha256', microtime() . mt_rand() . $random_state);
2287
        $bytes .= hash('sha256', mt_rand() . $random_state, TRUE);
2288
      }
2289
      while (strlen($bytes) < $count);
2290
    }
2291
  }
2292
  $output = substr($bytes, 0, $count);
2293
  $bytes = substr($bytes, $count);
2294
  return $output;
2295
}
2296

    
2297
/**
2298
 * Calculates a base-64 encoded, URL-safe sha-256 hmac.
2299
 *
2300
 * @param string $data
2301
 *   String to be validated with the hmac.
2302
 * @param string $key
2303
 *   A secret string key.
2304
 *
2305
 * @return string
2306
 *   A base-64 encoded sha-256 hmac, with + replaced with -, / with _ and
2307
 *   any = padding characters removed.
2308
 */
2309
function drupal_hmac_base64($data, $key) {
2310
  // Casting $data and $key to strings here is necessary to avoid empty string
2311
  // results of the hash function if they are not scalar values. As this
2312
  // function is used in security-critical contexts like token validation it is
2313
  // important that it never returns an empty string.
2314
  $hmac = base64_encode(hash_hmac('sha256', (string) $data, (string) $key, TRUE));
2315
  // Modify the hmac so it's safe to use in URLs.
2316
  return strtr($hmac, array('+' => '-', '/' => '_', '=' => ''));
2317
}
2318

    
2319
/**
2320
 * Calculates a base-64 encoded, URL-safe sha-256 hash.
2321
 *
2322
 * @param $data
2323
 *   String to be hashed.
2324
 *
2325
 * @return
2326
 *   A base-64 encoded sha-256 hash, with + replaced with -, / with _ and
2327
 *   any = padding characters removed.
2328
 */
2329
function drupal_hash_base64($data) {
2330
  $hash = base64_encode(hash('sha256', $data, TRUE));
2331
  // Modify the hash so it's safe to use in URLs.
2332
  return strtr($hash, array('+' => '-', '/' => '_', '=' => ''));
2333
}
2334

    
2335
/**
2336
 * Merges multiple arrays, recursively, and returns the merged array.
2337
 *
2338
 * This function is similar to PHP's array_merge_recursive() function, but it
2339
 * handles non-array values differently. When merging values that are not both
2340
 * arrays, the latter value replaces the former rather than merging with it.
2341
 *
2342
 * Example:
2343
 * @code
2344
 * $link_options_1 = array('fragment' => 'x', 'attributes' => array('title' => t('X'), 'class' => array('a', 'b')));
2345
 * $link_options_2 = array('fragment' => 'y', 'attributes' => array('title' => t('Y'), 'class' => array('c', 'd')));
2346
 *
2347
 * // This results in array('fragment' => array('x', 'y'), 'attributes' => array('title' => array(t('X'), t('Y')), 'class' => array('a', 'b', 'c', 'd'))).
2348
 * $incorrect = array_merge_recursive($link_options_1, $link_options_2);
2349
 *
2350
 * // This results in array('fragment' => 'y', 'attributes' => array('title' => t('Y'), 'class' => array('a', 'b', 'c', 'd'))).
2351
 * $correct = drupal_array_merge_deep($link_options_1, $link_options_2);
2352
 * @endcode
2353
 *
2354
 * @param ...
2355
 *   Arrays to merge.
2356
 *
2357
 * @return
2358
 *   The merged array.
2359
 *
2360
 * @see drupal_array_merge_deep_array()
2361
 */
2362
function drupal_array_merge_deep() {
2363
  $args = func_get_args();
2364
  return drupal_array_merge_deep_array($args);
2365
}
2366

    
2367
/**
2368
 * Merges multiple arrays, recursively, and returns the merged array.
2369
 *
2370
 * This function is equivalent to drupal_array_merge_deep(), except the
2371
 * input arrays are passed as a single array parameter rather than a variable
2372
 * parameter list.
2373
 *
2374
 * The following are equivalent:
2375
 * - drupal_array_merge_deep($a, $b);
2376
 * - drupal_array_merge_deep_array(array($a, $b));
2377
 *
2378
 * The following are also equivalent:
2379
 * - call_user_func_array('drupal_array_merge_deep', $arrays_to_merge);
2380
 * - drupal_array_merge_deep_array($arrays_to_merge);
2381
 *
2382
 * @see drupal_array_merge_deep()
2383
 */
2384
function drupal_array_merge_deep_array($arrays) {
2385
  $result = array();
2386

    
2387
  foreach ($arrays as $array) {
2388
    foreach ($array as $key => $value) {
2389
      // Renumber integer keys as array_merge_recursive() does. Note that PHP
2390
      // automatically converts array keys that are integer strings (e.g., '1')
2391
      // to integers.
2392
      if (is_integer($key)) {
2393
        $result[] = $value;
2394
      }
2395
      // Recurse when both values are arrays.
2396
      elseif (isset($result[$key]) && is_array($result[$key]) && is_array($value)) {
2397
        $result[$key] = drupal_array_merge_deep_array(array($result[$key], $value));
2398
      }
2399
      // Otherwise, use the latter value, overriding any previous value.
2400
      else {
2401
        $result[$key] = $value;
2402
      }
2403
    }
2404
  }
2405

    
2406
  return $result;
2407
}
2408

    
2409
/**
2410
 * Generates a default anonymous $user object.
2411
 *
2412
 * @return Object - the user object.
2413
 */
2414
function drupal_anonymous_user() {
2415
  $user = variable_get('drupal_anonymous_user_object', new stdClass);
2416
  $user->uid = 0;
2417
  $user->hostname = ip_address();
2418
  $user->roles = array();
2419
  $user->roles[DRUPAL_ANONYMOUS_RID] = 'anonymous user';
2420
  $user->cache = 0;
2421
  return $user;
2422
}
2423

    
2424
/**
2425
 * Ensures Drupal is bootstrapped to the specified phase.
2426
 *
2427
 * In order to bootstrap Drupal from another PHP script, you can use this code:
2428
 * @code
2429
 *   define('DRUPAL_ROOT', '/path/to/drupal');
2430
 *   require_once DRUPAL_ROOT . '/includes/bootstrap.inc';
2431
 *   drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
2432
 * @endcode
2433
 *
2434
 * @param int $phase
2435
 *   A constant telling which phase to bootstrap to. When you bootstrap to a
2436
 *   particular phase, all earlier phases are run automatically. Possible
2437
 *   values:
2438
 *   - DRUPAL_BOOTSTRAP_CONFIGURATION: Initializes configuration.
2439
 *   - DRUPAL_BOOTSTRAP_PAGE_CACHE: Tries to serve a cached page.
2440
 *   - DRUPAL_BOOTSTRAP_DATABASE: Initializes the database layer.
2441
 *   - DRUPAL_BOOTSTRAP_VARIABLES: Initializes the variable system.
2442
 *   - DRUPAL_BOOTSTRAP_SESSION: Initializes session handling.
2443
 *   - DRUPAL_BOOTSTRAP_PAGE_HEADER: Sets up the page header.
2444
 *   - DRUPAL_BOOTSTRAP_LANGUAGE: Finds out the language of the page.
2445
 *   - DRUPAL_BOOTSTRAP_FULL: Fully loads Drupal. Validates and fixes input
2446
 *     data.
2447
 * @param boolean $new_phase
2448
 *   A boolean, set to FALSE if calling drupal_bootstrap from inside a
2449
 *   function called from drupal_bootstrap (recursion).
2450
 *
2451
 * @return int
2452
 *   The most recently completed phase.
2453
 */
2454
function drupal_bootstrap($phase = NULL, $new_phase = TRUE) {
2455
  // Not drupal_static(), because does not depend on any run-time information.
2456
  static $phases = array(
2457
    DRUPAL_BOOTSTRAP_CONFIGURATION,
2458
    DRUPAL_BOOTSTRAP_PAGE_CACHE,
2459
    DRUPAL_BOOTSTRAP_DATABASE,
2460
    DRUPAL_BOOTSTRAP_VARIABLES,
2461
    DRUPAL_BOOTSTRAP_SESSION,
2462
    DRUPAL_BOOTSTRAP_PAGE_HEADER,
2463
    DRUPAL_BOOTSTRAP_LANGUAGE,
2464
    DRUPAL_BOOTSTRAP_FULL,
2465
  );
2466
  // Not drupal_static(), because the only legitimate API to control this is to
2467
  // call drupal_bootstrap() with a new phase parameter.
2468
  static $final_phase;
2469
  // Not drupal_static(), because it's impossible to roll back to an earlier
2470
  // bootstrap state.
2471
  static $stored_phase = -1;
2472

