/src/typo3_src-4.1.2/t3lib/class.gzip_encode.php

<?php
class gzip_encode {
        var $_version = 0.66; // Version of the gzip_encode class

        var $level;             // Compression level
        var $encoding;  // Encoding type
        var $crc;               // crc of the output
        var $size;              // size of the uncompressed content
        var $gzsize;    // size of the compressed content

        function gzip_encode($level=3, $debug=false, $outputCompressedSizes=false) {
                if (!function_exists('gzcompress')) {
                    trigger_error('gzcompress not found, ' .
                            'zlib needs to be installed for gzip_encode',
                            E_USER_WARNING);
                    return;
                }
                if (!function_exists('crc32')) {
                    trigger_error('crc32() not found, ' .
                            'PHP >= 4.0.1 needed for gzip_encode', E_USER_WARNING);
                    return;
                }
                if (headers_sent()) return;
                if (connection_status() !== 0) return;
                $encoding = $this->gzip_accepted();
                if (!$encoding) return;
                $this->encoding = $encoding;

                if (strtolower($level) == 'true' || $level === true) {
                    $level = $this->get_complevel();
                }
                $this->level = $level;

                $contents = ob_get_contents();
                if ($contents === false) return;

                $gzdata = "\x1f\x8b\x08\x00\x00\x00\x00\x00"; // gzip header

                        // By Kasper Skaarhoj, start
                if ($outputCompressedSizes)     {
                        $contents.=chr(10)."<!-- Compressed, level ".$level.", original size was ".strlen($contents)." bytes. New size is ".strlen(gzcompress($contents, $level))." bytes -->";
                        $size = strlen($contents);      // Must set again!
                }
                        // By Kasper Skaarhoj, end

                $size = strlen($contents);
                $crc = crc32($contents);
                $gzdata .= gzcompress($contents, $level);
                $gzdata = substr($gzdata, 0, strlen($gzdata) - 4); // fix crc bug
                $gzdata .= pack("V",$crc) . pack("V", $size);

                $this->size = $size;
                $this->crc = $crc;
                $this->gzsize = strlen($gzdata);

                if ($debug) {
                    return;
                }

                ob_end_clean();
                Header('Content-Encoding: ' . $encoding);
                Header('Content-Length: ' . strlen($gzdata));
                Header('X-Content-Encoded-By: class.gzip_encode '.$this->_version);

                echo $gzdata;
        }


        function gzip_accepted() {
                        // Checks, if the accepted encoding supports gzip or x-gzip.
                        // Furthermore a qvalue check is done. "gzip;q=0" means no gzip accepted at all.
                $acceptEncoding = t3lib_div::getIndpEnv('HTTP_ACCEPT_ENCODING');
                if (preg_match('/(^|,\s*)(x-)?gzip(;q=(\d(\.\d+)?))?(,|$)/i', $acceptEncoding, $match) && ($match[4] === '' || $match[4] > 0)) {
                        $encoding = 'gzip';
                } else {
                        return false;
                }

                        // Test file type. I wish I could get HTTP response headers.
                $magic = substr(ob_get_contents(),0,4);
                if (substr($magic,0,2) === '^_') {
                    // gzip data
                    $encoding = false;
                } else if (substr($magic,0,3) === 'GIF') {
                    // gif images
                    $encoding = false;
                } else if (substr($magic,0,2) === "\xFF\xD8") {
                    // jpeg images
                    $encoding = false;
                } else if (substr($magic,0,4) === "\x89PNG") {
                    // png images
                    $encoding = false;
                } else if (substr($magic,0,3) === 'FWS') {
                    // Don't gzip Shockwave Flash files. Flash on windows incorrectly
                    // claims it accepts gzip'd content.
                    $encoding = false;
                } else if (substr($magic,0,2) === 'PK') {
                    // pk zip file
                    $encoding = false;
                }

                return $encoding;
        }

    function get_complevel() {
                $uname = posix_uname();
                switch ($uname['sysname']) {
                    case 'Linux':
                                $cl = (1 - $this->linux_loadavg()) * 10;
                                $level = (int)max(min(9, $cl), 0);
                        break;
                    case 'FreeBSD':
                                $cl = (1 - $this->freebsd_loadavg()) * 10;
                                $level = (int)max(min(9, $cl), 0);
                                break;
                            default:
                                $level = 3;
                        break;
                }
                return $level;
        }

        function linux_loadavg() {
                $buffer = "0 0 0";
                $f = fopen("/proc/loadavg","rb");
                if (!feof($f)) {
                    $buffer = fgets($f, 1024);
                }
                fclose($f);
                $load = explode(" ",$buffer);
                return max((float)$load[0], (float)$load[1], (float)$load[2]);
        }

        function freebsd_loadavg() {
                $buffer= `uptime`;
                $load = array();
                ereg("averag(es|e): ([0-9][.][0-9][0-9]), ([0-9][.][0-9][0-9]), ([0-9][.][0-9][0-9]*)", $buffer, $load);

                return max((float)$load[2], (float)$load[3], (float)$load[4]);
        }
}

?>

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