The Tor Browser: gfx/thebes/gfxUserFontSet.h@97036ab72558 (annotated)

gfx/thebes/gfxUserFontSet.h@97036ab72558 (annotated)

gfx/thebes/gfxUserFontSet.h

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * 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/. */
 #ifndef GFX_USER_FONT_SET_H
 #define GFX_USER_FONT_SET_H
 #include "gfxFont.h"
 #include "nsPresContext.h"
 #include "nsRefPtrHashtable.h"
 #include "nsAutoPtr.h"
 #include "nsCOMPtr.h"
 #include "nsIURI.h"
 #include "nsIPrincipal.h"
 #include "nsIScriptError.h"
 #include "nsURIHashKey.h"
 class nsFontFaceLoader;
 //#define DEBUG_USERFONT_CACHE
 // parsed CSS @font-face rule information
 // lifetime: from when @font-face rule processed until font is loaded
 struct gfxFontFaceSrc {
     bool                   mIsLocal;       // url or local
     // if url, whether to use the origin principal or not
     bool                   mUseOriginPrincipal;
     // format hint flags, union of all possible formats
     // (e.g. TrueType, EOT, SVG, etc.)
     // see FLAG_FORMAT_* enum values below
     uint32_t               mFormatFlags;
     nsString               mLocalName;     // full font name if local
     nsCOMPtr<nsIURI>       mURI;           // uri if url
     nsCOMPtr<nsIURI>       mReferrer;      // referrer url if url
     nsCOMPtr<nsIPrincipal> mOriginPrincipal; // principal if url
 };
 inline bool
 operator==(const gfxFontFaceSrc& a, const gfxFontFaceSrc& b)
 {
     bool equals;
     return (a.mIsLocal && b.mIsLocal &&
             a.mLocalName == b.mLocalName) ||
            (!a.mIsLocal && !b.mIsLocal &&
             a.mUseOriginPrincipal == b.mUseOriginPrincipal &&
             a.mFormatFlags == b.mFormatFlags &&
             NS_SUCCEEDED(a.mURI->Equals(b.mURI, &equals)) && equals &&
             NS_SUCCEEDED(a.mReferrer->Equals(b.mReferrer, &equals)) && equals &&
             a.mOriginPrincipal->Equals(b.mOriginPrincipal));
 }
 // Subclassed to store platform-specific code cleaned out when font entry is
 // deleted.
 // Lifetime: from when platform font is created until it is deactivated.
 // If the platform does not need to add any platform-specific code/data here,
 // then the gfxUserFontSet will allocate a base gfxUserFontData and attach
 // to the entry to track the basic user font info fields here.
 class gfxUserFontData {
 public:
     gfxUserFontData()
         : mSrcIndex(0), mFormat(0), mMetaOrigLen(0)
     { }
     virtual ~gfxUserFontData() { }
     nsTArray<uint8_t> mMetadata;  // woff metadata block (compressed), if any
     nsCOMPtr<nsIURI>  mURI;       // URI of the source, if it was url()
     nsCOMPtr<nsIPrincipal> mPrincipal; // principal for the download, if url()
     nsString          mLocalName; // font name used for the source, if local()
     nsString          mRealName;  // original fullname from the font resource
     uint32_t          mSrcIndex;  // index in the rule's source list
     uint32_t          mFormat;    // format hint for the source used, if any
     uint32_t          mMetaOrigLen; // length needed to decompress metadata
     bool              mPrivate;   // whether font belongs to a private window
 };
 // initially contains a set of proxy font entry objects, replaced with
 // platform/user fonts as downloaded
 class gfxMixedFontFamily : public gfxFontFamily {
 public:
     friend class gfxUserFontSet;
     gfxMixedFontFamily(const nsAString& aName)
         : gfxFontFamily(aName) { }
     virtual ~gfxMixedFontFamily() { }
     // Add the given font entry to the end of the family's list.
