Project

General

Profile

Paste
Download (17.1 KB) Statistics
| Branch: | Revision:

root / drupal7 / includes / batch.inc @ a8cee257

1
<?php
2

    
3
/**
4
 * @file
5
 * Batch processing API for processes to run in multiple HTTP requests.
6
 *
7
 * Note that batches are usually invoked by form submissions, which is
8
 * why the core interaction functions of the batch processing API live in
9
 * form.inc.
10
 *
11
 * @see form.inc
12
 * @see batch_set()
13
 * @see batch_process()
14
 * @see batch_get()
15
 */
16

    
17
/**
18
 * Loads a batch from the database.
19
 *
20
 * @param $id
21
 *   The ID of the batch to load. When a progressive batch is being processed,
22
 *   the relevant ID is found in $_REQUEST['id'].
23
 *
24
 * @return
25
 *   An array representing the batch, or FALSE if no batch was found.
26
 */
27
function batch_load($id) {
28
  $batch = db_query("SELECT batch FROM {batch} WHERE bid = :bid AND token = :token", array(
29
    ':bid' => $id,
30
    ':token' => drupal_get_token($id),
31
  ))->fetchField();
32
  if ($batch) {
33
    return unserialize($batch);
34
  }
35
  return FALSE;
36
}
37

    
38
/**
39
 * Renders the batch processing page based on the current state of the batch.
40
 *
41
 * @see _batch_shutdown()
42
 */
43
function _batch_page() {
44
  $batch = &batch_get();
45

    
46
  if (!isset($_REQUEST['id'])) {
47
    return FALSE;
48
  }
49

    
50
  // Retrieve the current state of the batch.
51
  if (!$batch) {
52
    $batch = batch_load($_REQUEST['id']);
53
    if (!$batch) {
54
      drupal_set_message(t('No active batch.'), 'error');
55
      drupal_goto();
56
    }
57
  }
58

    
59
  // Register database update for the end of processing.
60
  drupal_register_shutdown_function('_batch_shutdown');
61

    
62
  // Add batch-specific CSS.
63
  foreach ($batch['sets'] as $batch_set) {
64
    if (isset($batch_set['css'])) {
65
      foreach ($batch_set['css'] as $css) {
66
        drupal_add_css($css);
67
      }
68
    }
69
  }
70

    
71
  $op = isset($_REQUEST['op']) ? $_REQUEST['op'] : '';
72
  $output = NULL;
73
  switch ($op) {
74
    case 'start':
75
      $output = _batch_start();
76
      break;
77

    
78
    case 'do':
79
      // JavaScript-based progress page callback.
80
      _batch_do();
81
      break;
82

    
83
    case 'do_nojs':
84
      // Non-JavaScript-based progress page.
85
      $output = _batch_progress_page_nojs();
86
      break;
87

    
88
    case 'finished':
89
      $output = _batch_finished();
90
      break;
91
  }
92

    
93
  return $output;
94
}
95

    
96
/**
97
 * Initializes the batch processing.
98
 *
99
 * JavaScript-enabled clients are identified by the 'has_js' cookie set in
100
 * drupal.js. If no JavaScript-enabled page has been visited during the current
101
 * user's browser session, the non-JavaScript version is returned.
102
 */
103
function _batch_start() {
104
  if (isset($_COOKIE['has_js']) && $_COOKIE['has_js']) {
105
    return _batch_progress_page_js();
106
  }
107
  else {
108
    return _batch_progress_page_nojs();
109
  }
110
}
111

    
112
/**
113
 * Outputs a batch processing page with JavaScript support.
114
 *
115
 * This initializes the batch and error messages. Note that in JavaScript-based
116
 * processing, the batch processing page is displayed only once and updated via
117
 * AHAH requests, so only the first batch set gets to define the page title.
118
 * Titles specified by subsequent batch sets are not displayed.
119
 *
120
 * @see batch_set()
121
 * @see _batch_do()
122
 */
123
function _batch_progress_page_js() {
124
  $batch = batch_get();
125