    
2473
  if (isset($phase)) {
2474
    // When not recursing, store the phase name so it's not forgotten while
2475
    // recursing but take care of not going backwards.
2476
    if ($new_phase && $phase >= $stored_phase) {
2477
      $final_phase = $phase;
2478
    }
2479

    
2480
    // Call a phase if it has not been called before and is below the requested
2481
    // phase.
2482
    while ($phases && $phase > $stored_phase && $final_phase > $stored_phase) {
2483
      $current_phase = array_shift($phases);
2484

    
2485
      // This function is re-entrant. Only update the completed phase when the
2486
      // current call actually resulted in a progress in the bootstrap process.
2487
      if ($current_phase > $stored_phase) {
2488
        $stored_phase = $current_phase;
2489
      }
2490

    
2491
      switch ($current_phase) {
2492
        case DRUPAL_BOOTSTRAP_CONFIGURATION:
2493
          _drupal_bootstrap_configuration();
2494
          break;
2495

    
2496
        case DRUPAL_BOOTSTRAP_PAGE_CACHE:
2497
          _drupal_bootstrap_page_cache();
2498
          break;
2499

    
2500
        case DRUPAL_BOOTSTRAP_DATABASE:
2501
          _drupal_bootstrap_database();
2502
          break;
2503

    
2504
        case DRUPAL_BOOTSTRAP_VARIABLES:
2505
          _drupal_bootstrap_variables();
2506
          break;
2507

    
2508
        case DRUPAL_BOOTSTRAP_SESSION:
2509
          require_once DRUPAL_ROOT . '/' . variable_get('session_inc', 'includes/session.inc');
2510
          drupal_session_initialize();
2511
          break;
2512

    
2513
        case DRUPAL_BOOTSTRAP_PAGE_HEADER:
2514
          _drupal_bootstrap_page_header();
2515
          break;
2516

    
2517
        case DRUPAL_BOOTSTRAP_LANGUAGE:
2518
          drupal_language_initialize();
2519
          break;
2520

    
2521
        case DRUPAL_BOOTSTRAP_FULL:
2522
          require_once DRUPAL_ROOT . '/includes/common.inc';
2523
          _drupal_bootstrap_full();
2524
          break;
2525
      }
2526
    }
2527
  }
2528
  return $stored_phase;
2529
}
2530

    
2531
/**
2532
 * Returns the time zone of the current user.
2533
 */
2534
function drupal_get_user_timezone() {
2535
  global $user;
2536
  if (variable_get('configurable_timezones', 1) && $user->uid && $user->timezone) {
2537
    return $user->timezone;
2538
  }
2539
  else {
2540
    // Ignore PHP strict notice if time zone has not yet been set in the php.ini
2541
    // configuration.
2542
    return variable_get('date_default_timezone', @date_default_timezone_get());
2543
  }
2544
}
2545

    
2546
/**
2547
 * Gets a salt useful for hardening against SQL injection.
2548
 *
2549
 * @return
2550
 *   A salt based on information in settings.php, not in the database.
2551
 */
2552
function drupal_get_hash_salt() {
2553
  global $drupal_hash_salt, $databases;
2554
  // If the $drupal_hash_salt variable is empty, a hash of the serialized
2555
  // database credentials is used as a fallback salt.
2556
  return empty($drupal_hash_salt) ? hash('sha256', serialize($databases)) : $drupal_hash_salt;
2557
}
2558

    
2559
/**
2560
 * Provides custom PHP error handling.
2561
 *
2562
 * @param $error_level
2563
 *   The level of the error raised.
2564
 * @param $message
2565
 *   The error message.
2566
 * @param $filename
2567
 *   The filename that the error was raised in.
2568
 * @param $line
2569
 *   The line number the error was raised at.
2570
 * @param $context
2571
 *   An array that points to the active symbol table at the point the error
2572
 *   occurred.
2573
 */
2574
function _drupal_error_handler($error_level, $message, $filename, $line, $context) {
2575
  require_once DRUPAL_ROOT . '/includes/errors.inc';
2576
  _drupal_error_handler_real($error_level, $message, $filename, $line, $context);
2577
}
2578

    
2579
/**
2580
 * Provides custom PHP exception handling.
2581
 *
2582
 * Uncaught exceptions are those not enclosed in a try/catch block. They are
2583
 * always fatal: the execution of the script will stop as soon as the exception
2584
 * handler exits.
2585
 *
2586
 * @param $exception
2587
 *   The exception object that was thrown.
2588
 */
2589
function _drupal_exception_handler($exception) {
2590
  require_once DRUPAL_ROOT . '/includes/errors.inc';
2591

    
2592
  try {
2593
    // Log the message to the watchdog and return an error page to the user.
2594
    _drupal_log_error(_drupal_decode_exception($exception), TRUE);
2595
  }
2596
  catch (Exception $exception2) {
2597
    // Another uncaught exception was thrown while handling the first one.
2598
    // If we are displaying errors, then do so with no possibility of a further uncaught exception being thrown.
2599
    if (error_displayable()) {
2600
      print '<h1>Additional uncaught exception thrown while handling exception.</h1>';
2601
      print '<h2>Original</h2><p>' . _drupal_render_exception_safe($exception) . '</p>';
2602
      print '<h2>Additional</h2><p>' . _drupal_render_exception_safe($exception2) . '</p><hr />';
2603
    }
2604
  }
2605
}
2606

    
2607
/**
2608
 * Sets up the script environment and loads settings.php.
2609
 */
2610
function _drupal_bootstrap_configuration() {
2611
  // Set the Drupal custom error handler.
2612
  set_error_handler('_drupal_error_handler');
2613
  set_exception_handler('_drupal_exception_handler');
2614

    
2615
  drupal_environment_initialize();
2616
  // Start a page timer:
2617
  timer_start('page');
2618
  // Initialize the configuration, including variables from settings.php.
2619
  drupal_settings_initialize();
2620
}
2621

    
2622
/**
2623
 * Attempts to serve a page from the cache.
2624
 */
2625
function _drupal_bootstrap_page_cache() {
2626
  global $user;
2627

    
2628
  // Allow specifying special cache handlers in settings.php, like
2629
  // using memcached or files for storing cache information.
2630
  require_once DRUPAL_ROOT . '/includes/cache.inc';
2631
  foreach (variable_get('cache_backends', array()) as $include) {
2632
    require_once DRUPAL_ROOT . '/' . $include;
2633
  }
2634
  // Check for a cache mode force from settings.php.
2635
  if (variable_get('page_cache_without_database')) {
2636
    $cache_enabled = TRUE;
2637
  }
2638
  else {
2639
    drupal_bootstrap(DRUPAL_BOOTSTRAP_VARIABLES, FALSE);
2640
    $cache_enabled = variable_get('cache');
2641
  }
2642
  drupal_block_denied(ip_address());
2643
  // If there is no session cookie and cache is enabled (or forced), try
2644
  // to serve a cached page.
2645
  if (!isset($_COOKIE[session_name()]) && $cache_enabled) {
2646
    // Make sure there is a user object because its timestamp will be
2647
    // checked, hook_boot might check for anonymous user etc.
2648
    $user = drupal_anonymous_user();
2649
    // Get the page from the cache.
2650
    $cache = drupal_page_get_cache();
2651
    // If there is a cached page, display it.
2652
    if (is_object($cache)) {
2653
      header('X-Drupal-Cache: HIT');
2654
      // Restore the metadata cached with the page.
2655
      $_GET['q'] = $cache->data['path'];
2656
      drupal_set_title($cache->data['title'], PASS_THROUGH);
2657
      date_default_timezone_set(drupal_get_user_timezone());
2658
      // If the skipping of the bootstrap hooks is not enforced, call
2659
      // hook_boot.
2660
      if (variable_get('page_cache_invoke_hooks', TRUE)) {
2661
        bootstrap_invoke_all('boot');
2662
      }
2663
      drupal_serve_page_from_cache($cache);
2664
      // If the skipping of the bootstrap hooks is not enforced, call
2665
      // hook_exit.
2666
      if (variable_get('page_cache_invoke_hooks', TRUE)) {
2667
        bootstrap_invoke_all('exit');
2668
      }
2669
      // We are done.
2670
      exit;
2671
    }
2672
    else {
2673
      header('X-Drupal-Cache: MISS');
2674
    }
2675
  }
2676
}
2677

