CSSmin::run PHP Метод

    public function run($css = '', $linebreak_pos = FALSE)
    {
        if (empty($css)) {
            return '';
        }
        if ($this->raise_php_limits) {
            $this->do_raise_php_limits();
        }
        $this->comments = array();
        $this->preserved_tokens = array();
        $start_index = 0;
        $length = strlen($css);
        $css = $this->extract_data_urls($css);
        // Clean up unclosed comments on the last line
        $last_newline = strrpos(rtrim($css), "\n");
        if ($last_newline !== false) {
            $last_comment_start = strrpos($css, '/*', $last_newline);
            if ($last_comment_start !== false) {
                $last_comment_end = strrpos($css, '*/', $last_comment_start);
                if ($last_comment_end === false) {
                    $css = substr($css, 0, $last_newline);
                }
            }
        }
        // collect all comment blocks...
        while (($start_index = $this->index_of($css, '/*', $start_index)) >= 0) {
            $end_index = $this->index_of($css, '*/', $start_index + 2);
            if ($end_index < 0) {
                $end_index = $length;
            }
            $comment_found = $this->str_slice($css, $start_index + 2, $end_index);
            $this->comments[] = $comment_found;
            $comment_preserve_string = self::COMMENT . (count($this->comments) - 1) . '___';
            $css = $this->str_slice($css, 0, $start_index + 2) . $comment_preserve_string . $this->str_slice($css, $end_index);
            // Set correct start_index: Fixes issue #2528130
            $start_index = $end_index + 2 + strlen($comment_preserve_string) - strlen($comment_found);
        }
        // preserve strings so their content doesn't get accidentally minified
        $css = preg_replace_callback('/(?:"(?:[^\\\\"]|\\\\.|\\\\)*")|' . "(?:'(?:[^\\\\']|\\\\.|\\\\)*')/S", array($this, 'replace_string'), $css);
        // Let's divide css code in chunks of 5.000 chars aprox.
        // Reason: PHP's PCRE functions like preg_replace have a "backtrack limit"
        // of 100.000 chars by default (php < 5.3.7) so if we're dealing with really
        // long strings and a (sub)pattern matches a number of chars greater than
        // the backtrack limit number (i.e. /(.*)/s) PCRE functions may fail silently
        // returning NULL and $css would be empty.
        $charset = '';
        $charset_regexp = '/(@charset)( [^;]+;)/i';
        $css_chunks = array();
        $css_chunk_length = 5000;
        // aprox size, not exact
        $start_index = 0;
        $i = $css_chunk_length;
        // save initial iterations
        $l = strlen($css);
        // if the number of characters is 5000 or less, do not chunk
        if ($l <= $css_chunk_length) {
            $css_chunks[] = $css;
        } else {
            // chunk css code securely
            while ($i < $l) {
                $i += 50;
                // save iterations
                if ($l - $start_index <= $css_chunk_length || $i >= $l) {
                    $css_chunks[] = $this->str_slice($css, $start_index);
                    break;
                }
                if ($css[$i - 1] === '}' && $i - $start_index > $css_chunk_length) {
                    // If there are two ending curly braces }} separated or not by spaces,
                    // join them in the same chunk (i.e. @media blocks)
                    $next_chunk = substr($css, $i);
                    if (preg_match('/^\\s*\\}/', $next_chunk)) {
                        $i = $i + $this->index_of($next_chunk, '}') + 1;
                    }
                    $css_chunks[] = $this->str_slice($css, $start_index, $i);
                    $start_index = $i;
                }
            }
        }
        // Minify each chunk
        for ($i = 0, $n = count($css_chunks); $i < $n; $i++) {
            $css_chunks[$i] = $this->minify($css_chunks[$i], $linebreak_pos);
            // Keep the first @charset at-rule found
            if (empty($charset) && preg_match($charset_regexp, $css_chunks[$i], $matches)) {
                $charset = strtolower($matches[1]) . $matches[2];
            }
            // Delete all @charset at-rules
            $css_chunks[$i] = preg_replace($charset_regexp, '', $css_chunks[$i]);
        }
        // Update the first chunk and push the charset to the top of the file.
        $css_chunks[0] = $charset . $css_chunks[0];
        return implode('', $css_chunks);
    }

 public function minify_css($content)
 {
     include_once 'lib/cssmin.php';
     $compressor = new CSSmin();
     $content = $compressor->run($content);
     return $content;
 }