gfxFontGroup::MakeTextRun with individual words. b=416725, r=roc

gfx/thebes/src/gfxTextRunWordCache.cpp

@@ -160,23 +160,11 @@ protected:
         PRUint32    mHashedByFont:1;
     };
     
-    // Used to track words that should be copied from one textrun to
-    // another during the textrun construction process
-    struct DeferredWord {
-        gfxTextRun *mSourceTextRun;
-        PRUint32    mSourceOffset;
-        PRUint32    mDestOffset;
-        PRUint32    mLength;
-        PRUint32    mHash;
-    };
-    
     PRBool LookupWord(gfxTextRun *aTextRun, gfxFont *aFirstFont,
-                      PRUint32 aStart, PRUint32 aEnd, PRUint32 aHash,
-                      nsTArray<DeferredWord>* aDeferredWords);
-    void FinishTextRun(gfxTextRun *aTextRun, gfxTextRun *aNewRun,
-                       const gfxFontGroup::Parameters *aParams,
-                       const nsTArray<DeferredWord>& aDeferredWords,
-                       PRBool aSuccessful);
+                      PRUint32 aStart, PRUint32 aEnd, PRUint32 aHash);
+    void AddWord(gfxTextRun *aTextRun, PRUint32 aDestOffset,
+                 gfxTextRun *aNewRun, PRUint32 aSourceOffset, PRUint32 aLength,
+                 PRUint32 aHash, const gfxFontGroup::Parameters *aParams);
     void RemoveWord(gfxTextRun *aTextRun, PRUint32 aStart,
                     PRUint32 aEnd, PRUint32 aHash);    
 
@@ -235,159 +223,83 @@ IsWordBoundary(PRUnichar aChar)
 /**
  * Looks up a word in the cache. If the word is found in the cache
  * (which could be from an existing textrun or an earlier word in the same
- * textrun), we copy the glyphs from the word into the textrun, unless
- * aDeferredWords is non-null (meaning that all words from now on must be
- * copied later instead of now), in which case we add the word to be copied
- * to the list.
- * 
- * If the word is not found in the cache then we add it to the cache with
- * aFirstFont as the key, on the assumption that the word will be matched
- * by aFirstFont. If this assumption is false we fix up the cache later in
- * FinishTextRun. We make this assumption for two reasons:
- * 1) it's usually true so it saves an extra cache lookup if we had to insert
- * the entry later
- * 2) we need to record words that appear in the string in some kind
- * of hash table so we can detect and use them if they appear later in the
- * (in general the string might be huge and contain many repeated words).
- * We might as well use the master hash table for this.
+ * textrun), we copy the glyphs from the word into the textrun.
  * 
  * @return true if the word was found in the cache, false otherwise.
  */
 PRBool
 TextRunWordCache::LookupWord(gfxTextRun *aTextRun, gfxFont *aFirstFont,
-                             PRUint32 aStart, PRUint32 aEnd, PRUint32 aHash,
-                             nsTArray<DeferredWord>* aDeferredWords)
+                             PRUint32 aStart, PRUint32 aEnd, PRUint32 aHash)
 {
     if (aEnd <= aStart)
         return PR_TRUE;
 
+    // Look for an entry keyed by font or fontgroup
     CacheHashKey key(aTextRun, aFirstFont, aStart, aEnd - aStart, aHash);
-    CacheHashEntry *fontEntry = mCache.PutEntry(key);
-    if (!fontEntry)
-        return PR_FALSE;
-    CacheHashEntry *existingEntry = nsnull;
-
-    if (fontEntry->mTextRun) {
-        existingEntry = fontEntry;
-    } else {
-        PR_LOG(gWordCacheLog, PR_LOG_DEBUG, ("%p(%d-%d,%d): added using font", aTextRun, aStart, aEnd - aStart, aHash));
+    CacheHashEntry *existingEntry = mCache.GetEntry(key);
+    if (!existingEntry) {
         key.mFontOrGroup = aTextRun->GetFontGroup();
-        CacheHashEntry *groupEntry = mCache.GetEntry(key);
-        if (groupEntry) {
-            existingEntry = groupEntry;
-            mCache.RawRemoveEntry(fontEntry);
-            PR_LOG(gWordCacheLog, PR_LOG_DEBUG, ("%p(%d-%d,%d): removed using font", aTextRun, aStart, aEnd - aStart, aHash));
-            fontEntry = nsnull;
-        }
-    }
-    // At this point, either existingEntry is non-null and points to (surprise!)
-    // an entry for a word in an existing textrun, or fontEntry points
-    // to a cache entry for this word with aFirstFont, which needs to be
-    // filled in or removed.
-
-    if (existingEntry) {
-        if (aDeferredWords) {
-            DeferredWord word = { existingEntry->mTextRun,
-                  existingEntry->mWordOffset, aStart, aEnd - aStart, aHash };
-            aDeferredWords->AppendElement(word);
-        } else {
-            aTextRun->CopyGlyphDataFrom(existingEntry->mTextRun,
-                existingEntry->mWordOffset, aEnd - aStart, aStart, PR_FALSE);
-        }
-        return PR_TRUE;
+        existingEntry = mCache.GetEntry(key);
     }
 
