/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkGlyphCache.h"
#include "SkGraphics.h"
#include "SkPaint.h"
#include "SkTemplates.h"
//#define SPEW_PURGE_STATUS
//#define USE_CACHE_HASH
//#define RECORD_HASH_EFFICIENCY
bool gSkSuppressFontCachePurgeSpew;
///////////////////////////////////////////////////////////////////////////////
#ifdef RECORD_HASH_EFFICIENCY
static uint32_t gHashSuccess;
static uint32_t gHashCollision;
static void RecordHashSuccess() {
gHashSuccess += 1;
}
static void RecordHashCollisionIf(bool pred) {
if (pred) {
gHashCollision += 1;
uint32_t total = gHashSuccess + gHashCollision;
SkDebugf("Font Cache Hash success rate: %d%%\n",
100 * gHashSuccess / total);
}
}
#else
#define RecordHashSuccess() (void)0
#define RecordHashCollisionIf(pred) (void)0
#endif
#define RecordHashCollision() RecordHashCollisionIf(true)
///////////////////////////////////////////////////////////////////////////////
#define kMinGlphAlloc (sizeof(SkGlyph) * 64)
#define kMinImageAlloc (24 * 64) // should be pointsize-dependent
#define METRICS_RESERVE_COUNT 128 // so we don't grow this array a lot
SkGlyphCache::SkGlyphCache(const SkDescriptor* desc)
: fGlyphAlloc(kMinGlphAlloc), fImageAlloc(kMinImageAlloc) {
fPrev = fNext = NULL;
fDesc = desc->copy();
fScalerContext = SkScalerContext::Create(desc);
fScalerContext->getFontMetrics(NULL, &fFontMetricsY);
// init to 0 so that all of the pointers will be null
memset(fGlyphHash, 0, sizeof(fGlyphHash));
// init with 0xFF so that the charCode field will be -1, which is invalid
memset(fCharToGlyphHash, 0xFF, sizeof(fCharToGlyphHash));
fMemoryUsed = sizeof(*this) + kMinGlphAlloc + kMinImageAlloc;
fGlyphArray.setReserve(METRICS_RESERVE_COUNT);
fMetricsCount = 0;
fAdvanceCount = 0;
fAuxProcList = NULL;
}
SkGlyphCache::~SkGlyphCache() {
SkGlyph** gptr = fGlyphArray.begin();
SkGlyph** stop = fGlyphArray.end();
while (gptr < stop) {
SkPath* path = (*gptr)->fPath;
if (path) {
SkDELETE(path);
}
gptr += 1;
}
SkDescriptor::Free(fDesc);
SkDELETE(fScalerContext);
this->invokeAndRemoveAuxProcs();
}
///////////////////////////////////////////////////////////////////////////////
#ifdef SK_DEBUG
#define VALIDATE() AutoValidate av(this)
#else
#define VALIDATE()
#endif
uint16_t SkGlyphCache::unicharToGlyph(SkUnichar charCode) {
VALIDATE();
uint32_t id = SkGlyph::MakeID(charCode);
const CharGlyphRec& rec = fCharToGlyphHash[ID2HashIndex(id)];
if (rec.fID == id) {
return rec.fGlyph->getGlyphID();
} else {
return fScalerContext->charToGlyphID(charCode);
}
}
SkUnichar SkGlyphCache::glyphToUnichar(uint16_t glyphID) {
return fScalerContext->glyphIDToChar(glyphID);
}
unsigned SkGlyphCache::getGlyphCount() {
return fScalerContext->getGlyphCount();
}
///////////////////////////////////////////////////////////////////////////////
const SkGlyph& SkGlyphCache::getUnicharAdvance(SkUnichar charCode) {
VALIDATE();
uint32_t id = SkGlyph::MakeID(charCode);
CharGlyphRec* rec = &fCharToGlyphHash[ID2HashIndex(id)];
if (rec->fID != id) {
// this ID is based on the UniChar
rec->fID = id;
// this ID is based on the glyph index
id = SkGlyph::MakeID(fScalerContext->charToGlyphID(charCode));
rec->fGlyph = this->lookupMetrics(id, kJustAdvance_MetricsType);
}
