Laravel-Cache

思考并回答以下问题：

• use Macroable {__call as macroCall;}为什么这样写？
• CacheManager维护了一个[string=>Repository对象]的数组，并管理了各种Cache种类，是一个工厂。怎么理解？

源码

文件结构

Cache门面

Illuminate\Support\Facades\Cache.php

<?php

namespace Illuminate\Support\Facades;

/**
 * @method static \Illuminate\Contracts\Cache\Repository  store(string|null $name = null)
 * @method static bool has(string $key)
 * @method static bool missing(string $key)
 * @method static mixed get(string $key, mixed $default = null)
 * @method static mixed pull(string $key, mixed $default = null)
 * @method static bool put(string $key, $value, \DateTimeInterface|\DateInterval|int $ttl = null)
 * @method static bool add(string $key, $value, \DateTimeInterface|\DateInterval|int $ttl = null)
 * @method static int|bool increment(string $key, $value = 1)
 * @method static int|bool decrement(string $key, $value = 1)
 * @method static bool forever(string $key, $value)
 * @method static mixed remember(string $key, \DateTimeInterface|\DateInterval|int $ttl, \Closure $callback)
 * @method static mixed sear(string $key, \Closure $callback)
 * @method static mixed rememberForever(string $key, \Closure $callback)
 * @method static bool forget(string $key)
 * @method static \Illuminate\Contracts\Cache\Store getStore()
 *
 * @see \Illuminate\Cache\CacheManager
 * @see \Illuminate\Cache\Repository
 */
class Cache extends Facade
{
    /**
     * Get the registered name of the component.
     *
     * @return string
     */
    protected static function getFacadeAccessor()
    {
        return 'cache';
    }
}

CacheServiceProvider

Illuminate\Cache\CacheServiceProvider.php

<?php

namespace Illuminate\Cache;

use Illuminate\Contracts\Support\DeferrableProvider;
use Illuminate\Support\ServiceProvider;
use Symfony\Component\Cache\Adapter\Psr16Adapter;

class CacheServiceProvider extends ServiceProvider implements DeferrableProvider
{
    /**
     * Register the service provider.
     *
     * @return void
     */
    public function register()
    {
        $this->app->singleton('cache', function ($app) {
            return new CacheManager($app);
        });

        $this->app->singleton('cache.store', function ($app) {
            return $app['cache']->driver();
        });

        $this->app->singleton('cache.psr6', function ($app) {
            return new Psr16Adapter($app['cache.store']);
        });

        $this->app->singleton('memcached.connector', function () {
            return new MemcachedConnector;
        });
    }

    /**
     * Get the services provided by the provider.
     *
     * @return array
     */
    public function provides()
    {
        return [
            'cache', 'cache.store', 'cache.psr6', 'memcached.connector',
        ];
    }
}

工厂

Illuminate\Contracts\Cache\Factory.php

<?php

namespace Illuminate\Contracts\Cache;

interface Factory
{
    /**
     * Get a cache store instance by name.
     *
     * @param  string|null  $name
     * @return \Illuminate\Contracts\Cache\Repository
     */
    public function store($name = null);
}

Illuminate\Cache\Repository.php

namespace Illuminate\Cache;

use ArrayAccess;
use BadMethodCallException;
use Closure;
use DateTimeInterface;
use Illuminate\Cache\Events\CacheHit;
use Illuminate\Cache\Events\CacheMissed;
use Illuminate\Cache\Events\KeyForgotten;
use Illuminate\Cache\Events\KeyWritten;
use Illuminate\Contracts\Cache\Repository as CacheContract;
use Illuminate\Contracts\Cache\Store;
use Illuminate\Contracts\Events\Dispatcher;
use Illuminate\Support\Carbon;
use Illuminate\Support\InteractsWithTime;
use Illuminate\Support\Traits\Macroable;

/**
 * @mixin \Illuminate\Contracts\Cache\Store
 */
class Repository implements ArrayAccess, CacheContract
{
    use InteractsWithTime;
    use Macroable {
        __call as macroCall;
    }

    /**
     * The cache store implementation.
     *
     * @var \Illuminate\Contracts\Cache\Store
     */
    protected $store;

    /**
     * The event dispatcher implementation.
     *
     * @var \Illuminate\Contracts\Events\Dispatcher
     */
    protected $events;

    /**
     * The default number of seconds to store items.
     *
     * @var int|null
     */
    protected $default = 3600;

    /**
     * Create a new cache repository instance.
     *
     * @param  \Illuminate\Contracts\Cache\Store  $store
     * @return void
     */
    public function __construct(Store $store)
    {
        $this->store = $store;
    }

    /**
     * Determine if an item exists in the cache.
     *
     * @param  string  $key
     * @return bool
     */
    public function has($key)
    {
        return ! is_null($this->get($key));
    }

    /**
     * Determine if an item doesn't exist in the cache.
     *
     * @param  string  $key
     * @return bool
     */
    public function missing($key)
    {
        return ! $this->has($key);
    }

    /**
     * Retrieve an item from the cache by key.
     *
     * @param  string  $key
     * @param  mixed  $default
     * @return mixed
     */
    public function get($key, $default = null)
    {
        if (is_array($key)) {
            return $this->many($key);
        }

        $value = $this->store->get($this->itemKey($key));

        // If we could not find the cache value, we will fire the missed event and get
        // the default value for this cache value. This default could be a callback
        // so we will execute the value function which will resolve it if needed.
        if (is_null($value)) {
            $this->event(new CacheMissed($key));

            $value = value($default);
        } else {
            $this->event(new CacheHit($key, $value));
        }

        return $value;
    }

    /**
     * Retrieve multiple items from the cache by key.
     *
     * Items not found in the cache will have a null value.
     *
     * @param  array  $keys
     * @return array
     */
    public function many(array $keys)
    {
        $values = $this->store->many(collect($keys)->map(function ($value, $key) {
            return is_string($key) ? $key : $value;
        })->values()->all());

        return collect($values)->map(function ($value, $key) use ($keys) {
            return $this->handleManyResult($keys, $key, $value);
        })->all();
    }

