Same name and namespace in other branches
  1. 8.x-3.x advagg_css_minify/yui/CSSMin.inc \CSSmin::extract_data_urls() 1 comment

Utility method to replace all data urls with tokens before we start compressing, to avoid performance issues running some of the subsequent regexes against large strings chunks.

Parameters

string $css:

Return value

string

1 call to CSSmin::extract_data_urls()
CSSmin::run in advagg_css_minify/yui/CSSMin.inc
Minify a string of CSS

File

advagg_css_minify/yui/CSSMin.inc, line 440

Class

CSSmin

Code

private function extract_data_urls($css) {
    // Leave data urls alone to increase parse performance.
    $max_index = strlen($css) - 1;
    $append_index = $index = $last_index = $offset = 0;
    $sb = array();
    $pattern = '/url\\(\\s*(["\']?)data\\:/i';
    // Since we need to account for non-base64 data urls, we need to handle
    // ' and ) being part of the data string. Hence switching to indexOf,
    // to determine whether or not we have matching string terminators and
    // handling sb appends directly, instead of using matcher.append* methods.
    while (preg_match($pattern, $css, $m, 0, $offset)) {
        $index = $this->index_of($css, $m[0], $offset);
        $last_index = $index + strlen($m[0]);
        $start_index = $index + 4;
        // "url(".length()
        $end_index = $last_index - 1;
        $terminator = $m[1];
        // ', " or empty (not quoted)
        $found_terminator = FALSE;
        if (strlen($terminator) === 0) {
            $terminator = ')';
        }
        while ($found_terminator === FALSE && $end_index + 1 <= $max_index) {
            $end_index = $this->index_of($css, $terminator, $end_index + 1);
            // endIndex == 0 doesn't really apply here
            if ($end_index > 0 && substr($css, $end_index - 1, 1) !== '\\') {
                $found_terminator = TRUE;
                if (')' != $terminator) {
                    $end_index = $this->index_of($css, ')', $end_index);
                }
            }
        }
        // Enough searching, start moving stuff over to the buffer
        $sb[] = $this->str_slice($css, $append_index, $index);
        if ($found_terminator) {
            $token = $this->str_slice($css, $start_index, $end_index);
            $token = preg_replace('/\\s+/', '', $token);
            $this->preserved_tokens[] = $token;
            $preserver = 'url(' . self::TOKEN . (count($this->preserved_tokens) - 1) . '___)';
            $sb[] = $preserver;
            $append_index = $end_index + 1;
        }
        else {
            // No end terminator found, re-add the whole match. Should we throw/warn here?
            $sb[] = $this->str_slice($css, $index, $last_index);
            $append_index = $last_index;
        }
        $offset = $last_index;
    }
    $sb[] = $this->str_slice($css, $append_index);
    return implode('', $sb);
}