return *rec->fGlyph;
}
const SkGlyph& SkGlyphCache::getGlyphIDAdvance(uint16_t glyphID) {
VALIDATE();
uint32_t id = SkGlyph::MakeID(glyphID);
unsigned index = ID2HashIndex(id);
SkGlyph* glyph = fGlyphHash[index];
if (NULL == glyph || glyph->fID != id) {
glyph = this->lookupMetrics(glyphID, kJustAdvance_MetricsType);
fGlyphHash[index] = glyph;
}
return *glyph;
}
///////////////////////////////////////////////////////////////////////////////
const SkGlyph& SkGlyphCache::getUnicharMetrics(SkUnichar charCode) {
VALIDATE();
uint32_t id = SkGlyph::MakeID(charCode);
CharGlyphRec* rec = &fCharToGlyphHash[ID2HashIndex(id)];
if (rec->fID != id) {
RecordHashCollisionIf(rec->fGlyph != NULL);
// this ID is based on the UniChar
rec->fID = id;
// this ID is based on the glyph index
id = SkGlyph::MakeID(fScalerContext->charToGlyphID(charCode));
rec->fGlyph = this->lookupMetrics(id, kFull_MetricsType);
} else {
RecordHashSuccess();
if (rec->fGlyph->isJustAdvance()) {
fScalerContext->getMetrics(rec->fGlyph);
}
}
SkASSERT(rec->fGlyph->isFullMetrics());
return *rec->fGlyph;
}
const SkGlyph& SkGlyphCache::getUnicharMetrics(SkUnichar charCode,
SkFixed x, SkFixed y) {
VALIDATE();
uint32_t id = SkGlyph::MakeID(charCode, x, y);
CharGlyphRec* rec = &fCharToGlyphHash[ID2HashIndex(id)];
if (rec->fID != id) {
RecordHashCollisionIf(rec->fGlyph != NULL);
// this ID is based on the UniChar
rec->fID = id;
// this ID is based on the glyph index
id = SkGlyph::MakeID(fScalerContext->charToGlyphID(charCode), x, y);
rec->fGlyph = this->lookupMetrics(id, kFull_MetricsType);
} else {
RecordHashSuccess();
if (rec->fGlyph->isJustAdvance()) {
fScalerContext->getMetrics(rec->fGlyph);
}
}
SkASSERT(rec->fGlyph->isFullMetrics());
return *rec->fGlyph;
}
const SkGlyph& SkGlyphCache::getGlyphIDMetrics(uint16_t glyphID) {
VALIDATE();
uint32_t id = SkGlyph::MakeID(glyphID);
unsigned index = ID2HashIndex(id);
SkGlyph* glyph = fGlyphHash[index];
if (NULL == glyph || glyph->fID != id) {
RecordHashCollisionIf(glyph != NULL);
glyph = this->lookupMetrics(glyphID, kFull_MetricsType);
fGlyphHash[index] = glyph;
} else {
RecordHashSuccess();
if (glyph->isJustAdvance()) {
fScalerContext->getMetrics(glyph);
}
}
SkASSERT(glyph->isFullMetrics());
return *glyph;
}
const SkGlyph& SkGlyphCache::getGlyphIDMetrics(uint16_t glyphID,
SkFixed x, SkFixed y) {
VALIDATE();
uint32_t id = SkGlyph::MakeID(glyphID, x, y);
unsigned index = ID2HashIndex(id);
SkGlyph* glyph = fGlyphHash[index];
if (NULL == glyph || glyph->fID != id) {
RecordHashCollisionIf(glyph != NULL);
glyph = this->lookupMetrics(id, kFull_MetricsType);
fGlyphHash[index] = glyph;
} else {
RecordHashSuccess();
if (glyph->isJustAdvance()) {
fScalerContext->getMetrics(glyph);
}
}
SkASSERT(glyph->isFullMetrics());
return *glyph;
}
SkGlyph* SkGlyphCache::lookupMetrics(uint32_t id, MetricsType mtype) {
SkGlyph* glyph;
int hi = 0;
int count = fGlyphArray.count();
if (count) {
SkGlyph** gptr = fGlyphArray.begin();
int lo = 0;
hi = count - 1;
while (lo < hi) {
int mid = (hi + lo) >> 1;
if (gptr[mid]->fID < id) {
lo = mid + 1;
} else {
hi = mid;
}
}
glyph = gptr[hi];
if (glyph->fID == id) {
if (kFull_MetricsType == mtype && glyph->isJustAdvance()) {
fScalerContext->getMetrics(glyph);