    
126
  $current_set = _batch_current_set();
127
  drupal_set_title($current_set['title'], PASS_THROUGH);
128

    
129
  // Merge required query parameters for batch processing into those provided by
130
  // batch_set() or hook_batch_alter().
131
  $batch['url_options']['query']['id'] = $batch['id'];
132

    
133
  $js_setting = array(
134
    'batch' => array(
135
      'errorMessage' => $current_set['error_message'] . '<br />' . $batch['error_message'],
136
      'initMessage' => $current_set['init_message'],
137
      'uri' => url($batch['url'], $batch['url_options']),
138
    ),
139
  );
140
  drupal_add_js($js_setting, 'setting');
141
  drupal_add_library('system', 'drupal.batch');
142

    
143
  return '<div id="progress"></div>';
144
}
145

    
146
/**
147
 * Does one execution pass with JavaScript and returns progress to the browser.
148
 *
149
 * @see _batch_progress_page_js()
150
 * @see _batch_process()
151
 */
152
function _batch_do() {
153
  // HTTP POST required.
154
  if ($_SERVER['REQUEST_METHOD'] != 'POST') {
155
    drupal_set_message(t('HTTP POST is required.'), 'error');
156
    drupal_set_title(t('Error'));
157
    return '';
158
  }
159

    
160
  // Perform actual processing.
161
  list($percentage, $message) = _batch_process();
162

    
163
  drupal_json_output(array('status' => TRUE, 'percentage' => $percentage, 'message' => $message));
164
}
165

    
166
/**
167
 * Outputs a batch processing page without JavaScript support.
168
 *
169
 * @see _batch_process()
170
 */
171
function _batch_progress_page_nojs() {
172
  $batch = &batch_get();
173

    
174
  $current_set = _batch_current_set();
175
  drupal_set_title($current_set['title'], PASS_THROUGH);
176

    
177
  $new_op = 'do_nojs';
178

    
179
  if (!isset($batch['running'])) {
180
    // This is the first page so we return some output immediately.
181
    $percentage       = 0;
182
    $message          = $current_set['init_message'];
183
    $batch['running'] = TRUE;
184
  }
185
  else {
186
    // This is one of the later requests; do some processing first.
187

    
188
    // Error handling: if PHP dies due to a fatal error (e.g. a nonexistent
189
    // function), it will output whatever is in the output buffer, followed by
190
    // the error message.
191
    ob_start();
192
    $fallback = $current_set['error_message'] . '<br />' . $batch['error_message'];
193
    $fallback = theme('maintenance_page', array('content' => $fallback, 'show_messages' => FALSE));
194

    
195
    // We strip the end of the page using a marker in the template, so any
196
    // additional HTML output by PHP shows up inside the page rather than below
197
    // it. While this causes invalid HTML, the same would be true if we didn't,
198
    // as content is not allowed to appear after </html> anyway.
199
    list($fallback) = explode('<!--partial-->', $fallback);
200
    print $fallback;
201

    
202
    // Perform actual processing.
203
    list($percentage, $message) = _batch_process($batch);
204
    if ($percentage == 100) {
205
      $new_op = 'finished';
206
    }
207

    
208
    // PHP did not die; remove the fallback output.
209
    ob_end_clean();
210
  }
211

    
212
  // Merge required query parameters for batch processing into those provided by
213
  // batch_set() or hook_batch_alter().
214
  $batch['url_options']['query']['id'] = $batch['id'];
215
  $batch['url_options']['query']['op'] = $new_op;
216

    
217
  $url = url($batch['url'], $batch['url_options']);
218
  $element = array(
219
    '#tag' => 'meta',
220
    '#attributes' => array(
221
      'http-equiv' => 'Refresh',
222
      'content' => '0; URL=' . $url,
223
    ),
224
  );
225
  drupal_add_html_head($element, 'batch_progress_meta_refresh');
226

    
227
  return theme('progress_bar', array('percent' => $percentage, 'message' => $message));
228
}
229

    
230
/**
231
 * Processes sets in a batch.
232
 *
233
 * If the batch was marked for progressive execution (default), this executes as
234
 * many operations in batch sets until an execution time of 1 second has been
235
 * exceeded. It will continue with the next operation of the same batch set in
236
 * the next request.
237
 *
238
 * @return
239
 *   An array containing a completion value (in percent) and a status message.
240
 */
241
function _batch_process() {
242
  $batch       = &batch_get();
243
  $current_set = &_batch_current_set();
244
  // Indicate that this batch set needs to be initialized.
245
  $set_changed = TRUE;
246

    
247
  // If this batch was marked for progressive execution (e.g. forms submitted by
248
  // drupal_form_submit()), initialize a timer to determine whether we need to
249
  // proceed with the same batch phase when a processing time of 1 second has
250
  // been exceeded.
251
  if ($batch['progressive']) {
252
    timer_start('batch_processing');
253
  }
254

    
255
  if (empty($current_set['start'])) {
256
    $current_set['start'] = microtime(TRUE);
257
  }
258

    
259
  $queue = _batch_queue($current_set);
260

    
261
  while (!$current_set['success']) {
262
    // If this is the first time we iterate this batch set in the current
263
    // request, we check if it requires an additional file for functions
264
    // definitions.
265
    if ($set_changed && isset($current_set['file']) && is_file($current_set['file'])) {
266
      include_once DRUPAL_ROOT . '/' . $current_set['file'];
267
    }
268

    
269
    $task_message = '';
270
    // Assume a single pass operation and set the completion level to 1 by
271
    // default.
272
    $finished = 1;
273

    
274
    if ($item = $queue->claimItem()) {
275
      list($function, $args) = $item->data;
276

    
277
      // Build the 'context' array and execute the function call.
278
      $batch_context = array(
279
        'sandbox'  => &$current_set['sandbox'],
280
        'results'  => &$current_set['results'],
281
        'finished' => &$finished,
282
        'message'  => &$task_message,
283
      );
284
      call_user_func_array($function, array_merge($args, array(&$batch_context)));
285

    
286
      if ($finished >= 1) {
287
        // Make sure this step is not counted twice when computing $current.
288
        $finished = 0;
289
        // Remove the processed operation and clear the sandbox.
290
        $queue->deleteItem($item);
291
        $current_set['count']--;
292
        $current_set['sandbox'] = array();
293
      }
294
    }
295

    
296
    // When all operations in the current batch set are completed, browse
297
    // through the remaining sets, marking them 'successfully processed'
298
    // along the way, until we find a set that contains operations.
299
    // _batch_next_set() executes form submit handlers stored in 'control'
300
    // sets (see form_execute_handlers()), which can in turn add new sets to
301
    // the batch.
302
    $set_changed = FALSE;
303
    $old_set = $current_set;
304
    while (empty($current_set['count']) && ($current_set['success'] = TRUE) && _batch_next_set()) {
305
      $current_set = &_batch_current_set();
306
      $current_set['start'] = microtime(TRUE);
307
      $set_changed = TRUE;
308
    }
309

    
310
    // At this point, either $current_set contains operations that need to be
311
    // processed or all sets have been completed.
312
    $queue = _batch_queue($current_set);
313

    
314
    // If we are in progressive mode, break processing after 1 second.
315
    if ($batch['progressive'] && timer_read('batch_processing') > 1000) {
316
      // Record elapsed wall clock time.
317
      $current_set['elapsed'] = round((microtime(TRUE) - $current_set['start']) * 1000, 2);
318
      break;
319
    }
320
  }
321

    
322
  if ($batch['progressive']) {
323
    // Gather progress information.
324

    
325
    // Reporting 100% progress will cause the whole batch to be considered
326
    // processed. If processing was paused right after moving to a new set,
327
    // we have to use the info from the new (unprocessed) set.
328
    if ($set_changed && isset($current_set['queue'])) {
329
      // Processing will continue with a fresh batch set.
330
      $remaining        = $current_set['count'];
331
      $total            = $current_set['total'];
332
      $progress_message = $current_set['init_message'];
333
      $task_message     = '';
334
    }
335
    else {
336
      // Processing will continue with the current batch set.
337
      $remaining        = $old_set['count'];
338
      $total            = $old_set['total'];
339
      $progress_message = $old_set['progress_message'];
340
    }
341