    
2678
/**
2679
 * Initializes the database system and registers autoload functions.
2680
 */
2681
function _drupal_bootstrap_database() {
2682
  // Redirect the user to the installation script if Drupal has not been
2683
  // installed yet (i.e., if no $databases array has been defined in the
2684
  // settings.php file) and we are not already installing.
2685
  if (empty($GLOBALS['databases']) && !drupal_installation_attempted()) {
2686
    include_once DRUPAL_ROOT . '/includes/install.inc';
2687
    install_goto('install.php');
2688
  }
2689

    
2690
  // The user agent header is used to pass a database prefix in the request when
2691
  // running tests. However, for security reasons, it is imperative that we
2692
  // validate we ourselves made the request.
2693
  if ($test_prefix = drupal_valid_test_ua()) {
2694
    // Set the test run id for use in other parts of Drupal.
2695
    $test_info = &$GLOBALS['drupal_test_info'];
2696
    $test_info['test_run_id'] = $test_prefix;
2697
    $test_info['in_child_site'] = TRUE;
2698

    
2699
    foreach ($GLOBALS['databases']['default'] as &$value) {
2700
      // Extract the current default database prefix.
2701
      if (!isset($value['prefix'])) {
2702
        $current_prefix = '';
2703
      }
2704
      elseif (is_array($value['prefix'])) {
2705
        $current_prefix = $value['prefix']['default'];
2706
      }
2707
      else {
2708
        $current_prefix = $value['prefix'];
2709
      }
2710

    
2711
      // Remove the current database prefix and replace it by our own.
2712
      $value['prefix'] = array(
2713
        'default' => $current_prefix . $test_prefix,
2714
      );
2715
    }
2716
  }
2717

    
2718
  // Initialize the database system. Note that the connection
2719
  // won't be initialized until it is actually requested.
2720
  require_once DRUPAL_ROOT . '/includes/database/database.inc';
2721

    
2722
  // Register autoload functions so that we can access classes and interfaces.
2723
  // The database autoload routine comes first so that we can load the database
2724
  // system without hitting the database. That is especially important during
2725
  // the install or upgrade process.
2726
  spl_autoload_register('drupal_autoload_class');
2727
  spl_autoload_register('drupal_autoload_interface');
2728
  if (version_compare(PHP_VERSION, '5.4') >= 0) {
2729
    spl_autoload_register('drupal_autoload_trait');
2730
  }
2731
}
2732

    
2733
/**
2734
 * Loads system variables and all enabled bootstrap modules.
2735
 */
2736
function _drupal_bootstrap_variables() {
2737
  global $conf;
2738

    
2739
  // Initialize the lock system.
2740
  require_once DRUPAL_ROOT . '/' . variable_get('lock_inc', 'includes/lock.inc');
2741
  lock_initialize();
2742

    
2743
  // Load variables from the database, but do not overwrite variables set in settings.php.
2744
  $conf = variable_initialize(isset($conf) ? $conf : array());
2745
  // Load bootstrap modules.
2746
  require_once DRUPAL_ROOT . '/includes/module.inc';
2747
  module_load_all(TRUE);
2748

    
2749
  // Sanitize the destination parameter (which is often used for redirects) to
2750
  // prevent open redirect attacks leading to other domains. Sanitize both
2751
  // $_GET['destination'] and $_REQUEST['destination'] to protect code that
2752
  // relies on either, but do not sanitize $_POST to avoid interfering with
2753
  // unrelated form submissions. The sanitization happens here because
2754
  // url_is_external() requires the variable system to be available.
2755
  if (isset($_GET['destination']) || isset($_REQUEST['destination'])) {
2756
    require_once DRUPAL_ROOT . '/includes/common.inc';
2757
    // If the destination is an external URL, remove it.
2758
    if (isset($_GET['destination']) && url_is_external($_GET['destination'])) {
2759
      unset($_GET['destination']);
2760
      unset($_REQUEST['destination']);
2761
    }
2762
    // If there's still something in $_REQUEST['destination'] that didn't come
2763
    // from $_GET, check it too.
2764
    if (isset($_REQUEST['destination']) && (!isset($_GET['destination']) || $_REQUEST['destination'] != $_GET['destination']) && url_is_external($_REQUEST['destination'])) {
2765
      unset($_REQUEST['destination']);
2766
    }
2767
  }
2768
}
2769

    
2770
/**
2771
 * Invokes hook_boot(), initializes locking system, and sends HTTP headers.
2772
 */
2773
function _drupal_bootstrap_page_header() {
2774
  bootstrap_invoke_all('boot');
2775

    
2776
  if (!drupal_is_cli()) {
2777
    ob_start();
2778
    drupal_page_header();
2779
  }
2780
}
2781

    
2782
/**
2783
 * Returns the current bootstrap phase for this Drupal process.
2784
 *
2785
 * The current phase is the one most recently completed by drupal_bootstrap().
2786
 *
2787
 * @see drupal_bootstrap()
2788
 */
2789
function drupal_get_bootstrap_phase() {
2790
  return drupal_bootstrap(NULL, FALSE);
2791
}
2792

    
2793
/**
2794
 * Returns the test prefix if this is an internal request from SimpleTest.
2795
 *
2796
 * @return
2797
 *   Either the simpletest prefix (the string "simpletest" followed by any
2798
 *   number of digits) or FALSE if the user agent does not contain a valid
2799
 *   HMAC and timestamp.
2800
 */
2801
function drupal_valid_test_ua() {
2802
  // No reason to reset this.
2803
  static $test_prefix;
2804

    
2805
  if (isset($test_prefix)) {
2806
    return $test_prefix;
2807
  }
2808

    
2809
  if (isset($_SERVER['HTTP_USER_AGENT']) && preg_match("/^(simpletest\d+);(.+);(.+);(.+)$/", $_SERVER['HTTP_USER_AGENT'], $matches)) {
2810
    list(, $prefix, $time, $salt, $hmac) = $matches;
2811
    $check_string =  $prefix . ';' . $time . ';' . $salt;
2812
    // We use the salt from settings.php to make the HMAC key, since
2813
    // the database is not yet initialized and we can't access any Drupal variables.
2814
    // The file properties add more entropy not easily accessible to others.
2815
    $key = drupal_get_hash_salt() . filectime(__FILE__) . fileinode(__FILE__);
2816
    $time_diff = REQUEST_TIME - $time;
2817
    // Since we are making a local request a 5 second time window is allowed,
2818
    // and the HMAC must match.
2819
    if ($time_diff >= 0 && $time_diff <= 5 && $hmac == drupal_hmac_base64($check_string, $key)) {
2820
      $test_prefix = $prefix;
2821
      return $test_prefix;
2822
    }
2823
  }
2824

    
2825
  $test_prefix = FALSE;
2826
  return $test_prefix;
2827
}
2828

    
2829
/**
2830
 * Generates a user agent string with a HMAC and timestamp for simpletest.
2831
 */
2832
function drupal_generate_test_ua($prefix) {
2833
  static $key;
2834

