Inheritance diagram for net_instaweb::CombiningFilter::Context:

Public Member Functions
	Context (RewriteDriver driver, CombiningFilter filter, MockScheduler *scheduler)

void	AddElement (HtmlElement element, HtmlElement::Attribute href, const ResourcePtr &resource)

Public Member Functions inherited from net_instaweb::RewriteContext
	RewriteContext (RewriteDriver driver, RewriteContext parent, ResourceContext *resource_context)

int	num_slots () const

ResourceSlotPtr	slot (int index) const

int	num_outputs () const

OutputResourcePtr	output (int i) const

int	num_output_partitions () const

const CachedResult *	output_partition (int i) const

CachedResult *	mutable_output_partition (int i)

bool	chained () const

void	AddSlot (const ResourceSlotPtr &slot)

void	RemoveLastSlot ()

void	AddNestedContext (RewriteContext *context)

void	CallFetchInputs ()

void	CallLockFailed ()

void	CallStartFetchImpl ()

void	Initiate ()

bool	Fetch (const OutputResourcePtr &output_resource, AsyncFetch fetch, MessageHandler message_handler)

bool	slow () const

bool	is_metadata_cache_miss () const
	This particular rewrite was a metadata cache miss.

bool	has_parent () const
	Returns true if this is a nested rewriter.

bool	IsNestedIn (StringPiece id) const

void	CheckNotFrozen ()

RewriteContext *	parent ()
	Allows a nested rewriter to walk up its parent hierarchy.

const RewriteContext *	parent () const

int	num_nested () const
	Accessors for the nested rewrites.

RewriteContext *	nested (int i) const

RewriteDriver *	Driver () const

void	set_force_rewrite (bool x)
	If called with true, forces a rewrite and re-generates the output.

bool	rewrite_uncacheable () const

void	set_rewrite_uncacheable (bool rewrite_uncacheable)

const ResourceContext *	resource_context () const

GoogleString	ToString () const
	Returns debug information about this RewriteContext.

GoogleString	ToStringWithPrefix (StringPiece prefix) const

Protected Member Functions
virtual bool	Partition (OutputPartitions partitions, OutputResourceVector outputs)

virtual void	Rewrite (int partition_index, CachedResult *partition, const OutputResourcePtr &output)

virtual bool	OptimizationOnly () const

void	DoRewrite (int partition_index, CachedResult *partition, OutputResourcePtr output)

bool	PolicyPermitsRendering () const override

virtual void	Render ()

virtual void	WillNotRender ()

virtual void	Cancel ()

void	DisableRemovedSlots (const CachedResult *partition)

virtual const UrlSegmentEncoder *	encoder () const

virtual const char *	id () const
	Returns the filter ID.

virtual OutputResourceKind	kind () const

Protected Member Functions inherited from net_instaweb::RewriteContext
ServerContext *	FindServerContext () const

const RewriteOptions *	Options () const

OutputPartitions *	partitions ()

void	AddRecheckDependency ()

virtual void	PartitionAsync (OutputPartitions partitions, OutputResourceVector outputs)

void	PartitionDone (RewriteResult result)

void	CrossThreadPartitionDone (RewriteResult result)

void	RewriteDone (RewriteResult result, int partition_index)

virtual bool	SendFallbackResponse (StringPiece output_url_base, StringPiece contents, AsyncFetch async_fetch, MessageHandler handler)

void	StartNestedTasks ()

virtual void	Harvest ()

bool	AreOutputsAllowedByCsp (CspDirective role) const
	Helper that checks that all output resources are OK with CSP as given role.

virtual GoogleString	CacheKeySuffix () const

virtual GoogleString	UserAgentCacheKey (const ResourceContext *context) const

virtual void	EncodeUserAgentIntoResourceContext (ResourceContext *context)

void	AttachDependentRequestTrace (const StringPiece &label)

RequestTrace *	dependent_request_trace ()

void	TracePrintf (const char *fmt,...)

virtual void	StartFetchReconstruction ()

void	DetachFetch ()

virtual bool	DecodeFetchUrls (const OutputResourcePtr &output_resource, MessageHandler message_handler, GoogleUrlStarVector url_vector)

virtual void	FixFetchFallbackHeaders (const CachedResult &cached_result, ResponseHeaders *headers)

virtual void	FetchCallbackDone (bool success)

virtual void	FetchTryFallback (const GoogleString &url, const StringPiece &hash)

void	Freshen ()
	Freshens resources proactively to avoid expiration in the near future.

bool	notify_driver_on_fetch_done () const

void	set_notify_driver_on_fetch_done (bool value)

AsyncFetch *	async_fetch ()
	Note that the following must only be called in the fetch flow.

bool	FetchContextDetached ()
	Is fetch_ detached? Only call this in the fetch flow.

MessageHandler *	fetch_message_handler ()
	The message handler for the fetch.

bool	stale_rewrite () const
	Indicates whether we are serving a stale rewrite.

virtual int64	GetRewriteDeadlineAlarmMs () const

virtual bool	CreationLockBeforeStartFetch () const
	Should the context call LockForCreation before checking the cache?

virtual bool	FailOnHashMismatch () const

virtual bool	ScheduleViaCentralController ()

virtual bool	ScheduleNestedContextViaCentalController () const

void	ObtainLockForCreation (ServerContext server_context, Function callback)

void	ReleaseCreationLock (bool succeeded)

Additional Inherited Members
Public Types inherited from net_instaweb::RewriteContext
typedef std::vector< InputInfo * >	InputInfoStarVector

Static Public Member Functions inherited from net_instaweb::RewriteContext
static void	InitStats (Statistics *stats)
	Initializes statistics.

Static Public Attributes inherited from net_instaweb::RewriteContext
static const char	kNumRewritesAbandonedForLockContention []

static const char	kNumDeadlineAlarmInvocations []

static const char	kHashMismatchMessage []

Protected Types inherited from net_instaweb::RewriteContext
typedef std::vector< GoogleUrl * >	GoogleUrlStarVector

Static Protected Member Functions inherited from net_instaweb::RewriteContext
static bool	LookupMetadataForOutputResourceImpl (OutputResourcePtr output_resource, const GoogleUrl &gurl, RewriteContext rewrite_context, RewriteDriver driver, GoogleString error_out, CacheLookupResultCallback callback)

Member Function Documentation

virtual void net_instaweb::CombiningFilter::Context::Cancel ( )

protectedvirtual

This method is invoked (in Rewrite thread) if this context got canceled due to an earlier filter sharing a slot with it having called set_disable_further_processing. Default implementation does nothing.

Reimplemented from net_instaweb::RewriteContext.

virtual const UrlSegmentEncoder* net_instaweb::CombiningFilter::Context::encoder ( ) const

inlineprotectedvirtual

This final set of protected methods can be optionally overridden by subclasses. All RewriteContexts define how they encode URLs and other associated information needed for a rewrite into a URL. The default implementation handles a single URL with no extra data. The RewriteContext owns the encoder.

Todo:: TODO(jmarantz): remove the encoder from RewriteFilter.

Reimplemented from net_instaweb::RewriteContext.

virtual OutputResourceKind net_instaweb::CombiningFilter::Context::kind ( ) const

inlineprotectedvirtual

Rewrites come in three flavors, as described in output_resource_kind.h, so this method must be defined by subclasses to indicate which it is.

For example, we will avoid caching output_resource content in the HTTP cache for rewrites that are so quick to complete that it's fine to do the rewrite on every request. extend_cache is obviously in this category, and it's arguable we could treat js minification that way too (though we don't at the moment).

Implements net_instaweb::RewriteContext.

virtual bool net_instaweb::CombiningFilter::Context::OptimizationOnly ( ) const

inlineprotectedvirtual

If this returns true, running the rewriter isn't required for correctness of the page, so the engine will be permitted to drop the rewrite if needed to preserve system responsiveness.

