web/Zend/Pdf/FileParser.php
changeset 0 4eba9c11703f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/Zend/Pdf/FileParser.php	Mon Dec 13 18:29:26 2010 +0100
@@ -0,0 +1,485 @@
+<?php
+/**
+ * Zend Framework
+ *
+ * LICENSE
+ *
+ * This source file is subject to the new BSD license that is bundled
+ * with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * http://framework.zend.com/license/new-bsd
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@zend.com so we can send you a copy immediately.
+ *
+ * @category   Zend
+ * @package    Zend_Pdf
+ * @subpackage FileParser
+ * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ * @version    $Id: FileParser.php 20096 2010-01-06 02:05:09Z bkarwin $
+ */
+
+/**
+ * Abstract utility class for parsing binary files.
+ *
+ * Provides a library of methods to quickly navigate and extract various data
+ * types (signed and unsigned integers, floating- and fixed-point numbers,
+ * strings, etc.) from the file.
+ *
+ * File access is managed via a {@link Zend_Pdf_FileParserDataSource} object.
+ * This allows the same parser code to work with many different data sources:
+ * in-memory objects, filesystem files, etc.
+ *
+ * @package    Zend_Pdf
+ * @subpackage FileParser
+ * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ */
+abstract class Zend_Pdf_FileParser
+{
+  /**** Class Constants ****/
+
+    /**
+     * Little-endian byte order (0x04 0x03 0x02 0x01).
+     */
+    const BYTE_ORDER_LITTLE_ENDIAN = 0;
+
+    /**
+     * Big-endian byte order (0x01 0x02 0x03 0x04).
+     */
+    const BYTE_ORDER_BIG_ENDIAN    = 1;
+
+
+
+  /**** Instance Variables ****/
+
+
+    /**
+     * Flag indicating that the file has passed a cursory validation check.
+     * @var boolean
+     */
+    protected $_isScreened = false;
+
+    /**
+     * Flag indicating that the file has been sucessfully parsed.
+     * @var boolean
+     */
+    protected $_isParsed = false;
+
+    /**
+     * Object representing the data source to be parsed.
+     * @var Zend_Pdf_FileParserDataSource
+     */
+    protected $_dataSource = null;
+
+
+
+  /**** Public Interface ****/
+
+
+  /* Abstract Methods */
+
+    /**
+     * Performs a cursory check to verify that the binary file is in the expected
+     * format. Intended to quickly weed out obviously bogus files.
+     *
+     * Must set $this->_isScreened to true if successful.
+     *
+     * @throws Zend_Pdf_Exception
+     */
+    abstract public function screen();
+
+    /**
+     * Reads and parses the complete binary file.
+     *
+     * Must set $this->_isParsed to true if successful.
+     *
+     * @throws Zend_Pdf_Exception
+     */
+    abstract public function parse();
+
+
+  /* Object Lifecycle */
+
+    /**
+     * Object constructor.
+     *
+     * Verifies that the data source has been properly initialized.
+     *
+     * @param Zend_Pdf_FileParserDataSource $dataSource
+     * @throws Zend_Pdf_Exception
+     */
+    public function __construct(Zend_Pdf_FileParserDataSource $dataSource)
+    {
+        if ($dataSource->getSize() == 0) {
+            require_once 'Zend/Pdf/Exception.php';
+            throw new Zend_Pdf_Exception('The data source has not been properly initialized',
+                                         Zend_Pdf_Exception::BAD_DATA_SOURCE);
+        }
+        $this->_dataSource = $dataSource;
+    }
+
+    /**
+     * Object destructor.
+     *
+     * Discards the data source object.
+     */
+    public function __destruct()
+    {
+        $this->_dataSource = null;
+    }
+
+
+  /* Accessors */
+
+    /**
+     * Returns true if the file has passed a cursory validation check.
+     *
+     * @return boolean
+     */
+    public function isScreened()
+    {
+        return $this->_isScreened;
+    }
+
+    /**
+     * Returns true if the file has been successfully parsed.
+     *
+     * @return boolean
+     */
+    public function isParsed()
+    {
+        return $this->_isParsed;
+    }
+
+    /**
+     * Returns the data source object representing the file being parsed.