}
return glyph;
}
// check if we need to bump hi before falling though to the allocator
if (glyph->fID < id) {
hi += 1;
}
}
// not found, but hi tells us where to inser the new glyph
fMemoryUsed += sizeof(SkGlyph);
glyph = (SkGlyph*)fGlyphAlloc.alloc(sizeof(SkGlyph),
SkChunkAlloc::kThrow_AllocFailType);
glyph->init(id);
*fGlyphArray.insert(hi) = glyph;
if (kJustAdvance_MetricsType == mtype) {
fScalerContext->getAdvance(glyph);
fAdvanceCount += 1;
} else {
SkASSERT(kFull_MetricsType == mtype);
fScalerContext->getMetrics(glyph);
fMetricsCount += 1;
}
return glyph;
}
const void* SkGlyphCache::findImage(const SkGlyph& glyph) {
if (glyph.fWidth > 0 && glyph.fWidth < kMaxGlyphWidth) {
if (glyph.fImage == NULL) {
size_t size = glyph.computeImageSize();
const_cast<SkGlyph&>(glyph).fImage = fImageAlloc.alloc(size,
SkChunkAlloc::kReturnNil_AllocFailType);
// check that alloc() actually succeeded
if (glyph.fImage) {
fScalerContext->getImage(glyph);
// TODO: the scaler may have changed the maskformat during
// getImage (e.g. from AA or LCD to BW) which means we may have
// overallocated the buffer. Check if the new computedImageSize
// is smaller, and if so, strink the alloc size in fImageAlloc.
fMemoryUsed += size;
}
}
}
return glyph.fImage;
}
const SkPath* SkGlyphCache::findPath(const SkGlyph& glyph) {
if (glyph.fWidth) {
if (glyph.fPath == NULL) {
const_cast<SkGlyph&>(glyph).fPath = SkNEW(SkPath);
fScalerContext->getPath(glyph, glyph.fPath);
fMemoryUsed += sizeof(SkPath) +
glyph.fPath->getPoints(NULL, 0x7FFFFFFF) * sizeof(SkPoint);
}
}
return glyph.fPath;
}
///////////////////////////////////////////////////////////////////////////////
bool SkGlyphCache::getAuxProcData(void (*proc)(void*), void** dataPtr) const {
const AuxProcRec* rec = fAuxProcList;
while (rec) {
if (rec->fProc == proc) {
if (dataPtr) {
*dataPtr = rec->fData;
}
return true;
}
rec = rec->fNext;
}
return false;
}
void SkGlyphCache::setAuxProc(void (*proc)(void*), void* data) {
if (proc == NULL) {
return;
}
AuxProcRec* rec = fAuxProcList;
while (rec) {
if (rec->fProc == proc) {
rec->fData = data;
return;
}
rec = rec->fNext;
}
// not found, create a new rec
rec = SkNEW(AuxProcRec);
rec->fProc = proc;
rec->fData = data;
rec->fNext = fAuxProcList;
fAuxProcList = rec;
}
void SkGlyphCache::removeAuxProc(void (*proc)(void*)) {
AuxProcRec* rec = fAuxProcList;
AuxProcRec* prev = NULL;
while (rec) {
AuxProcRec* next = rec->fNext;
if (rec->fProc == proc) {
if (prev) {
prev->fNext = next;
} else {
fAuxProcList = next;
}
SkDELETE(rec);
return;
}
prev = rec;
rec = next;
}
}
void SkGlyphCache::invokeAndRemoveAuxProcs() {
AuxProcRec* rec = fAuxProcList;
while (rec) {
rec->fProc(rec->fData);
AuxProcRec* next = rec->fNext;
SkDELETE(rec);
rec = next;
}
}
///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
#ifdef USE_CACHE_HASH
#define HASH_BITCOUNT 6
#define HASH_COUNT (1 << HASH_BITCOUNT)
#define HASH_MASK (HASH_COUNT - 1)
static unsigned desc_to_hashindex(const SkDescriptor* desc)
{
SkASSERT(HASH_MASK < 256); // since our munging reduces to 8 bits
uint32_t n = *(const uint32_t*)desc; //desc->getChecksum();
SkASSERT(n == desc->getChecksum());
// don't trust that the low bits of checksum vary enough, so...
