<?php
/**********************************************************\
|                                                          |
| The implementation of PHPRPC Protocol 3.0                |
|                                                          |
| compat.php                                               |
|                                                          |
| Release 3.0.0 beta 5                                     |
| Copyright (c) 2005-2007 by Team-PHPRPC                   |
|                                                          |
| WebSite:  http://www.phprpc.org/                         |
|           http://www.phprpc.net/                         |
|           http://www.phprpc.com/                         |
|           http://sourceforge.net/projects/php-rpc/       |
|                                                          |
| Authors:  Ma Bingyao <andot@ujn.edu.cn>                  |
|                                                          |
| This file may be distributed and/or modified under the   |
| terms of the GNU Lesser General Public License (LGPL)    |
| version 3.0 as published by the Free Software Foundation |
| and appearing in the included file LICENSE.              |
|                                                          |
\**********************************************************/

/* Provides missing functionality for older versions of PHP.
 *
 * Copyright (C) 2007 Ma Bingyao <andot@ujn.edu.cn>
 * Version: 1.2
 * LastModified: May 1, 2007
 * This library is free.  You can redistribute it and/or modify it.
 */

require_once("phprpc_date.php");

if (!function_exists('file_get_contents')) {
    function file_get_contents($filename, $incpath = false, $resource_context = null) {
        if (false === $fh = fopen($filename, 'rb', $incpath)) {
            user_error('file_get_contents() failed to open stream: No such file or directory',
                E_USER_WARNING);
            return false;
        }
        clearstatcache();
        if ($fsize = @filesize($filename)) {
            $data = fread($fh, $fsize);
        }
        else {
            $data = '';
            while (!feof($fh)) {
                $data .= fread($fh, 8192);
            }
        }
        fclose($fh);
        return $data;
    }
}

if (!function_exists('ob_get_clean')) {
    function ob_get_clean() {
        $contents = ob_get_contents();
        if ($contents !== false) ob_end_clean();
        return $contents;
    }
}

function gzdecode($data) {
    $len = strlen($data);
    if ($len < 18 || strcmp(substr($data, 0, 2), "\x1f\x8b")) {
        return null;  // Not GZIP format (See RFC 1952)
    }
    $method = ord(substr($data, 2, 1));  // Compression method
    $flags  = ord(substr($data, 3, 1));  // Flags
    if ($flags & 31 != $flags) {
        // Reserved bits are set -- NOT ALLOWED by RFC 1952
        return null;
    }
    // NOTE: $mtime may be negative (PHP integer limitations)
    $mtime = unpack("V", substr($data, 4, 4));
    $mtime = $mtime[1];
    $xfl  = substr($data, 8, 1);
    $os    = substr($data, 8, 1);
    $headerlen = 10;
    $extralen  = 0;
    $extra    = "";
    if ($flags & 4) {
        // 2-byte length prefixed EXTRA data in header
        if ($len - $headerlen - 2 < 8) {
            return false;    // Invalid format
        }
        $extralen = unpack("v",substr($data, 8, 2));
        $extralen = $extralen[1];
        if ($len - $headerlen - 2 - $extralen < 8) {
            return false;    // Invalid format
        }
        $extra = substr($data, 10, $extralen);
        $headerlen += 2 + $extralen;
    }

    $filenamelen = 0;
    $filename = "";
    if ($flags & 8) {
        // C-style string file NAME data in header
        if ($len - $headerlen - 1 < 8) {
            return false;    // Invalid format
        }
        $filenamelen = strpos(substr($data, 8 + $extralen), chr(0));
        if ($filenamelen === false || $len - $headerlen - $filenamelen - 1 < 8) {
            return false;    // Invalid format
        }
        $filename = substr($data,$headerlen,$filenamelen);
        $headerlen += $filenamelen + 1;
    }

    $commentlen = 0;
    $comment = "";
    if ($flags & 16) {
        // C-style string COMMENT data in header
        if ($len - $headerlen - 1 < 8) {
            return false;    // Invalid format
        }
        $commentlen = strpos(substr($data, 8 + $extralen + $filenamelen), chr(0));
        if ($commentlen === false || $len - $headerlen - $commentlen - 1 < 8) {
            return false;    // Invalid header format
        }
        $comment = substr($data, $headerlen, $commentlen);
        $headerlen += $commentlen + 1;
    }

    $headercrc = "";
    if ($flags & 1) {
        // 2-bytes (lowest order) of CRC32 on header present
        if ($len - $headerlen - 2 < 8) {
            return false;    // Invalid format
        }
        $calccrc = crc32(substr($data, 0, $headerlen)) & 0xffff;
        $headercrc = unpack("v", substr($data, $headerlen, 2));
        $headercrc = $headercrc[1];
        if ($headercrc != $calccrc) {
            return false;    // Bad header CRC
        }
        $headerlen += 2;
    }

    // GZIP FOOTER - These be negative due to PHP's limitations
    $datacrc = unpack("V", substr($data, -8, 4));
    $datacrc = $datacrc[1];
    $isize = unpack("V", substr($data, -4));
    $isize = $isize[1];

    // Perform the decompression:
    $bodylen = $len - $headerlen - 8;
    if ($bodylen < 1) {
        // This should never happen - IMPLEMENTATION BUG!
        return null;
    }
    $body = substr($data, $headerlen, $bodylen);
    $data = "";
    if ($bodylen > 0) {
        switch ($method) {
        case 8:
            // Currently the only supported compression method:
            $data = gzinflate($body);
            break;
        default:
            // Unknown compression method
            return false;
        }
    }
    else {
        // I'm not sure if zero-byte body content is allowed.
        // Allow it for now...  Do nothing...
    }

    // Verifiy decompressed size and CRC32:
    // NOTE: This may fail with large data sizes depending on how
    //      PHP's integer limitations affect strlen() since $isize
    //      may be negative for large sizes.
    if ($isize != strlen($data) || crc32($data) != $datacrc) {
        // Bad format!  Length or CRC doesn't match!
        return false;
    }
    return $data;
}

function declare_empty_class($classname) {
   static $callback = null;
   $classname = preg_replace('/[^a-zA-Z0-9\_]/', '', $classname);
   if ($callback===null) {
       $callback = $classname;
       return;
   }
   if ($callback) {
       call_user_func($callback, $classname);
   }
   if (!class_exists($classname)) {
       eval('class ' . $classname . ' { }');
   }
}
declare_empty_class(ini_get('unserialize_callback_func'));
ini_set('unserialize_callback_func', 'declare_empty_class');