PsrCachedReader.php

<?php

namespace Doctrine\Common\Annotations;

use Psr\Cache\CacheItemPoolInterface;
use ReflectionClass;
use ReflectionMethod;
use ReflectionProperty;
use Reflector;
use function array_map;
use function array_merge;
use function assert;
use function filemtime;
use function is_file;
use function max;
use function rawurlencode;
use function time;

/**
 * A cache aware annotation reader.
 */
final class PsrCachedReader implements Reader {
    
    /** @var Reader */
    private $delegate;
    
    /** @var CacheItemPoolInterface */
    private $cache;
    
    /** @var bool */
    private $debug;
    
    /** @var array<string, array<object>> */
    private $loadedAnnotations = [];
    
    /** @var int[] */
    private $loadedFilemtimes = [];
    public function __construct(Reader $reader, CacheItemPoolInterface $cache, bool $debug = false) {
        $this->delegate = $reader;
        $this->cache = $cache;
        $this->debug = (bool) $debug;
    }
    
    /**
     * {@inheritDoc}
     */
    public function getClassAnnotations(ReflectionClass $class) {
        $cacheKey = $class->getName();
        if (isset($this->loadedAnnotations[$cacheKey])) {
            return $this->loadedAnnotations[$cacheKey];
        }
        $annots = $this->fetchFromCache($cacheKey, $class, 'getClassAnnotations', $class);
        return $this->loadedAnnotations[$cacheKey] = $annots;
    }
    
    /**
     * {@inheritDoc}
     */
    public function getClassAnnotation(ReflectionClass $class, $annotationName) {
        foreach ($this->getClassAnnotations($class) as $annot) {
            if ($annot instanceof $annotationName) {
                return $annot;
            }
        }
        return null;
    }
    
    /**
     * {@inheritDoc}
     */
    public function getPropertyAnnotations(ReflectionProperty $property) {
        $class = $property->getDeclaringClass();
        $cacheKey = $class->getName() . '$' . $property->getName();
        if (isset($this->loadedAnnotations[$cacheKey])) {
            return $this->loadedAnnotations[$cacheKey];
        }
        $annots = $this->fetchFromCache($cacheKey, $class, 'getPropertyAnnotations', $property);
        return $this->loadedAnnotations[$cacheKey] = $annots;
    }
    
    /**
     * {@inheritDoc}
     */
    public function getPropertyAnnotation(ReflectionProperty $property, $annotationName) {
        foreach ($this->getPropertyAnnotations($property) as $annot) {
            if ($annot instanceof $annotationName) {
                return $annot;
            }
        }
        return null;
    }
    
    /**
     * {@inheritDoc}
     */
    public function getMethodAnnotations(ReflectionMethod $method) {
        $class = $method->getDeclaringClass();
        $cacheKey = $class->getName() . '#' . $method->getName();
        if (isset($this->loadedAnnotations[$cacheKey])) {
            return $this->loadedAnnotations[$cacheKey];
        }
        $annots = $this->fetchFromCache($cacheKey, $class, 'getMethodAnnotations', $method);
        return $this->loadedAnnotations[$cacheKey] = $annots;
    }
    
    /**
     * {@inheritDoc}
     */
    public function getMethodAnnotation(ReflectionMethod $method, $annotationName) {
        foreach ($this->getMethodAnnotations($method) as $annot) {
            if ($annot instanceof $annotationName) {
                return $annot;
            }
        }
        return null;
    }
    public function clearLoadedAnnotations() : void {
        $this->loadedAnnotations = [];
        $this->loadedFilemtimes = [];
    }
    
    /** @return mixed[] */
    private function fetchFromCache(string $cacheKey, ReflectionClass $class, string $method, Reflector $reflector) : array {
        $cacheKey = rawurlencode($cacheKey);
        $item = $this->cache
            ->getItem($cacheKey);
        if ($this->debug && !$this->refresh($cacheKey, $class) || !$item->isHit()) {
            $this->cache
                ->save($item->set($this->delegate
                ->{$method}($reflector)));
        }
        return $item->get();
    }
    
    /**
     * Used in debug mode to check if the cache is fresh.
     *
     * @return bool Returns true if the cache was fresh, or false if the class
     * being read was modified since writing to the cache.
     */
    private function refresh(string $cacheKey, ReflectionClass $class) : bool {
        $lastModification = $this->getLastModification($class);
        if ($lastModification === 0) {
            return true;
        }
        $item = $this->cache
            ->getItem('[C]' . $cacheKey);
        if ($item->isHit() && $item->get() >= $lastModification) {
            return true;
        }
        $this->cache
            ->save($item->set(time()));
        return false;
    }
    
    /**
     * Returns the time the class was last modified, testing traits and parents
     */
    private function getLastModification(ReflectionClass $class) : int {
        $filename = $class->getFileName();
        if (isset($this->loadedFilemtimes[$filename])) {
            return $this->loadedFilemtimes[$filename];
        }
        $parent = $class->getParentClass();
        $lastModification = max(array_merge([
            $filename !== false && is_file($filename) ? filemtime($filename) : 0,
        ], array_map(function (ReflectionClass $reflectionTrait) : int {
            return $this->getTraitLastModificationTime($reflectionTrait);
        }, $class->getTraits()), array_map(function (ReflectionClass $class) : int {
            return $this->getLastModification($class);
        }, $class->getInterfaces()), $parent ? [
            $this->getLastModification($parent),
        ] : []));
        assert($lastModification !== false);
        return $this->loadedFilemtimes[$filename] = $lastModification;
    }
    private function getTraitLastModificationTime(ReflectionClass $reflectionTrait) : int {
        $fileName = $reflectionTrait->getFileName();
        if (isset($this->loadedFilemtimes[$fileName])) {
            return $this->loadedFilemtimes[$fileName];
        }
        $lastModificationTime = max(array_merge([
            $fileName !== false && is_file($fileName) ? filemtime($fileName) : 0,
        ], array_map(function (ReflectionClass $reflectionTrait) : int {
            return $this->getTraitLastModificationTime($reflectionTrait);
        }, $reflectionTrait->getTraits())));
        assert($lastModificationTime !== false);
        return $this->loadedFilemtimes[$fileName] = $lastModificationTime;
    }

}