    /**
     * {@inheritdoc}
     */
    public function getMultiple($keys, $default = null)
    {
        $defaults = [];

        foreach ($keys as $key) {
            $defaults[$key] = $default;
        }

        return $this->many($defaults);
    }

    /**
     * Handle a result for the "many" method.
     *
     * @param  array  $keys
     * @param  string  $key
     * @param  mixed  $value
     * @return mixed
     */
    protected function handleManyResult($keys, $key, $value)
    {
        // If we could not find the cache value, we will fire the missed event and get
        // the default value for this cache value. This default could be a callback
        // so we will execute the value function which will resolve it if needed.
        if (is_null($value)) {
            $this->event(new CacheMissed($key));

            return isset($keys[$key]) ? value($keys[$key]) : null;
        }

        // If we found a valid value we will fire the "hit" event and return the value
        // back from this function. The "hit" event gives developers an opportunity
        // to listen for every possible cache "hit" throughout this applications.
        $this->event(new CacheHit($key, $value));

        return $value;
    }

    /**
     * Retrieve an item from the cache and delete it.
     *
     * @param  string  $key
     * @param  mixed  $default
     * @return mixed
     */
    public function pull($key, $default = null)
    {
        return tap($this->get($key, $default), function () use ($key) {
            $this->forget($key);
        });
    }

    /**
     * Store an item in the cache.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @param  \DateTimeInterface|\DateInterval|int|null  $ttl
     * @return bool
     */
    public function put($key, $value, $ttl = null)
    {
        if (is_array($key)) {
            return $this->putMany($key, $value);
        }

        if ($ttl === null) {
            return $this->forever($key, $value);
        }

        $seconds = $this->getSeconds($ttl);

        if ($seconds <= 0) {
            return $this->forget($key);
        }

        $result = $this->store->put($this->itemKey($key), $value, $seconds);

        if ($result) {
            $this->event(new KeyWritten($key, $value, $seconds));
        }

        return $result;
    }

    /**
     * {@inheritdoc}
     */
    public function set($key, $value, $ttl = null)
    {
        return $this->put($key, $value, $ttl);
    }

    /**
     * Store multiple items in the cache for a given number of seconds.
     *
     * @param  array  $values
     * @param  \DateTimeInterface|\DateInterval|int|null  $ttl
     * @return bool
     */
    public function putMany(array $values, $ttl = null)
    {
        if ($ttl === null) {
            return $this->putManyForever($values);
        }

        $seconds = $this->getSeconds($ttl);

        if ($seconds <= 0) {
            return $this->deleteMultiple(array_keys($values));
        }

        $result = $this->store->putMany($values, $seconds);

        if ($result) {
            foreach ($values as $key => $value) {
                $this->event(new KeyWritten($key, $value, $seconds));
            }
        }

        return $result;
    }

    /**
     * Store multiple items in the cache indefinitely.
     *
     * @param  array  $values
     * @return bool
     */
    protected function putManyForever(array $values)
    {
        $result = true;

        foreach ($values as $key => $value) {
            if (! $this->forever($key, $value)) {
                $result = false;
            }
        }

        return $result;
    }

    /**
     * {@inheritdoc}
     */
    public function setMultiple($values, $ttl = null)
    {
        return $this->putMany(is_array($values) ? $values : iterator_to_array($values), $ttl);
    }

    /**
     * Store an item in the cache if the key does not exist.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @param  \DateTimeInterface|\DateInterval|int|null  $ttl
     * @return bool
     */
    public function add($key, $value, $ttl = null)
    {
        if ($ttl !== null) {
            if ($this->getSeconds($ttl) <= 0) {
                return false;
            }

            // If the store has an "add" method we will call the method on the store so it
            // has a chance to override this logic. Some drivers better support the way
            // this operation should work with a total "atomic" implementation of it.
            if (method_exists($this->store, 'add')) {
                $seconds = $this->getSeconds($ttl);

                return $this->store->add(
                    $this->itemKey($key), $value, $seconds
                );
            }
        }

        // If the value did not exist in the cache, we will put the value in the cache
        // so it exists for subsequent requests. Then, we will return true so it is
        // easy to know if the value gets added. Otherwise, we will return false.
        if (is_null($this->get($key))) {
            return $this->put($key, $value, $ttl);
        }

        return false;
    }

    /**
     * Increment the value of an item in the cache.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return int|bool
     */
    public function increment($key, $value = 1)
    {
        return $this->store->increment($key, $value);
    }

    /**
     * Decrement the value of an item in the cache.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return int|bool
     */
    public function decrement($key, $value = 1)
    {
        return $this->store->decrement($key, $value);
    }

    /**
     * Store an item in the cache indefinitely.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return bool
     */
    public function forever($key, $value)
    {
        $result = $this->store->forever($this->itemKey($key), $value);

        if ($result) {
            $this->event(new KeyWritten($key, $value));
        }

        return $result;
    }

    /**
     * Get an item from the cache, or execute the given Closure and store the result.
     *
     * @param  string  $key
     * @param  \DateTimeInterface|\DateInterval|int|null  $ttl
     * @param  \Closure  $callback
     * @return mixed
     */
    public function remember($key, $ttl, Closure $callback)
    {
        $value = $this->get($key);

        // If the item exists in the cache we will just return this immediately and if
        // not we will execute the given Closure and cache the result of that for a
        // given number of seconds so it's available for all subsequent requests.
        if (! is_null($value)) {
            return $value;
        }

        $this->put($key, $value = $callback(), $ttl);

        return $value;
    }

    /**
     * Get an item from the cache, or execute the given Closure and store the result forever.
     *
     * @param  string  $key
     * @param  \Closure  $callback
     * @return mixed
     */
    public function sear($key, Closure $callback)
    {
        return $this->rememberForever($key, $callback);
    }

