1 files changed, 187 insertions, 0 deletions
diff --git a/vendor/setasign/fpdi/src/PdfParser/Filter/Lzw.php b/vendor/setasign/fpdi/src/PdfParser/Filter/Lzw.php
new file mode 100644
index 0000000..bedb5b7
--- /dev/null
+++ b/vendor/setasign/fpdi/src/PdfParser/Filter/Lzw.php
@@ -0,0 +1,187 @@
+<?php
+
+/**
+ * This file is part of FPDI
+ *
+ * @package   setasign\Fpdi
+ * @copyright Copyright (c) 2020 Setasign GmbH & Co. KG (https://www.setasign.com)
+ * @license   http://opensource.org/licenses/mit-license The MIT License
+ */
+
+namespace setasign\Fpdi\PdfParser\Filter;
+
+/**
+ * Class for handling LZW encoded data
+ */
+class Lzw implements FilterInterface
+{
+    /**
+     * @var null|string
+     */
+    protected $data;
+
+    /**
+     * @var array
+     */
+    protected $sTable = [];
+
+    /**
+     * @var int
+     */
+    protected $dataLength = 0;
+
+    /**
+     * @var int
+     */
+    protected $tIdx;
+
+    /**
+     * @var int
+     */
+    protected $bitsToGet = 9;
+
+    /**
+     * @var int
+     */
+    protected $bytePointer;
+
+    /**
+     * @var int
+     */
+    protected $nextData = 0;
+
+    /**
+     * @var int
+     */
+    protected $nextBits = 0;
+
+    /**
+     * @var array
+     */
+    protected $andTable = [511, 1023, 2047, 4095];
+
+    /**
+     * Method to decode LZW compressed data.
+     *
+     * @param string $data The compressed data
+     * @return string The uncompressed data
+     * @throws LzwException
+     */
+    public function decode($data)
+    {
+        if ($data[0] === "\x00" && $data[1] === "\x01") {
+            throw new LzwException(
+                'LZW flavour not supported.',
+                LzwException::LZW_FLAVOUR_NOT_SUPPORTED
+            );
+        }
+
+        $this->initsTable();
+
+        $this->data = $data;
+        $this->dataLength = \strlen($data);
+
+        // Initialize pointers
+        $this->bytePointer = 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;
+                }
+
+                $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[0];
+                    $uncompData .= $string;
+
+                    $this->addStringToTable($string);
+                    $oldCode = $code;
+                }
+            }
+        }
+
+        return $uncompData;
+    }
+
+    /**
+     * Initialize the string table.
+     */
+    protected function initsTable()
+    {
+        $this->sTable = [];
+
+        for ($i = 0; $i < 256; $i++) {
+            $this->sTable[$i] = \chr($i);
+        }
+
+        $this->tIdx = 258;
+        $this->bitsToGet = 9;
+    }
+
+    /**
+     * Add a new string to the string table.
+     *
+     * @param string $oldString
+     * @param string $newString
+     */
+    protected function addStringToTable($oldString, $newString = '')
+    {
+        $string = $oldString . $newString;
+
+        // Add this new String to the table
+        $this->sTable[$this->tIdx++] = $string;
+
+        if ($this->tIdx === 511) {
+            $this->bitsToGet = 10;
+        } elseif ($this->tIdx === 1023) {
+            $this->bitsToGet = 11;
+        } elseif ($this->tIdx === 2047) {
+            $this->bitsToGet = 12;
+        }
+    }
+
+    /**
+     * Returns the next 9, 10, 11 or 12 bits.
+     *
+     * @return integer
+     */
+    protected function getNextCode()
+    {
+        if ($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;
+    }
+}