Club Drupal

<?php

//

//  FPDI - Version 1.5.4

//

//    Copyright 2004-2015 Setasign - Jan Slabon

//

//  Licensed under the Apache License, Version 2.0 (the "License");

//  you may not use this file except in compliance with the License.

//  You may obtain a copy of the License at

//

//      http://www.apache.org/licenses/LICENSE-2.0

//

//  Unless required by applicable law or agreed to in writing, software

//  distributed under the License is distributed on an "AS IS" BASIS,

//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

//  See the License for the specific language governing permissions and

//  limitations under the License.

//

/**

 * Class FilterLZW

 */

class FilterLZW

{

    protected $_sTable = array();

    protected $_data = null;

    protected $_dataLength = 0;

    protected $_tIdx;

    protected $_bitsToGet = 9;

    protected $_bytePointer;

    protected $_bitPointer;

    protected $_nextData = 0;

    protected $_nextBits = 0;

    protected $_andTable = array(511, 1023, 2047, 4095);

    /**

     * Decodes LZW compressed data.

     *

     * @param string $data The compressed data.

     * @throws Exception

     * @return string

     */

    public function decode($data)

    {

        if ($data[0] == 0x00 && $data[1] == 0x01) {

            throw new Exception('LZW flavour not supported.');

        }

        $this->_initsTable();

        $this->_data = $data;

        $this->_dataLength = strlen($data);

        // Initialize pointers

        $this->_bytePointer = 0;

        $this->_bitPointer = 0;

        $this->_nextData = 0;

        $this->_nextBits = 0;

        $oldCode = 0;

        $unCompData = '';

        while (($code = $this->_getNextCode()) != 257) {

            if ($code == 256) {

                $this->_initsTable();

                $code = $this->_getNextCode();

                if ($code == 257) {

                    break;

                }

                if (!isset($this->_sTable[$code])) {

                    throw new Exception('Error while decompression LZW compressed data.');

                }

                $unCompData .= $this->_sTable[$code];

                $oldCode = $code;

            } else {

                if ($code < $this->_tIdx) {

                    $string = $this->_sTable[$code];

                    $unCompData .= $string;

                    $this->_addStringToTable($this->_sTable[$oldCode], $string[0]);

                    $oldCode = $code;

                } else {

                    $string = $this->_sTable[$oldCode];

                    $string = $string . $string[0];

                    $unCompData .= $string;

                    $this->_addStringToTable($string);

                    $oldCode = $code;

                }

            }

        }

        return $unCompData;

    }

    /**

     * Initialize the string table.

     */

    protected function _initsTable()

    {

        $this->_sTable = array();

        for ($i = 0; $i < 256; $i++)

            $this->_sTable[$i] = chr($i);

        $this->_tIdx = 258;

        $this->_bitsToGet = 9;

    }

    /**

     * Add a new string to the string table.

     */

    protected function _addStringToTable($oldString, $newString = '')

    {

        $string = $oldString . $newString;

        // Add this new String to the table

        $this->_sTable[$this->_tIdx++] = $string;

        if ($this->_tIdx == 511) {

            $this->_bitsToGet = 10;

        } else if ($this->_tIdx == 1023) {

            $this->_bitsToGet = 11;

        } else if ($this->_tIdx == 2047) {

            $this->_bitsToGet = 12;

        }

    }

    /**

     * Returns the next 9, 10, 11 or 12 bits

     *

     * @return int

     */

    protected function _getNextCode()

    {

        if ($this->_bytePointer == $this->_dataLength) {

            return 257;

        }

        $this->_nextData = ($this->_nextData << 8) | (ord($this->_data[$this->_bytePointer++]) & 0xff);

        $this->_nextBits += 8;

        if ($this->_nextBits < $this->_bitsToGet) {

            $this->_nextData = ($this->_nextData << 8) | (ord($this->_data[$this->_bytePointer++]) & 0xff);

            $this->_nextBits += 8;

        }

        $code = ($this->_nextData >> ($this->_nextBits - $this->_bitsToGet)) & $this->_andTable[$this->_bitsToGet-9];

        $this->_nextBits -= $this->_bitsToGet;

        return $code;

    }

    /**

     * NOT IMPLEMENTED

     *

     * @param string $in

     * @return string

     * @throws LogicException

     */

    public function encode($in)

    {

        throw new LogicException("LZW encoding not implemented.");

    }

}