    /**
     * Get an item from the cache, or execute the given Closure and store the result forever.
     *
     * @param  string  $key
     * @param  \Closure  $callback
     * @return mixed
     */
    public function rememberForever($key, Closure $callback)
    {
        $value = $this->get($key);

        // If the item exists in the cache we will just return this immediately
        // and if not we will execute the given Closure and cache the result
        // of that forever so it is available for all subsequent requests.
        if (! is_null($value)) {
            return $value;
        }

        $this->forever($key, $value = $callback());

        return $value;
    }

    /**
     * Remove an item from the cache.
     *
     * @param  string  $key
     * @return bool
     */
    public function forget($key)
    {
        return tap($this->store->forget($this->itemKey($key)), function ($result) use ($key) {
            if ($result) {
                $this->event(new KeyForgotten($key));
            }
        });
    }

    /**
     * {@inheritdoc}
     */
    public function delete($key)
    {
        return $this->forget($key);
    }

    /**
     * {@inheritdoc}
     */
    public function deleteMultiple($keys)
    {
        $result = true;

        foreach ($keys as $key) {
            if (! $this->forget($key)) {
                $result = false;
            }
        }

        return $result;
    }

    /**
     * {@inheritdoc}
     */
    public function clear()
    {
        return $this->store->flush();
    }

    /**
     * Begin executing a new tags operation if the store supports it.
     *
     * @param  array|mixed  $names
     * @return \Illuminate\Cache\TaggedCache
     *
     * @throws \BadMethodCallException
     */
    public function tags($names)
    {
        if (! method_exists($this->store, 'tags')) {
            throw new BadMethodCallException('This cache store does not support tagging.');
        }

        $cache = $this->store->tags(is_array($names) ? $names : func_get_args());

        if (! is_null($this->events)) {
            $cache->setEventDispatcher($this->events);
        }

        return $cache->setDefaultCacheTime($this->default);
    }

    /**
     * Format the key for a cache item.
     *
     * @param  string  $key
     * @return string
     */
    protected function itemKey($key)
    {
        return $key;
    }

    /**
     * Get the default cache time.
     *
     * @return int|null
     */
    public function getDefaultCacheTime()
    {
        return $this->default;
    }

    /**
     * Set the default cache time in seconds.
     *
     * @param  int|null  $seconds
     * @return $this
     */
    public function setDefaultCacheTime($seconds)
    {
        $this->default = $seconds;

        return $this;
    }

    /**
     * Get the cache store implementation.
     *
     * @return \Illuminate\Contracts\Cache\Store
     */
    public function getStore()
    {
        return $this->store;
    }

    /**
     * Fire an event for this cache instance.
     *
     * @param  string  $event
     * @return void
     */
    protected function event($event)
    {
        if (isset($this->events)) {
            $this->events->dispatch($event);
        }
    }

    /**
     * Get the event dispatcher instance.
     *
     * @return \Illuminate\Contracts\Events\Dispatcher
     */
    public function getEventDispatcher()
    {
        return $this->events;
    }

    /**
     * Set the event dispatcher instance.
     *
     * @param  \Illuminate\Contracts\Events\Dispatcher  $events
     * @return void
     */
    public function setEventDispatcher(Dispatcher $events)
    {
        $this->events = $events;
    }

    /**
     * Determine if a cached value exists.
     *
     * @param  string  $key
     * @return bool
     */
    public function offsetExists($key)
    {
        return $this->has($key);
    }

    /**
     * Retrieve an item from the cache by key.
     *
     * @param  string  $key
     * @return mixed
     */
    public function offsetGet($key)
    {
        return $this->get($key);
    }

    /**
     * Store an item in the cache for the default time.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return void
     */
    public function offsetSet($key, $value)
    {
        $this->put($key, $value, $this->default);
    }

    /**
     * Remove an item from the cache.
     *
     * @param  string  $key
     * @return void
     */
    public function offsetUnset($key)
    {
        $this->forget($key);
    }

    /**
     * Calculate the number of seconds for the given TTL.
     *
     * @param  \DateTimeInterface|\DateInterval|int  $ttl
     * @return int
     */
    protected function getSeconds($ttl)
    {
        $duration = $this->parseDateInterval($ttl);

        if ($duration instanceof DateTimeInterface) {
            $duration = Carbon::now()->diffInRealSeconds($duration, false);
        }

        return (int) $duration > 0 ? $duration : 0;
    }

    /**
     * Handle dynamic calls into macros or pass missing methods to the store.
     *
     * @param  string  $method
     * @param  array  $parameters
     * @return mixed
     */
    public function __call($method, $parameters)
    {
        if (static::hasMacro($method)) {
            return $this->macroCall($method, $parameters);
        }

        return $this->store->$method(...$parameters);
    }

    /**
     * Clone cache repository instance.
     *
     * @return void
     */
    public function __clone()
    {
        $this->store = clone $this->store;
    }
}

RedisStore

Illuminate\Cache\RedisStore.php

namespace Illuminate\Cache;

use Illuminate\Contracts\Cache\LockProvider;
use Illuminate\Contracts\Redis\Factory as Redis;

class RedisStore extends TaggableStore implements LockProvider
{
    /**
     * The Redis factory implementation.
     *
     * @var \Illuminate\Contracts\Redis\Factory
     */
    protected $redis;

    /**
     * A string that should be prepended to keys.
     *
     * @var string
     */
    protected $prefix;

    /**
     * The Redis connection that should be used.
     *
     * @var string
     */
    protected $connection;

    /**
     * Create a new Redis store.
     *
     * @param  \Illuminate\Contracts\Redis\Factory  $redis
     * @param  string  $prefix
     * @param  string  $connection
     * @return void
     */
    public function __construct(Redis $redis, $prefix = '', $connection = 'default')
    {
        $this->redis = $redis;
        $this->setPrefix($prefix);
        $this->setConnection($connection);
    }

