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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "TextLayoutCache.h"
namespace android {
TextLayoutCache::TextLayoutCache():
mCache(GenerationCache<TextLayoutCacheKey, TextLayoutCacheValue*>::kUnlimitedCapacity),
mSize(0), mMaxSize(MB(DEFAULT_TEXT_LAYOUT_CACHE_SIZE_IN_MB)),
mCacheHitCount(0), mNanosecondsSaved(0) {
init();
}
TextLayoutCache::TextLayoutCache(uint32_t max):
mCache(GenerationCache<TextLayoutCacheKey, TextLayoutCacheValue*>::kUnlimitedCapacity),
mSize(0), mMaxSize(max),
mCacheHitCount(0), mNanosecondsSaved(0) {
init();
}
TextLayoutCache::~TextLayoutCache() {
mCache.clear();
}
void TextLayoutCache::init() {
mCache.setOnEntryRemovedListener(this);
mDebugLevel = readRtlDebugLevel();
mDebugEnabled = mDebugLevel & kRtlDebugCaches;
LOGD("Using TextLayoutCache debug level: %d - Debug Enabled: %d", mDebugLevel, mDebugEnabled);
mCacheStartTime = systemTime(SYSTEM_TIME_MONOTONIC);
if (mDebugEnabled) {
LOGD("TextLayoutCache start time: %lld", mCacheStartTime);
}
mInitialized = true;
if (mDebugEnabled) {
#if RTL_USE_HARFBUZZ
LOGD("TextLayoutCache is using HARFBUZZ");
#else
LOGD("TextLayoutCache is using ICU");
#endif
}
if (mDebugEnabled) {
LOGD("TextLayoutCache initialization is done");
}
}
/*
* Size management
*/
uint32_t TextLayoutCache::getSize() {
return mSize;
}
uint32_t TextLayoutCache::getMaxSize() {
return mMaxSize;
}
void TextLayoutCache::setMaxSize(uint32_t maxSize) {
mMaxSize = maxSize;
removeOldests();
}
void TextLayoutCache::removeOldests() {
while (mSize > mMaxSize) {
mCache.removeOldest();
}
}
/**
* Callbacks
*/
void TextLayoutCache::operator()(TextLayoutCacheKey& text, TextLayoutCacheValue*& desc) {
if (desc) {
size_t totalSizeToDelete = text.getSize() + desc->getSize();
mSize -= totalSizeToDelete;
if (mDebugEnabled) {
LOGD("Cache value deleted, size = %d", totalSizeToDelete);
}
delete desc;
}
}
/*
* Cache clearing
*/
void TextLayoutCache::clear() {
mCache.clear();
}
/*
* Caching
*/
void TextLayoutCache::getRunAdvances(SkPaint* paint, const jchar* text,
jint start, jint count, jint contextCount, jint dirFlags,
jfloat* outAdvances, jfloat* outTotalAdvance) {
AutoMutex _l(mLock);
nsecs_t startTime = 0;
if (mDebugEnabled) {
startTime = systemTime(SYSTEM_TIME_MONOTONIC);
}
TextLayoutCacheKey key(paint, text, start, count, contextCount, dirFlags);
// Get entry for cache if possible
TextLayoutCacheValue* value = mCache.get(key);
// Value not found for the entry, we need to add a new value in the cache
if (!value) {
value = new TextLayoutCacheValue();
// Compute advances and store them
value->computeAdvances(paint, text, start, count, contextCount, dirFlags);
value->copyResult(outAdvances, outTotalAdvance);
// Don't bother to add in the cache if the entry is too big
size_t size = key.getSize() + value->getSize();
if (size <= mMaxSize) {
// Cleanup to make some room if needed
if (mSize + size > mMaxSize) {
if (mDebugEnabled) {
LOGD("TextLayoutCache: need to clean some entries "
"for making some room for a new entry");
}
while (mSize + size > mMaxSize) {
// This will call the callback
mCache.removeOldest();
}
}
// Update current cache size
mSize += size;
// Copy the text when we insert the new entry
key.internalTextCopy();
mCache.put(key, value);
if (mDebugEnabled) {
// Update timing information for statistics.