+     *
+     * @return Zend_Pdf_FileParserDataSource
+     */
+    public function getDataSource()
+    {
+        return $this->_dataSource;
+    }
+
+
+  /* Primitive Methods */
+
+    /**
+     * Convenience wrapper for the data source object's moveToOffset() method.
+     *
+     * @param integer $offset Destination byte offset.
+     * @throws Zend_Pdf_Exception
+     */
+    public function moveToOffset($offset)
+    {
+        $this->_dataSource->moveToOffset($offset);
+    }
+
+    public function getOffset() {
+       return $this->_dataSource->getOffset();
+    }
+
+    public function getSize() {
+       return $this->_dataSource->getSize();
+    }
+
+    /**
+     * Convenience wrapper for the data source object's readBytes() method.
+     *
+     * @param integer $byteCount Number of bytes to read.
+     * @return string
+     * @throws Zend_Pdf_Exception
+     */
+    public function readBytes($byteCount)
+    {
+        return $this->_dataSource->readBytes($byteCount);
+    }
+
+    /**
+     * Convenience wrapper for the data source object's skipBytes() method.
+     *
+     * @param integer $byteCount Number of bytes to skip.
+     * @throws Zend_Pdf_Exception
+     */
+    public function skipBytes($byteCount)
+    {
+        $this->_dataSource->skipBytes($byteCount);
+    }
+
+
+  /* Parser Methods */
+
+    /**
+     * Reads the signed integer value from the binary file at the current byte
+     * offset.
+     *
+     * Advances the offset by the number of bytes read. Throws an exception if
+     * an error occurs.
+     *
+     * @param integer $size Size of integer in bytes: 1-4
+     * @param integer $byteOrder (optional) Big- or little-endian byte order.
+     *   Use the BYTE_ORDER_ constants defined in {@link Zend_Pdf_FileParser}.
+     *   If omitted, uses big-endian.
+     * @return integer
+     * @throws Zend_Pdf_Exception
+     */
+    public function readInt($size, $byteOrder = Zend_Pdf_FileParser::BYTE_ORDER_BIG_ENDIAN)
+    {
+        if (($size < 1) || ($size > 4)) {
+            require_once 'Zend/Pdf/Exception.php';
+            throw new Zend_Pdf_Exception("Invalid signed integer size: $size",
+                                         Zend_Pdf_Exception::INVALID_INTEGER_SIZE);
+        }
+        $bytes = $this->_dataSource->readBytes($size);
+        /* unpack() will not work for this method because it always works in
+         * the host byte order for signed integers. It also does not allow for
+         * variable integer sizes.
+         */
+        if ($byteOrder == Zend_Pdf_FileParser::BYTE_ORDER_BIG_ENDIAN) {
+            $number = ord($bytes[0]);
+            if (($number & 0x80) == 0x80) {
+                /* This number is negative. Extract the positive equivalent.
+                 */
+                $number = (~ $number) & 0xff;
+                for ($i = 1; $i < $size; $i++) {
+                    $number = ($number << 8) | ((~ ord($bytes[$i])) & 0xff);
+                }
+                /* Now turn this back into a negative number by taking the
+                 * two's complement (we didn't add one above so won't
+                 * subtract it below). This works reliably on both 32- and
+                 * 64-bit systems.
+                 */
+                $number = ~$number;
+            } else {
+                for ($i = 1; $i < $size; $i++) {
+                    $number = ($number << 8) | ord($bytes[$i]);
+                }
+            }
+        } else if ($byteOrder == Zend_Pdf_FileParser::BYTE_ORDER_LITTLE_ENDIAN) {
+            $number = ord($bytes[$size - 1]);
+            if (($number & 0x80) == 0x80) {
+                /* Negative number. See discussion above.
+                 */
+                $number = 0;
+                for ($i = --$size; $i >= 0; $i--) {
+                    $number |= ((~ ord($bytes[$i])) & 0xff) << ($i * 8);
+                }
+                $number = ~$number;
+            } else {
+                $number = 0;
+                for ($i = --$size; $i >= 0; $i--) {
+                    $number |= ord($bytes[$i]) << ($i * 8);
+                }
+            }
+        } else {
+            require_once 'Zend/Pdf/Exception.php';
+            throw new Zend_Pdf_Exception("Invalid byte order: $byteOrder",
+                                         Zend_Pdf_Exception::INVALID_BYTE_ORDER);
+        }
+        return $number;
+    }
+
+    /**
+     * Reads the unsigned integer value from the binary file at the current byte
+     * offset.