    /**
     * Retrieve an item from the cache by key.
     *
     * @param  string|array  $key
     * @return mixed
     */
    public function get($key)
    {
        $value = $this->connection()->get($this->prefix.$key);

        return ! is_null($value) ? $this->unserialize($value) : null;
    }

    /**
     * Retrieve multiple items from the cache by key.
     *
     * Items not found in the cache will have a null value.
     *
     * @param  array  $keys
     * @return array
     */
    public function many(array $keys)
    {
        $results = [];

        $values = $this->connection()->mget(array_map(function ($key) {
            return $this->prefix.$key;
        }, $keys));

        foreach ($values as $index => $value) {
            $results[$keys[$index]] = ! is_null($value) ? $this->unserialize($value) : null;
        }

        return $results;
    }

    /**
     * Store an item in the cache for a given number of seconds.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @param  int  $seconds
     * @return bool
     */
    public function put($key, $value, $seconds)
    {
        return (bool) $this->connection()->setex(
            $this->prefix.$key, (int) max(1, $seconds), $this->serialize($value)
        );
    }

    /**
     * Store multiple items in the cache for a given number of seconds.
     *
     * @param  array  $values
     * @param  int  $seconds
     * @return bool
     */
    public function putMany(array $values, $seconds)
    {
        $this->connection()->multi();

        $manyResult = null;

        foreach ($values as $key => $value) {
            $result = $this->put($key, $value, $seconds);

            $manyResult = is_null($manyResult) ? $result : $result && $manyResult;
        }

        $this->connection()->exec();

        return $manyResult ?: false;
    }

    /**
     * Store an item in the cache if the key doesn't exist.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @param  int  $seconds
     * @return bool
     */
    public function add($key, $value, $seconds)
    {
        $lua = "return redis.call('exists',KEYS[1])<1 and redis.call('setex',KEYS[1],ARGV[2],ARGV[1])";

        return (bool) $this->connection()->eval(
            $lua, 1, $this->prefix.$key, $this->serialize($value), (int) max(1, $seconds)
        );
    }

    /**
     * Increment the value of an item in the cache.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return int
     */
    public function increment($key, $value = 1)
    {
        return $this->connection()->incrby($this->prefix.$key, $value);
    }

    /**
     * Decrement the value of an item in the cache.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return int
     */
    public function decrement($key, $value = 1)
    {
        return $this->connection()->decrby($this->prefix.$key, $value);
    }

    /**
     * Store an item in the cache indefinitely.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return bool
     */
    public function forever($key, $value)
    {
        return (bool) $this->connection()->set($this->prefix.$key, $this->serialize($value));
    }

    /**
     * Get a lock instance.
     *
     * @param  string  $name
     * @param  int  $seconds
     * @param  string|null  $owner
     * @return \Illuminate\Contracts\Cache\Lock
     */
    public function lock($name, $seconds = 0, $owner = null)
    {
        return new RedisLock($this->connection(), $this->prefix.$name, $seconds, $owner);
    }

    /**
     * Restore a lock instance using the owner identifier.
     *
     * @param  string  $name
     * @param  string  $owner
     * @return \Illuminate\Contracts\Cache\Lock
     */
    public function restoreLock($name, $owner)
    {
        return $this->lock($name, 0, $owner);
    }

    /**
     * Remove an item from the cache.
     *
     * @param  string  $key
     * @return bool
     */
    public function forget($key)
    {
        return (bool) $this->connection()->del($this->prefix.$key);
    }

    /**
     * Remove all items from the cache.
     *
     * @return bool
     */
    public function flush()
    {
        $this->connection()->flushdb();

        return true;
    }

    /**
     * Begin executing a new tags operation.
     *
     * @param  array|mixed  $names
     * @return \Illuminate\Cache\RedisTaggedCache
     */
    public function tags($names)
    {
        return new RedisTaggedCache(
            $this, new TagSet($this, is_array($names) ? $names : func_get_args())
        );
    }

    /**
     * Get the Redis connection instance.
     *
     * @return \Illuminate\Redis\Connections\Connection
     */
    public function connection()
    {
        return $this->redis->connection($this->connection);
    }

    /**
     * Set the connection name to be used.
     *
     * @param  string  $connection
     * @return void
     */
    public function setConnection($connection)
    {
        $this->connection = $connection;
    }

    /**
     * Get the Redis database instance.
     *
     * @return \Illuminate\Contracts\Redis\Factory
     */
    public function getRedis()
    {
        return $this->redis;
    }

    /**
     * Get the cache key prefix.
     *
     * @return string
     */
    public function getPrefix()
    {
        return $this->prefix;
    }

    /**
     * Set the cache key prefix.
     *
     * @param  string  $prefix
     * @return void
     */
    public function setPrefix($prefix)
    {
        $this->prefix = ! empty($prefix) ? $prefix.':' : '';
    }

    /**
     * Serialize the value.
     *
     * @param  mixed  $value
     * @return mixed
     */
    protected function serialize($value)
    {
        return is_numeric($value) && ! in_array($value, [INF, -INF]) && ! is_nan($value) ? $value : serialize($value);
    }

    /**
     * Unserialize the value.
     *
     * @param  mixed  $value
     * @return mixed
     */
    protected function unserialize($value)
    {
        return is_numeric($value) ? $value : unserialize($value);
    }
}

RedisLock

Illuminate\Cache\Lock.php

<?php

namespace Illuminate\Cache;

use Illuminate\Contracts\Cache\Lock as LockContract;
use Illuminate\Contracts\Cache\LockTimeoutException;
use Illuminate\Support\InteractsWithTime;
use Illuminate\Support\Str;

abstract class Lock implements LockContract
{
    use InteractsWithTime;