    
342
    // Total progress is the number of operations that have fully run plus the
343
    // completion level of the current operation.
344
    $current    = $total - $remaining + $finished;
345
    $percentage = _batch_api_percentage($total, $current);
346
    $elapsed    = isset($current_set['elapsed']) ? $current_set['elapsed'] : 0;
347
    $values     = array(
348
      '@remaining'  => $remaining,
349
      '@total'      => $total,
350
      '@current'    => floor($current),
351
      '@percentage' => $percentage,
352
      '@elapsed'    => format_interval($elapsed / 1000),
353
      // If possible, estimate remaining processing time.
354
      '@estimate'   => ($current > 0) ? format_interval(($elapsed * ($total - $current) / $current) / 1000) : '-',
355
    );
356
    $message = strtr($progress_message, $values);
357
    if (!empty($message)) {
358
      $message .= '<br />';
359
    }
360
    if (!empty($task_message)) {
361
      $message .= $task_message;
362
    }
363

    
364
    return array($percentage, $message);
365
  }
366
  else {
367
    // If we are not in progressive mode, the entire batch has been processed.
368
    return _batch_finished();
369
  }
370
}
371

    
372
/**
373
 * Formats the percent completion for a batch set.
374
 *
375
 * @param $total
376
 *   The total number of operations.
377
 * @param $current
378
 *   The number of the current operation. This may be a floating point number
379
 *   rather than an integer in the case of a multi-step operation that is not
380
 *   yet complete; in that case, the fractional part of $current represents the
381
 *   fraction of the operation that has been completed.
382
 *
383
 * @return
384
 *   The properly formatted percentage, as a string. We output percentages
385
 *   using the correct number of decimal places so that we never print "100%"
386
 *   until we are finished, but we also never print more decimal places than
387
 *   are meaningful.
388
 *
389
 * @see _batch_process()
390
 */
391
function _batch_api_percentage($total, $current) {
392
  if (!$total || $total == $current) {
393
    // If $total doesn't evaluate as true or is equal to the current set, then
394
    // we're finished, and we can return "100".
395
    $percentage = "100";
396
  }
397
  else {
398
    // We add a new digit at 200, 2000, etc. (since, for example, 199/200
399
    // would round up to 100% if we didn't).
400
    $decimal_places = max(0, floor(log10($total / 2.0)) - 1);
401
    do {
402
      // Calculate the percentage to the specified number of decimal places.
403
      $percentage = sprintf('%01.' . $decimal_places . 'f', round($current / $total * 100, $decimal_places));
404
      // When $current is an integer, the above calculation will always be
405
      // correct. However, if $current is a floating point number (in the case
406
      // of a multi-step batch operation that is not yet complete), $percentage
407
      // may be erroneously rounded up to 100%. To prevent that, we add one
408
      // more decimal place and try again.
409
      $decimal_places++;
410
    } while ($percentage == '100');
411
  }
412
  return $percentage;
413
}
414

    
415
/**
416
 * Returns the batch set being currently processed.
417
 */
418
function &_batch_current_set() {
419
  $batch = &batch_get();
420
  return $batch['sets'][$batch['current_set']];
421
}
422

    
423
/**
424
 * Retrieves the next set in a batch.
425
 *
426
 * If there is a subsequent set in this batch, assign it as the new set to
427
 * process and execute its form submit handler (if defined), which may add
428
 * further sets to this batch.
429
 *
430
 * @return
431
 *   TRUE if a subsequent set was found in the batch.
432
 */
433
function _batch_next_set() {
434
  $batch = &batch_get();
435
  if (isset($batch['sets'][$batch['current_set'] + 1])) {
436
    $batch['current_set']++;
437
    $current_set = &_batch_current_set();
438
    if (isset($current_set['form_submit']) && ($function = $current_set['form_submit']) && function_exists($function)) {
439
      // We use our stored copies of $form and $form_state to account for
440
      // possible alterations by previous form submit handlers.
441
      $function($batch['form_state']['complete form'], $batch['form_state']);
442
    }
443
    return TRUE;
444
  }
445
}
446