    
2835
  if (!isset($key)) {
2836
    // We use the salt from settings.php to make the HMAC key, since
2837
    // the database is not yet initialized and we can't access any Drupal variables.
2838
    // The file properties add more entropy not easily accessible to others.
2839
    $key = drupal_get_hash_salt() . filectime(__FILE__) . fileinode(__FILE__);
2840
  }
2841
  // Generate a moderately secure HMAC based on the database credentials.
2842
  $salt = uniqid('', TRUE);
2843
  $check_string = $prefix . ';' . time() . ';' . $salt;
2844
  return $check_string . ';' . drupal_hmac_base64($check_string, $key);
2845
}
2846

    
2847
/**
2848
 * Enables use of the theme system without requiring database access.
2849
 *
2850
 * Loads and initializes the theme system for site installs, updates and when
2851
 * the site is in maintenance mode. This also applies when the database fails.
2852
 *
2853
 * @see _drupal_maintenance_theme()
2854
 */
2855
function drupal_maintenance_theme() {
2856
  require_once DRUPAL_ROOT . '/includes/theme.maintenance.inc';
2857
  _drupal_maintenance_theme();
2858
}
2859

    
2860
/**
2861
 * Returns a simple 404 Not Found page.
2862
 *
2863
 * If fast 404 pages are enabled, and this is a matching page then print a
2864
 * simple 404 page and exit.
2865
 *
2866
 * This function is called from drupal_deliver_html_page() at the time when a
2867
 * a normal 404 page is generated, but it can also optionally be called directly
2868
 * from settings.php to prevent a Drupal bootstrap on these pages. See
2869
 * documentation in settings.php for the benefits and drawbacks of using this.
2870
 *
2871
 * Paths to dynamically-generated content, such as image styles, should also be
2872
 * accounted for in this function.
2873
 */
2874
function drupal_fast_404() {
2875
  $exclude_paths = variable_get('404_fast_paths_exclude', FALSE);
2876
  if ($exclude_paths && !preg_match($exclude_paths, $_GET['q'])) {
2877
    $fast_paths = variable_get('404_fast_paths', FALSE);
2878
    if ($fast_paths && preg_match($fast_paths, $_GET['q'])) {
2879
      drupal_add_http_header('Status', '404 Not Found');
2880
      $fast_404_html = variable_get('404_fast_html', '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN" "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title>404 Not Found</title></head><body><h1>Not Found</h1><p>The requested URL "@path" was not found on this server.</p></body></html>');
2881
      // Replace @path in the variable with the page path.
2882
      print strtr($fast_404_html, array('@path' => check_plain(request_uri())));
2883
      exit;
2884
    }
2885
  }
2886
}
2887

    
2888
/**
2889
 * Returns TRUE if a Drupal installation is currently being attempted.
2890
 */
2891
function drupal_installation_attempted() {
2892
  return defined('MAINTENANCE_MODE') && MAINTENANCE_MODE == 'install';
2893
}
2894

    
2895
/**
2896
 * Returns the name of the proper localization function.
2897
 *
2898
 * get_t() exists to support localization for code that might run during
2899
 * the installation phase, when some elements of the system might not have
2900
 * loaded.
2901
 *
2902
 * This would include implementations of hook_install(), which could run
2903
 * during the Drupal installation phase, and might also be run during
2904
 * non-installation time, such as while installing the module from the
2905
 * module administration page.
2906
 *
2907
 * Example usage:
2908
 * @code
2909
 *   $t = get_t();
2910
 *   $translated = $t('translate this');
2911
 * @endcode
2912
 *
2913
 * Use t() if your code will never run during the Drupal installation phase.
2914
 * Use st() if your code will only run during installation and never any other
2915
 * time. Use get_t() if your code could run in either circumstance.
2916
 *
2917
 * @see t()
2918
 * @see st()
2919
 * @ingroup sanitization
2920
 */
2921
function get_t() {
2922
  static $t;
2923
  // This is not converted to drupal_static because there is no point in
2924
  // resetting this as it can not change in the course of a request.
2925
  if (!isset($t)) {
2926
    $t = drupal_installation_attempted() ? 'st' : 't';
2927
  }
2928
  return $t;
2929
}
2930

    
2931
/**
2932
 * Initializes all the defined language types.
2933
 */
2934
function drupal_language_initialize() {
2935
  $types = language_types();
2936

    
2937
  // Ensure the language is correctly returned, even without multilanguage
2938
  // support. Also make sure we have a $language fallback, in case a language
2939
  // negotiation callback needs to do a full bootstrap.
2940
  // Useful for eg. XML/HTML 'lang' attributes.
2941
  $default = language_default();
2942
  foreach ($types as $type) {
2943
    $GLOBALS[$type] = $default;
2944
  }
2945
  if (drupal_multilingual()) {
2946
    include_once DRUPAL_ROOT . '/includes/language.inc';
2947
    foreach ($types as $type) {
2948
      $GLOBALS[$type] = language_initialize($type);
2949
    }
2950
    // Allow modules to react on language system initialization in multilingual
2951
    // environments.
2952
    bootstrap_invoke_all('language_init');
2953
  }
2954
}
2955

    
2956
/**
2957
 * Returns a list of the built-in language types.
2958
 *
2959
 * @return
2960
 *   An array of key-values pairs where the key is the language type and the
2961
 *   value is its configurability.
2962
 */
2963
function drupal_language_types() {
2964
  return array(
2965
    LANGUAGE_TYPE_INTERFACE => TRUE,
2966
    LANGUAGE_TYPE_CONTENT => FALSE,
2967
    LANGUAGE_TYPE_URL => FALSE,
2968
  );
2969
}
2970

    
2971
/**
2972
 * Returns TRUE if there is more than one language enabled.
2973
 *
2974
 * @return
2975
 *   TRUE if more than one language is enabled.
2976
 */
2977
function drupal_multilingual() {
2978
  // The "language_count" variable stores the number of enabled languages to
2979
  // avoid unnecessarily querying the database when building the list of
2980
  // enabled languages on monolingual sites.
2981
  return variable_get('language_count', 1) > 1;
2982
}
2983

    
2984
/**
2985
 * Returns an array of the available language types.
2986
 *
2987
 * @return
2988
 *   An array of all language types where the keys of each are the language type
2989
 *   name and its value is its configurability (TRUE/FALSE).
2990
 */
2991
function language_types() {
2992
  return array_keys(variable_get('language_types', drupal_language_types()));
2993
}
2994

    
2995
/**
2996
 * Returns a list of installed languages, indexed by the specified key.
2997
 *
2998
 * @param $field
2999
 *   (optional) The field to index the list with.
3000
 *
3001
 * @return
3002
 *   An associative array, keyed on the values of $field.
3003
 *   - If $field is 'weight' or 'enabled', the array is nested, with the outer
3004
 *     array's values each being associative arrays with language codes as
3005
 *     keys and language objects as values.
3006
 *   - For all other values of $field, the array is only one level deep, and
3007
 *     the array's values are language objects.
3008
 */
3009
function language_list($field = 'language') {
3010
  $languages = &drupal_static(__FUNCTION__);
3011
  // Init language list
3012
  if (!isset($languages)) {
3013
    if (drupal_multilingual() || module_exists('locale')) {
3014
      $languages['language'] = db_query('SELECT * FROM {languages} ORDER BY weight ASC, name ASC')->fetchAllAssoc('language');
3015
      // Users cannot uninstall the native English language. However, we allow
3016
      // it to be hidden from the installed languages. Therefore, at least one
3017
      // other language must be enabled then.
3018
      if (!$languages['language']['en']->enabled && !variable_get('language_native_enabled', TRUE)) {
3019
        unset($languages['language']['en']);
3020
      }
3021
    }
3022
    else {
3023
      // No locale module, so use the default language only.
3024
      $default = language_default();
3025
      $languages['language'][$default->language] = $default;
3026
    }
3027
  }
3028

    
3029
  // Return the array indexed by the right field
3030
  if (!isset($languages[$field])) {
3031
    $languages[$field] = array();
3032
    foreach ($languages['language'] as $lang) {
3033
      // Some values should be collected into an array
3034
      if (in_array($field, array('enabled', 'weight'))) {
3035
        $languages[$field][$lang->$field][$lang->language] = $lang;
3036
      }
3037
      else {
3038
        $languages[$field][$lang->$field] = $lang;
3039
      }
3040
    }
3041
  }
3042
  return $languages[$field];
3043
}
3044

