Zend\Cache

Zend\Cache\Storage\Adapter

Overview

Storage adapters are wrappers for real storage resources such as memory and the filesystem, using the well known adapter pattern.

They come with tons of methods to read, write and modify stored items and to get information about stored items and the storage.

All adapters implement the interface Zend\Cache\Storage\StorageInterface and most extend Zend\Cache\Storage\Adapter\AbstractAdapter, which comes with basic logic.

Configuration is handled by either Zend\Cache\Storage\Adapter\AdapterOptions, or an adapter-specific options class if it exists. You may pass the options instance to the class at instantiation or via the setOptions() method, or alternately pass an associative array of options in either place (internally, these are then passed to an options class instance). Alternately, you can pass either the options instance or associative array to the Zend\Cache\StorageFactory::factory method.

Note

Many methods throw exceptions

Because many caching operations throw an exception on error, you need to catch them manually or you can use the plug-in Zend\Cache\Storage\Plugin\ExceptionHandler with throw_exceptions set to false to automatically catch them. You can also define an exception_callback to log exceptions.

Quick Start

Caching adapters can either be created from the provided Zend\Cache\StorageFactory factory, or by simply instantiating one of the Zend\Cache\Storage\Adapter\* classes.

To make life easier, the Zend\Cache\StorageFactory comes with a factory method to create an adapter and create/add all requested plugins at once.

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use Zend\Cache\StorageFactory;

// Via factory:
$cache = StorageFactory::factory(array(
    'adapter' => 'apc',
    'plugins' => array(
        'exception_handler' => array('throw_exceptions' => false),
    ),
));

// Alternately:
$cache  = StorageFactory::adapterFactory('apc');
$plugin = StorageFactory::pluginFactory('exception_handler', array(
    'throw_exceptions' => false,
));
$cache->addPlugin($plugin);

// Or manually:
$cache  = new Zend\Cache\Storage\Adapter\Apc();
$plugin = new Zend\Cache\Storage\Plugin\ExceptionHandler(array(
    'throw_exceptions' => false,
));
$cache->addPlugin($plugin);

Basic Configuration Options

Basic configuration is handled by either Zend\Cache\Storage\Adapter\AdapterOptions, or an adapter-specific options class if it exists. You may pass the options instance to the class at instantiation or via the setOptions() method, or alternately pass an associative array of options in either place (internally, these are then passed to an options class instance). Alternately, you can pass either the options instance or associative array to the Zend\Cache\StorageFactory::factory method.

The following configuration options are defined by Zend\Cache\Storage\Adapter\AdapterOptions and are available for every supported adapter. Adapter-specific configuration options are described on adapter level below.

Option Data Type Default Value Description
ttl integer 0 Time to live
namespace string “zfcache” The “namespace” in which cache items will live
key_pattern null``|``string null Pattern against which to validate cache keys
readable boolean true Enable/Disable reading data from cache
writable boolean true Enable/Disable writing data to cache

The StorageInterface

The Zend\Cache\Storage\StorageInterface is the basic interface implemented by all storage adapters.

getItem(string $key, boolean & $success = null, mixed & $casToken = null)

Load an item with the given $key.

If item exists set parameter $success to true, set parameter $casToken and returns mixed value of item.

If item can’t load set parameter $success to false and returns null.

Return type:mixed
getItems(array $keys)

Load all items given by $keys returning key-value pairs.

Return type:array
hasItem(string $key)

Test if an item exists.

Return type:boolean
hasItems(array $keys)

Test multiple items.

Return type:string[]
getMetadata(string $key)

Get metadata of an item.

Return type:array|boolean
getMetadatas(array $keys)

Get multiple metadata.

Return type:array
setItem(string $key, mixed $value)

Store an item.

Return type:boolean
setItems(array $keyValuePairs)

Store multiple items.

Return type:boolean
addItem(string $key, mixed $value)

Add an item.

Return type:boolean
addItems(array $keyValuePairs)

Add multiple items.

Return type:boolean
replaceItem(string $key, mixed $value)

Replace an item.