    
447
/**
448
 * Ends the batch processing.
449
 *
450
 * Call the 'finished' callback of each batch set to allow custom handling of
451
 * the results and resolve page redirection.
452
 */
453
function _batch_finished() {
454
  $batch = &batch_get();
455

    
456
  // Execute the 'finished' callbacks for each batch set, if defined.
457
  foreach ($batch['sets'] as $batch_set) {
458
    if (isset($batch_set['finished'])) {
459
      // Check if the set requires an additional file for function definitions.
460
      if (isset($batch_set['file']) && is_file($batch_set['file'])) {
461
        include_once DRUPAL_ROOT . '/' . $batch_set['file'];
462
      }
463
      if (is_callable($batch_set['finished'])) {
464
        $queue = _batch_queue($batch_set);
465
        $operations = $queue->getAllItems();
466
        call_user_func($batch_set['finished'], $batch_set['success'], $batch_set['results'], $operations, format_interval($batch_set['elapsed'] / 1000));
467
      }
468
    }
469
  }
470

    
471
  // Clean up the batch table and unset the static $batch variable.
472
  if ($batch['progressive']) {
473
    db_delete('batch')
474
      ->condition('bid', $batch['id'])
475
      ->execute();
476
    foreach ($batch['sets'] as $batch_set) {
477
      if ($queue = _batch_queue($batch_set)) {
478
        $queue->deleteQueue();
479
      }
480
    }
481
  }
482
  $_batch = $batch;
483
  $batch = NULL;
484

    
485
  // Clean-up the session. Not needed for CLI updates.
486
  if (isset($_SESSION)) {
487
    unset($_SESSION['batches'][$batch['id']]);
488
    if (empty($_SESSION['batches'])) {
489
      unset($_SESSION['batches']);
490
    }
491
  }
492

    
493
  // Redirect if needed.
494
  if ($_batch['progressive']) {
495
    // Revert the 'destination' that was saved in batch_process().
496
    if (isset($_batch['destination'])) {
497
      $_GET['destination'] = $_batch['destination'];
498
    }
499

    
500
    // Determine the target path to redirect to.
501
    if (!isset($_batch['form_state']['redirect'])) {
502
      if (isset($_batch['redirect'])) {
503
        $_batch['form_state']['redirect'] = $_batch['redirect'];
504
      }
505
      else {
506
        $_batch['form_state']['redirect'] = $_batch['source_url'];
507
      }
508
    }
509

    
510
    // Use drupal_redirect_form() to handle the redirection logic.
511
    drupal_redirect_form($_batch['form_state']);
512

    
513
    // If no redirection happened, redirect to the originating page. In case the
514
    // form needs to be rebuilt, save the final $form_state for
515
    // drupal_build_form().
516
    if (!empty($_batch['form_state']['rebuild'])) {
517
      $_SESSION['batch_form_state'] = $_batch['form_state'];
518
    }
519
    $function = $_batch['redirect_callback'];
520
    if (function_exists($function)) {
521
      $function($_batch['source_url'], array('query' => array('op' => 'finish', 'id' => $_batch['id'])));
522
    }
523
  }
524
}
525

    
526
/**
527
 * Shutdown function: Stores the current batch data for the next request.
528
 *
529
 * @see _batch_page()
530
 * @see drupal_register_shutdown_function()
531
 */
532
function _batch_shutdown() {
533
  if ($batch = batch_get()) {
534
    db_update('batch')
535
      ->fields(array('batch' => serialize($batch)))
536
      ->condition('bid', $batch['id'])
537
      ->execute();
538
  }
539
}