    
3045
/**
3046
 * Returns the default language, as an object, or one of its properties.
3047
 *
3048
 * @param $property
3049
 *   (optional) The property of the language object to return.
3050
 *
3051
 * @return
3052
 *   Either the language object for the default language used on the site,
3053
 *   or the property of that object named in the $property parameter.
3054
 */
3055
function language_default($property = NULL) {
3056
  $language = variable_get('language_default', (object) array('language' => 'en', 'name' => 'English', 'native' => 'English', 'direction' => 0, 'enabled' => 1, 'plurals' => 0, 'formula' => '', 'domain' => '', 'prefix' => '', 'weight' => 0, 'javascript' => ''));
3057
  return $property ? $language->$property : $language;
3058
}
3059

    
3060
/**
3061
 * Returns the requested URL path of the page being viewed.
3062
 *
3063
 * Examples:
3064
 * - http://example.com/node/306 returns "node/306".
3065
 * - http://example.com/drupalfolder/node/306 returns "node/306" while
3066
 *   base_path() returns "/drupalfolder/".
3067
 * - http://example.com/path/alias (which is a path alias for node/306) returns
3068
 *   "path/alias" as opposed to the internal path.
3069
 * - http://example.com/index.php returns an empty string (meaning: front page).
3070
 * - http://example.com/index.php?page=1 returns an empty string.
3071
 *
3072
 * @return
3073
 *   The requested Drupal URL path.
3074
 *
3075
 * @see current_path()
3076
 */
3077
function request_path() {
3078
  static $path;
3079

    
3080
  if (isset($path)) {
3081
    return $path;
3082
  }
3083

    
3084
  if (isset($_GET['q']) && is_string($_GET['q'])) {
3085
    // This is a request with a ?q=foo/bar query string. $_GET['q'] is
3086
    // overwritten in drupal_path_initialize(), but request_path() is called
3087
    // very early in the bootstrap process, so the original value is saved in
3088
    // $path and returned in later calls.
3089
    $path = $_GET['q'];
3090
  }
3091
  elseif (isset($_SERVER['REQUEST_URI'])) {
3092
    // This request is either a clean URL, or 'index.php', or nonsense.
3093
    // Extract the path from REQUEST_URI.
3094
    $request_path = strtok($_SERVER['REQUEST_URI'], '?');
3095
    $base_path_len = strlen(rtrim(dirname($_SERVER['SCRIPT_NAME']), '\/'));
3096
    // Unescape and strip $base_path prefix, leaving q without a leading slash.
3097
    $path = substr(urldecode($request_path), $base_path_len + 1);
3098
    // If the path equals the script filename, either because 'index.php' was
3099
    // explicitly provided in the URL, or because the server added it to
3100
    // $_SERVER['REQUEST_URI'] even when it wasn't provided in the URL (some
3101
    // versions of Microsoft IIS do this), the front page should be served.
3102
    if ($path == basename($_SERVER['PHP_SELF'])) {
3103
      $path = '';
3104
    }
3105
  }
3106
  else {
3107
    // This is the front page.
3108
    $path = '';
3109
  }
3110

    
3111
  // Under certain conditions Apache's RewriteRule directive prepends the value
3112
  // assigned to $_GET['q'] with a slash. Moreover we can always have a trailing
3113
  // slash in place, hence we need to normalize $_GET['q'].
3114
  $path = trim($path, '/');
3115

    
3116
  return $path;
3117
}
3118

    
3119
/**
3120
 * Returns a component of the current Drupal path.
3121
 *
3122
 * When viewing a page at the path "admin/structure/types", for example, arg(0)
3123
 * returns "admin", arg(1) returns "structure", and arg(2) returns "types".
3124
 *
3125
 * Avoid use of this function where possible, as resulting code is hard to
3126
 * read. In menu callback functions, attempt to use named arguments. See the
3127
 * explanation in menu.inc for how to construct callbacks that take arguments.
3128
 * When attempting to use this function to load an element from the current
3129
 * path, e.g. loading the node on a node page, use menu_get_object() instead.
3130
 *
3131
 * @param $index
3132
 *   The index of the component, where each component is separated by a '/'
3133
 *   (forward-slash), and where the first component has an index of 0 (zero).
3134
 * @param $path
3135
 *   A path to break into components. Defaults to the path of the current page.
3136
 *
3137
 * @return
3138
 *   The component specified by $index, or NULL if the specified component was
3139
 *   not found. If called without arguments, it returns an array containing all
3140
 *   the components of the current path.
3141
 */
3142
function arg($index = NULL, $path = NULL) {
3143
  // Even though $arguments doesn't need to be resettable for any functional
3144
  // reasons (the result of explode() does not depend on any run-time
3145
  // information), it should be resettable anyway in case a module needs to
3146
  // free up the memory used by it.
3147
  // Use the advanced drupal_static() pattern, since this is called very often.
3148
  static $drupal_static_fast;
3149
  if (!isset($drupal_static_fast)) {
3150
    $drupal_static_fast['arguments'] = &drupal_static(__FUNCTION__);
3151
  }
3152
  $arguments = &$drupal_static_fast['arguments'];
3153

    
3154
  if (!isset($path)) {
3155
    $path = $_GET['q'];
3156
  }
3157
  if (!isset($arguments[$path])) {
3158
    $arguments[$path] = explode('/', $path);
3159
  }
3160
  if (!isset($index)) {
3161
    return $arguments[$path];
3162
  }
3163
  if (isset($arguments[$path][$index])) {
3164
    return $arguments[$path][$index];
3165
  }
3166
}
3167

    
3168
/**
3169
 * Returns the IP address of the client machine.
3170
 *
3171
 * If Drupal is behind a reverse proxy, we use the X-Forwarded-For header
3172
 * instead of $_SERVER['REMOTE_ADDR'], which would be the IP address of
3173
 * the proxy server, and not the client's. The actual header name can be
3174
 * configured by the reverse_proxy_header variable.
3175
 *
3176
 * @return
3177
 *   IP address of client machine, adjusted for reverse proxy and/or cluster
3178
 *   environments.
3179
 */
3180
function ip_address() {
3181
  $ip_address = &drupal_static(__FUNCTION__);
3182

    
3183
  if (!isset($ip_address)) {
3184
    $ip_address = $_SERVER['REMOTE_ADDR'];
3185

    
3186
    if (variable_get('reverse_proxy', 0)) {
3187
      $reverse_proxy_header = variable_get('reverse_proxy_header', 'HTTP_X_FORWARDED_FOR');
3188
      if (!empty($_SERVER[$reverse_proxy_header])) {
3189
        // If an array of known reverse proxy IPs is provided, then trust
3190
        // the XFF header if request really comes from one of them.
3191
        $reverse_proxy_addresses = variable_get('reverse_proxy_addresses', array());
3192

    
3193
        // Turn XFF header into an array.
3194
        $forwarded = explode(',', $_SERVER[$reverse_proxy_header]);
3195

    
3196
        // Trim the forwarded IPs; they may have been delimited by commas and spaces.
3197
        $forwarded = array_map('trim', $forwarded);
3198

    
3199
        // Tack direct client IP onto end of forwarded array.
3200
        $forwarded[] = $ip_address;
3201

    
3202
        // Eliminate all trusted IPs.
3203
        $untrusted = array_diff($forwarded, $reverse_proxy_addresses);
3204

    
3205
        if (!empty($untrusted)) {
3206
          // The right-most IP is the most specific we can trust.
3207
          $ip_address = array_pop($untrusted);
3208
        }
3209
        else {
3210
          // All IP addresses in the forwarded array are configured proxy IPs
3211
          // (and thus trusted). We take the leftmost IP.
3212
          $ip_address = array_shift($forwarded);
3213
        }
3214
      }
3215
    }
3216
  }
3217

