#include "beacon_critical_images_finder.h"

Inheritance diagram for net_instaweb::BeaconCriticalImagesFinder:

Public Member Functions
	BeaconCriticalImagesFinder (const PropertyCache::Cohort cohort, NonceGenerator nonce_generator, Statistics *stats)
	All constructor args are owned by the caller.

virtual Availability	Available (RewriteDriver *driver)

virtual int	PercentSeenForCritical () const

virtual int	SupportInterval () const

virtual void	ComputeCriticalImages (RewriteDriver *driver)
	Compute the critical images for the driver's url.

virtual bool	ShouldBeacon (RewriteDriver *driver)

virtual BeaconMetadata	PrepareForBeaconInsertion (RewriteDriver *driver)

virtual void	UpdateCandidateImagesForBeaconing (const StringSet &images, RewriteDriver *driver, bool beaconing)

Public Member Functions inherited from net_instaweb::CriticalImagesFinder
	CriticalImagesFinder (const PropertyCache::Cohort cohort, Statistics stats)

bool	IsHtmlCriticalImage (StringPiece image_url, RewriteDriver *driver)

bool	IsCssCriticalImage (StringPiece image_url, RewriteDriver *driver)

bool	GetRenderedImageDimensions (RewriteDriver driver, const GoogleUrl &image_src_gurl, std::pair< int32, int32 > dimensions)

const StringSet &	GetHtmlCriticalImages (RewriteDriver *driver)

const StringSet &	GetCssCriticalImages (RewriteDriver *driver)

StringSet *	mutable_html_critical_images (RewriteDriver *driver)

StringSet *	mutable_css_critical_images (RewriteDriver *driver)

const PropertyCache::Cohort *	cohort () const

bool	UpdateCriticalImagesCacheEntryFromDriver (const StringSet html_critical_images_set, const StringSet css_critical_images_set, RewriteDriver *driver)

virtual bool	IsCriticalImageInfoPresent (RewriteDriver *driver)

virtual RenderedImages *	ExtractRenderedImageDimensionsFromCache (RewriteDriver *driver)
	Extracts rendered images' dimensions from property cache.

void	AddHtmlCriticalImage (const GoogleString &url, RewriteDriver *driver)
	Adds the given url to the html critical image set for the driver.

RenderedImages *	JsonMapToRenderedImagesMap (const GoogleString &str, const RewriteOptions *options)

Static Public Member Functions
static bool	UpdateCriticalImagesCacheEntry (const StringSet html_critical_images_set, const StringSet css_critical_images_set, const RenderedImages rendered_images_set, const StringPiece &nonce, const PropertyCache::Cohort cohort, AbstractPropertyPage page, Timer timer)

Static Public Member Functions inherited from net_instaweb::CriticalImagesFinder
static void	InitStats (Statistics *statistics)

static bool	PopulateCriticalImagesFromPropertyValue (const PropertyValue property_value, CriticalImages critical_images)

static bool	UpdateCriticalImagesCacheEntry (const StringSet html_critical_images_set, const StringSet css_critical_images_set, const RenderedImages rendered_images_set, int support_interval, const PropertyCache::Cohort cohort, AbstractPropertyPage *page)

Additional Inherited Members
Public Types inherited from net_instaweb::CriticalImagesFinder
enum	Availability { kDisabled, kNoDataYet, kAvailable }

Static Public Attributes inherited from net_instaweb::CriticalImagesFinder
static const char	kCriticalImagesValidCount []

static const char	kCriticalImagesExpiredCount []

static const char	kCriticalImagesNotFoundCount []

static const char	kCriticalImagesPropertyName []

static const char	kRenderedImageDimensionsProperty []

Protected Member Functions inherited from net_instaweb::CriticalImagesFinder
virtual void	UpdateCriticalImagesSetInDriver (RewriteDriver *driver)

CriticalImagesInfo *	ExtractCriticalImagesFromCache (RewriteDriver driver, const PropertyValue property_value)

Static Protected Member Functions inherited from net_instaweb::CriticalImagesFinder
static bool	UpdateAndWriteBackCriticalImagesCacheEntry (const StringSet html_critical_images_set, const StringSet css_critical_images_set, const RenderedImages rendered_images_set, int support_interval, const PropertyCache::Cohort cohort, AbstractPropertyPage page, CriticalImages critical_images)

Detailed Description

Support critical (above the fold) image detection through a javascript beacon on the client.

Member Function Documentation

virtual Availability net_instaweb::BeaconCriticalImagesFinder::Available ( RewriteDriver * driver )

virtual

Checks whether IsHtmlCriticalImage will return meaningful results about critical images. Users of IsHtmlCriticalImage should check this function and supply default behaviors when Available != kAvailable.

Reimplemented from net_instaweb::CriticalImagesFinder.

virtual int net_instaweb::BeaconCriticalImagesFinder::PercentSeenForCritical ( ) const

inlinevirtual

In order to handle varying critical image sets returned by the beacon, we store a history of the last N critical images, and only declare an image critical if it appears critical in the last M out of N sets reported. This function returns what percentage of the sets need to include the image for it be considered critical.

Reimplemented from net_instaweb::CriticalImagesFinder.

virtual BeaconMetadata net_instaweb::BeaconCriticalImagesFinder::PrepareForBeaconInsertion ( RewriteDriver * driver )

virtual

Check beacon interval and nonce state, and return appropriate BeaconMetadata; result.status indicates whether beaconing should occur, and result.nonce contains the nonce (if required).

Reimplemented from net_instaweb::CriticalImagesFinder.

virtual bool net_instaweb::BeaconCriticalImagesFinder::ShouldBeacon ( RewriteDriver * driver )

virtual

Returns true if it's time to inject a beacon onto the page. The default finder doesn't use beaconing, so it always returns false.

Reimplemented from net_instaweb::CriticalImagesFinder.

virtual int net_instaweb::BeaconCriticalImagesFinder::SupportInterval ( ) const

inlinevirtual

Minimum interval to store support for critical image results. This affects how long we keep around evidence that an image might be critical; we'll remember the fact for at least SupportInterval beacon insertions if it only occurs once, and we'll remember it longer if multiple beacons support image criticality. By default, SupportInteval() = 1 and we only store one beacon result. The beacon critical image finder should override this to store a larger number of sets.

Reimplemented from net_instaweb::CriticalImagesFinder.

virtual void net_instaweb::BeaconCriticalImagesFinder::UpdateCandidateImagesForBeaconing	(	const StringSet &	images,
		RewriteDriver *	driver,
		bool	beaconing
	)

virtual

For implementations that use beaconing, update the candidate images in the property cache. New images are a signal that we should beacon more often for a few requests. The beaconing argument should indicate if the current request is injecting a beacon. If so, we don't need to trigger a beacon on the next request even if the candidate images have changed.

Reimplemented from net_instaweb::CriticalImagesFinder.

static bool net_instaweb::BeaconCriticalImagesFinder::UpdateCriticalImagesCacheEntry	(	const StringSet *	html_critical_images_set,
		const StringSet *	css_critical_images_set,
		const RenderedImages *	rendered_images_set,
		const StringPiece &	nonce,
		const PropertyCache::Cohort *	cohort,
		AbstractPropertyPage *	page,
		Timer *	timer
	)

static

Update the critical image entry in the property cache. This is meant to be called in the beacon handler, where there is no RewriteDriver available.

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

net/instaweb/rewriter/public/beacon_critical_images_finder.h

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation