#include "image_rewrite_filter.h"

Inheritance diagram for net_instaweb::ImageRewriteFilter:

Public Types
typedef std::map< GoogleString, AssociatedImageInfo >	AssociatedImageInfoMap

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

Public Member Functions
	ImageRewriteFilter (RewriteDriver *driver)

virtual void	StartDocumentImpl ()

virtual void	EndDocument ()

virtual void	RenderDone ()

virtual void	StartElementImpl (HtmlElement *element)

virtual void	EndElementImpl (HtmlElement *element)

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

virtual const char *	id () const

virtual void	EncodeUserAgentIntoResourceContext (ResourceContext *context) const

void	RegisterImageInfo (const AssociatedImageInfo &image_info)

InlineResult	TryInline (bool is_html, bool is_critical, int64 image_inline_max_bytes, const CachedResult cached_result, ResourceSlot slot, GoogleString *data_url)

RewriteContext *	MakeNestedRewriteContextForCss (int64 css_image_inline_max_bytes, RewriteContext *parent, const ResourceSlotPtr &slot)

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

bool	UpdateDesiredImageDimsIfNecessary (const ImageDim &image_dim, const ResourceContext &resource_context, ImageDim *desired_dim)

bool	ShouldResize (const ResourceContext &context, const GoogleString &url, Image image, ImageDim desired_dimensions)

bool	ResizeImageIfNecessary (const Context rewrite_context, const GoogleString &url, ResourceContext context, Image image, CachedResult cached)

Image::CompressionOptions *	ImageOptionsForLoadedResource (const ResourceContext &context, const ResourcePtr &input_resource)

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

virtual const StringPieceVector *	RelatedOptions () const

void	ReportDroppedRewrite ()
	Update stats for a rewrite dropped due to load.

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

virtual void	DetermineEnabled (GoogleString *disabled_reason)

virtual bool	CanModifyUrls ()

virtual bool	ComputeOnTheFly () 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)

virtual void	Characters (HtmlCharactersNode *characters)

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 ()

virtual RewriteDriver::InlineAuthorizationPolicy	AllowUnauthorizedDomain () const

virtual bool	IntendedForInlining () const

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 void	Initialize ()

static void	Terminate ()

static void	AddRelatedOptions (StringPieceVector *target)

static bool	ExtractAssociatedImageInfo (const CachedResult in, RewriteContext context, AssociatedImageInfo *out)

static bool	ParseDimensionAttribute (const char position, int value)

static void	DisableRelatedFilters (RewriteOptions *options)
	Disable all filters listed in kRelatedFilters in options.

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	kImageNoRewritesHighResolution []
	Statistic names:

static const char	kImageOngoingRewrites []

static const char	kImageResizedUsingRenderedDimensions []

static const char	kImageRewriteLatencyFailedMs []

static const char	kImageRewriteLatencyOkMs []

static const char	kImageRewriteLatencyTotalMs []

static const char	kImageRewritesDroppedDecodeFailure []

static const char	kImageRewritesDroppedDueToLoad []

static const char	kImageRewritesDroppedMIMETypeUnknown []

static const char	kImageRewritesDroppedNoSavingNoResize []

static const char	kImageRewritesDroppedNoSavingResize []

static const char	kImageRewritesDroppedServerWriteFail []

static const char	kImageRewritesSquashingForMobileScreen []

static const char	kImageRewrites []

static const char	kImageWebpRewrites []

static const char	kImageWebpFromGifFailureMs []

static const char	kImageWebpFromGifSuccessMs []

static const char	kImageWebpFromGifTimeouts []

static const char	kImageWebpFromJpegFailureMs []

static const char	kImageWebpFromJpegSuccessMs []

static const char	kImageWebpFromJpegTimeouts []

static const char	kImageWebpFromPngFailureMs []

static const char	kImageWebpFromPngSuccessMs []

static const char	kImageWebpFromPngTimeouts []

static const char	kImageWebpOpaqueFailureMs []