     // Any earlier occurrence is removed, so this has the effect of "advancing"
     // the entry to the end of the list.
     void AddFontEntry(gfxFontEntry *aFontEntry) {
         // We append to mAvailableFonts -before- searching for and removing
         // any existing reference to avoid the risk that we'll remove the last
         // reference to the font entry, and thus delete it.
         mAvailableFonts.AppendElement(aFontEntry);
         uint32_t i = mAvailableFonts.Length() - 1;
         while (i > 0) {
             if (mAvailableFonts[--i] == aFontEntry) {
                 mAvailableFonts.RemoveElementAt(i);
                 break;
             }
         }
         aFontEntry->mFamilyName = Name();
         ResetCharacterMap();
     }
     // Replace aProxyFontEntry in the family's list with aRealFontEntry.
     void ReplaceFontEntry(gfxFontEntry *aProxyFontEntry,
                           gfxFontEntry *aRealFontEntry) {
         uint32_t numFonts = mAvailableFonts.Length();
         uint32_t i;
         for (i = 0; i < numFonts; i++) {
             gfxFontEntry *fe = mAvailableFonts[i];
             if (fe == aProxyFontEntry) {
                 // Note that this may delete aProxyFontEntry, if there's no
                 // other reference to it except from its family.
                 mAvailableFonts[i] = aRealFontEntry;
                 aRealFontEntry->mFamilyName = Name();
                 break;
             }
         }
         NS_ASSERTION(i < numFonts, "font entry not found in family!");
         ResetCharacterMap();
     }
     // Remove all font entries from the family
     void DetachFontEntries() {
         mAvailableFonts.Clear();
     }
 };
 class gfxProxyFontEntry;
 class gfxUserFontSet {
 public:
     NS_INLINE_DECL_REFCOUNTING(gfxUserFontSet)
     gfxUserFontSet();
     enum {
         // no flags ==> no hint set
         // unknown ==> unknown format hint set
         FLAG_FORMAT_UNKNOWN        = 1,
         FLAG_FORMAT_OPENTYPE       = 1 << 1,
         FLAG_FORMAT_TRUETYPE       = 1 << 2,
         FLAG_FORMAT_TRUETYPE_AAT   = 1 << 3,
         FLAG_FORMAT_EOT            = 1 << 4,
         FLAG_FORMAT_SVG            = 1 << 5,
         FLAG_FORMAT_WOFF           = 1 << 6,
         // mask of all unused bits, update when adding new formats
         FLAG_FORMAT_NOT_USED       = ~((1 << 7)-1)
     };
     enum LoadStatus {
         STATUS_LOADING = 0,
         STATUS_LOADED,
         STATUS_FORMAT_NOT_SUPPORTED,
         STATUS_ERROR,
         STATUS_END_OF_LIST
     };
     // add in a font face
     // weight - 0 == unknown, [100, 900] otherwise (multiples of 100)
     // stretch = [NS_FONT_STRETCH_ULTRA_CONDENSED, NS_FONT_STRETCH_ULTRA_EXPANDED]
     // italic style = constants in gfxFontConstants.h, e.g. NS_FONT_STYLE_NORMAL
     // TODO: support for unicode ranges not yet implemented
     gfxFontEntry *AddFontFace(const nsAString& aFamilyName,
                               const nsTArray<gfxFontFaceSrc>& aFontFaceSrcList,
                               uint32_t aWeight,
                               int32_t aStretch,
                               uint32_t aItalicStyle,
                               const nsTArray<gfxFontFeature>& aFeatureSettings,
                               const nsString& aLanguageOverride,
                               gfxSparseBitSet *aUnicodeRanges = nullptr);
     // add in a font face for which we have the gfxFontEntry already
     void AddFontFace(const nsAString& aFamilyName, gfxFontEntry* aFontEntry);
     // Whether there is a face with this family name
     bool HasFamily(const nsAString& aFamilyName) const
     {
         return GetFamily(aFamilyName) != nullptr;
     }
     gfxFontFamily *GetFamily(const nsAString& aName) const;
     // Lookup a font entry for a given style, returns null if not loaded.