    
3218
  return $ip_address;
3219
}
3220

    
3221
/**
3222
 * @addtogroup schemaapi
3223
 * @{
3224
 */
3225

    
3226
/**
3227
 * Gets the schema definition of a table, or the whole database schema.
3228
 *
3229
 * The returned schema will include any modifications made by any
3230
 * module that implements hook_schema_alter(). To get the schema without
3231
 * modifications, use drupal_get_schema_unprocessed().
3232
 *
3233
 *
3234
 * @param $table
3235
 *   The name of the table. If not given, the schema of all tables is returned.
3236
 * @param $rebuild
3237
 *   If true, the schema will be rebuilt instead of retrieved from the cache.
3238
 */
3239
function drupal_get_schema($table = NULL, $rebuild = FALSE) {
3240
  static $schema;
3241

    
3242
  if ($rebuild || !isset($table)) {
3243
    $schema = drupal_get_complete_schema($rebuild);
3244
  }
3245
  elseif (!isset($schema)) {
3246
    $schema = new SchemaCache();
3247
  }
3248

    
3249
  if (!isset($table)) {
3250
    return $schema;
3251
  }
3252
  if (isset($schema[$table])) {
3253
    return $schema[$table];
3254
  }
3255
  else {
3256
    return FALSE;
3257
  }
3258
}
3259

    
3260
/**
3261
 * Extends DrupalCacheArray to allow for dynamic building of the schema cache.
3262
 */
3263
class SchemaCache extends DrupalCacheArray {
3264

    
3265
  /**
3266
   * Constructs a SchemaCache object.
3267
   */
3268
  public function __construct() {
3269
    // Cache by request method.
3270
    parent::__construct('schema:runtime:' . ($_SERVER['REQUEST_METHOD'] == 'GET'), 'cache');
3271
  }
3272

    
3273
  /**
3274
   * Overrides DrupalCacheArray::resolveCacheMiss().
3275
   */
3276
  protected function resolveCacheMiss($offset) {
3277
    $complete_schema = drupal_get_complete_schema();
3278
    $value = isset($complete_schema[$offset]) ? $complete_schema[$offset] :  NULL;
3279
    $this->storage[$offset] = $value;
3280
    $this->persist($offset);
3281
    return $value;
3282
  }
3283
}
3284

    
3285
/**
3286
 * Gets the whole database schema.
3287
 *
3288
 * The returned schema will include any modifications made by any
3289
 * module that implements hook_schema_alter().
3290
 *
3291
 * @param $rebuild
3292
 *   If true, the schema will be rebuilt instead of retrieved from the cache.
3293
 */
3294
function drupal_get_complete_schema($rebuild = FALSE) {
3295
  static $schema = array();
3296

    
3297
  if (empty($schema) || $rebuild) {
3298
    // Try to load the schema from cache.
3299
    if (!$rebuild && $cached = cache_get('schema')) {
3300
      $schema = $cached->data;
3301
    }
3302
    // Otherwise, rebuild the schema cache.
3303
    else {
3304
      $schema = array();
3305
      // Load the .install files to get hook_schema.
3306
      // On some databases this function may be called before bootstrap has
3307
      // been completed, so we force the functions we need to load just in case.
3308
      if (function_exists('module_load_all_includes')) {
3309
        // This function can be called very early in the bootstrap process, so
3310
        // we force the module_list() cache to be refreshed to ensure that it
3311
        // contains the complete list of modules before we go on to call
3312
        // module_load_all_includes().
3313
        module_list(TRUE);
3314
        module_load_all_includes('install');
3315
      }
3316

    
3317
      require_once DRUPAL_ROOT . '/includes/common.inc';
3318
      // Invoke hook_schema for all modules.
3319
      foreach (module_implements('schema') as $module) {
3320
        // Cast the result of hook_schema() to an array, as a NULL return value
3321
        // would cause array_merge() to set the $schema variable to NULL as well.
3322
        // That would break modules which use $schema further down the line.
3323
        $current = (array) module_invoke($module, 'schema');
3324
        // Set 'module' and 'name' keys for each table, and remove descriptions,
3325
        // as they needlessly slow down cache_get() for every single request.
3326
        _drupal_schema_initialize($current, $module);
3327
        $schema = array_merge($schema, $current);
3328
      }
3329

    
3330
      drupal_alter('schema', $schema);
3331
      // If the schema is empty, avoid saving it: some database engines require
3332
      // the schema to perform queries, and this could lead to infinite loops.
3333
      if (!empty($schema) && (drupal_get_bootstrap_phase() == DRUPAL_BOOTSTRAP_FULL)) {
3334
        cache_set('schema', $schema);
3335
      }
3336
      if ($rebuild) {
3337
        cache_clear_all('schema:', 'cache', TRUE);
3338
      }
3339
    }
3340
  }
3341

    
3342
  return $schema;
3343
}
3344

    
3345
/**
3346
 * @} End of "addtogroup schemaapi".
3347
 */
3348

    
3349

    
3350
/**
3351
 * @addtogroup registry
3352
 * @{
3353
 */
3354

    
3355
/**
3356
 * Confirms that an interface is available.
3357
 *
3358
 * This function is rarely called directly. Instead, it is registered as an
3359
 * spl_autoload()  handler, and PHP calls it for us when necessary.
3360
 *
3361
 * @param $interface
3362
 *   The name of the interface to check or load.
3363
 *
3364
 * @return
3365
 *   TRUE if the interface is currently available, FALSE otherwise.
3366
 */
3367
function drupal_autoload_interface($interface) {
3368
  return _registry_check_code('interface', $interface);
3369
}
3370

    
3371
/**
3372
 * Confirms that a class is available.
3373
 *
3374
 * This function is rarely called directly. Instead, it is registered as an
3375
 * spl_autoload()  handler, and PHP calls it for us when necessary.
3376
 *
3377
 * @param $class
3378
 *   The name of the class to check or load.
3379
 *
3380
 * @return
3381
 *   TRUE if the class is currently available, FALSE otherwise.
3382
 */
3383
function drupal_autoload_class($class) {
3384
  return _registry_check_code('class', $class);
3385
}
3386

    
3387
/**
3388
 * Confirms that a trait is available.
3389
 *
3390
 * This function is rarely called directly. Instead, it is registered as an
3391
 * spl_autoload() handler, and PHP calls it for us when necessary.
3392
 *
3393
 * @param string $trait
3394
 *   The name of the trait to check or load.
3395
 *
3396
 * @return bool
3397
 *   TRUE if the trait is currently available, FALSE otherwise.
3398
 */
3399
function drupal_autoload_trait($trait) {
3400
  return _registry_check_code('trait', $trait);
3401
}
3402

    
3403
/**
3404
 * Checks for a resource in the registry.
3405
 *
3406
 * @param $type
3407
 *   The type of resource we are looking up, or one of the constants
3408
 *   REGISTRY_RESET_LOOKUP_CACHE or REGISTRY_WRITE_LOOKUP_CACHE, which
3409
 *   signal that we should reset or write the cache, respectively.
3410
 * @param $name
3411
 *   The name of the resource, or NULL if either of the REGISTRY_* constants
3412
 *   is passed in.
3413
 *
3414
 * @return
3415
 *   TRUE if the resource was found, FALSE if not.
3416
 *   NULL if either of the REGISTRY_* constants is passed in as $type.
3417
 */
3418
function _registry_check_code($type, $name = NULL) {
3419
  static $lookup_cache, $cache_update_needed;
3420

    
3421
  if ($type == 'class' && class_exists($name) || $type == 'interface' && interface_exists($name) || $type == 'trait' && trait_exists($name)) {
3422
    return TRUE;
3423
  }
3424

    
3425
  if (!isset($lookup_cache)) {
3426
    $lookup_cache = array();
3427
    if ($cache = cache_get('lookup_cache', 'cache_bootstrap')) {
3428
      $lookup_cache = $cache->data;
3429
    }
3430
  }
3431

    
3432
  // When we rebuild the registry, we need to reset this cache so
3433
  // we don't keep lookups for resources that changed during the rebuild.
3434
  if ($type == REGISTRY_RESET_LOOKUP_CACHE) {
3435
    $cache_update_needed = TRUE;
3436
    $lookup_cache = NULL;
3437
    return;
3438
  }
3439

