BrowscapPHP\IniParser\IniParser::createPatterns()

Complexity

Conditions	19
Paths	1665

Size

Total Lines

121

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	0
CRAP Score	380

Importance

Changes

0

<?php
    public function createPatterns($content) : \Generator
    {
        // 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)[0];
            $tmpLength = Pattern::getPatternLength($pattern);

            // special handling of default entry
            if (0 === $tmpLength) {
                $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 (false !== strpbrk($pattern, '0123456789')) {
                $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) {
            yield $subkey => $content;

            unset($subkeys[$subkey]);
        }

        foreach (array_keys($subkeys) as $subkey) {
            $subkey = (string) $subkey;

            yield $subkey => '';
        }
    }