name : RouteCompiler.php <?php /* * This file is part of the Symfony package. * * (c) Fabien Potencier <fabien@symfony.com> * * For the full copyright and license information, please view the LICENSE * file that was distributed with this source code. */ namespace Symfony\Component\Routing; /** * RouteCompiler compiles Route instances to CompiledRoute instances. * * @author Fabien Potencier <fabien@symfony.com> * @author Tobias Schultze <http://tobion.de> */ class RouteCompiler implements RouteCompilerInterface { /** * This string defines the characters that are automatically considered separators in front of * optional placeholders (with default and no static text following). Such a single separator * can be left out together with the optional placeholder from matching and generating URLs. */ public const SEPARATORS = '/,;.:-_~+*=@|'; /** * The maximum supported length of a PCRE subpattern name * http://pcre.org/current/doc/html/pcre2pattern.html#SEC16. * * @internal */ public const VARIABLE_MAXIMUM_LENGTH = 32; /** * @throws \InvalidArgumentException if a path variable is named _fragment * @throws \LogicException if a variable is referenced more than once * @throws \DomainException if a variable name starts with a digit or if it is too long to be successfully used as * a PCRE subpattern */ public static function compile(Route $route): CompiledRoute { $hostVariables = []; $variables = []; $hostRegex = null; $hostTokens = []; if ('' !== $host = $route->getHost()) { $result = self::compilePattern($route, $host, true); $hostVariables = $result['variables']; $variables = $hostVariables; $hostTokens = $result['tokens']; $hostRegex = $result['regex']; } $locale = $route->getDefault('_locale'); if (null !== $locale && null !== $route->getDefault('_canonical_route') && preg_quote($locale) === $route->getRequirement('_locale')) { $requirements = $route->getRequirements(); unset($requirements['_locale']); $route->setRequirements($requirements); $route->setPath(str_replace('{_locale}', $locale, $route->getPath())); } $path = $route->getPath(); $result = self::compilePattern($route, $path, false); $staticPrefix = $result['staticPrefix']; $pathVariables = $result['variables']; foreach ($pathVariables as $pathParam) { if ('_fragment' === $pathParam) { throw new \InvalidArgumentException(sprintf('Route pattern "%s" cannot contain "_fragment" as a path parameter.', $route->getPath())); } } $variables = array_merge($variables, $pathVariables); $tokens = $result['tokens']; $regex = $result['regex']; return new CompiledRoute( $staticPrefix, $regex, $tokens, $pathVariables, $hostRegex, $hostTokens, $hostVariables, array_unique($variables) ); } private static function compilePattern(Route $route, string $pattern, bool $isHost): array { $tokens = []; $variables = []; $matches = []; $pos = 0; $defaultSeparator = $isHost ? '.' : '/'; $useUtf8 = preg_match('//u', $pattern); $needsUtf8 = $route->getOption('utf8'); if (!$needsUtf8 && $useUtf8 && preg_match('/[\x80-\xFF]/', $pattern)) { throw new \LogicException(sprintf('Cannot use UTF-8 route patterns without setting the "utf8" option for route "%s".', $route->getPath())); } if (!$useUtf8 && $needsUtf8) { throw new \LogicException(sprintf('Cannot mix UTF-8 requirements with non-UTF-8 pattern "%s".', $pattern)); } // Match all variables enclosed in "{}" and iterate over them. But we only want to match the innermost variable // in case of nested "{}", e.g. {foo{bar}}. This in ensured because \w does not match "{" or "}" itself. preg_match_all('#\{(!)?([\w\x80-\xFF]+)\}#', $pattern, $matches, \PREG_OFFSET_CAPTURE | \PREG_SET_ORDER); foreach ($matches as $match) { $important = $match[1][1] >= 0; $varName = $match[2][0]; // get all static text preceding the current variable $precedingText = substr($pattern, $pos, $match[0][1] - $pos); $pos = $match[0][1] + \strlen($match[0][0]); if (!\strlen($precedingText)) { $precedingChar = ''; } elseif ($useUtf8) { preg_match('/.$/u', $precedingText, $precedingChar); $precedingChar = $precedingChar[0]; } else { $precedingChar = substr($precedingText, -1); } $isSeparator = '' !== $precedingChar && str_contains(static::SEPARATORS, $precedingChar); // A PCRE subpattern name must start with a non-digit. Also a PHP variable cannot start with a digit so the // variable would not be usable as a Controller action argument. if (preg_match('/^\d/', $varName)) { throw new \DomainException(sprintf('Variable name "%s" cannot start with a digit in route pattern "%s". Please use a different name.', $varName, $pattern)); } if (\in_array($varName, $variables)) { throw new \LogicException(sprintf('Route pattern "%s" cannot reference variable name "%s" more than once.', $pattern, $varName)); } if (\strlen($varName) > self::VARIABLE_MAXIMUM_LENGTH) { throw new \DomainException(sprintf('Variable name "%s" cannot be longer than %d characters in route pattern "%s". Please use a shorter name.', $varName, self::VARIABLE_MAXIMUM_LENGTH, $pattern)); } if ($isSeparator && $precedingText !== $precedingChar) { $tokens[] = ['text', substr($precedingText, 0, -\strlen($precedingChar))]; } elseif (!$isSeparator && '' !== $precedingText) { $tokens[] = ['text', $precedingText]; } $regexp = $route->getRequirement($varName); if (null === $regexp) { $followingPattern = (string) substr($pattern, $pos); // Find the next static character after the variable that functions as a separator. By default, this separator and '/' // are disallowed for the variable. This default requirement makes sure that optional variables can be matched at all // and that the generating-matching-combination of URLs unambiguous, i.e. the params used for generating the URL are // the same that will be matched. Example: new Route('/{page}.{_format}', ['_format' => 'html']) // If {page} would also match the separating dot, {_format} would never match as {page} will eagerly consume everything. // Also even if {_format} was not optional the requirement prevents that {page} matches something that was originally // part of {_format} when generating the URL, e.g. _format = 'mobile.html'. $nextSeparator = self::findNextSeparator($followingPattern, $useUtf8); $regexp = sprintf( '[^%s%s]+', preg_quote($defaultSeparator), $defaultSeparator !== $nextSeparator && '' !== $nextSeparator ? preg_quote($nextSeparator) : '' ); if (('' !== $nextSeparator && !preg_match('#^\{[\w\x80-\xFF]+\}#', $followingPattern)) || '' === $followingPattern) { // When we have a separator, which is disallowed for the variable, we can optimize the regex with a possessive // quantifier. This prevents useless backtracking of PCRE and improves performance by 20% for matching those patterns. // Given the above example, there is no point in backtracking into {page} (that forbids the dot) when a dot must follow // after it. This optimization cannot be applied when the next char is no real separator or when the next variable is // directly adjacent, e.g. '/{x}{y}'. $regexp .= '+'; } } else { if (!preg_match('//u', $regexp)) { $useUtf8 = false; } elseif (!$needsUtf8 && preg_match('/[\x80-\xFF]|(?<!\\\\)\\\\(?:\\\\\\\\)*+(?-i:X|[pP][\{CLMNPSZ]|x\{[A-Fa-f0-9]{3})/', $regexp)) { throw new \LogicException(sprintf('Cannot use UTF-8 route requirements without setting the "utf8" option for variable "%s" in pattern "%s".', $varName, $pattern)); } if (!$useUtf8 && $needsUtf8) { throw new \LogicException(sprintf('Cannot mix UTF-8 requirement with non-UTF-8 charset for variable "%s" in pattern "%s".', $varName, $pattern)); } $regexp = self::transformCapturingGroupsToNonCapturings($regexp); } if ($important) { $token = ['variable', $isSeparator ? $precedingChar : '', $regexp, $varName, false, true]; } else { $token = ['variable', $isSeparator ? $precedingChar : '', $regexp, $varName]; } $tokens[] = $token; $variables[] = $varName; } if ($pos < \strlen($pattern)) { $tokens[] = ['text', substr($pattern, $pos)]; } // find the first optional token $firstOptional = \PHP_INT_MAX; if (!