Backend

Abstract base class for cache backend implementations.

class Backend implements \Hazaar\Cache\Interface\Backend

Implements: Hazaar\Cache\Interface\Backend

Provides shared option/state handling and capability registration used by concrete cache backends (file, shm, sqlite, etc.). The frontend cache adapter queries backend capabilities via Hazaar\Cache\Backend::can to determine behavior such as object serialization strategy and array export support.

Subclasses are responsible for implementing storage operations defined by Hazaar\Cache\Interface\Backend, while this class supplies common defaults for optional behaviors like locking and connection closing.

Properties

options

The backend options.

public array $options

Type: array

weight

Backend preference/priority weight used when selecting among candidates.

protected int $weight = 10

Type: int

namespace

public string $namespace

Type: string

capabilities

The backends list of capabilities.

private array $capabilities

Type: array

Standard capabilities are:

• store_objects - Backend can directly store & return objects. Whether the backend itself really can (like APCu) or the backend class takes care of this.
• compress - Can compress objects being stored. If the backend can do this, then we don't want the frontend to ever do it.
• array - Can return all elements in the cache as an associative array
• expire_ns - Backend supports storage TTLs on the namespace as a whole.
• expire_val - Backend supports storage TTLs on individual values stored within the namespace
• keepalive - When a value is accessed it's TTL can be reset to keep it alive in cache.

Methods

__construct

public __construct(array $options, string $namespace): void

Parameters

Parameter	Type	Description
$options	array
$namespace	string

close

Closes backend resources, if applicable.

public close(): bool

Returns: bool

Default implementation is a no-op.

can

Checks whether a backend capability is supported.

public can(string $key): bool

Returns: bool

Parameters

Parameter	Type	Description
$key	string	capability name

getWeight

Returns backend selection weight.

public getWeight(): int

Returns: int

setOption

Sets or overrides a backend option.

public setOption(string $key, mixed $value): void

Returns: void

Parameters

Parameter	Type	Description
$key	string	option key
$value	mixed	option value

lock

Attempts to acquire a lock for a cache key.

public lock(string $key): bool

Returns: bool

Default implementation indicates unsupported locking.

Parameters

Parameter	Type	Description
$key	string	lock key

unlock

Attempts to release a lock for a cache key.

public unlock(string $key): bool

Returns: bool

Default implementation indicates unsupported locking.

Parameters

Parameter	Type	Description
$key	string	lock key

addCapabilities

Registers one or more backend capabilities.

protected addCapabilities(string $args): void

Returns: void

Parameters

Parameter	Type	Description
$args	string

configure

protected configure(array $options): void

Returns: void

Parameters

Parameter	Type	Description
$options	array

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Generated by Hazaar API Doc Generator on Fri, 04 Sep 2026 23:32:16 +0000