     // aFamily must be a family returned by our GetFamily method.
     gfxFontEntry *FindFontEntry(gfxFontFamily *aFamily,
                                 const gfxFontStyle& aFontStyle,
                                 bool& aNeedsBold,
                                 bool& aWaitForUserFont);
     // Find a family (possibly one of several!) that owns the given entry.
     // This may be somewhat expensive, as it enumerates all the fonts in
     // the set. Currently used only by the Linux (gfxPangoFontGroup) backend,
     // which does not directly track families in the font group's list.
     gfxFontFamily *FindFamilyFor(gfxFontEntry *aFontEntry) const;
     // check whether the given source is allowed to be loaded;
     // returns the Principal (for use in the key when caching the loaded font),
     // and whether the load should bypass the cache (force-reload).
     virtual nsresult CheckFontLoad(const gfxFontFaceSrc *aFontFaceSrc,
                                    nsIPrincipal **aPrincipal,
                                    bool *aBypassCache) = 0;
     // initialize the process that loads external font data, which upon
     // completion will call OnLoadComplete method
     virtual nsresult StartLoad(gfxMixedFontFamily *aFamily,
                                gfxProxyFontEntry *aProxy,
                                const gfxFontFaceSrc *aFontFaceSrc) = 0;
     // when download has been completed, pass back data here
     // aDownloadStatus == NS_OK ==> download succeeded, error otherwise
     // returns true if platform font creation sucessful (or local()
     // reference was next in line)
     // Ownership of aFontData is passed in here; the font set must
     // ensure that it is eventually deleted with NS_Free().
     bool OnLoadComplete(gfxMixedFontFamily *aFamily,
                         gfxProxyFontEntry *aProxy,
                         const uint8_t *aFontData, uint32_t aLength,
                         nsresult aDownloadStatus);
     // Replace a proxy with a real fontEntry; this is implemented in
     // nsUserFontSet in order to keep track of the entry corresponding
     // to each @font-face rule.
     virtual void ReplaceFontEntry(gfxMixedFontFamily *aFamily,
                                   gfxProxyFontEntry *aProxy,
                                   gfxFontEntry *aFontEntry) = 0;
     // generation - each time a face is loaded, generation is
     // incremented so that the change can be recognized
     uint64_t GetGeneration() { return mGeneration; }
     // increment the generation on font load
     void IncrementGeneration();
     // rebuild if local rules have been used
     void RebuildLocalRules();
     virtual nsPresContext *GetPresContext() { return NULL; }
     class UserFontCache {
     public:
         // Record a loaded user-font in the cache. This requires that the
         // font-entry's userFontData has been set up already, as it relies
         // on the URI and Principal recorded there.
         static void CacheFont(gfxFontEntry *aFontEntry);
         // The given gfxFontEntry is being destroyed, so remove any record that
         // refers to it.
         static void ForgetFont(gfxFontEntry *aFontEntry);
         // Return the gfxFontEntry corresponding to a given URI and principal,
         // and the features of the given proxy, or nullptr if none is available.
         // The aPrivate flag is set for requests coming from private windows,
         // so we can avoid leaking fonts cached in private windows mode out to
         // normal windows.
         static gfxFontEntry* GetFont(nsIURI            *aSrcURI,
                                      nsIPrincipal      *aPrincipal,
                                      gfxProxyFontEntry *aProxy,
                                      bool               aPrivate);
         // Clear everything so that we don't leak URIs and Principals.
         static void Shutdown();
 #ifdef DEBUG_USERFONT_CACHE
         // dump contents
         static void Dump();
 #endif
     private:
         // Helper that we use to observe the empty-cache notification
         // from nsICacheService.
         class Flusher : public nsIObserver
         {
         public:
             NS_DECL_ISUPPORTS
             NS_DECL_NSIOBSERVER
             Flusher() {}
             virtual ~Flusher() {}
         };
         // Key used to look up entries in the user-font cache.
         // Note that key comparison does *not* use the mFontEntry field
         // as a whole; it only compares specific fields within the entry
         // (weight/width/style/features) that could affect font selection
         // or rendering, and that must match between a font-set's proxy
         // entry and the corresponding "real" font entry.
         struct Key {
             nsCOMPtr<nsIURI>        mURI;
             nsCOMPtr<nsIPrincipal>  mPrincipal;
             gfxFontEntry           *mFontEntry;
             bool                    mPrivate;
             Key(nsIURI* aURI, nsIPrincipal* aPrincipal,
                 gfxFontEntry* aFontEntry, bool aPrivate)
                 : mURI(aURI),
                   mPrincipal(aPrincipal),
                   mFontEntry(aFontEntry),
                   mPrivate(aPrivate)
             { }
         };
         class Entry : public PLDHashEntryHdr {
         public:
             typedef const Key& KeyType;
             typedef const Key* KeyTypePointer;
             Entry(KeyTypePointer aKey)
                 : mURI(aKey->mURI),
                   mPrincipal(aKey->mPrincipal),
                   mFontEntry(aKey->mFontEntry),
                   mPrivate(aKey->mPrivate)
             { }
             Entry(const Entry& aOther)
                 : mURI(aOther.mURI),
                   mPrincipal(aOther.mPrincipal),
                   mFontEntry(aOther.mFontEntry),
                   mPrivate(aOther.mPrivate)
             { }
             ~Entry() { }
             bool KeyEquals(const KeyTypePointer aKey) const;
             static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
             static PLDHashNumber HashKey(const KeyTypePointer aKey) {
                 uint32_t principalHash;
                 aKey->mPrincipal->GetHashValue(&principalHash);
                 return mozilla::HashGeneric(principalHash + int(aKey->mPrivate),
                                             nsURIHashKey::HashKey(aKey->mURI),
                                             HashFeatures(aKey->mFontEntry->mFeatureSettings),
                                             mozilla::HashString(aKey->mFontEntry->mFamilyName),
                                             ((uint32_t)aKey->mFontEntry->mItalic |
                                              (aKey->mFontEntry->mWeight << 1) |
                                              (aKey->mFontEntry->mStretch << 10) ) ^
                                              aKey->mFontEntry->mLanguageOverride);
             }
             enum { ALLOW_MEMMOVE = false };
             gfxFontEntry* GetFontEntry() const { return mFontEntry; }
             static PLDHashOperator RemoveIfPrivate(Entry* aEntry, void* aUserData);
             static PLDHashOperator RemoveIfMatches(Entry* aEntry, void* aUserData);
             static PLDHashOperator DisconnectSVG(Entry* aEntry, void* aUserData);
 #ifdef DEBUG_USERFONT_CACHE
             static PLDHashOperator DumpEntry(Entry* aEntry, void* aUserData);
 #endif
         private:
             static uint32_t
             HashFeatures(const nsTArray<gfxFontFeature>& aFeatures) {
                 return mozilla::HashBytes(aFeatures.Elements(),
                                           aFeatures.Length() * sizeof(gfxFontFeature));
             }
             nsCOMPtr<nsIURI>       mURI;
             nsCOMPtr<nsIPrincipal> mPrincipal;
             // The "real" font entry corresponding to this downloaded font.
             // The font entry MUST notify the cache when it is destroyed
             // (by calling Forget()).
             gfxFontEntry          *mFontEntry;
             // Whether this font was loaded from a private window.
             bool                   mPrivate;
         };
         static nsTHashtable<Entry> *sUserFonts;
     };
 protected:
     // Protected destructor, to discourage deletion outside of Release():
     virtual ~gfxUserFontSet();
     // Return whether the font set is associated with a private-browsing tab.
     virtual bool GetPrivateBrowsing() = 0;
     // for a given proxy font entry, attempt to load the next resource
     // in the src list
     LoadStatus LoadNext(gfxMixedFontFamily *aFamily,
                         gfxProxyFontEntry *aProxyEntry);
     // helper method for creating a platform font
     // returns font entry if platform font creation successful
     // Ownership of aFontData is passed in here; the font set must
     // ensure that it is eventually deleted with NS_Free().