value->setElapsedTime(systemTime(SYSTEM_TIME_MONOTONIC) - startTime);
LOGD("CACHE MISS: Added entry for text='%s' with start=%d, count=%d, "
"contextCount=%d, entry size %d bytes, remaining space %d bytes"
" - Compute time in nanos: %d",
String8(text, contextCount).string(), start, count, contextCount,
size, mMaxSize - mSize, value->getElapsedTime());
}
} else {
if (mDebugEnabled) {
LOGD("CACHE MISS: Calculated but not storing entry because it is too big "
"for text='%s' with start=%d, count=%d, contextCount=%d, "
"entry size %d bytes, remaining space %d bytes"
" - Compute time in nanos: %d",
String8(text, contextCount).string(), start, count, contextCount,
size, mMaxSize - mSize, value->getElapsedTime());
}
delete value;
}
} else {
// This is a cache hit, just copy the pre-computed results
value->copyResult(outAdvances, outTotalAdvance);
if (mDebugEnabled) {
nsecs_t elapsedTimeThruCacheGet = systemTime(SYSTEM_TIME_MONOTONIC) - startTime;
mNanosecondsSaved += (value->getElapsedTime() - elapsedTimeThruCacheGet);
++mCacheHitCount;
if (value->getElapsedTime() > 0) {
float deltaPercent = 100 * ((value->getElapsedTime() - elapsedTimeThruCacheGet)
/ ((float)value->getElapsedTime()));
LOGD("CACHE HIT #%d for text='%s' with start=%d, count=%d, contextCount=%d "
"- Compute time in nanos: %d - "
"Cache get time in nanos: %lld - Gain in percent: %2.2f",
mCacheHitCount, String8(text, contextCount).string(), start, count,
contextCount,
value->getElapsedTime(), elapsedTimeThruCacheGet, deltaPercent);
}
if (mCacheHitCount % DEFAULT_DUMP_STATS_CACHE_HIT_INTERVAL == 0) {
dumpCacheStats();
}
}
}
}
void TextLayoutCache::dumpCacheStats() {
float remainingPercent = 100 * ((mMaxSize - mSize) / ((float)mMaxSize));
float timeRunningInSec = (systemTime(SYSTEM_TIME_MONOTONIC) - mCacheStartTime) / 1000000000;
LOGD("------------------------------------------------");
LOGD("TextLayoutCache stats");
LOGD("------------------------------------------------");
LOGD("running : %.0f seconds", timeRunningInSec);
LOGD("size : %d bytes", mMaxSize);
LOGD("remaining : %d bytes or %2.2f percent", mMaxSize - mSize, remainingPercent);
LOGD("hits : %d", mCacheHitCount);
LOGD("saved : %lld milliseconds", mNanosecondsSaved / 1000000);
LOGD("------------------------------------------------");
}
/**
* TextLayoutCacheKey
*/
TextLayoutCacheKey::TextLayoutCacheKey() : text(NULL), start(0), count(0), contextCount(0),
dirFlags(0), typeface(NULL), textSize(0), textSkewX(0), textScaleX(0), flags(0),
hinting(SkPaint::kNo_Hinting) {
}
TextLayoutCacheKey::TextLayoutCacheKey(const SkPaint* paint,
const UChar* text, size_t start, size_t count,
size_t contextCount, int dirFlags) :
text(text), start(start), count(count), contextCount(contextCount),
dirFlags(dirFlags) {
typeface = paint->getTypeface();
textSize = paint->getTextSize();
textSkewX = paint->getTextSkewX();
textScaleX = paint->getTextScaleX();
flags = paint->getFlags();
hinting = paint->getHinting();
}
bool TextLayoutCacheKey::operator<(const TextLayoutCacheKey& rhs) const {
LTE_INT(count) {
LTE_INT(contextCount) {
LTE_INT(start) {
LTE_INT(typeface) {
LTE_FLOAT(textSize) {
LTE_FLOAT(textSkewX) {
LTE_FLOAT(textScaleX) {
LTE_INT(flags) {
LTE_INT(hinting) {
LTE_INT(dirFlags) {
return strncmp16(text, rhs.text, contextCount) < 0;
}
}
}
}
}
}
}
}
}
}
return false;
}
void TextLayoutCacheKey::internalTextCopy() {
textCopy.setTo(text, contextCount);
text = textCopy.string();
}
size_t TextLayoutCacheKey::getSize() {
return sizeof(TextLayoutCacheKey) + sizeof(UChar) * contextCount;
}
/**
* TextLayoutCacheValue
*/
TextLayoutCacheValue::TextLayoutCacheValue() {
advances = NULL;
totalAdvance = 0;
}
TextLayoutCacheValue::~TextLayoutCacheValue() {
delete[] advances;
}
void TextLayoutCacheValue::setElapsedTime(uint32_t time) {
elapsedTime = time;
}
uint32_t TextLayoutCacheValue::getElapsedTime() {
return elapsedTime;
}
void TextLayoutCacheValue::computeAdvances(SkPaint* paint, const UChar* chars, size_t start,
size_t count, size_t contextCount, int dirFlags) {
advances = new float[count];
this->count = count;
#if RTL_USE_HARFBUZZ
computeAdvancesWithHarfbuzz(paint, chars, start, count, contextCount, dirFlags,
advances, &totalAdvance);
#else
computeAdvancesWithICU(paint, chars, start, count, contextCount, dirFlags,
advances, &totalAdvance);
#endif
#if DEBUG_ADVANCES
LOGD("Advances - count=%d - countextCount=%d - totalAdvance=%f - "
"adv[0]=%f adv[1]=%f adv[2]=%f adv[3]=%f", count, contextCount, totalAdvance,
advances[0], advances[1], advances[2], advances[3]);
#endif
}
void TextLayoutCacheValue::copyResult(jfloat* outAdvances, jfloat* outTotalAdvance) {
memcpy(outAdvances, advances, count * sizeof(jfloat));
*outTotalAdvance = totalAdvance;
}
size_t TextLayoutCacheValue::getSize() {
return sizeof(TextLayoutCacheValue) + sizeof(jfloat) * count;
}
void TextLayoutCacheValue::setupShaperItem(HB_ShaperItem* shaperItem, HB_FontRec* font,
FontData* fontData, SkPaint* paint, const UChar* chars, size_t start, size_t count,
size_t contextCount, int dirFlags) {
bool isRTL = dirFlags & 0x1;
font->klass = &harfbuzzSkiaClass;
font->userData = 0;
// The values which harfbuzzSkiaClass returns are already scaled to
// pixel units, so we just set all these to one to disable further
// scaling.
