gecko-dev/layout/style/Loader.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* loading of CSS style sheets using the network APIs */
#ifndef mozilla_css_Loader_h
#define mozilla_css_Loader_h
#include "nsIPrincipal.h"
#include "nsCompatibility.h"
#include "nsCycleCollectionParticipant.h"
#include "nsDataHashtable.h"
#include "nsRefPtrHashtable.h"
#include "nsStringFwd.h"
#include "nsTArray.h"
#include "nsTObserverArray.h"
#include "nsURIHashKey.h"
#include "nsIStyleSheetLinkingElement.h"
#include "mozilla/Attributes.h"
#include "mozilla/CORSMode.h"
#include "mozilla/StyleSheetInlines.h"
#include "mozilla/Maybe.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/StyleSheet.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/net/ReferrerPolicy.h"
class nsICSSLoaderObserver;
class nsIConsoleReportCollector;
class nsIContent;
class nsIDocument;
namespace mozilla {
namespace dom {
class DocGroup;
class Element;
} // namespace dom
} // namespace mozilla
namespace mozilla {
class URIPrincipalReferrerPolicyAndCORSModeHashKey : public nsURIHashKey
{
public:
typedef URIPrincipalReferrerPolicyAndCORSModeHashKey* KeyType;
typedef const URIPrincipalReferrerPolicyAndCORSModeHashKey* KeyTypePointer;
typedef mozilla::net::ReferrerPolicy ReferrerPolicy;
explicit URIPrincipalReferrerPolicyAndCORSModeHashKey(const URIPrincipalReferrerPolicyAndCORSModeHashKey* aKey)
: nsURIHashKey(aKey->mKey),
mPrincipal(aKey->mPrincipal),
mCORSMode(aKey->mCORSMode),
mReferrerPolicy(aKey->mReferrerPolicy)
{
MOZ_COUNT_CTOR(URIPrincipalReferrerPolicyAndCORSModeHashKey);
}
URIPrincipalReferrerPolicyAndCORSModeHashKey(nsIURI* aURI,
nsIPrincipal* aPrincipal,
CORSMode aCORSMode,
ReferrerPolicy aReferrerPolicy)
: nsURIHashKey(aURI),
mPrincipal(aPrincipal),
mCORSMode(aCORSMode),
mReferrerPolicy(aReferrerPolicy)
{
MOZ_COUNT_CTOR(URIPrincipalReferrerPolicyAndCORSModeHashKey);
}
URIPrincipalReferrerPolicyAndCORSModeHashKey(const URIPrincipalReferrerPolicyAndCORSModeHashKey& toCopy)
: nsURIHashKey(toCopy),
mPrincipal(toCopy.mPrincipal),
mCORSMode(toCopy.mCORSMode),
mReferrerPolicy(toCopy.mReferrerPolicy)
{
MOZ_COUNT_CTOR(URIPrincipalReferrerPolicyAndCORSModeHashKey);
}
~URIPrincipalReferrerPolicyAndCORSModeHashKey()
{
MOZ_COUNT_DTOR(URIPrincipalReferrerPolicyAndCORSModeHashKey);
}
URIPrincipalReferrerPolicyAndCORSModeHashKey* GetKey() const {
return const_cast<URIPrincipalReferrerPolicyAndCORSModeHashKey*>(this);
}
const URIPrincipalReferrerPolicyAndCORSModeHashKey* GetKeyPointer() const { return this; }
bool KeyEquals(const URIPrincipalReferrerPolicyAndCORSModeHashKey* aKey) const {
if (!nsURIHashKey::KeyEquals(aKey->mKey)) {
return false;
}
if (!mPrincipal != !aKey->mPrincipal) {
// One or the other has a principal, but not both... not equal
return false;
}
if (mCORSMode != aKey->mCORSMode) {
// Different CORS modes; we don't match
return false;
}
if (mReferrerPolicy != aKey->mReferrerPolicy) {
// Different ReferrerPolicy; we don't match
return false;
}
bool eq;
return !mPrincipal ||
(NS_SUCCEEDED(mPrincipal->Equals(aKey->mPrincipal, &eq)) && eq);
}
static const URIPrincipalReferrerPolicyAndCORSModeHashKey*
KeyToPointer(URIPrincipalReferrerPolicyAndCORSModeHashKey* aKey) { return aKey; }
static PLDHashNumber HashKey(const URIPrincipalReferrerPolicyAndCORSModeHashKey* aKey) {