static const char	kImageWebpOpaqueSuccessMs []

static const char	kImageWebpOpaqueTimeouts []

static const char	kImageWebpWithAlphaFailureMs []

static const char	kImageWebpWithAlphaSuccessMs []

static const char	kImageWebpWithAlphaTimeouts []

static const char	kImageWebpFromGifAnimatedFailureMs []

static const char	kImageWebpFromGifAnimatedSuccessMs []

static const char	kImageWebpFromGifAnimatedTimeouts []

static const char	kInlinableImageUrlsPropertyName []

static const RewriteOptions::Filter	kRelatedFilters []

static const int	kRelatedFiltersSize

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 const UrlSegmentEncoder *	encoder () const

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 ()

Friends
class	Context

Detailed Description

Identify img tags in html and optimize them.

Todo:: TODO(jmaessen): Big open question: how best to link pulled-in resources to rewritten urls, when in general those urls will be in a different domain.

Member Function Documentation

virtual const UrlSegmentEncoder* net_instaweb::ImageRewriteFilter::encoder ( ) const

protectedvirtual

All RewriteFilters 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 filter owns the encoder.

Reimplemented from net_instaweb::RewriteFilter.

virtual void net_instaweb::ImageRewriteFilter::EncodeUserAgentIntoResourceContext ( ResourceContext * context ) const

virtual

Encodes user agent information needed by the filter into ResourceContext. See additional header document for RewriteContext::EncodeUserAgentIntoResourceContext.

Reimplemented from net_instaweb::RewriteFilter.

virtual void net_instaweb::ImageRewriteFilter::EndDocument ( )

virtual

Note: EndDocument will be called immediately before the last Flush call. (which also means that in the RewriteDriver use it is called before rendering for the last flush window).

Reimplemented from net_instaweb::EmptyHtmlFilter.

static bool net_instaweb::ImageRewriteFilter::ExtractAssociatedImageInfo	(	const CachedResult *	in,
		RewriteContext *	context,
		AssociatedImageInfo *	out
	)

static

Tries to extract information stored by the image rewrite filter in *in, and to store it in *out. Returns whether successful.

The context is used to try to find a name for the image if it was not optimized.

Image::CompressionOptions* net_instaweb::ImageRewriteFilter::ImageOptionsForLoadedResource	(	const ResourceContext &	context,
		const ResourcePtr &	input_resource
	)

Allocate and initialize CompressionOptions object based on RewriteOptions and ResourceContext.

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

virtual

Creates a nested rewrite for the given parent and slot and returns it. The result is not registered with the parent.

Reimplemented from net_instaweb::RewriteFilter.

RewriteContext* net_instaweb::ImageRewriteFilter::MakeNestedRewriteContextForCss	(	int64	css_image_inline_max_bytes,
		RewriteContext *	parent,
		const ResourceSlotPtr &	slot
	)

Creates a nested rewrite for an image inside a CSS file with the given parent and slot, and returns it. The result is not registered with the parent.

virtual RewriteContext* net_instaweb::ImageRewriteFilter::MakeRewriteContext ( )

protectedvirtual

Generates a RewriteContext appropriate for this filter. Default implementation returns NULL. This must be overridden by filters. This is used to implement Fetch.

Reimplemented from net_instaweb::RewriteFilter.

static bool net_instaweb::ImageRewriteFilter::ParseDimensionAttribute	(	const char *	position,
		int *	value
	)

static

The valid contents of a dimension attribute on an image element have one of the following forms: "45%" "45%px" "+45.0%" [45% of browser width; we can't handle this] "45", "+45", "45px", "45arbitraryjunk" "45px%" [45 pixels regardless of junk] Technically 0 is an invalid dimension, so we'll reject those as well; note that 0 dimensions occur in the wild and Safari and Chrome at least don't display anything.

We actually reject the arbitraryjunk cases, as older browsers (eg FF9, which isn't that old) don't deal with them at all. So the only trailing stuff we allow is px possibly with some white space. Note that some older browsers (like FF9) accept other units such as "in" or "pt" as synonyms for px!