n ^= (n >> 24) ^ (n >> 16) ^ (n >> 8) ^ (n >> 30);
return n & HASH_MASK;
}
#endif
#include "SkThread.h"
class SkGlyphCache_Globals {
public:
SkGlyphCache_Globals() {
fHead = NULL;
fTotalMemoryUsed = 0;
#ifdef USE_CACHE_HASH
sk_bzero(fHash, sizeof(fHash));
#endif
}
SkMutex fMutex;
SkGlyphCache* fHead;
size_t fTotalMemoryUsed;
#ifdef USE_CACHE_HASH
SkGlyphCache* fHash[HASH_COUNT];
#endif
#ifdef SK_DEBUG
void validate() const;
#else
void validate() const {}
#endif
};
static SkGlyphCache_Globals& getGlobals() {
// we leak this, so we don't incur any shutdown cost of the destructor
static SkGlyphCache_Globals* gGlobals = new SkGlyphCache_Globals;
return *gGlobals;
}
void SkGlyphCache::VisitAllCaches(bool (*proc)(SkGlyphCache*, void*),
void* context) {
SkGlyphCache_Globals& globals = getGlobals();
SkAutoMutexAcquire ac(globals.fMutex);
SkGlyphCache* cache;
globals.validate();
for (cache = globals.fHead; cache != NULL; cache = cache->fNext) {
if (proc(cache, context)) {
break;
}
}
globals.validate();
}
/* This guy calls the visitor from within the mutext lock, so the visitor
cannot:
- take too much time
- try to acquire the mutext again
- call a fontscaler (which might call into the cache)
*/
SkGlyphCache* SkGlyphCache::VisitCache(const SkDescriptor* desc,
bool (*proc)(const SkGlyphCache*, void*),
void* context) {
SkASSERT(desc);
SkGlyphCache_Globals& globals = getGlobals();
SkAutoMutexAcquire ac(globals.fMutex);
SkGlyphCache* cache;
bool insideMutex = true;
globals.validate();
#ifdef USE_CACHE_HASH
SkGlyphCache** hash = globals.fHash;
unsigned index = desc_to_hashindex(desc);
cache = hash[index];
if (cache && *cache->fDesc == *desc) {
cache->detach(&globals.fHead);
goto FOUND_IT;
}
#endif
for (cache = globals.fHead; cache != NULL; cache = cache->fNext) {
if (cache->fDesc->equals(*desc)) {
cache->detach(&globals.fHead);
goto FOUND_IT;
}
}
/* Release the mutex now, before we create a new entry (which might have
side-effects like trying to access the cache/mutex (yikes!)