    /**
     * The name of the lock.
     *
     * @var string
     */
    protected $name;

    /**
     * The number of seconds the lock should be maintained.
     *
     * @var int
     */
    protected $seconds;

    /**
     * The scope identifier of this lock.
     *
     * @var string
     */
    protected $owner;

    /**
     * Create a new lock instance.
     *
     * @param  string  $name
     * @param  int  $seconds
     * @param  string|null  $owner
     * @return void
     */
    public function __construct($name, $seconds, $owner = null)
    {
        if (is_null($owner)) {
            $owner = Str::random();
        }

        $this->name = $name;
        $this->owner = $owner;
        $this->seconds = $seconds;
    }

    /**
     * Attempt to acquire the lock.
     *
     * @return bool
     */
    abstract public function acquire();

    /**
     * Release the lock.
     *
     * @return bool
     */
    abstract public function release();

    /**
     * Returns the owner value written into the driver for this lock.
     *
     * @return string
     */
    abstract protected function getCurrentOwner();

    /**
     * Attempt to acquire the lock.
     *
     * @param  callable|null  $callback
     * @return mixed
     */
    public function get($callback = null)
    {
        $result = $this->acquire();

        if ($result && is_callable($callback)) {
            try {
                return $callback();
            } finally {
                $this->release();
            }
        }

        return $result;
    }

    /**
     * Attempt to acquire the lock for the given number of seconds.
     *
     * @param  int  $seconds
     * @param  callable|null  $callback
     * @return bool
     *
     * @throws \Illuminate\Contracts\Cache\LockTimeoutException
     */
    public function block($seconds, $callback = null)
    {
        $starting = $this->currentTime();

        while (! $this->acquire()) {
            usleep(250 * 1000);

            if ($this->currentTime() - $seconds >= $starting) {
                throw new LockTimeoutException;
            }
        }

        if (is_callable($callback)) {
            try {
                return $callback();
            } finally {
                $this->release();
            }
        }

        return true;
    }

    /**
     * Returns the current owner of the lock.
     *
     * @return string
     */
    public function owner()
    {
        return $this->owner;
    }

    /**
     * Determines whether this lock is allowed to release the lock in the driver.
     *
     * @return bool
     */
    protected function isOwnedByCurrentProcess()
    {
        return $this->getCurrentOwner() === $this->owner;
    }
}

Illuminate\Cache\RedisLock

<?php

namespace Illuminate\Cache;

class RedisLock extends Lock
{
    /**
     * The Redis factory implementation.
     *
     * @var \Illuminate\Redis\Connections\Connection
     */
    protected $redis;

    /**
     * Create a new lock instance.
     *
     * @param  \Illuminate\Redis\Connections\Connection  $redis
     * @param  string  $name
     * @param  int  $seconds
     * @param  string|null  $owner
     * @return void
     */
    public function __construct($redis, $name, $seconds, $owner = null)
    {
        parent::__construct($name, $seconds, $owner);

        $this->redis = $redis;
    }

    /**
     * Attempt to acquire the lock.
     *
     * @return bool
     */
    public function acquire()
    {
        if ($this->seconds > 0) {
            return $this->redis->set($this->name, $this->owner, 'EX', $this->seconds, 'NX') == true;
        } else {
            return $this->redis->setnx($this->name, $this->owner) === 1;
        }
    }

    /**
     * Release the lock.
     *
     * @return bool
     */
    public function release()
    {
        return (bool) $this->redis->eval(LuaScripts::releaseLock(), 1, $this->name, $this->owner);
    }

    /**
     * Releases this lock in disregard of ownership.
     *
     * @return void
     */
    public function forceRelease()
    {
        $this->redis->del($this->name);
    }

    /**
     * Returns the owner value written into the driver for this lock.
     *
     * @return string
     */
    protected function getCurrentOwner()
    {
        return $this->redis->get($this->name);
    }
}

CacheManager

Illuminate\CacheManager.php

namespace Illuminate\Cache;

use Closure;
use Illuminate\Contracts\Cache\Factory as FactoryContract;
use Illuminate\Contracts\Cache\Store;
use Illuminate\Contracts\Events\Dispatcher as DispatcherContract
use Illuminate\Support\Arr;
use InvalidArgumentException;

/**
 * @mixin \Illuminate\Contracts\Cache\Repository
 */
class CacheManager implements FactoryContract
{
    /**
     * The application instance.
     *
     * @var \Illuminate\Contracts\Foundation\Application
     */
    protected $app;

    /**
     * The array of resolved cache stores.
     *
     * @var array
     */
    protected $stores = [];

    /**
     * The registered custom driver creators.
     *
     * @var array
     */
    protected $customCreators = [];

    /**
     * Create a new Cache manager instance.
     *
     * @param  \Illuminate\Contracts\Foundation\Application  $app
     * @return void
     */
    public function __construct($app)
    {
        $this->app = $app;
    }

    /**
     * Get a cache store instance by name, wrapped in a repository.
     *
     * @param  string|null  $name
     * @return \Illuminate\Contracts\Cache\Repository
     */
    public function store($name = null)
    {
        $name = $name ?: $this->getDefaultDriver();

        return $this->stores[$name] = $this->get($name);
    }

    /**
     * Get a cache driver instance.
     *
     * @param  string|null  $driver
     * @return \Illuminate\Contracts\Cache\Repository
     */
    public function driver($driver = null)
    {
        return $this->store($driver);
    }

    /**
     * Attempt to get the store from the local cache.
     *
     * @param  string  $name
     * @return \Illuminate\Contracts\Cache\Repository
     */
    protected function get($name)
    {
        return $this->stores[$name] ?? $this->resolve($name);
    }