return nsURIHashKey::HashKey(aKey->mKey);
}
nsIURI* GetURI() const { return nsURIHashKey::GetKey(); }
enum { ALLOW_MEMMOVE = true };
protected:
nsCOMPtr<nsIPrincipal> mPrincipal;
CORSMode mCORSMode;
ReferrerPolicy mReferrerPolicy;
};
namespace css {
class SheetLoadData;
class ImportRule;
/*********************
* Style sheet reuse *
*********************/
class MOZ_RAII LoaderReusableStyleSheets
{
public:
LoaderReusableStyleSheets()
{
}
/**
* Look for a reusable sheet (see AddReusableSheet) matching the
* given URL. If found, set aResult, remove the reused sheet from
* the internal list, and return true. If not found, return false;
* in this case, aResult is not modified.
*
* @param aURL the url to match
* @param aResult [out] the style sheet which can be reused
*/
bool FindReusableStyleSheet(nsIURI* aURL, RefPtr<StyleSheet>& aResult);
/**
* Indicate that a certain style sheet is available for reuse if its
* URI matches the URI of an @import. Sheets should be added in the
* opposite order in which they are intended to be reused.
*
* @param aSheet the sheet which can be reused
*/
void AddReusableSheet(StyleSheet* aSheet) {
mReusableSheets.AppendElement(aSheet);
}
private:
LoaderReusableStyleSheets(const LoaderReusableStyleSheets&) = delete;
LoaderReusableStyleSheets& operator=(const LoaderReusableStyleSheets&) = delete;
// The sheets that can be reused.
nsTArray<RefPtr<StyleSheet>> mReusableSheets;
};
/***********************************************************************
* Enum that describes the state of the sheet returned by CreateSheet. *
***********************************************************************/
enum StyleSheetState {
eSheetStateUnknown = 0,
eSheetNeedsParser,
eSheetPending,
eSheetLoading,
eSheetComplete
};
class Loader final {
typedef mozilla::net::ReferrerPolicy ReferrerPolicy;
public:
typedef nsIStyleSheetLinkingElement::Completed Completed;
typedef nsIStyleSheetLinkingElement::HasAlternateRel HasAlternateRel;
typedef nsIStyleSheetLinkingElement::IsAlternate IsAlternate;
typedef nsIStyleSheetLinkingElement::IsInline IsInline;
typedef nsIStyleSheetLinkingElement::MediaMatched MediaMatched;
typedef nsIStyleSheetLinkingElement::Update LoadSheetResult;
typedef nsIStyleSheetLinkingElement::SheetInfo SheetInfo;
Loader();
// aDocGroup is used for dispatching SheetLoadData in PostLoadEvent(). It
// can be null if you want to use this constructor, and there's no
// document when the Loader is constructed.
explicit Loader(mozilla::dom::DocGroup*);
explicit Loader(nsIDocument*);
private:
// Private destructor, to discourage deletion outside of Release():
~Loader();
public:
NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(Loader)
NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(Loader)
void DropDocumentReference(); // notification that doc is going away
void SetCompatibilityMode(nsCompatibility aCompatMode)
{ mCompatMode = aCompatMode; }
nsCompatibility GetCompatibilityMode() { return mCompatMode; }
// TODO(emilio): Is the complexity of this method and carrying the titles
// around worth it? The alternate sheets will load anyhow eventually...
void DocumentStyleSheetSetChanged();
// XXXbz sort out what the deal is with events! When should they fire?
