#include "critical_css_beacon_filter.h"

Inheritance diagram for net_instaweb::CriticalCssBeaconFilter:

Public Member Functions
	CriticalCssBeaconFilter (RewriteDriver *driver)

virtual const char *	Name () const
	The name of this filter – used for logging and debugging.

virtual const char *	id () const

virtual RewriteDriver::InlineAuthorizationPolicy	AllowUnauthorizedDomain () const

virtual bool	IntendedForInlining () const
	Selectors are inlined into javascript.

ScriptUsage	GetScriptUsage () const override

Public Member Functions inherited from net_instaweb::CssSummarizerBase
	CssSummarizerBase (RewriteDriver *driver)

Public Member Functions inherited from net_instaweb::RewriteFilter
	RewriteFilter (RewriteDriver *driver)

virtual bool	CanModifyUrls ()

virtual const UrlSegmentEncoder *	encoder () const

virtual bool	ComputeOnTheFly () const

virtual RewriteContext *	MakeNestedRewriteContext (RewriteContext *parent, const ResourceSlotPtr &slot)

virtual void	EncodeUserAgentIntoResourceContext (ResourceContext *context) const

virtual const RewriteOptions::Filter *	RelatedFilters (int *num_filters) const

virtual const StringPieceVector *	RelatedOptions () const

Public Member Functions inherited from net_instaweb::CommonFilter
	CommonFilter (RewriteDriver *driver)

const GoogleUrl &	base_url () const
	Getters. More...

const GoogleUrl &	decoded_base_url () const

RewriteDriver *	driver () const

HtmlElement *	noscript_element () const

void	InsertNodeAtBodyEnd (HtmlNode *data)

virtual void	StartDocument ()
	Note: Don't overload these methods, overload the implementers instead!

virtual void	StartElement (HtmlElement *element)

virtual void	EndElement (HtmlElement *element)

ResourcePtr	CreateInputResource (StringPiece input_url, RewriteDriver::InputRole role, bool *is_authorized)

ResourcePtr	CreateInputResourceOrInsertDebugComment (StringPiece input_url, RewriteDriver::InputRole role, HtmlElement *element)

void	ResolveUrl (StringPiece input_url, GoogleUrl *out_url)

bool	IsRelativeUrlLoadPermittedByCsp (StringPiece url, CspDirective role)

bool	BaseUrlIsValid () const

bool	DebugMode () const

bool	CanAddPagespeedOnloadToImage (const HtmlElement &)

virtual void	LogFilterModifiedContent ()

void	AddJsToElement (StringPiece js, HtmlElement *script)

Public Member Functions inherited from net_instaweb::EmptyHtmlFilter
virtual void	Cdata (HtmlCdataNode *cdata)
	Called for CDATA blocks (e.g. <![CDATA[foobar]]>)

virtual void	Comment (HtmlCommentNode *comment)
	Called for HTML comments that aren't IE directives (e.g. ).

virtual void	IEDirective (HtmlIEDirectiveNode *directive)

virtual void	Directive (HtmlDirectiveNode *directive)
	Called for HTML directives (e.g. <!doctype foobar>).

virtual void	Flush ()

ScriptUsage	GetScriptUsage () const override

Public Member Functions inherited from net_instaweb::HtmlFilter
bool	is_enabled () const

void	set_is_enabled (bool is_enabled)

Static Public Member Functions
static void	InitStats (Statistics *statistics)

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

Static Public Member Functions inherited from net_instaweb::RewriteFilter
static StringPiece	GetCharsetForScript (const Resource *script, const StringPiece attribute_charset, const StringPiece enclosing_charset)

static GoogleString	GetCharsetForStylesheet (const Resource *stylesheet, const StringPiece attribute_charset, const StringPiece enclosing_charset)

Static Public Member Functions inherited from net_instaweb::CommonFilter
static bool	ExtractMetaTagDetails (const HtmlElement &element, const ResponseHeaders headers, GoogleString content, GoogleString mime_type, GoogleString charset)

Static Public Attributes
static const char	kInitializePageSpeedJs []

static const char	kCriticalCssBeaconAddedCount []
	Statistics:

static const char	kCriticalCssNoBeaconDueToMissingData []

static const char	kCriticalCssSkippedDueToCharset []

Static Public Attributes inherited from net_instaweb::CssSummarizerBase
static const char	kNumCssUsedForCriticalCssComputation []

static const char	kNumCssNotUsedForCriticalCssComputation []

Static Public Attributes inherited from net_instaweb::CommonFilter
static const char	kCreateResourceFailedDebugMsg []
	Debug message to be inserted when resource creation fails.

