4eee88f22b
My benchmarks showed a performance improvement of 20% when matching routes that make use of possesive quantifiers because it prevents backtracking when it's not needed
183 lines
8.5 KiB
PHP
183 lines
8.5 KiB
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
|
|
{
|
|
const REGEX_DELIMITER = '#';
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
const SEPARATORS = '/,;.:-_~+*=@|';
|
|
|
|
/**
|
|
* {@inheritDoc}
|
|
*
|
|
* @throws \LogicException If a variable is referenced more than once
|
|
* @throws \DomainException If a variable name is numeric because PHP raises an error for such
|
|
* subpatterns in PCRE and thus would break matching, e.g. "(?<123>.+)".
|
|
*/
|
|
public function compile(Route $route)
|
|
{
|
|
$pattern = $route->getPattern();
|
|
$tokens = array();
|
|
$variables = array();
|
|
$matches = array();
|
|
$pos = 0;
|
|
|
|
// 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+\}#', $pattern, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER);
|
|
foreach ($matches as $match) {
|
|
$varName = substr($match[0][0], 1, -1);
|
|
// get all static text preceding the current variable
|
|
$precedingText = substr($pattern, $pos, $match[0][1] - $pos);
|
|
$pos = $match[0][1] + strlen($match[0][0]);
|
|
$precedingChar = strlen($precedingText) > 0 ? substr($precedingText, -1) : '';
|
|
$isSeparator = '' !== $precedingChar && false !== strpos(static::SEPARATORS, $precedingChar);
|
|
|
|
if (is_numeric($varName)) {
|
|
throw new \DomainException(sprintf('Variable name "%s" cannot be numeric 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, $varName));
|
|
}
|
|
|
|
if ($isSeparator && strlen($precedingText) > 1) {
|
|
$tokens[] = array('text', substr($precedingText, 0, -1));
|
|
} elseif (!$isSeparator && strlen($precedingText) > 0) {
|
|
$tokens[] = array('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}', array('_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 = $this->findNextSeparator($followingPattern);
|
|
$regexp = sprintf('[^/%s]+', '/' !== $nextSeparator && '' !== $nextSeparator ? preg_quote($nextSeparator, self::REGEX_DELIMITER) : '');
|
|
if (('' !== $nextSeparator && !preg_match('#^\{\w+\}#', $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 .= '+';
|
|
}
|
|
}
|
|
|
|
$tokens[] = array('variable', $isSeparator ? $precedingChar : '', $regexp, $varName);
|
|
$variables[] = $varName;
|
|
}
|
|
|
|
if ($pos < strlen($pattern)) {
|
|
$tokens[] = array('text', substr($pattern, $pos));
|
|
}
|
|
|
|
// find the first optional token
|
|
$firstOptional = INF;
|
|
for ($i = count($tokens) - 1; $i >= 0; $i--) {
|
|
$token = $tokens[$i];
|
|
if ('variable' === $token[0] && $route->hasDefault($token[3])) {
|
|
$firstOptional = $i;
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
|
|
// compute the matching regexp
|
|
$regexp = '';
|
|
for ($i = 0, $nbToken = count($tokens); $i < $nbToken; $i++) {
|
|
$regexp .= $this->computeRegexp($tokens, $i, $firstOptional);
|
|
}
|
|
|
|
return new CompiledRoute(
|
|
'text' === $tokens[0][0] ? $tokens[0][1] : '',
|
|
self::REGEX_DELIMITER.'^'.$regexp.'$'.self::REGEX_DELIMITER.'s',
|
|
array_reverse($tokens),
|
|
$variables
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Returns the next static character in the Route pattern that will serve as a separator.
|
|
*
|
|
* @param string $pattern The route pattern
|
|
*
|
|
* @return string The next static character that functions as separator (or empty string when none available)
|
|
*/
|
|
private function findNextSeparator($pattern)
|
|
{
|
|
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
|
|
$pattern = preg_replace('#\{\w+\}#', '', $pattern);
|
|
|
|
return isset($pattern[0]) && false !== strpos(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 integer $index The index of the current token
|
|
* @param integer $firstOptional The index of the first optional token
|
|
*
|
|
* @return string The regexp pattern for a single token
|
|
*/
|
|
private function computeRegexp(array $tokens, $index, $firstOptional)
|
|
{
|
|
$token = $tokens[$index];
|
|
if ('text' === $token[0]) {
|
|
// Text tokens
|
|
return preg_quote($token[1], self::REGEX_DELIMITER);
|
|
} else {
|
|
// Variable tokens
|
|
if (0 === $index && 0 === $firstOptional) {
|
|
// When the only token is an optional variable token, the separator is required
|
|
return sprintf('%s(?<%s>%s)?', preg_quote($token[1], self::REGEX_DELIMITER), $token[3], $token[2]);
|
|
} else {
|
|
$regexp = sprintf('%s(?<%s>%s)', preg_quote($token[1], self::REGEX_DELIMITER), $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;
|
|
}
|
|
}
|
|
}
|
|
}
|