/**
* Load an inline style sheet. If a successful result is returned and
* result.WillNotify() is true, then aObserver is guaranteed to be notified
* asynchronously once the sheet is marked complete. If an error is
* returned, or if result.WillNotify() is false, aObserver will not be
* notified. In addition to parsing the sheet, this method will insert it
* into the stylesheet list of this CSSLoader's document.
* @param aObserver the observer to notify when the load completes.
* May be null.
* @param aBuffer the stylesheet data
* @param aLineNumber the line number at which the stylesheet data started.
*/
Result<LoadSheetResult, nsresult>
LoadInlineStyle(const SheetInfo&,
const nsAString& aBuffer,
uint32_t aLineNumber,
nsICSSLoaderObserver* aObserver);
/**
* Load a linked (document) stylesheet. If a successful result is returned,
* aObserver is guaranteed to be notified asynchronously once the sheet is
* loaded and marked complete, i.e., result.WillNotify() will always return
* true. If an error is returned, aObserver will not be notified. In
* addition to loading the sheet, this method will insert it into the
* stylesheet list of this CSSLoader's document.
* @param aObserver the observer to notify when the load completes.
* May be null.
*/
Result<LoadSheetResult, nsresult>
LoadStyleLink(const SheetInfo&, nsICSSLoaderObserver* aObserver);
/**
* Load a child (@import-ed) style sheet. In addition to loading the sheet,
* this method will insert it into the child sheet list of aParentSheet. If
* there is no sheet currently being parsed and the child sheet is not
* complete when this method returns, then when the child sheet becomes
* complete aParentSheet will be QIed to nsICSSLoaderObserver and
* asynchronously notified, just like for LoadStyleLink. Note that if the
* child sheet is already complete when this method returns, no
* nsICSSLoaderObserver notification will be sent.
*
* @param aParentSheet the parent of this child sheet
* @param aParentData the SheetLoadData corresponding to the load of the
* parent sheet.
* @param aURL the URL of the child sheet
* @param aMedia the already-parsed media list for the child sheet
* @param aSavedSheets any saved style sheets which could be reused
* for this load
*/
nsresult LoadChildSheet(StyleSheet* aParentSheet,
SheetLoadData* aParentData,
nsIURI* aURL,
dom::MediaList* aMedia,
LoaderReusableStyleSheets* aSavedSheets);
/**
* Synchronously load and return the stylesheet at aURL. Any child sheets
* will also be loaded synchronously. Note that synchronous loads over some
* protocols may involve spinning up a new event loop, so use of this method
* does NOT guarantee not receiving any events before the sheet loads. This
* method can be used to load sheets not associated with a document.
*
* @param aURL the URL of the sheet to load
* @param aParsingMode the mode in which to parse the sheet
* (see comments at enum SheetParsingMode, above).
* @param aUseSystemPrincipal if true, give the resulting sheet the system
* principal no matter where it's being loaded from.
* @param [out] aSheet the loaded, complete sheet.
*
* NOTE: At the moment, this method assumes the sheet will be UTF-8, but
* ideally it would allow arbitrary encodings. Callers should NOT depend on
* non-UTF8 sheets being treated as UTF-8 by this method.
*
* NOTE: A successful return from this method doesn't indicate anything about
* whether the data could be parsed as CSS and doesn't indicate anything
* about the status of child sheets of the returned sheet.
*/
nsresult LoadSheetSync(nsIURI* aURL,
SheetParsingMode aParsingMode,
bool aUseSystemPrincipal,
RefPtr<StyleSheet>* aSheet);
/**
* As above, but defaults aParsingMode to eAuthorSheetFeatures and
* aUseSystemPrincipal to false.