+     *
+     * Advances the offset by the number of bytes read. Throws an exception if
+     * an error occurs.
+     *
+     * NOTE: If you ask for a 4-byte unsigned integer on a 32-bit machine, the
+     * resulting value WILL BE SIGNED because PHP uses signed integers internally
+     * for everything. To guarantee portability, be sure to use bitwise operators
+     * operators on large unsigned integers!
+     *
+     * @param integer $size Size of integer in bytes: 1-4
+     * @param integer $byteOrder (optional) Big- or little-endian byte order.
+     *   Use the BYTE_ORDER_ constants defined in {@link Zend_Pdf_FileParser}.
+     *   If omitted, uses big-endian.
+     * @return integer
+     * @throws Zend_Pdf_Exception
+     */
+    public function readUInt($size, $byteOrder = Zend_Pdf_FileParser::BYTE_ORDER_BIG_ENDIAN)
+    {
+        if (($size < 1) || ($size > 4)) {
+            require_once 'Zend/Pdf/Exception.php';
+            throw new Zend_Pdf_Exception("Invalid unsigned integer size: $size",
+                                         Zend_Pdf_Exception::INVALID_INTEGER_SIZE);
+        }
+        $bytes = $this->_dataSource->readBytes($size);
+        /* unpack() is a bit heavyweight for this simple conversion. Just
+         * work the bytes directly.
+         */
+        if ($byteOrder == Zend_Pdf_FileParser::BYTE_ORDER_BIG_ENDIAN) {
+            $number = ord($bytes[0]);
+            for ($i = 1; $i < $size; $i++) {
+                $number = ($number << 8) | ord($bytes[$i]);
+            }
+        } else if ($byteOrder == Zend_Pdf_FileParser::BYTE_ORDER_LITTLE_ENDIAN) {
+            $number = 0;
+            for ($i = --$size; $i >= 0; $i--) {
+                $number |= ord($bytes[$i]) << ($i * 8);
+            }
+        } else {
+            require_once 'Zend/Pdf/Exception.php';
+            throw new Zend_Pdf_Exception("Invalid byte order: $byteOrder",
+                                         Zend_Pdf_Exception::INVALID_BYTE_ORDER);
+        }
+        return $number;
+    }
+
+    /**
+     * Returns true if the specified bit is set in the integer bitfield.
+     *
+     * @param integer $bit Bit number to test (i.e. - 0-31)
+     * @param integer $bitField
+     * @return boolean
+     */
+    public function isBitSet($bit, $bitField)
+    {
+        $bitMask = 1 << $bit;
+        $isSet = (($bitField & $bitMask) == $bitMask);
+        return $isSet;
+    }
+
+    /**
+     * Reads the signed fixed-point number from the binary file at the current
+     * byte offset.
+     *
+     * Common fixed-point sizes are 2.14 and 16.16.
+     *
+     * Advances the offset by the number of bytes read. Throws an exception if
+     * an error occurs.
+     *
+     * @param integer $mantissaBits Number of bits in the mantissa
+     * @param integer $fractionBits Number of bits in the fraction
+     * @param integer $byteOrder (optional) Big- or little-endian byte order.
+     *   Use the BYTE_ORDER_ constants defined in {@link Zend_Pdf_FileParser}.
+     *   If omitted, uses big-endian.
+     * @return float
+     * @throws Zend_Pdf_Exception
+     */
+    public function readFixed($mantissaBits, $fractionBits,
+                              $byteOrder = Zend_Pdf_FileParser::BYTE_ORDER_BIG_ENDIAN)
+    {
+        $bitsToRead = $mantissaBits + $fractionBits;
+        if (($bitsToRead % 8) !== 0) {
+            require_once 'Zend/Pdf/Exception.php';
+            throw new Zend_Pdf_Exception('Fixed-point numbers are whole bytes',
+                                         Zend_Pdf_Exception::BAD_FIXED_POINT_SIZE);
+        }
+        $number = $this->readInt(($bitsToRead >> 3), $byteOrder) / (1 << $fractionBits);
+        return $number;
+    }
+
+    /**
+     * Reads the Unicode UTF-16-encoded string from the binary file at the
+     * current byte offset.