*/
ac.release(); // release the mutex now
insideMutex = false; // can't use globals anymore
cache = SkNEW_ARGS(SkGlyphCache, (desc));
FOUND_IT:
AutoValidate av(cache);
if (proc(cache, context)) { // stay detached
if (insideMutex) {
SkASSERT(globals.fTotalMemoryUsed >= cache->fMemoryUsed);
globals.fTotalMemoryUsed -= cache->fMemoryUsed;
#ifdef USE_CACHE_HASH
hash[index] = NULL;
#endif
}
} else { // reattach
if (insideMutex) {
cache->attachToHead(&globals.fHead);
#ifdef USE_CACHE_HASH
hash[index] = cache;
#endif
} else {
AttachCache(cache);
}
cache = NULL;
}
return cache;
}
void SkGlyphCache::AttachCache(SkGlyphCache* cache) {
SkASSERT(cache);
SkASSERT(cache->fNext == NULL);
SkGlyphCache_Globals& globals = getGlobals();
SkAutoMutexAcquire ac(globals.fMutex);
globals.validate();
cache->validate();
// if we have a fixed budget for our cache, do a purge here
{
size_t allocated = globals.fTotalMemoryUsed + cache->fMemoryUsed;
size_t budgeted = SkGraphics::GetFontCacheLimit();
if (allocated > budgeted) {
(void)InternalFreeCache(&globals, allocated - budgeted);
}
}
cache->attachToHead(&globals.fHead);
globals.fTotalMemoryUsed += cache->fMemoryUsed;
#ifdef USE_CACHE_HASH
unsigned index = desc_to_hashindex(cache->fDesc);
SkASSERT(globals.fHash[index] != cache);
globals.fHash[index] = cache;
#endif
globals.validate();
}
size_t SkGlyphCache::GetCacheUsed() {
SkGlyphCache_Globals& globals = getGlobals();
SkAutoMutexAcquire ac(globals.fMutex);
return SkGlyphCache::ComputeMemoryUsed(globals.fHead);
}
bool SkGlyphCache::SetCacheUsed(size_t bytesUsed) {
size_t curr = SkGlyphCache::GetCacheUsed();
if (curr > bytesUsed) {
SkGlyphCache_Globals& globals = getGlobals();
SkAutoMutexAcquire ac(globals.fMutex);
return InternalFreeCache(&globals, curr - bytesUsed) > 0;
}
return false;
}
///////////////////////////////////////////////////////////////////////////////
SkGlyphCache* SkGlyphCache::FindTail(SkGlyphCache* cache) {
if (cache) {
while (cache->fNext) {
cache = cache->fNext;
}
}
return cache;
}
size_t SkGlyphCache::ComputeMemoryUsed(const SkGlyphCache* head) {
size_t size = 0;
while (head != NULL) {
size += head->fMemoryUsed;
head = head->fNext;
}
return size;
}
#ifdef SK_DEBUG
void SkGlyphCache_Globals::validate() const {
size_t computed = SkGlyphCache::ComputeMemoryUsed(fHead);
if (fTotalMemoryUsed != computed) {
printf("total %d, computed %d\n", (int)fTotalMemoryUsed, (int)computed);
}
SkASSERT(fTotalMemoryUsed == computed);
}
#endif
size_t SkGlyphCache::InternalFreeCache(SkGlyphCache_Globals* globals,
size_t bytesNeeded) {
globals->validate();
size_t bytesFreed = 0;
int count = 0;
// don't do any "small" purges
size_t minToPurge = globals->fTotalMemoryUsed >> 2;
if (bytesNeeded < minToPurge)
bytesNeeded = minToPurge;
SkGlyphCache* cache = FindTail(globals->fHead);
while (cache != NULL && bytesFreed < bytesNeeded) {
SkGlyphCache* prev = cache->fPrev;
bytesFreed += cache->fMemoryUsed;
#ifdef USE_CACHE_HASH
unsigned index = desc_to_hashindex(cache->fDesc);
if (cache == globals->fHash[index]) {
globals->fHash[index] = NULL;
}
#endif
cache->detach(&globals->fHead);
SkDELETE(cache);
cache = prev;
count += 1;
}
SkASSERT(bytesFreed <= globals->fTotalMemoryUsed);
globals->fTotalMemoryUsed -= bytesFreed;
globals->validate();
#ifdef SPEW_PURGE_STATUS
if (count && !gSkSuppressFontCachePurgeSpew) {
SkDebugf("purging %dK from font cache [%d entries]\n",
(int)(bytesFreed >> 10), count);
}
#endif
return bytesFreed;
}
///////////////////////////////////////////////////////////////////////////////
#ifdef SK_DEBUG
void SkGlyphCache::validate() const {
int count = fGlyphArray.count();
for (int i = 0; i < count; i++) {
const SkGlyph* glyph = fGlyphArray[i];
SkASSERT(glyph);
SkASSERT(fGlyphAlloc.contains(glyph));
if (glyph->fImage) {
SkASSERT(fImageAlloc.contains(glyph->fImage));
}
}
}
#endif