font->x_ppem = 1;
font->y_ppem = 1;
font->x_scale = 1;
font->y_scale = 1;
memset(shaperItem, 0, sizeof(*shaperItem));
shaperItem->font = font;
shaperItem->face = HB_NewFace(shaperItem->font, harfbuzzSkiaGetTable);
shaperItem->kerning_applied = false;
// We cannot know, ahead of time, how many glyphs a given script run
// will produce. We take a guess that script runs will not produce more
// than twice as many glyphs as there are code points plus a bit of
// padding and fallback if we find that we are wrong.
createGlyphArrays(shaperItem, (contextCount + 2) * 2);
// Free memory for clusters if needed and recreate the clusters array
if (shaperItem->log_clusters) {
delete shaperItem->log_clusters;
}
shaperItem->log_clusters = new unsigned short[contextCount];
shaperItem->item.pos = start;
shaperItem->item.length = count;
shaperItem->item.bidiLevel = isRTL;
shaperItem->item.script = isRTL ? HB_Script_Arabic : HB_Script_Common;
shaperItem->string = chars;
shaperItem->stringLength = contextCount;
fontData->typeFace = paint->getTypeface();
fontData->textSize = paint->getTextSize();
fontData->textSkewX = paint->getTextSkewX();
fontData->textScaleX = paint->getTextScaleX();
fontData->flags = paint->getFlags();
fontData->hinting = paint->getHinting();
shaperItem->font->userData = fontData;
}
void TextLayoutCacheValue::shapeWithHarfbuzz(HB_ShaperItem* shaperItem, HB_FontRec* font,
FontData* fontData, SkPaint* paint, const UChar* chars, size_t start, size_t count,
size_t contextCount, int dirFlags) {
// Setup Harfbuzz Shaper
setupShaperItem(shaperItem, font, fontData, paint, chars, start, count,
contextCount, dirFlags);
// Shape
resetGlyphArrays(shaperItem);
while (!HB_ShapeItem(shaperItem)) {
// We overflowed our arrays. Resize and retry.
// HB_ShapeItem fills in shaperItem.num_glyphs with the needed size.