Reimplemented from net_instaweb::RewriteContext.

virtual bool net_instaweb::CombiningFilter::Context::Partition	(	OutputPartitions *	partitions,
		OutputResourceVector *	outputs
	)

protectedvirtual

Partitions the input resources into one or more outputs. Return 'true' if the partitioning could complete (whether a rewrite was found or not), false if the attempt was abandoned and no conclusion can be drawn.

Note that if partitioner finds that the resources are not rewritable, it will still return true; it will simply have an empty inputs-array in OutputPartitions and leave 'outputs' unmodified. 'false' is only returned if the subclass skipped the rewrite attempt due to a lock conflict.

You must override one of Partition() or PartitionAsync(). Partition() is normally fine unless you need to do computations that can take a noticeable amount of time, since there are some scenarios under which page output may end up being held up for a partitioning step. If you do need to do something computationally expensive in partitioning steps, override PartitionAsync() instead.

Reimplemented from net_instaweb::RewriteContext.

bool net_instaweb::CombiningFilter::Context::PolicyPermitsRendering ( ) const

inlineoverrideprotectedvirtual

This method gives the context a chance to verify that rendering the result is consistent with the current document's (Content Security) Policy, which may be different than that of the page for which the result was first computed + cached. Most subclasses can just call AreOutputsAllowedByCsp(), with appropriate role.

Implements net_instaweb::RewriteContext.

virtual void net_instaweb::CombiningFilter::Context::Render ( )

protectedvirtual

Performs rendering activities that span multiple HTML slots. For example, in a filter that combines N slots to 1, N-1 of the HTML elements might need to be removed. That can be performed in Render(). This method is optional; the base-class implementation is empty.

Note that unlike Harvest(), this method runs in the HTML thread (for top-level rewrites), and only runs if the rewrite completes prior to the rewrite-deadline. If the rewrite does make it by the deadline, RewriteContext::Render() will be invoked regardless of whether any slots were actually optimized successfully.

Reimplemented from net_instaweb::RewriteContext.

virtual void net_instaweb::CombiningFilter::Context::Rewrite	(	int	partition_index,
		CachedResult *	partition,
		const OutputResourcePtr &	output
	)

protectedvirtual

Takes a completed rewrite partition and rewrites it. When complete, implementations should call RewriteDone(kRewriteOk) if they successfully created an output resource using RewriteDriver::Write, and RewriteDone(kRewriteFailed) if they didn't. They may also call RewriteDone(kTooBusy) in case system load/resource usage makes it dangerous for the filter to do optimization at this time.

Any information about the inputs or output that may be needed to update the containing document should be stored inside the CachedResult.

If implementors wish to rewrite resources referred to from within the inputs (e.g. images in CSS), they may create nested rewrite contexts and call AddNestedContext() on each, and then StartNestedTasks() when all have been added.

Todo:: TODO(jmarantz): check for resource completion from a different thread (while we were waiting for resource fetches) when Rewrite gets called.

Implements net_instaweb::RewriteContext.

virtual void net_instaweb::CombiningFilter::Context::WillNotRender ( )

protectedvirtual

Notifies the subclass that the filter will not be able to render its output to the containing HTML document, because it wasn't ready in time. Note that neither Render() nor WillNotRender() may be called in case this rewrite got canceled due to disable_further_processing(), or in case Partition() failed. This is called from the HTML thread, but should only be used for read access, and subclasss implementations are required to be reasonably quick since it's called with rewrite_mutex() held. It's called after any earlier contexts in filter order had completed their rendering, if any, but with no order guarantees with respect to other WillNotRender() invocations.

Reimplemented from net_instaweb::RewriteContext.

The documentation for this class was generated from the following file:

net/instaweb/rewriter/public/rewrite_context_test_base.h

Public Member Functions

Protected Member Functions

Additional Inherited Members

Member Function Documentation