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Speed up cache lookup

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Avoid copying the string for cache lookup.

Bug: 17111260
Change-Id: Ic220bfc991fc6b3dada197304aabdf72a8941bd7
This commit is contained in:
Behdad Esfahbod 2014-08-20 17:41:51 -04:00
parent 2f24599f4a
commit a33151e9c7
2 changed files with 66 additions and 35 deletions
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2
engine/src/flutter/include/minikin/Layout.h
View File

@ -97,6 +97,8 @@ public:
static void purgeCaches();
private:
friend class LayoutCacheKey;
// Find a face in the mFaces vector, or create a new entry
int findFace(FakedFont face, LayoutContext* ctx);

99
engine/src/flutter/libs/minikin/Layout.cpp
View File

@ -56,6 +56,19 @@ enum {
const int kDirection_Mask = 0x1;
struct LayoutContext {
MinikinPaint paint;
FontStyle style;
std::vector<hb_font_t*> hbFonts; // parallel to mFaces
void clearHbFonts() {
for (size_t i = 0; i < hbFonts.size(); i++) {
hb_font_destroy(hbFonts[i]);
}
hbFonts.clear();
}
};
// Layout cache datatypes
class LayoutCacheKey {
@ -65,16 +78,32 @@ public:
: mStart(start), mCount(count), mId(collection->getId()), mStyle(style),
mSize(paint.size), mScaleX(paint.scaleX), mSkewX(paint.skewX),
mLetterSpacing(paint.letterSpacing),
mPaintFlags(paint.paintFlags), mIsRtl(dir) {
mText.setTo(chars, nchars);
mPaintFlags(paint.paintFlags), mIsRtl(dir),
mChars(chars), mNchars(nchars) {
}
bool operator==(const LayoutCacheKey &other) const;
hash_t hash() const;
// This is present to avoid having to copy the text more than once.
const uint16_t* textBuf() { return mText.string(); }
void copyText() {
uint16_t* charsCopy = new uint16_t[mNchars];
memcpy(charsCopy, mChars, mNchars * sizeof(uint16_t));
mChars = charsCopy;
}
void freeText() {
delete[] mChars;
mChars = NULL;
}
void doLayout(Layout* layout, LayoutContext* ctx, const FontCollection* collection) const {
layout->setFontCollection(collection);
layout->mAdvances.resize(mCount, 0);
ctx->clearHbFonts();
layout->doLayoutRun(mChars, mStart, mCount, mNchars, mIsRtl, ctx);
}
private:
String16 mText;
const uint16_t* mChars;
size_t mNchars;
size_t mStart;
size_t mCount;
uint32_t mId; // for the font collection
@ -95,13 +124,30 @@ public:
mCache.setOnEntryRemovedListener(this);
}
void clear() {
mCache.clear();
}
Layout* get(LayoutCacheKey& key, LayoutContext* ctx, const FontCollection* collection) {
Layout* layout = mCache.get(key);
if (layout == NULL) {
key.copyText();
layout = new Layout();
key.doLayout(layout, ctx, collection);
mCache.put(key, layout);
}
return layout;
}
private:
// callback for OnEntryRemoved
void operator()(LayoutCacheKey& key, Layout*& value) {
key.freeText();
delete value;
}
LruCache<LayoutCacheKey, Layout*> mCache;
private:
//static const size_t kMaxEntries = LruCache<LayoutCacheKey, Layout*>::kUnlimitedCapacity;
// TODO: eviction based on memory footprint; for now, we just use a constant
@ -149,7 +195,8 @@ bool LayoutCacheKey::operator==(const LayoutCacheKey& other) const {
&& mLetterSpacing == other.mLetterSpacing
&& mPaintFlags == other.mPaintFlags
&& mIsRtl == other.mIsRtl
&& mText == other.mText;
&& mNchars == other.mNchars
&& !memcmp(mChars, other.mChars, mNchars * sizeof(uint16_t));
}
hash_t LayoutCacheKey::hash() const {
@ -163,16 +210,10 @@ hash_t LayoutCacheKey::hash() const {
hash = JenkinsHashMix(hash, hash_type(mLetterSpacing));
hash = JenkinsHashMix(hash, hash_type(mPaintFlags));
hash = JenkinsHashMix(hash, hash_type(mIsRtl));
hash = JenkinsHashMixShorts(hash, mText.string(), mText.size());
hash = JenkinsHashMixShorts(hash, mChars, mNchars);
return JenkinsHashWhiten(hash);
}
struct LayoutContext {
MinikinPaint paint;
FontStyle style;
std::vector<hb_font_t*> hbFonts; // parallel to mFaces
};
hash_t hash_type(const LayoutCacheKey& key) {
return key.hash();
}
@ -467,13 +508,6 @@ static size_t getNextWordBreak(const uint16_t* chars, size_t offset, size_t len)
return len;
}
static void clearHbFonts(LayoutContext* ctx) {
for (size_t i = 0; i < ctx->hbFonts.size(); i++) {
hb_font_destroy(ctx->hbFonts[i]);
}
ctx->hbFonts.clear();
}
void Layout::doLayout(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
int bidiFlags, const FontStyle &style, const MinikinPaint &paint) {
AutoMutex _l(gMinikinLock);
@ -543,7 +577,7 @@ void Layout::doLayout(const uint16_t* buf, size_t start, size_t count, size_t bu
if (doSingleRun) {
doLayoutRunCached(buf, start, count, bufSize, isRtl, &ctx, start);
}
clearHbFonts(&ctx);
ctx.clearHbFonts();
}
void Layout::doLayoutRunCached(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
@ -579,19 +613,14 @@ void Layout::doLayoutWord(const uint16_t* buf, size_t start, size_t count, size_
LayoutCache& cache = LayoutEngine::getInstance().layoutCache;
LayoutCacheKey key(mCollection, ctx->paint, ctx->style, buf, start, count, bufSize, isRtl);
bool skipCache = ctx->paint.skipCache();
Layout* value = skipCache ? NULL : cache.mCache.get(key);
if (value == NULL) {
value = new Layout();
value->setFontCollection(mCollection);
value->mAdvances.resize(count, 0);
clearHbFonts(ctx);
// Note: we do the layout from the copy stored in the key, in case a
// badly-behaved client is mutating the buffer in a separate thread.
value->doLayoutRun(key.textBuf(), start, count, bufSize, isRtl, ctx);
if (skipCache) {
Layout layout;
key.doLayout(&layout, ctx, mCollection);
appendLayout(&layout, bufStart);
} else {
Layout* layout = cache.get(key, ctx, mCollection);
appendLayout(layout, bufStart);
}
appendLayout(value, bufStart);
if (!skipCache)
cache.mCache.put(key, value);
}
static void addFeatures(const string &str, vector<hb_feature_t>* features) {
@ -821,7 +850,7 @@ void Layout::getBounds(MinikinRect* bounds) {
void Layout::purgeCaches() {
AutoMutex _l(gMinikinLock);
LayoutCache& layoutCache = LayoutEngine::getInstance().layoutCache;
layoutCache.mCache.clear();
layoutCache.clear();
HbFaceCache& hbCache = LayoutEngine::getInstance().hbFaceCache;
hbCache.mCache.clear();
}