BrowscapPHP\Parser\Helper\SubKey::getAllPatternCacheSubkeys PHP 메소드

    public static function getAllPatternCacheSubkeys()
    {
        $subkeys = [];
        $chars = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'];
        foreach ($chars as $charOne) {
            foreach ($chars as $charTwo) {
                $subkeys[$charOne . $charTwo] = '';
            }
        }
        return $subkeys;
    }

 /**
  * Creates new pattern cache files
  *
  * @param string $content
  *
  * @return \Generator
  */
 public function createPatterns($content)
 {
     // get all relevant patterns from the INI file
     // - containing "*" or "?"
     // - not containing "*" or "?", but not having a comment
     preg_match_all('/(?<=\\[)(?:[^\\r\\n]*[?*][^\\r\\n]*)(?=\\])|(?<=\\[)(?:[^\\r\\n*?]+)(?=\\])(?![^\\[]*Comment=)/m', $content, $matches);
     if (empty($matches[0]) || !is_array($matches[0])) {
         (yield []);
         return;
     }
     $quoterHelper = new Quoter();
     $matches = $matches[0];
     usort($matches, [$this, 'compareBcStrings']);
     // build an array to structure the data. this requires some memory, but we need this step to be able to
     // sort the data in the way we need it (see below).
     $data = [];
     foreach ($matches as $pattern) {
         if ('GJK_Browscap_Version' === $pattern) {
             continue;
         }
         $pattern = strtolower($pattern);
         $patternhash = Pattern::getHashForPattern($pattern, false);
         $tmpLength = Pattern::getPatternLength($pattern);
         // special handling of default entry
         if ($tmpLength === 0) {
             $patternhash = str_repeat('z', 32);
         }
         if (!isset($data[$patternhash])) {
             $data[$patternhash] = [];
         }
         if (!isset($data[$patternhash][$tmpLength])) {
             $data[$patternhash][$tmpLength] = [];
         }
         $pattern = $quoterHelper->pregQuote($pattern);
         // Check if the pattern contains digits - in this case we replace them with a digit regular expression,
         // so that very similar patterns (e.g. only with different browser version numbers) can be compressed.
         // This helps to speed up the first (and most expensive) part of the pattern search a lot.
         if (strpbrk($pattern, '0123456789') !== false) {
             $compressedPattern = preg_replace('/\\d/', '[\\d]', $pattern);
             if (!in_array($compressedPattern, $data[$patternhash][$tmpLength])) {
                 $data[$patternhash][$tmpLength][] = $compressedPattern;
             }
         } else {
             $data[$patternhash][$tmpLength][] = $pattern;
         }
     }
     unset($matches);
     // sorting of the data is important to check the patterns later in the correct order, because
     // we need to check the most specific (=longest) patterns first, and the least specific
     // (".*" for "Default Browser")  last.
     //
     // sort by pattern start to group them
     ksort($data);
     // and then by pattern length (longest first)
     foreach (array_keys($data) as $key) {
         krsort($data[$key]);
     }
     // write optimized file (grouped by the first character of the has, generated from the pattern
     // start) with multiple patterns joined by tabs. this is to speed up loading of the data (small
     // array with pattern strings instead of an large array with single patterns) and also enables
     // us to search for multiple patterns in one preg_match call for a fast first search
     // (3-10 faster), followed by a detailed search for each single pattern.
     $contents = [];
     foreach ($data as $patternhash => $tmpEntries) {
         if (empty($tmpEntries)) {
             continue;
         }
         $subkey = SubKey::getPatternCacheSubkey($patternhash);
         if (!isset($contents[$subkey])) {
             $contents[$subkey] = [];
         }
         foreach ($tmpEntries as $tmpLength => $tmpPatterns) {
             if (empty($tmpPatterns)) {
                 continue;
             }
             $chunks = array_chunk($tmpPatterns, self::COUNT_PATTERN);
             foreach ($chunks as $chunk) {
                 $contents[$subkey][] = $patternhash . "\t" . $tmpLength . "\t" . implode("\t", $chunk);
             }
         }
     }
     unset($data);
     $subkeys = SubKey::getAllPatternCacheSubkeys();
     foreach ($contents as $subkey => $content) {
         $subkey = (string) $subkey;
         (yield [$subkey => $content]);
         unset($subkeys[$subkey]);
     }
     foreach (array_keys($subkeys) as $subkey) {
         $subkey = (string) $subkey;
         (yield [$subkey => []]);
     }
 }