$isHost) { for ($i = \count($tokens) - 1; $i >= 0; --$i) { $token = $tokens[$i]; // variable is optional when it is not important and has a default value if ('variable' === $token[0] && !($token[5] ?? false) && $route->hasDefault($token[3])) { $firstOptional = $i; } else { break; } } } // compute the matching regexp $regexp = ''; for ($i = 0, $nbToken = \count($tokens); $i < $nbToken; ++$i) { $regexp .= self::computeRegexp($tokens, $i, $firstOptional); } $regexp = '{^'.$regexp.'$}sD'.($isHost ? 'i' : ''); // enable Utf8 matching if really required if ($needsUtf8) { $regexp .= 'u'; for ($i = 0, $nbToken = \count($tokens); $i < $nbToken; ++$i) { if ('variable' === $tokens[$i][0]) { $tokens[$i][4] = true; } } } return [ 'staticPrefix' => self::determineStaticPrefix($route, $tokens), 'regex' => $regexp, 'tokens' => array_reverse($tokens), 'variables' => $variables, ]; } /** * Determines the longest static prefix possible for a route. */ private static function determineStaticPrefix(Route $route, array $tokens): string { if ('text' !== $tokens[0][0]) { return ($route->hasDefault($tokens[0][3]) || '/' === $tokens[0][1]) ? '' : $tokens[0][1]; } $prefix = $tokens[0][1]; if (isset($tokens[1][1]) && '/' !== $tokens[1][1] && false === $route->hasDefault($tokens[1][3])) { $prefix .= $tokens[1][1]; } return $prefix; } /** * Returns the next static character in the Route pattern that will serve as a separator (or the empty string when none available). */ private static function findNextSeparator(string $pattern, bool $useUtf8): string { if ('' == $pattern) { // return empty string if pattern is empty or false (false which can be returned by substr) return ''; } // first remove all placeholders from the pattern so we can find the next real static character if ('' === $pattern = preg_replace('#\{[\w\x80-\xFF]+\}#', '', $pattern)) { return ''; } if ($useUtf8) { preg_match('/^./u', $pattern, $pattern); } return str_contains(static::SEPARATORS, $pattern[0]) ? $pattern[0] : ''; } /** * Computes the regexp used to match a specific token. It can be static text or a subpattern. * * @param array $tokens The route tokens * @param int $index The index of the current token * @param int $firstOptional The index of the first optional token */ private static function computeRegexp(array $tokens, int $index, int $firstOptional): string { $token = $tokens[$index]; if ('text' === $token[0]) { // Text tokens return preg_quote($token[1]); } else { // Variable tokens if (0 === $index && 0 === $firstOptional) { // When the only token is an optional variable token, the separator is required return sprintf('%s(?P<%s>%s)?', preg_quote($token[1]), $token[3], $token[2]); } else { $regexp = sprintf('%s(?P<%s>%s)', preg_quote($token[1]), $token[3], $token[2]); if ($index >= $firstOptional) { // Enclose each optional token in a subpattern to make it optional. // "?:" means it is non-capturing, i.e. the portion of the subject string that // matched the optional subpattern is not passed back. $regexp = "(?:$regexp"; $nbTokens = \count($tokens); if ($nbTokens - 1 == $index) { // Close the optional subpatterns $regexp .= str_repeat(')?', $nbTokens - $firstOptional - (0 === $firstOptional ? 1 : 0)); } } return $regexp; } } } private static function transformCapturingGroupsToNonCapturings(string $regexp): string { for ($i = 0; $i < \strlen($regexp); ++$i) { if ('\\' === $regexp[$i]) { ++$i; continue; } if ('(' !== $regexp[$i] || !isset($regexp[$i + 2])) { continue; } if ('*' === $regexp[++$i] || '?' === $regexp[$i]) { ++$i; continue; } $regexp = substr_replace($regexp, '?:', $i, 0); ++$i; } return $regexp; } }