     gfxFontEntry* LoadFont(gfxMixedFontFamily *aFamily,
                            gfxProxyFontEntry *aProxy,
                            const uint8_t *aFontData, uint32_t &aLength);
     // parse data for a data URL
     virtual nsresult SyncLoadFontData(gfxProxyFontEntry *aFontToLoad,
                                       const gfxFontFaceSrc *aFontFaceSrc,
                                       uint8_t* &aBuffer,
                                       uint32_t &aBufferLength) = 0;
     // report a problem of some kind (implemented in nsUserFontSet)
     virtual nsresult LogMessage(gfxMixedFontFamily *aFamily,
                                 gfxProxyFontEntry *aProxy,
                                 const char *aMessage,
                                 uint32_t aFlags = nsIScriptError::errorFlag,
                                 nsresult aStatus = NS_OK) = 0;
     const uint8_t* SanitizeOpenTypeData(gfxMixedFontFamily *aFamily,
                                         gfxProxyFontEntry *aProxy,
                                         const uint8_t* aData,
                                         uint32_t aLength,
                                         uint32_t& aSaneLength,
                                         bool aIsCompressed);
     static bool OTSMessage(void *aUserData, const char *format, ...);
     // helper method for performing the actual userfont set rebuild
     virtual void DoRebuildUserFontSet() = 0;
     // font families defined by @font-face rules
     nsRefPtrHashtable<nsStringHashKey, gfxMixedFontFamily> mFontFamilies;
     uint64_t        mGeneration;
     // true when local names have been looked up, false otherwise
     bool mLocalRulesUsed;
     static PRLogModuleInfo* GetUserFontsLog();
 private:
     static void CopyWOFFMetadata(const uint8_t* aFontData,
                                  uint32_t aLength,
                                  FallibleTArray<uint8_t>* aMetadata,
                                  uint32_t* aMetaOrigLen);
 };
 // acts a placeholder until the real font is downloaded
 class gfxProxyFontEntry : public gfxFontEntry {
     friend class gfxUserFontSet;
 public:
     gfxProxyFontEntry(const nsTArray<gfxFontFaceSrc>& aFontFaceSrcList,
                       uint32_t aWeight,
                       int32_t aStretch,
                       uint32_t aItalicStyle,
                       const nsTArray<gfxFontFeature>& aFeatureSettings,
                       uint32_t aLanguageOverride,
                       gfxSparseBitSet *aUnicodeRanges);
     virtual ~gfxProxyFontEntry();
     // Return whether the entry matches the given list of attributes
     bool Matches(const nsTArray<gfxFontFaceSrc>& aFontFaceSrcList,
                  uint32_t aWeight,
                  int32_t aStretch,
                  uint32_t aItalicStyle,
                  const nsTArray<gfxFontFeature>& aFeatureSettings,
                  uint32_t aLanguageOverride,
                  gfxSparseBitSet *aUnicodeRanges);
     virtual gfxFont *CreateFontInstance(const gfxFontStyle *aFontStyle, bool aNeedsBold);
     // note that code depends on the ordering of these values!
     enum LoadingState {
         NOT_LOADING = 0,     // not started to load any font resources yet
         LOADING_STARTED,     // loading has started; hide fallback font
         LOADING_ALMOST_DONE, // timeout happened but we're nearly done,
                              // so keep hiding fallback font
         LOADING_SLOWLY,      // timeout happened and we're not nearly done,
                              // so use the fallback font
         LOADING_FAILED       // failed to load any source: use fallback
     };
     LoadingState             mLoadingState;
     bool                     mUnsupportedFormat;
     nsTArray<gfxFontFaceSrc> mSrcList;
     uint32_t                 mSrcIndex; // index of loading src item
     nsFontFaceLoader        *mLoader; // current loader for this entry, if any
     nsCOMPtr<nsIPrincipal>   mPrincipal;
 };
 #endif /* GFX_USER_FONT_SET_H */

The Tor Browser / annotate

gfx/thebes/gfxUserFontSet.h@97036ab72558 (annotated)

gfx/thebes/gfxUserFontSet.h