     /**
     * Resolve the given store.
     *
     * @param  string  $name
     * @return \Illuminate\Contracts\Cache\Repository
     *
     * @throws \InvalidArgumentException
     */
    protected function resolve($name)
    {
        $config = $this->getConfig($name);

        if (is_null($config)) {
            throw new InvalidArgumentException("Cache store [{$name}] is not defined.");
        }         

        if (isset($this->customCreators[$config['driver']])) {
            return $this->callCustomCreator($config);
        } else {
            $driverMethod = 'create'.ucfirst($config['driver']).'Driver';

            if (method_exists($this, $driverMethod)) {
                return $this->{$driverMethod}($config);
            } else {
                throw new InvalidArgumentException("Driver [{$config['driver']}] is not supported.");
            }
        }      
    }

    /**
     * Call a custom driver creator.
     *
     * @param  array  $config
     * @return mixed
     */
    protected function callCustomCreator(array $config)
    {
        return $this->customCreators[$config['driver']]($this->app, $config);
    }

    /**
     * Create an instance of the array cache driver.
     *
     * @param  array  $config
     * @return \Illuminate\Cache\Repository
     */
    protected function createArrayDriver(array $config)
    {
        return $this->repository(new ArrayStore($config['serialize'] ?? false));
    }

    /**
     * Create an instance of the file cache driver.
     *
     * @param  array  $config
     * @return \Illuminate\Cache\Repository
     */
    protected function createFileDriver(array $config)
    {
        return $this->repository(new FileStore($this->app['files'], $config['path'], $config['permission'] ?? null));
    }

    /**
     * Create an instance of the Null cache driver.
     *
     * @return \Illuminate\Cache\Repository
     */
    protected function createNullDriver()
    {
        return $this->repository(new NullStore);
    }

    /**
     * Create an instance of the Redis cache driver.
     *
     * @param  array  $config
     * @return \Illuminate\Cache\Repository
     */
    protected function createRedisDriver(array $config)
    {
        $redis = $this->app['redis'];

        $connection = $config['connection'] ?? 'default';

        return $this->repository(new RedisStore($redis, $this->getPrefix($config), $connection));
    }

    /**
     * Create an instance of the database cache driver.
     *
     * @param  array  $config
     * @return \Illuminate\Cache\Repository
     */
    protected function createDatabaseDriver(array $config)
    {
        $connection = $this->app['db']->connection($config['connection'] ?? null);

        return $this->repository(
            new DatabaseStore(
                $connection, $config['table'], $this->getPrefix($config)
            )
        );
    }

    /**
     * Create a new cache repository with the given implementation.
     *
     * @param  \Illuminate\Contracts\Cache\Store  $store
     * @return \Illuminate\Cache\Repository
     */
    public function repository(Store $store)
    {
        return tap(new Repository($store), function ($repository) {
            $this->setEventDispatcher($repository);
        });
    }

    /**
     * Set the event dispatcher on the given repository instance.
     *
     * @param  \Illuminate\Cache\Repository  $repository
     * @return void
     */
    protected function setEventDispatcher(Repository $repository)
    {
        if (! $this->app->bound(DispatcherContract::class)) {
            return;
        }

        $repository->setEventDispatcher(
            $this->app[DispatcherContract::class]
        );
    }

    /**
     * Re-set the event dispatcher on all resolved cache repositories.
     *
     * @return void
     */
    public function refreshEventDispatcher()
    {
        array_map([$this, 'setEventDispatcher'], $this->stores);
    }

    /**
     * Get the cache prefix.
     *
     * @param  array  $config
     * @return string
     */
    protected function getPrefix(array $config)
    {
        return $config['prefix'] ?? $this->app['config']['cache.prefix'];
    }

    /**
     * Get the cache connection configuration.
     *
     * @param  string  $name
     * @return array
     */
    protected function getConfig($name)
    {
        return $this->app['config']["cache.stores.{$name}"];
    }

    /**
     * Get the default cache driver name.
     *
     * @return string
     */
    public function getDefaultDriver()
    {
        return $this->app['config']['cache.default'];
    }

    /**
     * Set the default cache driver name.
     *
     * @param  string  $name
     * @return void
     */
    public function setDefaultDriver($name)
    {
        $this->app['config']['cache.default'] = $name;
    }

    /**
     * Unset the given driver instances.
     *
     * @param  array|string|null  $name
     * @return $this
     */
    public function forgetDriver($name = null)
    {
        $name = $name ?? $this->getDefaultDriver();

        foreach ((array) $name as $cacheName) {
            if (isset($this->stores[$cacheName])) {
                unset($this->stores[$cacheName]);
            }
        }

        return $this;
    }

    /**
     * Register a custom driver creator Closure.
     *
     * @param  string  $driver
     * @param  \Closure  $callback
     * @return $this
     */
    public function extend($driver, Closure $callback)
    {
        $this->customCreators[$driver] = $callback->bindTo($this, $this);

        return $this;
    }

    /**
     * Dynamically call the default driver instance.
     *
     * @param  string  $method
     * @param  array  $parameters
     * @return mixed
     */
    public function __call($method, $parameters)
    {
        return $this->store()->$method(...$parameters);
    }
}

缓存

缓存使用

原子锁

注：要使用这个功能，应用必须使用Memcached、Redis缓存驱动作为应用默认的缓存驱动，此外，所有服务器必须和同一台中央缓存服务器进行通信。

原子锁允许你对分布式锁进行操作而不必担心竞争条件，例如，Laravel Forge使用原子锁来确保在一台服务器上同时只有一个远程任务在执行，你可以通过Cache::lock方法来创建和管理锁：

if (Cache::lock('foo', 10)->get()) {
    // Lock acquired for 10 seconds...

