CombinedStore.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\Lock\Store;

use Psr\Log\LoggerAwareInterface;
use Psr\Log\LoggerAwareTrait;
use Symfony\Component\Lock\Exception\InvalidArgumentException;
use Symfony\Component\Lock\Exception\LockConflictedException;
use Symfony\Component\Lock\Key;
use Symfony\Component\Lock\PersistingStoreInterface;
use Symfony\Component\Lock\SharedLockStoreInterface;
use Symfony\Component\Lock\Strategy\StrategyInterface;

/**
 * CombinedStore is a PersistingStoreInterface implementation able to manage and synchronize several StoreInterfaces.
 *
 * @author Jérémy Derussé <jeremy@derusse.com>
 */
class CombinedStore implements SharedLockStoreInterface, LoggerAwareInterface {
    use ExpiringStoreTrait;
    use LoggerAwareTrait;
    
    /**
     * @param PersistingStoreInterface[] $stores The list of synchronized stores
     *
     * @throws InvalidArgumentException
     */
    public function __construct(array $stores, StrategyInterface $strategy) {
        foreach ($stores as $store) {
            if (!$store instanceof PersistingStoreInterface) {
                throw new InvalidArgumentException(\sprintf('The store must implement "%s". Got "%s".', PersistingStoreInterface::class, get_debug_type($store)));
            }
        }
    }
    public function save(Key $key) : void {
        $successCount = 0;
        $failureCount = 0;
        $storesCount = \count($this->stores);
        foreach ($this->stores as $store) {
            try {
                $store->save($key);
                ++$successCount;
            } catch (\Exception $e) {
                $this->logger?->debug('One store failed to save the "{resource}" lock.', [
                    'resource' => $key,
                    'store' => $store,
                    'exception' => $e,
                ]);
                ++$failureCount;
            }
            if (!$this->strategy
                ->canBeMet($failureCount, $storesCount)) {
                break;
            }
        }
        $this->checkNotExpired($key);
        if ($this->strategy
            ->isMet($successCount, $storesCount)) {
            return;
        }
        $this->logger?->info('Failed to store the "{resource}" lock. Quorum has not been met.', [
            'resource' => $key,
            'success' => $successCount,
            'failure' => $failureCount,
        ]);
        // clean up potential locks
        $this->delete($key);
        throw new LockConflictedException();
    }
    public function saveRead(Key $key) : void {
        $successCount = 0;
        $failureCount = 0;
        $storesCount = \count($this->stores);
        foreach ($this->stores as $store) {
            try {
                if ($store instanceof SharedLockStoreInterface) {
                    $store->saveRead($key);
                }
                else {
                    $store->save($key);
                }
                ++$successCount;
            } catch (\Exception $e) {
                $this->logger?->debug('One store failed to save the "{resource}" lock.', [
                    'resource' => $key,
                    'store' => $store,
                    'exception' => $e,
                ]);
                ++$failureCount;
            }
            if (!$this->strategy
                ->canBeMet($failureCount, $storesCount)) {
                break;
            }
        }
        $this->checkNotExpired($key);
        if ($this->strategy
            ->isMet($successCount, $storesCount)) {
            return;
        }
        $this->logger?->info('Failed to store the "{resource}" lock. Quorum has not been met.', [
            'resource' => $key,
            'success' => $successCount,
            'failure' => $failureCount,
        ]);
        // clean up potential locks
        $this->delete($key);
        throw new LockConflictedException();
    }
    public function putOffExpiration(Key $key, float $ttl) : void {
        $successCount = 0;
        $failureCount = 0;
        $storesCount = \count($this->stores);
        $expireAt = microtime(true) + $ttl;
        foreach ($this->stores as $store) {
            try {
                if (0.0 >= ($adjustedTtl = $expireAt - microtime(true))) {
                    $this->logger?->debug('Stores took to long to put off the expiration of the "{resource}" lock.', [
                        'resource' => $key,
                        'store' => $store,
                        'ttl' => $ttl,
                    ]);
                    $key->reduceLifetime(0);
                    break;
                }
                $store->putOffExpiration($key, $adjustedTtl);
                ++$successCount;
            } catch (\Exception $e) {
                $this->logger?->debug('One store failed to put off the expiration of the "{resource}" lock.', [
                    'resource' => $key,
                    'store' => $store,
                    'exception' => $e,
                ]);
                ++$failureCount;
            }
            if (!$this->strategy
                ->canBeMet($failureCount, $storesCount)) {
                break;
            }
        }
        $this->checkNotExpired($key);
        if ($this->strategy
            ->isMet($successCount, $storesCount)) {
            return;
        }
        $this->logger?->notice('Failed to define the expiration for the "{resource}" lock. Quorum has not been met.', [
            'resource' => $key,
            'success' => $successCount,
            'failure' => $failureCount,
        ]);
        // clean up potential locks
        $this->delete($key);
        throw new LockConflictedException();
    }
    public function delete(Key $key) : void {
        foreach ($this->stores as $store) {
            try {
                $store->delete($key);
            } catch (\Exception $e) {
                $this->logger?->notice('One store failed to delete the "{resource}" lock.', [
                    'resource' => $key,
                    'store' => $store,
                    'exception' => $e,
                ]);
            }
        }
    }
    public function exists(Key $key) : bool {
        $successCount = 0;
        $failureCount = 0;
        $storesCount = \count($this->stores);
        foreach ($this->stores as $store) {
            try {
                if ($store->exists($key)) {
                    ++$successCount;
                }
                else {
                    ++$failureCount;
                }
            } catch (\Exception $e) {
                $this->logger?->debug('One store failed to check the "{resource}" lock.', [
                    'resource' => $key,
                    'store' => $store,
                    'exception' => $e,
                ]);
                ++$failureCount;
            }
            if ($this->strategy
                ->isMet($successCount, $storesCount)) {
                return true;
            }
            if (!$this->strategy
                ->canBeMet($failureCount, $storesCount)) {
                return false;
            }
        }
        return false;
    }

}