Return type:boolean
replaceItems(array $keyValuePairs)

Replace multiple items.

Return type:boolean
checkAndSetItem(mixed $token, string $key, mixed $value)

Set item only if token matches. It uses the token received from getItem() to check if the item has changed before overwriting it.

Return type:boolean
touchItem(string $key)

Reset lifetime of an item.

Return type:boolean
touchItems(array $keys)

Reset lifetime of multiple items.

Return type:boolean
removeItem(string $key)

Remove an item.

Return type:boolean
removeItems(array $keys)

Remove multiple items.

Return type:boolean
incrementItem(string $key, int $value)

Increment an item.

Return type:integer|boolean
incrementItems(array $keyValuePairs)

Increment multiple items.

Return type:boolean
decrementItem(string $key, int $value)

Decrement an item.

Return type:integer|boolean
decrementItems(array $keyValuePairs)

Decrement multiple items.

Return type:boolean
getCapabilities()

Capabilities of this storage.

Return type:Zend\Cache\Storage\Capabilities

The AvailableSpaceCapableInterface

The Zend\Cache\Storage\AvailableSpaceCapableInterface implements a method to make it possible getting the current available space of the storage.

getAvailableSpace()

Get available space in bytes.

Return type:integer|float

The TotalSpaceCapableInterface

The Zend\Cache\Storage\TotalSpaceCapableInterface implements a method to make it possible getting the total space of the storage.

getTotalSpace()

Get total space in bytes.

Return type:integer|float

The ClearByNamespaceInterface

The Zend\Cache\Storage\ClearByNamespaceInterface implements a method to clear all items of a given namespace.

clearByNamespace(string $namespace)

Remove items of given namespace.

Return type:boolean

The ClearByPrefixInterface

The Zend\Cache\Storage\ClearByPrefixInterface implements a method to clear all items of a given prefix (within the current configured namespace).

clearByPrefix(string $prefix)

Remove items matching given prefix.

Return type:boolean

The ClearExpiredInterface

The Zend\Cache\Storage\ClearExpiredInterface implements a method to clear all expired items (within the current configured namespace).

clearExpired()

Remove expired items.

Return type:boolean

The FlushableInterface

The Zend\Cache\Storage\FlushableInterface implements a method to flush the complete storage.

flush()

Flush the whole storage.

Return type:boolean

The IterableInterface

The Zend\Cache\Storage\IterableInterface implements a method to get an iterator to iterate over items of the storage. It extends IteratorAggregate so it’s possible to directly iterate over the storage using foreach.

getIterator()

Get an Iterator.

Return type:Zend\Cache\Storage\IteratorInterface

The OptimizableInterface

The Zend\Cache\Storage\OptimizableInterface implements a method to run optimization processes on the storage.

optimize()

Optimize the storage.

Return type:boolean

The TaggableInterface

The Zend\Cache\Storage\TaggableInterface implements methods to mark items with one or more tags and to clean items matching tags.

setTags(string $key, string[] $tags)

Set tags to an item by given key. (An empty array will remove all tags)

Return type:boolean
getTags(string $key)

Get tags of an item by given key.

Return type:string[]|false
clearByTags(string[] $tags, boolean $disjunction = false)

Remove items matching given tags.

If $disjunction is true only one of the given tags must match else all given tags must match.

Return type:boolean

The Apc Adapter

The Zend\Cache\Storage\Adapter\Apc adapter stores cache items in shared memory through the required PHP extension APC (Alternative PHP Cache).

This adapter implements the following interfaces:

  • Zend\Cache\Storage\StorageInterface
  • Zend\Cache\Storage\AvailableSpaceCapableInterface
  • Zend\Cache\Storage\ClearByNamespaceInterface
  • Zend\Cache\Storage\ClearByPrefixInterface
  • Zend\Cache\Storage\FlushableInterface
  • Zend\Cache\Storage\IterableInterface
  • Zend\Cache\Storage\TotalSpaceCapableInterface
Capabilities
Capability Value
supportedDatatypes null, boolean, integer, double, string, array (serialized), object (serialized)
supportedMetadata internal_key, atime, ctime, mtime, rtime, size, hits, ttl
minTtl 1
maxTtl 0
staticTtl true
ttlPrecision 1
useRequestTime <ini value of apc.use_request_time>
expiredRead false
maxKeyLength 5182
namespaceIsPrefix true
namespaceSeparator <Option value of namespace_separator>

Adapter specific options
Name Data Type Default Value Description
namespace_separator string ”:” A separator for the namespace and prefix

The Dba Adapter

The Zend\Cache\Storage\Adapter\Dba adapter stores cache items into dbm like databases using the required PHP extension dba.