Protected Member Functions
virtual bool	MustSummarize (HtmlElement *element) const

virtual void	Summarize (Css::Stylesheet stylesheet, GoogleString out) const

virtual void	SummariesDone ()

virtual void	DetermineEnabled (GoogleString *disabled_reason)

Protected Member Functions inherited from net_instaweb::CssSummarizerBase
virtual GoogleString	CacheKeySuffix () const

virtual void	RenderSummary (int pos, HtmlElement element, HtmlCharactersNode char_node, bool *is_element_deleted)

virtual void	WillNotRenderSummary (int pos, HtmlElement element, HtmlCharactersNode char_node)

int	NumStyles () const

const SummaryInfo &	GetSummaryForStyle (int pos) const

virtual void	StartDocumentImpl ()

virtual void	EndDocument ()

virtual void	StartElementImpl (HtmlElement *element)

virtual void	Characters (HtmlCharactersNode *characters)

virtual void	EndElementImpl (HtmlElement *element)

virtual void	RenderDone ()

virtual RewriteContext *	MakeRewriteContext ()

Protected Member Functions inherited from net_instaweb::RewriteFilter
virtual const char *	LoggingId ()
	This class logs using id().

Protected Member Functions inherited from net_instaweb::CommonFilter
ServerContext *	server_context () const

const RewriteOptions *	rewrite_options ()

Additional Inherited Members
Public Types inherited from net_instaweb::HtmlFilter
enum	ScriptUsage { kWillInjectScripts, kMayInjectScripts, kNeverInjectsScripts }
	Describes a filter's relationship with scripts. More...

Protected Types inherited from net_instaweb::CssSummarizerBase
enum	SummaryState { kSummaryOk, kSummaryStillPending, kSummaryCssParseError, kSummaryResourceCreationFailed, kSummaryInputUnavailable, kSummarySlotRemoved }

Detailed Description

Figure out the set of CSS selectors referenced from a page, saving those selectors in an OutputResource for each CSS <style> or <link> on the page. Based on that set of candidate critical selectors, inject javascript for detecting critical above the fold css selectors after the page has loaded. Assumes CSS have been flattened first.

Member Function Documentation

virtual RewriteDriver::InlineAuthorizationPolicy net_instaweb::CriticalCssBeaconFilter::AllowUnauthorizedDomain ( ) const

inlinevirtual

This filter needs access to all critical selectors (even those from unauthorized domains) in order to let the clients use them while detecting critical selectors that can be subsequently beaconed back to the server and eventually inlined into the HTML.

Reimplemented from net_instaweb::CommonFilter.

virtual void net_instaweb::CriticalCssBeaconFilter::DetermineEnabled ( GoogleString * disabled_reason )

protectedvirtual

Override DetermineEnabled so that filters that use the DOM cohort of the property cache can enable writing of it in the RewriterDriver. Filters inheriting from RewriteDriver that use the DOM cohort should override UsePropertyCacheDomCohort to return true.

Reimplemented from net_instaweb::RewriteFilter.

ScriptUsage net_instaweb::CriticalCssBeaconFilter::GetScriptUsage ( ) const

inlineoverridevirtual

Note: there is also kRequiresScriptExecutionFilterSet in rewrite_options.cc, which identifies filters that will leave broken pages if javascript is disabled, and hence require noscript handing. The set of filters that CanInjectScripts is larger, as it includes filters that might inject beacons or other optional functionality that is not page-critical.

Implements net_instaweb::HtmlFilter.

virtual bool net_instaweb::CriticalCssBeaconFilter::MustSummarize ( HtmlElement * element ) const

protectedvirtual

This method should be overridden if some CSS should not go through the summarization process (eg because it uses an inapplicable media type and we'll just throw it away when we're done anyway). By default all CSS must be summarized.

Reimplemented from net_instaweb::CssSummarizerBase.

virtual void net_instaweb::CriticalCssBeaconFilter::SummariesDone ( )

protectedvirtual

This is called at the end of the document when all outstanding summary computations have completed, regardless of whether successful or not. It will not be called at all if they are still ongoing, however.

It's called from a context which allows HTML parser state access. You can insert things at end of document by constructing an HtmlNode* using the factories in HtmlParse and calling CommonFilter::InsertNodeAtBodyEnd(node).

Note that the timing of this can vary widely — it can occur during initial parse, during the render phase, or even at RenderDone, so implementors should not make assumptions about what other filters may have done to the DOM.

Base version does nothing.

Reimplemented from net_instaweb::CssSummarizerBase.

virtual void net_instaweb::CriticalCssBeaconFilter::Summarize	(	Css::Stylesheet *	stylesheet,
		GoogleString *	out
	)		const

protectedvirtual

This should be overridden to compute a per-resource summary. The method should not modify the object state, and only put the result into *out as it may not be invoked in case of a cache hit. The subclass may mutate *stylesheet if it so wishes.

Note: this is called on a rewrite thread, so it should not access HTML parser state.

Implements net_instaweb::CssSummarizerBase.

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

net/instaweb/rewriter/public/critical_css_beacon_filter.h

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation