layout/style/SheetLoadData.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_css_SheetLoadData_h
   8 #define mozilla_css_SheetLoadData_h
   9
  10 #include "mozilla/css/Loader.h"
  11 #include "mozilla/css/SheetParsingMode.h"
  12 #include "mozilla/Encoding.h"
  13 #include "mozilla/NotNull.h"
  14 #include "nsIThreadInternal.h"
  15 #include "nsProxyRelease.h"
  16
  17 namespace mozilla {
  18 class StyleSheet;
  19 }
  20 class nsICSSLoaderObserver;
  21 class nsINode;
  22 class nsIPrincipal;
  23 class nsIURI;
  24 class nsIReferrerInfo;
  25
  26 namespace mozilla {
  27 namespace css {
  28
  29 /*********************************************
  30  * Data needed to properly load a stylesheet *
  31  *********************************************/
  32
  33 static_assert(eAuthorSheetFeatures == 0 && eUserSheetFeatures == 1 &&
  34                   eAgentSheetFeatures == 2,
  35               "sheet parsing mode constants won't fit "
  36               "in SheetLoadData::mParsingMode");
  37
  38 class SheetLoadData final : public nsIRunnable, public nsIThreadObserver {
  39   using MediaMatched = nsIStyleSheetLinkingElement::MediaMatched;
  40   using IsAlternate = nsIStyleSheetLinkingElement::IsAlternate;
  41   using IsPreload = Loader::IsPreload;
  42   using UseSystemPrincipal = Loader::UseSystemPrincipal;
  43
  44  protected:
  45   virtual ~SheetLoadData();
  46
  47  public:
  48   // Data for loading a sheet linked from a document
  49   SheetLoadData(Loader* aLoader, const nsAString& aTitle, nsIURI* aURI,
  50                 StyleSheet* aSheet, bool aSyncLoad,
  51                 nsIStyleSheetLinkingElement* aOwningElement,
  52                 IsAlternate aIsAlternate, MediaMatched aMediaMatched,
  53                 IsPreload aIsPreload, nsICSSLoaderObserver* aObserver,
  54                 nsIPrincipal* aLoaderPrincipal, nsIReferrerInfo* aReferrerInfo,
  55                 nsINode* aRequestingNode);
  56
  57   // Data for loading a sheet linked from an @import rule
  58   SheetLoadData(Loader* aLoader, nsIURI* aURI, StyleSheet* aSheet,
  59                 SheetLoadData* aParentData, nsICSSLoaderObserver* aObserver,
  60                 nsIPrincipal* aLoaderPrincipal, nsIReferrerInfo* aReferrerInfo,
  61                 nsINode* aRequestingNode);
  62
  63   // Data for loading a non-document sheet
  64   SheetLoadData(Loader* aLoader, nsIURI* aURI, StyleSheet* aSheet,
  65                 bool aSyncLoad, UseSystemPrincipal, IsPreload,
  66                 const Encoding* aPreloadEncoding,
  67                 nsICSSLoaderObserver* aObserver, nsIPrincipal* aLoaderPrincipal,
  68                 nsIReferrerInfo* aReferrerInfo, nsINode* aRequestingNode);
  69
  70   nsIReferrerInfo* ReferrerInfo() { return mReferrerInfo; }
  71
  72   void ScheduleLoadEventIfNeeded();
  73
  74   NotNull<const Encoding*> DetermineNonBOMEncoding(nsACString const& aSegment,
  75                                                    nsIChannel* aChannel);
  76
  77   // The caller may have the bytes for the stylesheet split across two strings,
  78   // so aBytes1 and aBytes2 refer to those pieces.
  79   nsresult VerifySheetReadyToParse(nsresult aStatus, const nsACString& aBytes1,
  80                                    const nsACString& aBytes2,
  81                                    nsIChannel* aChannel);
  82
  83   NS_DECL_ISUPPORTS
  84   NS_DECL_NSIRUNNABLE
  85   NS_DECL_NSITHREADOBSERVER
  86
  87   // Hold a ref to the CSSLoader so we can call back to it to let it
  88   // know the load finished
  89   const RefPtr<Loader> mLoader;
  90
  91   // Title needed to pull datas out of the pending datas table when
  92   // the preferred title is changed
  93   const nsString mTitle;
  94
  95   // The encoding we decided to use for the sheet
  96   const Encoding* mEncoding;
  97
  98   // URI we're loading.  Null for inline sheets
  99   nsCOMPtr<nsIURI> mURI;
 100
 101   // Should be 1 for non-inline sheets.
 102   uint32_t mLineNumber;
 103
 104   // The sheet we're loading data for
 105   const RefPtr<StyleSheet> mSheet;
 106
 107   // Linked list of datas for the same URI as us.
 108   RefPtr<SheetLoadData> mNext;
 109
 110   // Load data for the sheet that @import-ed us if we were @import-ed
 111   // during the parse
 112   const RefPtr<SheetLoadData> mParentData;
 113
 114   // Number of sheets we @import-ed that are still loading
 115   uint32_t mPendingChildren;
 116
 117   // mSyncLoad is true when the load needs to be synchronous.
 118   // For LoadSheetSync, <link> to chrome stylesheets in UA Widgets,
 119   // and children of sync loads.