This adapter implements the following interfaces:

  • Zend\Cache\Storage\StorageInterface
  • Zend\Cache\Storage\AvailableSpaceCapableInterface
  • Zend\Cache\Storage\ClearByNamespaceInterface
  • Zend\Cache\Storage\ClearByPrefixInterface
  • Zend\Cache\Storage\FlushableInterface
  • Zend\Cache\Storage\IterableInterface
  • Zend\Cache\Storage\OptimizableInterface
  • Zend\Cache\Storage\TotalSpaceCapableInterface
Capabilities
Capability Value
supportedDatatypes string, null => string, boolean => string, integer => string, double => string
supportedMetadata <none>
minTtl 0
maxKeyLength 0
namespaceIsPrefix true
namespaceSeparator <Option value of namespace_separator>

Adapter specific options
Name Data Type Default Value Description
namespace_separator string ”:” A separator for the namespace and prefix
pathname string “” Pathname to the database file
mode string “c” The mode to open the database Please read dba_open for more information
handler string “flatfile” The name of the handler which shall be used for accessing the database.

Note

This adapter doesn’t support automatically expire items

Because of this adapter doesn’t support automatically expire items it’s very important to clean outdated items by self.

The Filesystem Adapter

The Zend\Cache\Storage\Adapter\Filesystem adapter stores cache items into the filesystem.

This adapter implements the following interfaces:

  • Zend\Cache\Storage\StorageInterface
  • Zend\Cache\Storage\AvailableSpaceCapableInterface
  • Zend\Cache\Storage\ClearByNamespaceInterface
  • Zend\Cache\Storage\ClearByPrefixInterface
  • Zend\Cache\Storage\ClearExpiredInterface
  • Zend\Cache\Storage\FlushableInterface
  • Zend\Cache\Storage\IterableInterface
  • Zend\Cache\Storage\OptimizableInterface
  • Zend\Cache\Storage\TaggableInterface
  • Zend\Cache\Storage\TotalSpaceCapableInterface
Capabilities
Capability Value
supportedDatatypes string, null => string, boolean => string, integer => string, double => string
supportedMetadata mtime, filespec, atime, ctime
minTtl 1
maxTtl 0
staticTtl false
ttlPrecision 1
useRequestTime false
expiredRead true
maxKeyLength 251
namespaceIsPrefix true
namespaceSeparator <Option value of namespace_separator>

Adapter specific options
Name Data Type Default Value Description
namespace_separator string ”:” A separator for the namespace and prefix
cache_dir string “” Directory to store cache files
clear_stat_cache boolean true Call clearstatcache() enabled?
dir_level integer 1 Defines how much sub-directories should be created
dir_permission integer false 0700 Set explicit permission on creating new directories
file_locking boolean true Lock files on writing
file_permission integer false 0600 Set explicit permission on creating new files
key_pattern string /^[a-z0-9_\+\-]*$/Di Validate key against pattern
no_atime boolean true Don’t get ‘fileatime’ as ‘atime’ on metadata
no_ctime boolean true Don’t get ‘filectime’ as ‘ctime’ on metadata
umask integer false false Use umask to set file and directory permissions

The Memcached Adapter

The Zend\Cache\Storage\Adapter\Memcached adapter stores cache items over the memcached protocol. It’s using the required PHP extension memcached which is based on Libmemcached.

This adapter implements the following interfaces:

  • Zend\Cache\Storage\StorageInterface
  • Zend\Cache\Storage\AvailableSpaceCapableInterface
  • Zend\Cache\Storage\FlushableInterface
  • Zend\Cache\Storage\TotalSpaceCapableInterface
Capabilities
Capability Value
supportedDatatypes null, boolean, integer, double, string, array (serialized), object (serialized)
supportedMetadata <none>
minTtl 1
maxTtl 0
staticTtl true
ttlPrecision 1
useRequestTime false
expiredRead false
maxKeyLength 255
namespaceIsPrefix true
namespaceSeparator <none>

Adapter specific options
Name Data Type Default Value Description
servers array [] List of servers in [] = array(string host, integer port)
lib_options array []

Associative array of Libmemcached options were the array key is the option name (without the prefix “OPT_”) or the constant value. The array value is the option value

Please read this<http://php.net/manual/memcached.setoption.php> for more information

The Memory Adapter

The Zend\Cache\Storage\Adapter\Memory adapter stores cache items into the PHP process using an array.

This adapter implements the following interfaces:

  • Zend\Cache\Storage\StorageInterface
  • Zend\Cache\Storage\AvailableSpaceCapableInterface
  • Zend\Cache\Storage\ClearByPrefixInterface
  • Zend\Cache\Storage\ClearExpiredInterface
  • Zend\Cache\Storage\FlushableInterface
  • Zend\Cache\Storage\IterableInterface
  • Zend\Cache\Storage\TaggableInterface
  • Zend\Cache\Storage\TotalSpaceCapableInterface
Capabilities
Capability Value
supportedDatatypes string, null, boolean, integer, double, array, object, resource
supportedMetadata mtime
minTtl 1
maxTtl <Value of PHP_INT_MAX>
staticTtl false
ttlPrecision 0.05
useRequestTime false
expiredRead true
maxKeyLength 0
namespaceIsPrefix false

Adapter specific options
Name Data Type Default Value Description
memory_limit string integer <50% of ini value memory_limit>

Limit of how much memory can PHP allocate to allow store items into this adapter

  • If the used memory of PHP exceeds this limit an OutOfSpaceException will be thrown.
  • A number less or equal 0 will disable the memory limit
  • When a number is used, the value is measured in bytes (Shorthand notation may also be used)

Note

All stored items will be lost after terminating the script.

The WinCache Adapter

The Zend\Cache\Storage\Adapter\WinCache adapter stores cache items into shared memory through the required PHP extension WinCache.

This adapter implements the following interfaces:

  • Zend\Cache\Storage\StorageInterface
  • Zend\Cache\Storage\AvailableSpaceCapableInterface
  • Zend\Cache\Storage\FlushableInterface
  • Zend\Cache\Storage\TotalSpaceCapableInterface
Capabilities
Capability Value
supportedDatatypes null, boolean, integer, double, string, array (serialized), object (serialized)
supportedMetadata internal_key, ttl, hits, size
minTtl 1
maxTtl 0
staticTtl true
ttlPrecision 1
useRequestTime <ini value of apc.use_request_time>
expiredRead false
namespaceIsPrefix true
namespaceSeparator <Option value of namespace_separator>

Adapter specific options
Name Data Type Default Value Description
namespace_separator string ”:” A separator for the namespace and prefix

The XCache Adapter

The Zend\Cache\Storage\Adapter\XCache adapter stores cache items into shared memory through the required PHP extension XCache.

This adapter implements the following interfaces:

  • Zend\Cache\Storage\StorageInterface
  • Zend\Cache\Storage\AvailableSpaceCapableInterface
  • Zend\Cache\Storage\ClearByNamespaceInterface
  • Zend\Cache\Storage\ClearByPrefixInterface
  • Zend\Cache\Storage\FlushableInterface
  • Zend\Cache\Storage\IterableInterface
  • Zend\Cache\Storage\TotalSpaceCapableInterface
Capabilities
Capability Value
supportedDatatypes boolean, integer, double, string, array (serialized), object (serialized)
supportedMetadata internal_key, size, refcount, hits, ctime, atime, hvalue
minTtl 1
maxTtl <ini value of xcache.var_maxttl>
staticTtl true
ttlPrecision 1
useRequestTime true
expiredRead false
maxKeyLength 5182
namespaceIsPrefix true
namespaceSeparator <Option value of namespace_separator>

Adapter specific options
Name Data Type Default Value Description
namespace_separator string ”:” A separator for the namespace and prefix
admin_auth boolean false

Enable admin authentication by configuration options admin_user and admin_pass

This makes XCache administration functions accessible if xcache.admin.enable_auth is enabled without the need of HTTP-Authentication.

admin_user string “” The username of xcache.admin.user
admin_pass string “” The password of xcache.admin.pass in plain text

The ZendServerDisk Adapter

This Zend\Cache\Storage\Adapter\ZendServerDisk adapter stores cache items on filesystem through the Zend Server Data Caching API.

This adapter implements the following interfaces:

  • Zend\Cache\Storage\StorageInterface
  • Zend\Cache\Storage\AvailableSpaceCapableInterface
  • Zend\Cache\Storage\ClearByNamespaceInterface
  • Zend\Cache\Storage\FlushableInterface
  • Zend\Cache\Storage\TotalSpaceCapableInterface
Capabilities
Capability Value
supportedDatatypes null, boolean, integer, double, string, array (serialized), object (serialized)
supportedMetadata <none>
minTtl 1
maxTtl 0
maxKeyLength 0
staticTtl true
ttlPrecision 1
useRequestTime false
expiredRead false
namespaceIsPrefix true
namespaceSeparator ::

The ZendServerShm Adapter

The Zend\Cache\Storage\Adapter\ZendServerShm adapter stores cache items in shared memory through the Zend Server Data Caching API.

This adapter implements the following interfaces:

  • Zend\Cache\Storage\StorageInterface
  • Zend\Cache\Storage\ClearByNamespaceInterface
  • Zend\Cache\Storage\FlushableInterface
  • Zend\Cache\Storage\TotalSpaceCapableInterface
Capabilities
Capability Value
supportedDatatypes null, boolean, integer, double, string, array (serialized), object (serialized)
supportedMetadata <none>
minTtl 1
maxTtl 0
maxKeyLength 0
staticTtl true
ttlPrecision 1
useRequestTime false
expiredRead false
namespaceIsPrefix true
namespaceSeparator ::

Examples

Basic usage

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$cache   = \Zend\Cache\StorageFactory::factory(array(
    'adapter' => array(
        'name' => 'filesystem'
    ),
    'plugins' => array(
        // Don't throw exceptions on cache errors
        'exception_handler' => array(
            'throw_exceptions' => false
        ),
    )
));
$key    = 'unique-cache-key';
$result = $cache->getItem($key, $success);
if (!$success) {
    $result = doExpansiveStuff();
    $cache->setItem($key, $result);
}

Get multiple rows from db

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// Instantiate the cache instance using a namespace for the same type of items
$cache   = \Zend\Cache\StorageFactory::factory(array(
    'adapter' => array(
        'name'    => 'filesystem'
        // With a namespace we can indicate the same type of items
        // -> So we can simple use the db id as cache key
        'options' => array(
            'namespace' => 'dbtable'
        ),
    ),
    'plugins' => array(
        // Don't throw exceptions on cache errors
        'exception_handler' => array(
            'throw_exceptions' => false
        ),
        // We store database rows on filesystem so we need to serialize them
        'Serializer'
    )
));

// Load two rows from cache if possible
$ids     = array(1, 2);
$results = $cache->getItems($ids);
if (count($results) < count($ids)) {
    // Load rows from db if loading from cache failed
    $missingIds     = array_diff($ids, array_keys($results));
    $missingResults = array();
    $query          = 'SELECT * FROM dbtable WHERE id IN (' . implode(',', $missingIds) . ')';
    foreach ($pdo->query($query, PDO::FETCH_ASSOC) as $row) {
        $missingResults[ $row['id'] ] = $row;
    }

    // Update cache items of the loaded rows from db
    $cache->setItems($missingResults);

    // merge results from cache and db
    $results = array_merge($results, $missingResults);
}
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