deleteGlyphArrays(shaperItem);
createGlyphArrays(shaperItem, shaperItem->num_glyphs << 1);
resetGlyphArrays(shaperItem);
}
}
void TextLayoutCacheValue::computeAdvancesWithHarfbuzz(SkPaint* paint, const UChar* chars,
size_t start, size_t count, size_t contextCount, int dirFlags,
jfloat* outAdvances, jfloat* outTotalAdvance) {
bool isRTL = dirFlags & 0x1;
HB_ShaperItem shaperItem;
HB_FontRec font;
FontData fontData;
shapeWithHarfbuzz(&shaperItem, &font, &fontData, paint, chars, start, count,
contextCount, dirFlags);
#if DEBUG_ADVANCES
LOGD("HARFBUZZ -- num_glypth=%d - kerning_applied=%d", shaperItem.num_glyphs,
shaperItem.kerning_applied);
LOGD(" -- string= '%s'", String8(chars, contextCount).string());
LOGD(" -- isDevKernText=%d", paint->isDevKernText());
#endif
jfloat totalAdvance = 0;
for (size_t i = 0; i < count; i++) {
totalAdvance += outAdvances[i] = HBFixedToFloat(shaperItem.advances[i]);
#if DEBUG_ADVANCES
LOGD("hb-adv = %d - rebased = %f - total = %f", shaperItem.advances[i], outAdvances[i],
totalAdvance);
#endif
}
deleteGlyphArrays(&shaperItem);
HB_FreeFace(shaperItem.face);
*outTotalAdvance = totalAdvance;
}
void TextLayoutCacheValue::computeAdvancesWithICU(SkPaint* paint, const UChar* chars,
size_t start, size_t count, size_t contextCount, int dirFlags,
jfloat* outAdvances, jfloat* outTotalAdvance) {
SkAutoSTMalloc<CHAR_BUFFER_SIZE, jchar> tempBuffer(contextCount);
jchar* buffer = tempBuffer.get();
SkScalar* scalarArray = (SkScalar*)outAdvances;
// this is where we'd call harfbuzz
// for now we just use ushape.c
size_t widths;
const jchar* text;
if (dirFlags & 0x1) { // rtl, call arabic shaping in case
UErrorCode status = U_ZERO_ERROR;
// Use fixed length since we need to keep start and count valid
u_shapeArabic(chars, contextCount, buffer, contextCount,
U_SHAPE_LENGTH_FIXED_SPACES_NEAR |
U_SHAPE_TEXT_DIRECTION_LOGICAL | U_SHAPE_LETTERS_SHAPE |
U_SHAPE_X_LAMALEF_SUB_ALTERNATE, &status);
// we shouldn't fail unless there's an out of memory condition,
// in which case we're hosed anyway
for (int i = start, e = i + count; i < e; ++i) {
if (buffer[i] == UNICODE_NOT_A_CHAR) {
buffer[i] = UNICODE_ZWSP; // zero-width-space for skia
}
}
text = buffer + start;
widths = paint->getTextWidths(text, count << 1, scalarArray);
} else {
text = chars + start;
widths = paint->getTextWidths(text, count << 1, scalarArray);
}
jfloat totalAdvance = 0;
if (widths < count) {
#if DEBUG_ADVANCES
LOGD("ICU -- count=%d", widths);
#endif
// Skia operates on code points, not code units, so surrogate pairs return only
// one value. Expand the result so we have one value per UTF-16 code unit.
// Note, skia's getTextWidth gets confused if it encounters a surrogate pair,
// leaving the remaining widths zero. Not nice.
for (size_t i = 0, p = 0; i < widths; ++i) {
totalAdvance += outAdvances[p++] = SkScalarToFloat(scalarArray[i]);
if (p < count &&
text[p] >= UNICODE_FIRST_LOW_SURROGATE &&
text[p] < UNICODE_FIRST_PRIVATE_USE &&
text[p-1] >= UNICODE_FIRST_HIGH_SURROGATE &&
text[p-1] < UNICODE_FIRST_LOW_SURROGATE) {
outAdvances[p++] = 0;
}
#if DEBUG_ADVANCES
LOGD("icu-adv = %f - total = %f", outAdvances[i], totalAdvance);
#endif
}
} else {
#if DEBUG_ADVANCES
LOGD("ICU -- count=%d", count);
#endif
for (size_t i = 0; i < count; i++) {
totalAdvance += outAdvances[i] = SkScalarToFloat(scalarArray[i]);
#if DEBUG_ADVANCES
LOGD("icu-adv = %f - total = %f", outAdvances[i], totalAdvance);
#endif
}
}
*outTotalAdvance = totalAdvance;
}
void TextLayoutCacheValue::deleteGlyphArrays(HB_ShaperItem* shaperItem) {
delete[] shaperItem->glyphs;
delete[] shaperItem->attributes;
delete[] shaperItem->advances;
delete[] shaperItem->offsets;
}
void TextLayoutCacheValue::createGlyphArrays(HB_ShaperItem* shaperItem, int size) {
shaperItem->glyphs = new HB_Glyph[size];
shaperItem->attributes = new HB_GlyphAttributes[size];
shaperItem->advances = new HB_Fixed[size];
shaperItem->offsets = new HB_FixedPoint[size];
shaperItem->num_glyphs = size;
}
void TextLayoutCacheValue::resetGlyphArrays(HB_ShaperItem* shaperItem) {
int size = shaperItem->num_glyphs;
// All the types here don't have pointers. It is safe to reset to
// zero unless Harfbuzz breaks the compatibility in the future.
memset(shaperItem->glyphs, 0, size * sizeof(shaperItem->glyphs[0]));
memset(shaperItem->attributes, 0, size * sizeof(shaperItem->attributes[0]));
memset(shaperItem->advances, 0, size * sizeof(shaperItem->advances[0]));
memset(shaperItem->offsets, 0, size * sizeof(shaperItem->offsets[0]));
}
} // namespace android