    
3440
  // Called from drupal_page_footer, we write to permanent storage if there
3441
  // changes to the lookup cache for this request.
3442
  if ($type == REGISTRY_WRITE_LOOKUP_CACHE) {
3443
    if ($cache_update_needed) {
3444
      cache_set('lookup_cache', $lookup_cache, 'cache_bootstrap');
3445
    }
3446
    return;
3447
  }
3448

    
3449
  // $type is either 'interface' or 'class', so we only need the first letter to
3450
  // keep the cache key unique.
3451
  $cache_key = $type[0] . $name;
3452
  if (isset($lookup_cache[$cache_key])) {
3453
    if ($lookup_cache[$cache_key]) {
3454
      include_once DRUPAL_ROOT . '/' . $lookup_cache[$cache_key];
3455
    }
3456
    return (bool) $lookup_cache[$cache_key];
3457
  }
3458

    
3459
  // This function may get called when the default database is not active, but
3460
  // there is no reason we'd ever want to not use the default database for
3461
  // this query.
3462
  $file = Database::getConnection('default', 'default')
3463
    ->select('registry', 'r', array('target' => 'default'))
3464
    ->fields('r', array('filename'))
3465
    // Use LIKE here to make the query case-insensitive.
3466
    ->condition('r.name', db_like($name), 'LIKE')
3467
    ->condition('r.type', $type)
3468
    ->execute()
3469
    ->fetchField();
3470

    
3471
  // Flag that we've run a lookup query and need to update the cache.
3472
  $cache_update_needed = TRUE;
3473

    
3474
  // Misses are valuable information worth caching, so cache even if
3475
  // $file is FALSE.
3476
  $lookup_cache[$cache_key] = $file;
3477

    
3478
  if ($file) {
3479
    include_once DRUPAL_ROOT . '/' . $file;
3480
    return TRUE;
3481
  }
3482
  else {
3483
    return FALSE;
3484
  }
3485
}
3486

    
3487
/**
3488
 * Rescans all enabled modules and rebuilds the registry.
3489
 *
3490
 * Rescans all code in modules or includes directories, storing the location of
3491
 * each interface or class in the database.
3492
 */
3493
function registry_rebuild() {
3494
  system_rebuild_module_data();
3495
  registry_update();
3496
}
3497

    
3498
/**
3499
 * Updates the registry based on the latest files listed in the database.
3500
 *
3501
 * This function should be used when system_rebuild_module_data() does not need
3502
 * to be called, because it is already known that the list of files in the
3503
 * {system} table matches those in the file system.
3504
 *
3505
 * @return
3506
 *   TRUE if the registry was rebuilt, FALSE if another thread was rebuilding
3507
 *   in parallel and the current thread just waited for completion.
3508
 *
3509
 * @see registry_rebuild()
3510
 */
3511
function registry_update() {
3512
  // install_system_module() calls module_enable() which calls into this
3513
  // function during initial system installation, so the lock system is neither
3514
  // loaded nor does its storage exist yet.
3515
  $in_installer = drupal_installation_attempted();
3516
  if (!$in_installer && !lock_acquire(__FUNCTION__)) {
3517
    // Another request got the lock, wait for it to finish.
3518
    lock_wait(__FUNCTION__);
3519
    return FALSE;
3520
  }
3521

    
3522
  require_once DRUPAL_ROOT . '/includes/registry.inc';
3523
  _registry_update();
3524

    
3525
  if (!$in_installer) {
3526
    lock_release(__FUNCTION__);
3527
  }
3528
  return TRUE;
3529
}
3530

    
3531
/**
3532
 * @} End of "addtogroup registry".
3533
 */
3534

    
3535
/**
3536
 * Provides central static variable storage.
3537
 *
3538
 * All functions requiring a static variable to persist or cache data within
3539
 * a single page request are encouraged to use this function unless it is
3540
 * absolutely certain that the static variable will not need to be reset during
3541
 * the page request. By centralizing static variable storage through this
3542
 * function, other functions can rely on a consistent API for resetting any
3543
 * other function's static variables.
3544
 *
3545
 * Example:
3546
 * @code
3547
 * function language_list($field = 'language') {
3548
 *   $languages = &drupal_static(__FUNCTION__);
3549
 *   if (!isset($languages)) {
3550
 *     // If this function is being called for the first time after a reset,
3551
 *     // query the database and execute any other code needed to retrieve
3552
 *     // information about the supported languages.
3553
 *     ...
3554
 *   }
3555
 *   if (!isset($languages[$field])) {
3556
 *     // If this function is being called for the first time for a particular
3557
 *     // index field, then execute code needed to index the information already
3558
 *     // available in $languages by the desired field.
3559
 *     ...
3560
 *   }
3561
 *   // Subsequent invocations of this function for a particular index field
3562
 *   // skip the above two code blocks and quickly return the already indexed
3563
 *   // information.
3564
 *   return $languages[$field];
3565
 * }
3566
 * function locale_translate_overview_screen() {
3567
 *   // When building the content for the translations overview page, make
3568
 *   // sure to get completely fresh information about the supported languages.
3569
 *   drupal_static_reset('language_list');
3570
 *   ...
3571
 * }
3572
 * @endcode
3573
 *
3574
 * In a few cases, a function can have certainty that there is no legitimate
3575
 * use-case for resetting that function's static variable. This is rare,
3576
 * because when writing a function, it's hard to forecast all the situations in
3577
 * which it will be used. A guideline is that if a function's static variable
3578
 * does not depend on any information outside of the function that might change
3579
 * during a single page request, then it's ok to use the "static" keyword
3580
 * instead of the drupal_static() function.
3581
 *
3582
 * Example:
3583
 * @code
3584
 * function actions_do(...) {
3585
 *   // $stack tracks the number of recursive calls.
3586
 *   static $stack;
3587
 *   $stack++;
3588
 *   if ($stack > variable_get('actions_max_stack', 35)) {
3589
 *     ...
3590
 *     return;
3591
 *   }
3592
 *   ...
3593
 *   $stack--;
3594
 * }
3595
 * @endcode
3596
 *
3597
 * In a few cases, a function needs a resettable static variable, but the
3598
 * function is called many times (100+) during a single page request, so
3599
 * every microsecond of execution time that can be removed from the function
3600
 * counts. These functions can use a more cumbersome, but faster variant of
3601
 * calling drupal_static(). It works by storing the reference returned by
3602
 * drupal_static() in the calling function's own static variable, thereby
3603
 * removing the need to call drupal_static() for each iteration of the function.
3604
 * Conceptually, it replaces:
3605
 * @code
3606
 * $foo = &drupal_static(__FUNCTION__);
3607
 * @endcode
3608
 * with:
3609
 * @code
3610
 * // Unfortunately, this does not work.
3611
 * static $foo = &drupal_static(__FUNCTION__);
3612
 * @endcode
3613
 * However, the above line of code does not work, because PHP only allows static
3614
 * variables to be initializied by literal values, and does not allow static
3615
 * variables to be assigned to references.
3616
 * - http://php.net/manual/language.variables.scope.php#language.variables.scope.static
3617
 * - http://php.net/manual/language.variables.scope.php#language.variables.scope.references
3618
 * The example below shows the syntax needed to work around both limitations.
3619
 * For benchmarks and more information, see http://drupal.org/node/619666.
3620
 *
3621
 * Example:
3622
 * @code
3623
 * function user_access($string, $account = NULL) {
3624
 *   // Use the advanced drupal_static() pattern, since this is called very often.
3625
 *   static $drupal_static_fast;
3626
 *   if (!isset($drupal_static_fast)) {
3627
 *     $drupal_static_fast['perm'] = &drupal_static(__FUNCTION__);
3628
 *   }
3629
 *   $perm = &$drupal_static_fast['perm'];
3630
 *   ...
3631
 * }
3632
 * @endcode
3633
 *
3634
 * @param $name
3635
 *   Globally unique name for the variable. For a function with only one static,
3636
 *   variable, the function name (e.g. via the PHP magic __FUNCTION__ constant)
3637
 *   is recommended. For a function with multiple static variables add a
3638
 *   distinguishing suffix to the function name for each one.
3639
 * @param $default_value
3640
 *   Optional default value.
3641
 * @param $reset
3642
 *   TRUE to reset one or all variables(s). This parameter is only used
3643
 *   internally and should not be passed in; use drupal_static_reset() instead.
3644
 *   (This function's return value should not be used when TRUE is passed in.)
3645
 *
3646
 * @return
3647
 *   Returns a variable by reference.
3648
 *
3649
 * @see drupal_static_reset()
3650
 */
3651
function &drupal_static($name, $default_value = NULL, $reset = FALSE) {
3652
  static $data = array(), $default = array();
3653
  // First check if dealing with a previously defined static variable.
3654
  if (isset($data[$name]) || array_key_exists($name, $data)) {
3655
    // Non-NULL $name and both $data[$name] and $default[$name] statics exist.
3656
    if ($reset) {
3657
      // Reset pre-existing static variable to its default value.
3658
      $data[$name] = $default[$name];
3659
    }
3660
    return $data[$name];
3661
  }
3662
  // Neither $data[$name] nor $default[$name] static variables exist.
3663
  if (isset($name)) {
3664
    if ($reset) {
3665
      // Reset was called before a default is set and yet a variable must be
3666
      // returned.
3667
      return $data;
3668
    }
3669
    // First call with new non-NULL $name. Initialize a new static variable.
3670
    $default[$name] = $data[$name] = $default_value;
3671
    return $data[$name];
3672
  }
3673
  // Reset all: ($name == NULL). This needs to be done one at a time so that
3674
  // references returned by earlier invocations of drupal_static() also get
3675
  // reset.
3676
  foreach ($default as $name => $value) {
3677
    $data[$name] = $value;
3678
  }
3679
  // As the function returns a reference, the return should always be a
3680
  // variable.
3681
  return $data;
3682
}
3683