-#ifdef DEBUG
-    ++aTextRun->mCachedWords;
-#endif
-    // Set up the cache entry so that if later in this textrun we hit this
-    // entry, we'll copy within our own textrun
-    fontEntry->mTextRun = aTextRun;
-    fontEntry->mWordOffset = aStart;
-    fontEntry->mHashedByFont = PR_TRUE;
+    if (!existingEntry)
         return PR_FALSE;
+
+    // Copy the glyphs from the word into the text run
+    aTextRun->CopyGlyphDataFrom(existingEntry->mTextRun,
+                                existingEntry->mWordOffset,
+                                aEnd - aStart, aStart, PR_FALSE);
+    return PR_TRUE;
 }
 
 /**
- * Processes all deferred words. Each word is copied from the source
- * textrun to the output textrun. (The source may be an earlier word in the
- * output textrun.) If the word was not matched by the textrun's fontgroup's
- * first font, then we remove the entry we optimistically added to the cache
- * with that font in the key, and add a new entry keyed with the fontgroup
- * instead.
- * 
- * @param aSuccessful if false, then we don't do any word copies and we don't
- * add anything to the cache, but we still remove all the optimistic cache
- * entries.
+ * Processes a word that doesn't yet exist in the cache.  The word is copied
+ * from the source textrun to the output textrun. (The source may be an
+ * earlier word in the output textrun.)
  */
 void
-TextRunWordCache::FinishTextRun(gfxTextRun *aTextRun, gfxTextRun *aNewRun,
-                                const gfxFontGroup::Parameters *aParams,
-                                const nsTArray<DeferredWord>& aDeferredWords,
-                                PRBool aSuccessful)
+TextRunWordCache::AddWord(gfxTextRun *aTextRun, PRUint32 aDestOffset,
+                          gfxTextRun *aNewRun, PRUint32 aSourceOffset,
+                          PRUint32 aLength, PRUint32 aHash,
+                          const gfxFontGroup::Parameters *aParams)
 {
+    gfxTextRun *source = aNewRun;
+    PRUint32 sourceOffset = aSourceOffset;
+    PRUint32 destOffset = aDestOffset;
+    PRUint32 length = aLength;
+    nsAutoPtr<gfxTextRun> tmpTextRun;
+
+    // If the word starts inside a cluster we don't want this word
+    // in the cache.
+    PRBool wordStartsInsideCluster =
+        aNewRun && !aNewRun->IsClusterStart(aSourceOffset);
+
+    if (!wordStartsInsideCluster) {
+        CacheHashKey key(aTextRun,
+                         GetWordFontOrGroup(aNewRun, aSourceOffset, aLength),
+                         aDestOffset, aLength, aHash);
+        CacheHashEntry *entry = mCache.PutEntry(key);
+        NS_ASSERTION(!entry->mTextRun, "Entry shouldn't have existed!");
+
+        if (entry) {
             aTextRun->SetFlagBits(gfxTextRunWordCache::TEXT_IN_CACHE);
 