    Cache::lock('foo')->release();
}

get方法还可以接收一个闭包，在闭包执行之后，Laravel会自动释放锁：

Cache::lock('foo')->get(function () {
    // Lock acquired indefinitely and automatically released...
});

如果锁在你请求的时候无效，可以告知Laravel等待直到锁有效。如果锁在指定限制时间内无法获取，会抛出Illuminate\Contracts\Cache\LockTimeoutException异常：

use Illuminate\Contracts\Cache\LockTimeoutException;

$lock = Cache::lock('foo', 10);

try {
    $lock->block(5);

    // Lock acquired after waiting maximum of 5 seconds...
} catch (LockTimeoutException $e) {
    // Unable to acquire lock...
} finally {
    optional($lock)->release();
}

Cache::lock('foo', 10)->block(5, function () {
    // Lock acquired after waiting maximum of 5 seconds...
});

管理跨进程的锁

有时候，你可能想要在一个进程中获取锁，在另一个进程中释放锁。例如，你可以在Web请求期间获取锁，然后在该请求触发的某个队列任务最后释放这把锁。在这种场景下，你应该传递锁的域「所有者令牌」到队列任务以便该任务可以使用给定令牌重新实例化锁：

// 在控制器中...
$podcast = Podcast::find($id);

$lock = Cache::lock('foo', 120);

if ($result = $lock->get()) {
    ProcessPodcast::dispatch($podcast, $lock->owner());
}

// 在 ProcessPodcast 任务中...
Cache::restoreLock('foo', $this->owner)->release();

如果你想要在不管当前所有者的情况下释放锁，可以使用forceRelease方法：

Cache::lock('foo')->forceRelease();

缓存标签

注：缓存标签目前不支持file或database缓存驱动，此外，当使用多标签的缓存被设置为永久存储时，使用Memcached驱动的缓存有着最佳性能表现，因为Memcached会自动清除陈旧记录。

存储被打上标签的缓存项

缓存标签允许你给相关缓存项打上同一个标签以便于后续清除这些缓存值，被打上标签的缓存可以通过传递一个被排序的标签数组来访问。例如，我们可以通过以下方式在添加缓存的时候设置标签：

Cache::tags(['people', 'artists'])->put('John', $john, $seconds);
Cache::tags(['people', 'authors'])->put('Anne', $anne, $seconds);

访问被打上标签的缓存项

要获取被打上标签的缓存项，传递同样的有序标签数组到tags方法然后使用你想要获取的key来调用get方法：

$john = Cache::tags(['people', 'artists'])->get('John');
$anne = Cache::tags(['people', 'authors'])->get('Anne');

移除被打上标签的数据项

你可以同时清除被打上同一标签/标签列表的所有缓存项，例如，以下语句会移除被打上people或authors标签的所有缓存：

Cache::tags(['people', 'authors'])->flush();

这样，上面设置的Anne和John缓存项都会从缓存中移除。

相反，以下语句只移除被打上authors标签的语句，所以只有Anne会被移除而John不会：

Cache::tags('authors')->flush();

源码

Illuminate\Cache\TaggableStore.php

<?php

namespace Illuminate\Cache;

use Illuminate\Contracts\Cache\Store;

abstract class TaggableStore implements Store
{
    /**
     * Begin executing a new tags operation.
     *
     * @param  array|mixed  $names
     * @return \Illuminate\Cache\TaggedCache
     */
    public function tags($names)
    {
        return new TaggedCache($this, new TagSet($this, is_array($names) ? $names : func_get_args()));
    }
}

Illuminate\Cache\TaggedCache.php

namespace Illuminate\Cache;

use Illuminate\Contracts\Cache\Store;

class TaggedCache extends Repository
{
    use RetrievesMultipleKeys {
        putMany as putManyAlias;
    }

    /**
     * The tag set instance.
     *
     * @var \Illuminate\Cache\TagSet
     */
    protected $tags;

    /**
     * Create a new tagged cache instance.
     *
     * @param  \Illuminate\Contracts\Cache\Store  $store
     * @param  \Illuminate\Cache\TagSet  $tags
     * @return void
     */
    public function __construct(Store $store, TagSet $tags)
    {
        parent::__construct($store);

        $this->tags = $tags;
    }

    /**
     * Store multiple items in the cache for a given number of seconds.
     *
     * @param  array  $values
     * @param  int|null  $ttl
     * @return bool
     */
    public function putMany(array $values, $ttl = null)
    {
        if ($ttl === null) {
            return $this->putManyForever($values);
        }

        return $this->putManyAlias($values, $ttl);
    }

    /**
     * Increment the value of an item in the cache.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return void
     */
    public function increment($key, $value = 1)
    {
        $this->store->increment($this->itemKey($key), $value);
    }

    /**
     * Decrement the value of an item in the cache.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return void
     */
    public function decrement($key, $value = 1)
    {
        $this->store->decrement($this->itemKey($key), $value);
    }

    /**
     * Remove all items from the cache.
     *
     * @return bool
     */
    public function flush()
    {
        $this->tags->reset();

        return true;
    }

    /**
     * {@inheritdoc}
     */
    protected function itemKey($key)
    {
        return $this->taggedItemKey($key);
    }

    /**
     * Get a fully qualified key for a tagged item.
     *
     * @param  string  $key
     * @return string
     */
    public function taggedItemKey($key)
    {
        return sha1($this->tags->getNamespace()).':'.$key;
    }

    /**
     * Fire an event for this cache instance.
     *
     * @param  string  $event
     * @return void
     */
    protected function event($event)
    {
        parent::event($event->setTags($this->tags->getNames()));
    }

    /**
     * Get the tag set instance.
     *
     * @return \Illuminate\Cache\TagSet
     */
    public function getTags()
    {
        return $this->tags;
    }
}

Illuminate\Cache\TagSet.php

<?php

namespace Illuminate\Cache;

use Illuminate\Contracts\Cache\Store;

class TagSet
{
    /**
     * The cache store implementation.
     *
     * @var \Illuminate\Contracts\Cache\Store
     */
    protected $store;

    /**
     * The tag names.
     *
     * @var array
     */
    protected $names = [];