*/
nsresult LoadSheetSync(nsIURI* aURL, RefPtr<StyleSheet>* aSheet) {
return LoadSheetSync(aURL, eAuthorSheetFeatures, false, aSheet);
}
/**
* Asynchronously load the stylesheet at aURL. If a successful result is
* returned, aObserver is guaranteed to be notified asynchronously once the
* sheet is loaded and marked complete. This method can be used to load
* sheets not associated with a document.
*
* @param aURL the URL of the sheet to load
* @param aParsingMode the mode in which to parse the sheet
* (see comments at enum SheetParsingMode, above).
* @param aUseSystemPrincipal if true, give the resulting sheet the system
* principal no matter where it's being loaded from.
* @param aObserver the observer to notify when the load completes.
* Must not be null.
* @param [out] aSheet the sheet to load. Note that the sheet may well
* not be loaded by the time this method returns.
*
* NOTE: At the moment, this method assumes the sheet will be UTF-8, but
* ideally it would allow arbitrary encodings. Callers should NOT depend on
* non-UTF8 sheets being treated as UTF-8 by this method.
*/
nsresult LoadSheet(nsIURI* aURL,
SheetParsingMode aParsingMode,
bool aUseSystemPrincipal,
nsICSSLoaderObserver* aObserver,
RefPtr<StyleSheet>* aSheet);
/**
* Asynchronously load the stylesheet at aURL. If a successful result is
* returned, aObserver is guaranteed to be notified asynchronously once the
* sheet is loaded and marked complete. This method can be used to load
* sheets not associated with a document. This method cannot be used to
* load user or agent sheets.
*
* @param aURL the URL of the sheet to load
* @param aOriginPrincipal the principal to use for security checks. This
* can be null to indicate that these checks should
* be skipped.
* @param aObserver the observer to notify when the load completes.
* Must not be null.
* @param [out] aSheet the sheet to load. Note that the sheet may well
* not be loaded by the time this method returns.
*/
nsresult LoadSheet(nsIURI* aURL,
nsIPrincipal* aOriginPrincipal,
nsICSSLoaderObserver* aObserver,
RefPtr<StyleSheet>* aSheet);
/**
* Same as above, to be used when the caller doesn't care about the
* not-yet-loaded sheet.
*/
nsresult LoadSheet(nsIURI* aURL,
bool aIsPreload,
nsIPrincipal* aOriginPrincipal,
const Encoding* aPreloadEncoding,
nsICSSLoaderObserver* aObserver,
CORSMode aCORSMode = CORS_NONE,
ReferrerPolicy aReferrerPolicy = mozilla::net::RP_Unset,
const nsAString& aIntegrity = EmptyString());
/**
* Stop loading all sheets. All nsICSSLoaderObservers involved will be
* notified with NS_BINDING_ABORTED as the status, possibly synchronously.
*/
void Stop();
/**
* nsresult Loader::StopLoadingSheet(nsIURI* aURL), which notifies the
* nsICSSLoaderObserver with NS_BINDING_ABORTED, was removed in Bug 556446.
* It can be found in revision 2c44a32052ad.
*/
/**
* Whether the loader is enabled or not.
* When disabled, processing of new styles is disabled and an attempt
* to do so will fail with a return code of
* NS_ERROR_NOT_AVAILABLE. Note that this DOES NOT disable
* currently loading styles or already processed styles.
*/
bool GetEnabled() { return mEnabled; }
void SetEnabled(bool aEnabled) { mEnabled = aEnabled; }
/**
* Get the document we live for. May return null.
*/
nsIDocument* GetDocument() const { return mDocument; }
/**
* Return true if this loader has pending loads (ones that would send
* notifications to an nsICSSLoaderObserver attached to this loader).
* If called from inside nsICSSLoaderObserver::StyleSheetLoaded, this will
* return false if and only if that is the last StyleSheetLoaded
* notification the CSSLoader knows it's going to send. In other words, if
* two sheets load at once (via load coalescing, e.g.), HasPendingLoads()
* will return true during notification for the first one, and false
* during notification for the second one.