We round fractions, as fractional pixels appear to be rounded in practice (and our image resize algorithms require integer pixel sizes).

Far more detail in the spec at: http://www.whatwg.org/specs/web-apps/current-work/multipage/ common-microsyntaxes.html#percentages-and-dimensions

void net_instaweb::ImageRewriteFilter::RegisterImageInfo ( const AssociatedImageInfo & image_info )

Registers image information associated with a URL, for use by experiment_collect_mob_image_info. Should be called from DOM-safe context: the parser thread or a Render() method.

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

virtual

Determines which filters are related to this RewriteFilter. Note, for example, that the ImageRewriteFilter class implements lots of different RewriteOptions::Filters.

This is used for embedding the relevant enabled filter IDs. See the doc for RewriteOptions::add_options_to_urls_. We want to support that without bloating URLs excessively adding unrelated filter settings.

The vector is returned in numerically increasing order so binary_search is possible.

*num_filters is set to the size of this array.

Ownership of the filter-vector is not transferred to the caller; it is expected to return a pointer to a static vector.

Reimplemented from net_instaweb::RewriteFilter.

virtual const StringPieceVector* net_instaweb::ImageRewriteFilter::RelatedOptions ( ) const

inlinevirtual

Return the names of options related to this RewriteFilter in case-insensitive alphabetical order. NULL means there are none. Ownership of the vector is not transferred to the caller.

Reimplemented from net_instaweb::RewriteFilter.

virtual void net_instaweb::ImageRewriteFilter::RenderDone ( )

virtual

Notifies a filter that an asynchronous rewrite & render computation phase has finished. This is not used by HtmlParse itself, but only by RewriteDriver for pre-render filters. Happens after the corresponding flush, for every flush window. Default implementation does nothing.

Todo:: TODO(morlovich): Push this down into CommonFilter and convert all the pre-render filters to inherit off it.

Reimplemented from net_instaweb::HtmlFilter.

bool net_instaweb::ImageRewriteFilter::ResizeImageIfNecessary	(	const Context *	rewrite_context,
		const GoogleString &	url,
		ResourceContext *	context,
		Image *	image,
		CachedResult *	cached
	)

Resize image if necessary, returning true if this resizing succeeds and false if it's unnecessary or fails.

bool net_instaweb::ImageRewriteFilter::ShouldResize	(	const ResourceContext &	context,
		const GoogleString &	url,
		Image *	image,
		ImageDim *	desired_dimensions
	)

Determines whether an image should be resized based on the current options.

Returns the dimensions to resize to in *desired_dimensions.

virtual void net_instaweb::ImageRewriteFilter::StartDocumentImpl ( )

virtual

Overload these implementer methods: Intentionally left abstract so that implementers don't forget to change the name from Blah to BlahImpl.

Implements net_instaweb::CommonFilter.

InlineResult net_instaweb::ImageRewriteFilter::TryInline	(	bool	is_html,
		bool	is_critical,
		int64	image_inline_max_bytes,
		const CachedResult *	cached_result,
		ResourceSlot *	slot,
		GoogleString *	data_url
	)

Can we inline resource? If so, encode its contents into the data_url, otherwise leave data_url alone.

bool net_instaweb::ImageRewriteFilter::UpdateDesiredImageDimsIfNecessary	(	const ImageDim &	image_dim,
		const ResourceContext &	resource_context,
		ImageDim *	desired_dim
	)

Update desired image dimensions if necessary. Returns true if it is updated.

Member Data Documentation

const char net_instaweb::ImageRewriteFilter::kInlinableImageUrlsPropertyName[]

static

The property cache property name used to store URLs discovered when image_inlining_identify_and_cache_without_rewriting() is set in the RewriteOptions.

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

net/instaweb/rewriter/public/image_rewrite_filter.h

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Friends

Detailed Description

Member Function Documentation

Member Data Documentation