__construct(HttpKernelInterface $kernel, StoreInterface $store, SurrogateInterface $surrogate = null, array $options = array())

Constructor.

The available options are:

• debug: If true, the traces are added as a HTTP header to ease debugging

• default_ttl The number of seconds that a cache entry should be considered fresh when no explicit freshness information is provided in a response. Explicit Cache-Control or Expires headers override this value. (default: 0)

• private_headers Set of request headers that trigger "private" cache-control behavior on responses that don't explicitly state whether the response is public or private via a Cache-Control directive. (default: Authorization and Cookie)

• allow_reload Specifies whether the client can force a cache reload by including a Cache-Control "no-cache" directive in the request. Set it to true for compliance with RFC 2616. (default: false)

• allow_revalidate Specifies whether the client can force a cache revalidate by including a Cache-Control "max-age=0" directive in the request. Set it to true for compliance with RFC 2616. (default: false)

• stale_while_revalidate Specifies the default number of seconds (the granularity is the second as the Response TTL precision is a second) during which the cache can immediately return a stale response while it revalidates it in the background (default: 2). This setting is overridden by the stale-while-revalidate HTTP Cache-Control extension (see RFC 5861).

• stale_if_error Specifies the default number of seconds (the granularity is the second) during which the cache can serve a stale response when an error is encountered (default: 60). This setting is overridden by the stale-if-error HTTP Cache-Control extension (see RFC 5861).

Parameters

HttpKernelInterface	$kernel
StoreInterface	$store
SurrogateInterface	$surrogate
array	$options

StoreInterface getStore()

Gets the current store.

Return Value

StoreInterface

$store A StoreInterface instance

array getTraces()

Returns an array of events that took place during processing of the last request.

Return Value

array

An array of events

string getLog()

Returns a log message for the events of the last request processing.

Return Value

string

A log message

Request getRequest()

Gets the Request instance associated with the master request.

Return Value

Request

A Request instance

HttpKernelInterface getKernel()

Gets the Kernel instance.

Return Value

HttpKernelInterface

An HttpKernelInterface instance

SurrogateInterface getSurrogate()

Gets the Surrogate instance.

Return Value

SurrogateInterface

A Surrogate instance

Exceptions

LogicException

Response handle(Request $request, int $type = HttpKernelInterface::MASTER_REQUEST, bool $catch = true)

Handles a Request to convert it to a Response.

When $catch is true, the implementation must catch all exceptions and do its best to convert them to a Response instance.

Parameters

Request	$request	A Request instance
int	$type	The type of the request (one of HttpKernelInterface::MASTER_REQUEST or HttpKernelInterface::SUB_REQUEST)
bool	$catch	Whether to catch exceptions or not

Return Value

Response

A Response instance

Exceptions

Exception

When an Exception occurs during processing

terminate(Request $request, Response $response)

Terminates a request/response cycle.

Should be called after sending the response and before shutting down the kernel.

Parameters

Request	$request
Response	$response

protected Response pass(Request $request, bool $catch = false)

Forwards the Request to the backend without storing the Response in the cache.

Parameters

Request	$request	A Request instance
bool	$catch	Whether to process exceptions

Return Value

Response

A Response instance

protected Response invalidate(Request $request, bool $catch = false)

Invalidates non-safe methods (like POST, PUT, and DELETE).

Parameters

Request	$request	A Request instance
bool	$catch	Whether to process exceptions

Return Value

Response

A Response instance

Exceptions

Exception

See also

RFC2616

13.10

protected Response lookup(Request $request, bool $catch = false)

Lookups a Response from the cache for the given Request.

When a matching cache entry is found and is fresh, it uses it as the response without forwarding any request to the backend. When a matching cache entry is found but is stale, it attempts to "validate" the entry with the backend using conditional GET. When no matching cache entry is found, it triggers "miss" processing.

Parameters

Request	$request	A Request instance
bool	$catch	Whether to process exceptions

Return Value

Response

A Response instance

Exceptions

Exception

protected Response validate(Request $request, Response $entry, bool $catch = false)

Validates that a cache entry is fresh.

The original request is used as a template for a conditional GET request with the backend.

Parameters

Request	$request	A Request instance
Response	$entry	A Response instance to validate
bool	$catch	Whether to process exceptions

Return Value

Response

A Response instance

protected Response fetch(Request $request, bool $catch = false)

Unconditionally fetches a fresh response from the backend and stores it in the cache if is cacheable.

Parameters

Request	$request	A Request instance
bool	$catch	Whether to process exceptions

Return Value

Response

A Response instance

protected Response forward(Request $request, bool $catch = false, Response $entry = null)

Forwards the Request to the backend and returns the Response.

All backend requests (cache passes, fetches, cache validations) run through this method.

Parameters

Request	$request	A Request instance
bool	$catch	Whether to catch exceptions or not
Response	$entry	A Response instance (the stale entry if present, null otherwise)

Return Value

Response

A Response instance

protected bool isFreshEnough(Request $request, Response $entry)

Checks whether the cache entry is "fresh enough" to satisfy the Request.

Parameters

Request	$request
Response	$entry

Return Value

bool	true if the cache entry if fresh enough, false otherwise

protected bool lock(Request $request, Response $entry)

Locks a Request during the call to the backend.

Parameters

Request	$request
Response	$entry

Return Value

bool	true if the cache entry can be returned even if it is staled, false otherwise

protected store(Request $request, Response $response)

Writes the Response to the cache.

Parameters

Request	$request
Response	$response

Exceptions

Exception

protected processResponseBody(Request $request, Response $response)

Parameters

Request	$request
Response	$response