-    PRUint32 i;
+            entry->mTextRun = aTextRun;
+            entry->mWordOffset = aDestOffset;
             gfxFontGroup *fontGroup = aTextRun->GetFontGroup();
-    gfxFont *font = fontGroup->GetFontAt(0);
-    // copy deferred words from various sources into destination textrun
-    for (i = 0; i < aDeferredWords.Length(); ++i) {
-        const DeferredWord *word = &aDeferredWords[i];
-        gfxTextRun *source = word->mSourceTextRun;
-        if (!source) {
-            source = aNewRun;
-        }
-        // If the word starts inside a cluster we don't want this word
-        // in the cache, so we'll remove the associated cache entry
-        PRBool wordStartsInsideCluster =
-            !source->IsClusterStart(word->mSourceOffset);
-        if (source == aNewRun) {
-            // We created a cache entry for this word based on the assumption
-            // that the word matches GetFontAt(0). If this assumption is false,
-            // we need to remove that cache entry and replace it with an entry
-            // keyed off the fontgroup.
-            PRBool rekeyWithFontGroup =
-                GetWordFontOrGroup(aNewRun, word->mSourceOffset, word->mLength) != font;
-            if (!aSuccessful || wordStartsInsideCluster || rekeyWithFontGroup) {
-                // We need to remove the current placeholder cache entry
-                CacheHashKey key(aTextRun, font, word->mDestOffset, word->mLength,
-                                 word->mHash);
-                NS_ASSERTION(mCache.GetEntry(key),
-                             "This entry should have been added previously!");
-                mCache.RemoveEntry(key);
-#ifdef DEBUG
-                --aTextRun->mCachedWords;
-#endif
-                PR_LOG(gWordCacheLog, PR_LOG_DEBUG, ("%p(%d-%d,%d): removed using font", aTextRun, word->mDestOffset, word->mLength, word->mHash));
-                
-                if (aSuccessful && !wordStartsInsideCluster) {
-                    key.mFontOrGroup = fontGroup;
-                    CacheHashEntry *groupEntry = mCache.PutEntry(key);
-                    if (groupEntry) {
+            entry->mHashedByFont = key.mFontOrGroup != fontGroup;
 #ifdef DEBUG
             ++aTextRun->mCachedWords;
-#endif
-                        PR_LOG(gWordCacheLog, PR_LOG_DEBUG, ("%p(%d-%d,%d): added using fontgroup", aTextRun, word->mDestOffset, word->mLength, word->mHash));
-                        groupEntry->mTextRun = aTextRun;
-                        groupEntry->mWordOffset = word->mDestOffset;
-                        groupEntry->mHashedByFont = PR_FALSE;
+            PR_LOG(gWordCacheLog, PR_LOG_DEBUG,
+                   ("%p(%d-%d,%d): added using %s",
+                    aTextRun, aDestOffset, aLength, aHash,
+                    entry->mHashedByFont ? "font" :"fontgroup"));
             NS_ASSERTION(mCache.GetEntry(key),
                          "We should find the thing we just added!");
+#endif
         }
     }
-            }
-        }
-        if (aSuccessful) {
-            // Copy the word. If the source is aNewRun, then
-            // allow CopyGlyphDataFrom to steal the internal data of
-            // aNewRun since that's only temporary anyway.
-            PRUint32 sourceOffset = word->mSourceOffset;
-            PRUint32 destOffset = word->mDestOffset;
-            PRUint32 length = word->mLength;
-            nsAutoPtr<gfxTextRun> tmpTextRun;
-            PRBool stealData = source == aNewRun;
-            if (wordStartsInsideCluster) {
+    else { // wordStartsInsideCluster
         NS_ASSERTION(sourceOffset > 0, "How can the first character be inside a cluster?");
         if (destOffset > 0 && IsBoundarySpace(aTextRun->GetChar(destOffset - 1))) {
             // We should copy over data for the preceding space
@@ -404,32 +316,18 @@ TextRunWordCache::FinishTextRun(gfxTextRun *aTextRun, gfxTextRun *aNewRun,
             // But now the data in aNewRun is no use to us. We
             // need to find out what the platform would do
             // if the marks were at the start of the text.
-                    tmpTextRun = aNewRun->GetFontGroup()->MakeTextRun(
-                        aTextRun->GetTextUnicode(), length, aParams,
+            tmpTextRun = aNewRun->GetFontGroup()->
+                MakeTextRun(aTextRun->GetTextUnicode(), length, aParams,
                             aNewRun->GetFlags());
             source = tmpTextRun;
             sourceOffset = 0;
-                    stealData = PR_TRUE;
         }
     }
+    // Copy the word.
+    // Allow CopyGlyphDataFrom to steal the internal data of
+    // aNewRun or tmpTextRun since they are only temporary anyway.
     aTextRun->CopyGlyphDataFrom(source, sourceOffset, length,
-                destOffset, stealData);
-            // Fill in additional spaces
-            PRUint32 endCharIndex;
-            if (i + 1 < aDeferredWords.Length()) {
-                endCharIndex = aDeferredWords[i + 1].mDestOffset;
-            } else {
-                endCharIndex = aTextRun->GetLength();
-            }
-            PRUint32 charIndex;
-            for (charIndex = word->mDestOffset + word->mLength;
-                 charIndex < endCharIndex; ++charIndex) {
-                if (IsBoundarySpace(aTextRun->GetChar(charIndex))) {
-                    aTextRun->SetSpaceGlyph(font, aParams->mContext, charIndex);
-                }
-            }
-        }
-    }
+                                destOffset, PR_TRUE);
 }
 