    /**
     * Create a new TagSet instance.
     *
     * @param  \Illuminate\Contracts\Cache\Store  $store
     * @param  array  $names
     * @return void
     */
    public function __construct(Store $store, array $names = [])
    {
        $this->store = $store;
        $this->names = $names;
    }

    /**
     * Reset all tags in the set.
     *
     * @return void
     */
    public function reset()
    {
        array_walk($this->names, [$this, 'resetTag']);
    }

    /**
     * Reset the tag and return the new tag identifier.
     *
     * @param  string  $name
     * @return string
     */
    public function resetTag($name)
    {
        $this->store->forever($this->tagKey($name), $id = str_replace('.', '', uniqid('', true)));

        return $id;
    }

    /**
     * Get a unique namespace that changes when any of the tags are flushed.
     *
     * @return string
     */
    public function getNamespace()
    {
        return implode('|', $this->tagIds());
    }

    /**
     * Get an array of tag identifiers for all of the tags in the set.
     *
     * @return array
     */
    protected function tagIds()
    {
        return array_map([$this, 'tagId'], $this->names);
    }

    /**
     * Get the unique tag identifier for a given tag.
     *
     * @param  string  $name
     * @return string
     */
    public function tagId($name)
    {
        return $this->store->get($this->tagKey($name)) ?: $this->resetTag($name);
    }

    /**
     * Get the tag identifier key for a given tag.
     *
     * @param  string  $name
     * @return string
     */
    public function tagKey($name)
    {
        return 'tag:'.$name.':key';
    }

    /**
     * Get all of the tag names in the set.
     *
     * @return array
     */
    public function getNames()
    {
        return $this->names;
    }
}

Illuminate\Cache\RedisTaggedCache.php

<?php

namespace Illuminate\Cache;

class RedisTaggedCache extends TaggedCache
{
    /**
     * Forever reference key.
     *
     * @var string
     */
    const REFERENCE_KEY_FOREVER = 'forever_ref';
    /**
     * Standard reference key.
     *
     * @var string
     */
    const REFERENCE_KEY_STANDARD = 'standard_ref';

    /**
     * Store an item in the cache.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @param  \DateTimeInterface|\DateInterval|int|null  $ttl
     * @return bool
     */
    public function put($key, $value, $ttl = null)
    {
        if ($ttl === null) {
            return $this->forever($key, $value);
        }

        $this->pushStandardKeys($this->tags->getNamespace(), $key);

        return parent::put($key, $value, $ttl);
    }

    /**
     * Increment the value of an item in the cache.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return void
     */
    public function increment($key, $value = 1)
    {
        $this->pushStandardKeys($this->tags->getNamespace(), $key);

        parent::increment($key, $value);
    }

    /**
     * Decrement the value of an item in the cache.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return void
     */
    public function decrement($key, $value = 1)
    {
        $this->pushStandardKeys($this->tags->getNamespace(), $key);

        parent::decrement($key, $value);
    }

    /**
     * Store an item in the cache indefinitely.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return bool
     */
    public function forever($key, $value)
    {
        $this->pushForeverKeys($this->tags->getNamespace(), $key);

        return parent::forever($key, $value);
    }

    /**
     * Remove all items from the cache.
     *
     * @return bool
     */
    public function flush()
    {
        $this->deleteForeverKeys();
        $this->deleteStandardKeys();

        return parent::flush();
    }

    /**
     * Store standard key references into store.
     *
     * @param  string  $namespace
     * @param  string  $key
     * @return void
     */
    protected function pushStandardKeys($namespace, $key)
    {
        $this->pushKeys($namespace, $key, self::REFERENCE_KEY_STANDARD);
    }

    /**
     * Store forever key references into store.
     *
     * @param  string  $namespace
     * @param  string  $key
     * @return void
     */
    protected function pushForeverKeys($namespace, $key)
    {
        $this->pushKeys($namespace, $key, self::REFERENCE_KEY_FOREVER);
    }

    /**
     * Store a reference to the cache key against the reference key.
     *
     * @param  string  $namespace
     * @param  string  $key
     * @param  string  $reference
     * @return void
     */
    protected function pushKeys($namespace, $key, $reference)
    {
        $fullKey = $this->store->getPrefix().sha1($namespace).':'.$key;

        foreach (explode('|', $namespace) as $segment) {
            $this->store->connection()->sadd($this->referenceKey($segment, $reference), $fullKey);
        }
    }

    /**
     * Delete all of the items that were stored forever.
     *
     * @return void
     */
    protected function deleteForeverKeys()
    {
        $this->deleteKeysByReference(self::REFERENCE_KEY_FOREVER);
    }

    /**
     * Delete all standard items.
     *
     * @return void
     */
    protected function deleteStandardKeys()
    {
        $this->deleteKeysByReference(self::REFERENCE_KEY_STANDARD);
    }

    /**
     * Find and delete all of the items that were stored against a reference.
     *
     * @param  string  $reference
     * @return void
     */
    protected function deleteKeysByReference($reference)
    {
        foreach (explode('|', $this->tags->getNamespace()) as $segment) {
            $this->deleteValues($segment = $this->referenceKey($segment, $reference));

            $this->store->connection()->del($segment);
        }
    }

    /**
     * Delete item keys that have been stored against a reference.
     *
     * @param  string  $referenceKey
     * @return void
     */
    protected function deleteValues($referenceKey)
    {
        $values = array_unique($this->store->connection()->smembers($referenceKey));

        if (count($values) > 0) {
            foreach (array_chunk($values, 1000) as $valuesChunk) {
                call_user_func_array([$this->store->connection(), 'del'], $valuesChunk);
            }
        }
    }

    /**
     * Get the reference key for the segment.
     *
     * @param  string  $segment
     * @param  string  $suffix
     * @return string
     */
    protected function referenceKey($segment, $suffix)
    {
        return $this->store->getPrefix().$segment.':'.$suffix;
    }
}