donner::svg::components::ResourceManagerContext Class Reference

Resource manager, which handles loading resources from URLs and caching results. More...

#include "donner/svg/components/resources/ResourceManagerContext.h"

Classes
struct	FetchSecurityStats

Public Member Functions
	ResourceManagerContext (Registry &registry, size_t maximumAggregateResourceSize=kDefaultMaximumAggregateResourceSize, size_t maximumExternalFetchAttempts=kDefaultMaximumExternalFetchAttempts)
	Constructor.
void	loadResources (ParseWarningSink &warningSink)
	Load resources such as images.
void	setResourceLoader (std::unique_ptr< ResourceLoaderInterface > &&loader)
	Set the user-supplied ResourceLoaderInterface which handles loading URLs and returning their contents.
const FetchSecurityStats &	fetchSecurityStats () const
	Return external callback/cache resource-limit accounting.
void	setProcessingMode (ProcessingMode mode)
	Set the processing mode for this document.
void	setSvgParseCallback (SubDocumentCache::ParseCallback callback)
	Set the callback used to parse SVG content into sub-documents.
std::optional< SVGDocumentHandle >	loadExternalSVG (std::string_view url, ParseWarningSink &warningSink)
	Load an external SVG document by URL, for use by <use> elements referencing external files.
std::optional< Vector2i >	getImageSize (Entity entity) const
	Get the size of an image resource for an entity, if it has one and successfully loaded.
void	addFontFaces (std::span< const css::FontFace > fontFaces)
	Add a list of css::FontFace objects to be loaded.
void	synchronizeStylesheetFontFaces (Entity stylesheetEntity, std::span< const css::FontFace > fontFaces)
	Register a stylesheet's font faces once for its current parsed storage.
const std::vector< css::FontFace > &	fontFaces () const
	Get all registered @font-face declarations.
size_t	pendingFontFaceCount () const
bool	stylesheetFontFaceLimitRejected () const
size_t	stylesheetFontFaceCountForTesting () const
size_t	stylesheetFontFaceRegistrationCountForTesting () const

Static Public Attributes
static constexpr size_t	kDefaultMaximumAggregateResourceSize = 64 * 1024 * 1024
	Default aggregate byte budget for raw and decoded document resources.
static constexpr size_t	kMaximumResourceFetchAttempts = 256
	Maximum number of application resource-loader calls for one document.
static constexpr size_t	kDefaultMaximumExternalFetchAttempts = kMaximumResourceFetchAttempts
	Default number of unique external resource callbacks allowed per document.
static constexpr size_t	kMaximumStylesheetFontFaces = 1024
	Maximum stylesheet-provided font faces retained by one untrusted document.

Detailed Description

Resource manager, which handles loading resources from URLs and caching results.

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Class Documentation

donner::svg::components::ResourceManagerContext::FetchSecurityStats

struct donner::svg::components::ResourceManagerContext::FetchSecurityStats

Class Members
size_t	attempts = 0
size_t	cachedBytes = 0
size_t	cacheHits = 0
bool	rejected = false

Member Function Documentation

addFontFaces()

void donner::svg::components::ResourceManagerContext::addFontFaces

(

std::span< const css::FontFace >

fontFaces

)

Add a list of css::FontFace objects to be loaded.

Registration is idempotent. The style pass re-announces every stylesheet's @font-face rules on each recompute, so a declaration already registered is not stored a second time; it is only re-queued for loading, which retries a source that has not resolved yet and does nothing for one that has. Storing duplicates instead would re-fetch each URL and re-wrap its bytes in a fresh buffer every recompute, which in turn gives the font layer a new identity for a font that never changed.

Parameters

fontFaces

Font faces to load.

getImageSize()

std::optional< Vector2i > donner::svg::components::ResourceManagerContext::getImageSize

(

Entity

entity

)

const

Get the size of an image resource for an entity, if it has one and successfully loaded.

Parameters

entity

Entity to get the image size for.

loadExternalSVG()

std::optional< SVGDocumentHandle > donner::svg::components::ResourceManagerContext::loadExternalSVG	(	std::string_view	url,
		ParseWarningSink &	warningSink )

Load an external SVG document by URL, for use by <use> elements referencing external files.

The document is cached in the \ref SubDocumentCache.

Parameters

url	URL of the external SVG to load.
warningSink	Sink to collect warnings.

Returns

Parsed document handle, or std::nullopt on failure.

loadResources()

void donner::svg::components::ResourceManagerContext::loadResources

(

ParseWarningSink &

warningSink

)

Load resources such as images.

Note that this doesn't issue network calls directly, but relies on the user's application to handle callbacks for loading URLs and returning their contents.

Parameters

warningSink

Sink to collect warnings.

setProcessingMode()

void donner::svg::components::ResourceManagerContext::setProcessingMode ( ProcessingMode mode )

inline

Set the processing mode for this document.

In secure modes (ProcessingMode::SecureStatic, ProcessingMode::SecureAnimated), external resource loading is disabled per SVG2 §2.7.1.

Parameters

mode	Processing mode to set.

setResourceLoader()

void donner::svg::components::ResourceManagerContext::setResourceLoader

(

std::unique_ptr< ResourceLoaderInterface > &&

loader

)

Set the user-supplied ResourceLoaderInterface which handles loading URLs and returning their contents.

Parameters

loader

Resource loader interface, which will be held until overridden. Call this API again with nullptr to unset.

setSvgParseCallback()

void donner::svg::components::ResourceManagerContext::setSvgParseCallback ( SubDocumentCache::ParseCallback callback )

inline

Set the callback used to parse SVG content into sub-documents.

This is called when an <image> element references an SVG file. The callback is injected to avoid circular build dependencies between the component layer and SVGParser.

Parameters

callback

Callback that parses SVG bytes into an SVGDocumentHandle.

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

• donner/svg/components/resources/ResourceManagerContext.h