 static gfxTextRun *
@@ -472,38 +370,47 @@ TextRunWordCache::MakeTextRun(const PRUnichar *aText, PRUint32 aLength,
     nsresult rv = textRun->AddGlyphRun(font, 0);
     NS_ENSURE_SUCCESS(rv, nsnull);
 
+    gfxTextRunFactory::Parameters params =
+        { aParams->mContext, nsnull, nsnull, nsnull, 0, aParams->mAppUnitsPerDevUnit };
     nsAutoTArray<PRUnichar,200> tempString;
-    nsAutoTArray<DeferredWord,50> deferredWords;
     PRUint32 i;
     PRUint32 wordStart = 0;
     PRUint32 hash = 0;
     for (i = 0; i <= aLength; ++i) {
         PRUnichar ch = i < aLength ? aText[i] : ' ';
         if (IsWordBoundary(ch)) {
-            PRBool hit = LookupWord(textRun, font, wordStart, i, hash,
-                                    deferredWords.Length() == 0 ? nsnull : &deferredWords);
+            PRBool hit = LookupWord(textRun, font, wordStart, i, hash);
             if (!hit) {
                 // Always put a space before the word so we can detect
                 // combining characters at the start of a word
                 tempString.AppendElement(' ');
                 PRUint32 offset = tempString.Length();
                 PRUint32 length = i - wordStart;
+
                 PRUnichar *chars = tempString.AppendElements(length);
-                if (!chars) {
-                    FinishTextRun(textRun, nsnull, nsnull, deferredWords, PR_FALSE);
+                if (!chars)
                     return nsnull;
-                }
                 memcpy(chars, aText + wordStart, length*sizeof(PRUnichar));
-                DeferredWord word = { nsnull, offset, wordStart, length, hash };
-                deferredWords.AppendElement(word);
+
+                // create textrun for this unknown word
+                nsAutoPtr<gfxTextRun> newRun;
+                newRun = aFontGroup->
+                    MakeTextRun(tempString.Elements(), tempString.Length(),
+                                &params,
+                                aFlags | gfxTextRunFactory::TEXT_IS_PERSISTENT);
+
+                if (newRun) {
+                    AddWord(textRun, wordStart, newRun, offset, length, hash,
+                            aParams);
+                }
+                tempString.Clear();
             }
             
-            if (deferredWords.Length() == 0) {
             if (IsBoundarySpace(ch) && i < aLength) {
                 textRun->SetSpaceGlyph(font, aParams->mContext, i);
             } // else we should set this character to be invisible missing,
               // but it already is because the textrun is blank!
-            }
+
             hash = 0;
             wordStart = i + 1;
         } else {
@@ -511,21 +418,6 @@ TextRunWordCache::MakeTextRun(const PRUnichar *aText, PRUint32 aLength,
         }
     }
 
-    if (deferredWords.Length() == 0) {
-        // We got everything from the cache, so we're done. No point in calling
-        // FinishTextRun.
-        // This textrun is not referenced by the cache.
-        return textRun.forget();
-    }
-
-    // create textrun for unknown words
-    gfxTextRunFactory::Parameters params =
-        { aParams->mContext, nsnull, nsnull, nsnull, 0, aParams->mAppUnitsPerDevUnit };
-    nsAutoPtr<gfxTextRun> newRun;
-    newRun = aFontGroup->MakeTextRun(tempString.Elements(), tempString.Length(),
-                                     &params, aFlags | gfxTextRunFactory::TEXT_IS_PERSISTENT);
-
-    FinishTextRun(textRun, newRun, aParams, deferredWords, newRun != nsnull);
     return textRun.forget();
 }
 