    
3684
/**
3685
 * Resets one or all centrally stored static variable(s).
3686
 *
3687
 * @param $name
3688
 *   Name of the static variable to reset. Omit to reset all variables.
3689
 *   Resetting all variables should only be used, for example, for running unit
3690
 *   tests with a clean environment.
3691
 */
3692
function drupal_static_reset($name = NULL) {
3693
  drupal_static($name, NULL, TRUE);
3694
}
3695

    
3696
/**
3697
 * Detects whether the current script is running in a command-line environment.
3698
 */
3699
function drupal_is_cli() {
3700
  return (!isset($_SERVER['SERVER_SOFTWARE']) && (php_sapi_name() == 'cli' || (is_numeric($_SERVER['argc']) && $_SERVER['argc'] > 0)));
3701
}
3702

    
3703
/**
3704
 * Formats text for emphasized display in a placeholder inside a sentence.
3705
 *
3706
 * Used automatically by format_string().
3707
 *
3708
 * @param $text
3709
 *   The text to format (plain-text).
3710
 *
3711
 * @return
3712
 *   The formatted text (html).
3713
 */
3714
function drupal_placeholder($text) {
3715
  return '<em class="placeholder">' . check_plain($text) . '</em>';
3716
}
3717

    
3718
/**
3719
 * Registers a function for execution on shutdown.
3720
 *
3721
 * Wrapper for register_shutdown_function() that catches thrown exceptions to
3722
 * avoid "Exception thrown without a stack frame in Unknown".
3723
 *
3724
 * @param $callback
3725
 *   The shutdown function to register.
3726
 * @param ...
3727
 *   Additional arguments to pass to the shutdown function.
3728
 *
3729
 * @return
3730
 *   Array of shutdown functions to be executed.
3731
 *
3732
 * @see register_shutdown_function()
3733
 * @ingroup php_wrappers
3734
 */
3735
function &drupal_register_shutdown_function($callback = NULL) {
3736
  // We cannot use drupal_static() here because the static cache is reset during
3737
  // batch processing, which breaks batch handling.
3738
  static $callbacks = array();
3739

    
3740
  if (isset($callback)) {
3741
    // Only register the internal shutdown function once.
3742
    if (empty($callbacks)) {
3743
      register_shutdown_function('_drupal_shutdown_function');
3744
    }
3745
    $args = func_get_args();
3746
    array_shift($args);
3747
    // Save callback and arguments
3748
    $callbacks[] = array('callback' => $callback, 'arguments' => $args);
3749
  }
3750
  return $callbacks;
3751
}
3752

    
3753
/**
3754
 * Executes registered shutdown functions.
3755
 */
3756
function _drupal_shutdown_function() {
3757
  $callbacks = &drupal_register_shutdown_function();
3758

    
3759
  // Set the CWD to DRUPAL_ROOT as it is not guaranteed to be the same as it
3760
  // was in the normal context of execution.
3761
  chdir(DRUPAL_ROOT);
3762

    
3763
  try {
3764
    while (list($key, $callback) = each($callbacks)) {
3765
      call_user_func_array($callback['callback'], $callback['arguments']);
3766
    }
3767
  }
3768
  catch (Exception $exception) {
3769
    // If we are displaying errors, then do so with no possibility of a further uncaught exception being thrown.
3770
   require_once DRUPAL_ROOT . '/includes/errors.inc';
3771
   if (error_displayable()) {
3772
      print '<h1>Uncaught exception thrown in shutdown function.</h1>';
3773
      print '<p>' . _drupal_render_exception_safe($exception) . '</p><hr />';
3774
    }
3775
  }
3776
}
3777

    
3778
/**
3779
 * Compares the memory required for an operation to the available memory.
3780
 *
3781
 * @param $required
3782
 *   The memory required for the operation, expressed as a number of bytes with
3783
 *   optional SI or IEC binary unit prefix (e.g. 2, 3K, 5MB, 10G, 6GiB, 8bytes,
3784
 *   9mbytes).
3785
 * @param $memory_limit
3786
 *   (optional) The memory limit for the operation, expressed as a number of
3787
 *   bytes with optional SI or IEC binary unit prefix (e.g. 2, 3K, 5MB, 10G,
3788
 *   6GiB, 8bytes, 9mbytes). If no value is passed, the current PHP
3789
 *   memory_limit will be used. Defaults to NULL.
3790
 *
3791
 * @return
3792
 *   TRUE if there is sufficient memory to allow the operation, or FALSE
3793
 *   otherwise.
3794
 */
3795
function drupal_check_memory_limit($required, $memory_limit = NULL) {
3796
  if (!isset($memory_limit)) {
3797
    $memory_limit = ini_get('memory_limit');
3798
  }
3799

    
3800
  // There is sufficient memory if:
3801
  // - No memory limit is set.
3802
  // - The memory limit is set to unlimited (-1).
3803
  // - The memory limit is greater than the memory required for the operation.
3804
  return ((!$memory_limit) || ($memory_limit == -1) || (parse_size($memory_limit) >= parse_size($required)));
3805
}
3806

    
3807
/**
3808
 * Invalidates a PHP file from any active opcode caches.
3809
 *
3810
 * If the opcode cache does not support the invalidation of individual files,
3811
 * the entire cache will be flushed.
3812
 *
3813
 * @param string $filepath
3814
 *   The absolute path of the PHP file to invalidate.
3815
 */
3816
function drupal_clear_opcode_cache($filepath) {
3817
  if (!defined('PHP_VERSION_ID') || PHP_VERSION_ID < 50300) {
3818
    // Below PHP 5.3, clearstatcache does not accept any function parameters.
3819
    clearstatcache();
3820
  }
3821
  else {
3822
    clearstatcache(TRUE, $filepath);
3823
  }
3824

    
3825
  // Zend OPcache.
3826
  if (function_exists('opcache_invalidate')) {
3827
    opcache_invalidate($filepath, TRUE);
3828
  }
3829
  // APC.
3830
  if (function_exists('apc_delete_file')) {
3831
    // apc_delete_file() throws a PHP warning in case the specified file was
3832
    // not compiled yet.
3833
    // @see http://php.net/apc-delete-file
3834
    @apc_delete_file($filepath);
3835
  }
3836
}