 120   const bool mSyncLoad : 1;
 121
 122   // mIsNonDocumentSheet is true if the load was triggered by LoadSheetSync or
 123   // LoadSheet or an @import from such a sheet.  Non-document sheet loads can
 124   // proceed even if we have no document.
 125   const bool mIsNonDocumentSheet : 1;
 126
 127   // mIsLoading is true from the moment we are placed in the loader's
 128   // "loading datas" table (right after the async channel is opened)
 129   // to the moment we are removed from said table (due to the load
 130   // completing or being cancelled).
 131   bool mIsLoading : 1;
 132
 133   // mIsBeingParsed is true if this stylesheet is currently being parsed.
 134   bool mIsBeingParsed : 1;
 135
 136   // mIsCancelled is set to true when a sheet load is stopped by
 137   // Stop() or StopLoadingSheet() (which was removed in Bug 556446).
 138   // SheetLoadData::OnStreamComplete() checks this to avoid parsing
 139   // sheets that have been cancelled and such.
 140   bool mIsCancelled : 1;
 141
 142   // mMustNotify is true if the load data is being loaded async and
 143   // the original function call that started the load has returned.
 144   // This applies only to observer notifications; load/error events
 145   // are fired for any SheetLoadData that has a non-null
 146   // mOwningElement.
 147   bool mMustNotify : 1;
 148
 149   // mWasAlternate is true if the sheet was an alternate when the load data was
 150   // created.
 151   const bool mWasAlternate : 1;
 152
 153   // mMediaMatched is true if the sheet matched its medialist when the load data
 154   // was created.
 155   const bool mMediaMatched : 1;
 156
 157   // mUseSystemPrincipal is true if the system principal should be used for
 158   // this sheet, no matter what the channel principal is.  Only true for sync
 159   // loads.
 160   const bool mUseSystemPrincipal : 1;
 161
 162   // If true, this SheetLoadData is being used as a way to handle
 163   // async observer notification for an already-complete sheet.
 164   bool mSheetAlreadyComplete : 1;
 165
 166   // If true, the sheet is being loaded cross-origin without CORS permissions.
 167   // This is completely normal and CORS isn't needed for such loads.  This
 168   // flag is simply useful in determining whether to set mBlockResourceTiming
 169   // for a child sheet.
 170   bool mIsCrossOriginNoCORS : 1;
 171
 172   // If this flag is true, LoadSheet will call SetReportResourceTiming(false)
 173   // on the timedChannel. This is to mark resources that are loaded by a
 174   // cross-origin stylesheet with a no-cors policy.
 175   // https://www.w3.org/TR/resource-timing/#processing-model
 176   bool mBlockResourceTiming : 1;
 177
 178   // Boolean flag indicating whether the load has failed.  This will be set
 179   // to true if this load, or the load of any descendant import, fails.
 180   bool mLoadFailed : 1;
 181
 182   // Whether this is a preload, and which kind of preload it is.
 183   //
 184   // TODO(emilio): This can become a bitfield once we build with a GCC version
 185   // that has the fix for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61414,
 186   // which causes a false positive warning here.
 187   const IsPreload mIsPreload;
 188
 189   // This is the element that imported the sheet.  Needed to get the
 190   // charset set on it and to fire load/error events.
 191   const nsCOMPtr<nsIStyleSheetLinkingElement> mOwningElement;
 192
 193   // The observer that wishes to be notified of load completion
 194   const nsCOMPtr<nsICSSLoaderObserver> mObserver;
 195
 196   // The principal that identifies who started loading us.
 197   const nsCOMPtr<nsIPrincipal> mLoaderPrincipal;
 198
 199   // Referrer info of the load.
 200   const nsCOMPtr<nsIReferrerInfo> mReferrerInfo;
 201
 202   // The node that identifies who started loading us.
 203   const nsCOMPtr<nsINode> mRequestingNode;
 204
 205   // The encoding to use for preloading Must be empty if mOwningElement
 206   // is non-null.
 207   const Encoding* const mPreloadEncoding;
 208
 209 #ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
 210   // Whether SheetComplete was called.
 211   bool mSheetCompleteCalled = false;
 212 #endif
 213
 214   bool ShouldDefer() const { return mWasAlternate || !mMediaMatched; }
 215
 216   // If there are no child sheets outstanding, mark us as complete.
 217   // Otherwise, the children are holding strong refs to the data
 218   // and will call SheetComplete() on it when they complete.
 219   void SheetFinishedParsingAsync() {
 220     MOZ_ASSERT(mIsBeingParsed);
 221     mIsBeingParsed = false;
 222     if (!mPendingChildren) {
 223       mLoader->SheetComplete(*this, NS_OK);
 224     }
 225   }
 226
 227   bool IsLinkPreload() const { return mIsPreload == IsPreload::FromLink; }
 228
 229  private:
 230   void FireLoadEvent(nsIThreadInternal* aThread);
 231 };
 232
 233 using SheetLoadDataHolder = nsMainThreadPtrHolder<SheetLoadData>;
 234
 235 }  // namespace css
 236 }  // namespace mozilla
 237
 238 /**
 239  * Casting SheetLoadData to nsISupports is ambiguous.
 240  * This method handles that.
 241  */
 242 inline nsISupports* ToSupports(mozilla::css::SheetLoadData* p) {
 243   return NS_ISUPPORTS_CAST(nsIRunnable*, p);
 244 }
 245
 246 #endif  // mozilla_css_SheetLoadData_h