*/
bool HasPendingLoads();
/**
* Add an observer to this loader. The observer will be notified
* for all loads that would have notified their own observers (even
* if those loads don't have observers attached to them).
* Load-specific observers will be notified before generic
* observers. The loader holds a reference to the observer.
*
* aObserver must not be null.
*/
nsresult AddObserver(nsICSSLoaderObserver* aObserver);
/**
* Remove an observer added via AddObserver.
*/
void RemoveObserver(nsICSSLoaderObserver* aObserver);
// These interfaces are public only for the benefit of static functions
// within nsCSSLoader.cpp.
// IsAlternateSheet can change our currently selected style set if none is
// selected and aHasAlternateRel is false.
IsAlternate IsAlternateSheet(const nsAString& aTitle, bool aHasAlternateRel);
typedef nsTArray<RefPtr<SheetLoadData>> LoadDataArray;
// Measure our size.
size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
private:
friend class SheetLoadData;
friend class StreamLoader;
// Helpers to conditionally block onload if mDocument is non-null.
void BlockOnload();
void UnblockOnload(bool aFireSync);
// Helper to select the correct dispatch target for asynchronous events for
// this loader.
already_AddRefed<nsISerialEventTarget> DispatchTarget();
nsresult CheckContentPolicy(nsIPrincipal* aLoadingPrincipal,
nsIPrincipal* aTriggeringPrincipal,
nsIURI* aTargetURI,
nsINode* aRequestingNode,
bool aIsPreload);
nsresult CreateSheet(const SheetInfo& aInfo,
nsIPrincipal* aLoaderPrincipal,
css::SheetParsingMode aParsingMode,
bool aSyncLoad,
StyleSheetState& aSheetState,
RefPtr<StyleSheet>* aSheet)
{
return CreateSheet(aInfo.mURI,
aInfo.mContent,
aLoaderPrincipal,
aParsingMode,
aInfo.mCORSMode,
aInfo.mReferrerPolicy,
aInfo.mIntegrity,
aSyncLoad,
aSheetState,
aSheet);
}
// For inline style, the aURI param is null, but the aLinkingContent
// must be non-null then. The loader principal must never be null
// if aURI is not null.
nsresult CreateSheet(nsIURI* aURI,
nsIContent* aLinkingContent,
nsIPrincipal* aLoaderPrincipal,
css::SheetParsingMode aParsingMode,
CORSMode aCORSMode,
ReferrerPolicy aReferrerPolicy,
const nsAString& aIntegrity,
bool aSyncLoad,
StyleSheetState& aSheetState,
RefPtr<StyleSheet>* aSheet);
// Pass in either a media string or the MediaList from the CSSParser. Don't
// pass both.
//
// This method will set the sheet's enabled state based on aIsAlternate
MediaMatched PrepareSheet(StyleSheet* aSheet,
const nsAString& aTitle,
const nsAString& aMediaString,
dom::MediaList* aMediaList,
IsAlternate);
// Inserts a style sheet in a document or a ShadowRoot.
void InsertSheetInTree(StyleSheet& aSheet, nsIContent* aLinkingContent);
// Inserts a style sheet into a parent style sheet.
void InsertChildSheet(StyleSheet& aSheet, StyleSheet& aParentSheet);
nsresult InternalLoadNonDocumentSheet(
nsIURI* aURL,
bool aIsPreload,
SheetParsingMode aParsingMode,
bool aUseSystemPrincipal,
nsIPrincipal* aOriginPrincipal,
const Encoding* aPreloadEncoding,
RefPtr<StyleSheet>* aSheet,
nsICSSLoaderObserver* aObserver,
CORSMode aCORSMode = CORS_NONE,
ReferrerPolicy aReferrerPolicy = mozilla::net::RP_Unset,
const nsAString& aIntegrity = EmptyString());
// Post a load event for aObserver to be notified about aSheet. The
// notification will be sent with status NS_OK unless the load event is
// canceled at some point (in which case it will be sent with
// NS_BINDING_ABORTED). aWasAlternate indicates the state when the load was
// initiated, not the state at some later time. aURI should be the URI the
// sheet was loaded from (may be null for inline sheets). aElement is the
// owning element for this sheet.
