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

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

Classes
struct	FetchSecurityStats
	External resource fetch attempts, cache use, and limit state. More...

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.
uint64_t	cacheGeneration () const
	Identity of the resource loader, processing mode and SVG parse callback for derived caches.
ProcessingMode	processingMode () const
	Current processing policy, shared with non-resource document systems.
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
	Font faces still awaiting loading or registration.
bool	stylesheetFontFaceLimitRejected () const
	Whether stylesheet font-face registration exceeded its document limit.
size_t	stylesheetFontFaceCountForTesting () const
	Current stylesheet font-face count exposed to tests.
size_t	stylesheetFontFaceRegistrationCountForTesting () const
	Number of stylesheet registration records exposed to tests.

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.

Class Documentation

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

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

External resource fetch attempts, cache use, and limit state.

Class Members
size_t	attempts = 0	Fetch attempts charged against the document limit.
size_t	cachedBytes = 0	Cumulative response bytes admitted to the cache.
size_t	cacheHits = 0	Requests answered by cached positive or failed outcomes.
bool	rejected = false	Whether URL validation or a fetch budget rejected a request.

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.

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

donner/svg/components/resources/ResourceManagerContext.h

Classes

Public Member Functions

Static Public Attributes

Detailed Description

Class Documentation

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

Member Function Documentation

◆ addFontFaces()

◆ getImageSize()

◆ loadExternalSVG()

◆ loadResources()

◆ setProcessingMode()

◆ setResourceLoader()

◆ setSvgParseCallback()