CacheTagsChecksumDecorator.php

<?php

declare (strict_types=1);
namespace Drupal\performance_test\Cache;

use Drupal\Core\Cache\CacheTagsChecksumInterface;
use Drupal\Core\Cache\CacheTagsInvalidatorInterface;
use Drupal\performance_test\PerformanceDataCollector;

/**
 * Wraps an existing cache tags checksum invalidator to track calls separately.
 */
class CacheTagsChecksumDecorator implements CacheTagsChecksumInterface, CacheTagsInvalidatorInterface {
    public function __construct(CacheTagsChecksumInterface $checksumInvalidator, PerformanceDataCollector $performanceDataCollector) {
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCurrentChecksum(array $tags) {
        // If there are no cache tags, there is no checksum to get and the decorated
        // method will be a no-op, so don't log anything.
        if (empty($tags)) {
            return $this->checksumInvalidator
                ->getCurrentChecksum($tags);
        }
        $start = microtime(TRUE);
        $return = $this->checksumInvalidator
            ->getCurrentChecksum($tags);
        $stop = microtime(TRUE);
        $this->logCacheTagOperation($tags, $start, $stop, CacheTagOperation::GetCurrentChecksum);
        return $return;
    }
    
    /**
     * {@inheritdoc}
     */
    public function isValid($checksum, array $tags) {
        // If there are no cache tags, the cache item is always valid, and the child
        // method will be a no-op, so don't log anything.
        if (empty($tags)) {
            return $this->checksumInvalidator
                ->isValid($checksum, $tags);
        }
        $start = microtime(TRUE);
        $return = $this->checksumInvalidator
            ->isValid($checksum, $tags);
        $stop = microtime(TRUE);
        $this->logCacheTagOperation($tags, $start, $stop, CacheTagOperation::IsValid);
        return $return;
    }
    
    /**
     * {@inheritdoc}
     */
    public function invalidateTags(array $tags) {
        // If there are no cache tags, there is nothing to invalidate, and the
        // decorated method will be a no-op, so don't log anything.
        if (empty($tags)) {
            return $this->checksumInvalidator
                ->invalidateTags($tags);
        }
        $start = microtime(TRUE);
        $return = $this->checksumInvalidator
            ->invalidateTags($tags);
        $stop = microtime(TRUE);
        $this->logCacheTagOperation($tags, $start, $stop, CacheTagOperation::InvalidateTags);
        return $return;
    }
    
    /**
     * {@inheritdoc}
     */
    public function reset() {
        $this->checksumInvalidator
            ->reset();
    }
    
    /**
     * Logs a cache tag operation.
     *
     * @param string[] $tags
     *   The cache tags.
     * @param float $start
     *   The start microtime.
     * @param float $stop
     *   The stop microtime.
     * @param \Drupal\performance_test\Cache\CacheTagOperation $operation
     *   The type of operation being logged.
     *
     * @return void
     */
    protected function logCacheTagOperation(array $tags, float $start, float $stop, CacheTagOperation $operation) : void {
        $this->performanceDataCollector
            ->addCacheTagOperation([
            'operation' => $operation,
            'tags' => implode(', ', $tags),
            'start' => $start,
            'stop' => $stop,
        ]);
    }

}