@@ -555,38 +447,34 @@ TextRunWordCache::MakeTextRun(const PRUint8 *aText, PRUint32 aLength,
     nsresult rv = textRun->AddGlyphRun(font, 0);
     NS_ENSURE_SUCCESS(rv, nsnull);
 
-    nsAutoTArray<PRUint8,200> tempString;
-    nsAutoTArray<DeferredWord,50> deferredWords;
+    gfxTextRunFactory::Parameters params =
+        { aParams->mContext, nsnull, nsnull, nsnull, 0, aParams->mAppUnitsPerDevUnit };
     PRUint32 i;
     PRUint32 wordStart = 0;
     PRUint32 hash = 0;
     for (i = 0; i <= aLength; ++i) {
         PRUint8 ch = i < aLength ? aText[i] : ' ';
         if (IsWordBoundary(ch)) {
-            PRBool hit = LookupWord(textRun, font, wordStart, i, hash,
-                                    deferredWords.Length() == 0 ? nsnull : &deferredWords);
+            PRBool hit = LookupWord(textRun, font, wordStart, i, hash);
             if (!hit) {
-                if (tempString.Length() > 0) {
-                    tempString.AppendElement(' ');
-                }
-                PRUint32 offset = tempString.Length();
                 PRUint32 length = i - wordStart;
-                PRUint8 *chars = tempString.AppendElements(length);
-                if (!chars) {
-                    FinishTextRun(textRun, nsnull, nsnull, deferredWords, PR_FALSE);
-                    return nsnull;
+
+                // create textrun for this unknown word
+                nsAutoPtr<gfxTextRun> newRun;
+                newRun = aFontGroup->
+                    MakeTextRun(aText + wordStart, length, &params,
+                                aFlags | gfxTextRunFactory::TEXT_IS_PERSISTENT);
+                if (newRun) {
+                    AddWord(textRun, wordStart, newRun, 0, length, hash,
+                            aParams);
                 }
-                memcpy(chars, aText + wordStart, length*sizeof(PRUint8));
-                DeferredWord word = { nsnull, offset, wordStart, length, hash };
-                deferredWords.AppendElement(word);
             }
             
-            if (deferredWords.Length() == 0) {
             if (IsBoundarySpace(ch) && i < aLength) {
                 textRun->SetSpaceGlyph(font, aParams->mContext, i);
             } // else we should set this character to be invisible missing,
               // but it already is because the textrun is blank!
-            }
+
             hash = 0;
             wordStart = i + 1;
         } else {
@@ -594,21 +482,6 @@ TextRunWordCache::MakeTextRun(const PRUint8 *aText, PRUint32 aLength,
         }
     }
 
-    if (deferredWords.Length() == 0) {
-        // We got everything from the cache, so we're done. No point in calling
-        // FinishTextRun.
-        // This textrun is not referenced by the cache.
-        return textRun.forget();
-    }
-
-    // create textrun for unknown words
-    gfxTextRunFactory::Parameters params =
-        { aParams->mContext, nsnull, nsnull, nsnull, 0, aParams->mAppUnitsPerDevUnit };
-    nsAutoPtr<gfxTextRun> newRun;
-    newRun = aFontGroup->MakeTextRun(tempString.Elements(), tempString.Length(),
-                                     &params, aFlags | gfxTextRunFactory::TEXT_IS_PERSISTENT);
-
-    FinishTextRun(textRun, newRun, aParams, deferredWords, newRun != nsnull);
     return textRun.forget();
 }
 
@@ -739,7 +612,7 @@ TextRunWordCache::CacheDumpEntry(CacheHashEntry* aEntry, void* userArg)
         fprintf(output, "<EMPTY>\n");
         return PL_DHASH_NEXT;
     }
-    fprintf(output, "Word at %x:%d => ", aEntry->mTextRun, aEntry->mWordOffset);
+    fprintf(output, "Word at %p:%d => ", static_cast<void*>(aEntry->mTextRun), aEntry->mWordOffset);
     aEntry->mTextRun->Dump(output);
     fprintf(output, " (hashed by %s)\n", aEntry->mHashedByFont ? "font" : "fontgroup");
     return PL_DHASH_NEXT;