+     *
+     * The byte order of the UTF-16 string must be specified. You must also
+     * supply the desired resulting character set.
+     *
+     * Advances the offset by the number of bytes read. Throws an exception if
+     * an error occurs.
+     *
+     * @todo Consider changing $byteCount to a character count. They are not
+     *   always equivalent (in the case of surrogates).
+     * @todo Make $byteOrder optional if there is a byte-order mark (BOM) in the
+     *   string being extracted.
+     *
+     * @param integer $byteCount Number of bytes (characters * 2) to return.
+     * @param integer $byteOrder (optional) Big- or little-endian byte order.
+     *   Use the BYTE_ORDER_ constants defined in {@link Zend_Pdf_FileParser}.
+     *   If omitted, uses big-endian.
+     * @param string $characterSet (optional) Desired resulting character set.
+     *   You may use any character set supported by {@link iconv()}. If omitted,
+     *   uses 'current locale'.
+     * @return string
+     * @throws Zend_Pdf_Exception
+     */
+    public function readStringUTF16($byteCount,
+                                    $byteOrder = Zend_Pdf_FileParser::BYTE_ORDER_BIG_ENDIAN,
+                                    $characterSet = '')
+    {
+        if ($byteCount == 0) {
+            return '';
+        }
+        $bytes = $this->_dataSource->readBytes($byteCount);
+        if ($byteOrder == Zend_Pdf_FileParser::BYTE_ORDER_BIG_ENDIAN) {
+            if ($characterSet == 'UTF-16BE') {
+                return $bytes;
+            }
+            return iconv('UTF-16BE', $characterSet, $bytes);
+        } else if ($byteOrder == Zend_Pdf_FileParser::BYTE_ORDER_LITTLE_ENDIAN) {
+            if ($characterSet == 'UTF-16LE') {
+                return $bytes;
+            }
+            return iconv('UTF-16LE', $characterSet, $bytes);
+        } else {
+            require_once 'Zend/Pdf/Exception.php';
+            throw new Zend_Pdf_Exception("Invalid byte order: $byteOrder",
+                                         Zend_Pdf_Exception::INVALID_BYTE_ORDER);
+        }
+    }
+
+    /**
+     * Reads the Mac Roman-encoded string from the binary file at the current
+     * byte offset.
+     *
+     * You must supply the desired resulting character set.
+     *
+     * Advances the offset by the number of bytes read. Throws an exception if
+     * an error occurs.
+     *
+     * @param integer $byteCount Number of bytes (characters) to return.
+     * @param string $characterSet (optional) Desired resulting character set.
+     *   You may use any character set supported by {@link iconv()}. If omitted,
+     *   uses 'current locale'.
+     * @return string
+     * @throws Zend_Pdf_Exception
+     */
+    public function readStringMacRoman($byteCount, $characterSet = '')
+    {
+        if ($byteCount == 0) {
+            return '';
+        }
+        $bytes = $this->_dataSource->readBytes($byteCount);
+        if ($characterSet == 'MacRoman') {
+            return $bytes;
+        }
+        return iconv('MacRoman', $characterSet, $bytes);
+    }
+
+    /**
+     * Reads the Pascal string from the binary file at the current byte offset.
+     *
+     * The length of the Pascal string is determined by reading the length bytes
+     * which preceed the character data. You must supply the desired resulting
+     * character set.
+     *
+     * Advances the offset by the number of bytes read. Throws an exception if
+     * an error occurs.
+     *
+     * @param string $characterSet (optional) Desired resulting character set.
+     *   You may use any character set supported by {@link iconv()}. If omitted,
+     *   uses 'current locale'.
+     * @param integer $lengthBytes (optional) Number of bytes that make up the
+     *   length. Default is 1.
+     * @return string
+     * @throws Zend_Pdf_Exception
+     */
+    public function readStringPascal($characterSet = '', $lengthBytes = 1)
+    {
+        $byteCount = $this->readUInt($lengthBytes);
+        if ($byteCount == 0) {
+            return '';
+        }
+        $bytes = $this->_dataSource->readBytes($byteCount);
+        if ($characterSet == 'ASCII') {
+            return $bytes;
+        }
+        return iconv('ASCII', $characterSet, $bytes);
+    }
+
+}