nsresult PostLoadEvent(nsIURI* aURI,
StyleSheet* aSheet,
nsICSSLoaderObserver* aObserver,
IsAlternate aWasAlternate,
MediaMatched aMediaMatched,
nsIStyleSheetLinkingElement* aElement);
// Start the loads of all the sheets in mPendingDatas
void StartDeferredLoads();
// Handle an event posted by PostLoadEvent
void HandleLoadEvent(SheetLoadData* aEvent);
// Note: LoadSheet is responsible for releasing aLoadData and setting the
// sheet to complete on failure.
nsresult LoadSheet(SheetLoadData* aLoadData,
StyleSheetState aSheetState,
bool aIsPreLoad);
enum class AllowAsyncParse
{
Yes,
No,
};
// Parse the stylesheet in the load data.
//
// Returns whether the parse finished. It may not finish e.g. if the sheet had
// an @import.
//
// If this function returns Completed::Yes, then ParseSheet also called
// SheetComplete on aLoadData.
Completed ParseSheet(const nsACString& aBytes, SheetLoadData*, AllowAsyncParse);
// The load of the sheet in aLoadData is done, one way or another. Do final
// cleanup, including releasing aLoadData.
void SheetComplete(SheetLoadData* aLoadData, nsresult aStatus);
// The guts of SheetComplete. This may be called recursively on parent datas
// or datas that had glommed on to a single load. The array is there so load
// datas whose observers need to be notified can be added to it.
void DoSheetComplete(SheetLoadData* aLoadData, LoadDataArray& aDatasToNotify);
// Mark the given SheetLoadData, as well as any of its siblings, parents, etc
// transitively, as failed. The idea is to mark as failed any load that was
// directly or indirectly @importing the sheet this SheetLoadData represents.
void MarkLoadTreeFailed(SheetLoadData* aLoadData);
struct Sheets {
nsBaseHashtable<URIPrincipalReferrerPolicyAndCORSModeHashKey,
RefPtr<StyleSheet>,
StyleSheet*> mCompleteSheets;
nsDataHashtable<URIPrincipalReferrerPolicyAndCORSModeHashKey, SheetLoadData*>
mLoadingDatas; // weak refs
nsDataHashtable<URIPrincipalReferrerPolicyAndCORSModeHashKey, SheetLoadData*>
mPendingDatas; // weak refs
};
UniquePtr<Sheets> mSheets;
// The array of posted stylesheet loaded events (SheetLoadDatas) we have.
// Note that these are rare.
LoadDataArray mPostedEvents;
// Our array of "global" observers
nsTObserverArray<nsCOMPtr<nsICSSLoaderObserver> > mObservers;
// This reference is nulled by the Document in it's destructor through
// DropDocumentReference().
nsIDocument* MOZ_NON_OWNING_REF mDocument; // the document we live for
// For dispatching events via DocGroup::Dispatch() when mDocument is nullptr.
RefPtr<mozilla::dom::DocGroup> mDocGroup;
// Number of datas still waiting to be notified on if we're notifying on a
// whole bunch at once (e.g. in one of the stop methods). This is used to
// make sure that HasPendingLoads() won't return false until we're notifying
// on the last data we're working with.
uint32_t mDatasToNotifyOn;
nsCompatibility mCompatMode;
bool mEnabled; // is enabled to load new styles
nsCOMPtr<nsIConsoleReportCollector> mReporter;
#ifdef DEBUG
bool mSyncCallback;
#endif
};
} // namespace css
} // namespace mozilla
#endif /* mozilla_css_Loader_h */