Big Cleanup: SkBitmapFactory, SkLazyPixelRef, SkImageCache

src/lazy/SkLruImageCache.cpp

-/*
- * Copyright 2013 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkLruImageCache.h"
-
-SK_DEFINE_INST_COUNT(SkImageCache)
-SK_DEFINE_INST_COUNT(SkLruImageCache)
-
-static intptr_t NextGenerationID() {
-    static intptr_t gNextID;
-    do {
-        gNextID++;
-    } while (SkImageCache::UNINITIALIZED_ID == gNextID);
-    return gNextID;
-}
-
-class CachedPixels : public SkNoncopyable {
-
-public:
-    CachedPixels(size_t length)
-        : fLength(length)
-        , fID(NextGenerationID())
-        , fLocked(false) {
-        fAddr = sk_malloc_throw(length);
-    }
-
-    ~CachedPixels() {
-        sk_free(fAddr);
-    }
-
-    void* getData() { return fAddr; }
-
-    intptr_t getID() const { return fID; }
-
-    size_t getLength() const { return fLength; }
-
-    void lock() { SkASSERT(!fLocked); fLocked = true; }
-
-    void unlock() { SkASSERT(fLocked); fLocked = false; }
-
-    bool isLocked() const { return fLocked; }
-
-private:
-    void*          fAddr;
-    size_t         fLength;
-    const intptr_t fID;
-    bool           fLocked;
-    SK_DECLARE_INTERNAL_LLIST_INTERFACE(CachedPixels);
-};
-
-////////////////////////////////////////////////////////////////////////////////////
-
-SkLruImageCache::SkLruImageCache(size_t budget)
-    : fRamBudget(budget)
-    , fRamUsed(0) {}
-
-SkLruImageCache::~SkLruImageCache() {
-    // Don't worry about updating pointers. All will be deleted.
-    Iter iter;
-    CachedPixels* pixels = iter.init(fLRU, Iter::kTail_IterStart);
-    while (pixels != NULL) {
-        CachedPixels* prev = iter.prev();
-        SkASSERT(!pixels->isLocked());
-#ifdef SK_DEBUG
-        fRamUsed -= pixels->getLength();
-#endif
-        SkDELETE(pixels);
-        pixels = prev;
-    }
-#ifdef SK_DEBUG
-    SkASSERT(fRamUsed == 0);
-#endif
-}
-
-#ifdef SK_DEBUG
-SkImageCache::MemoryStatus SkLruImageCache::getMemoryStatus(intptr_t ID) const {
-    if (SkImageCache::UNINITIALIZED_ID == ID) {
-        return SkImageCache::kFreed_MemoryStatus;
-    }
-    SkAutoMutexAcquire ac(&fMutex);
-    CachedPixels* pixels = this->findByID(ID);
-    if (NULL == pixels) {
-        return SkImageCache::kFreed_MemoryStatus;
-    }
-    if (pixels->isLocked()) {
-        return SkImageCache::kPinned_MemoryStatus;
-    }
-    return SkImageCache::kUnpinned_MemoryStatus;
-}
-
-void SkLruImageCache::purgeAllUnpinnedCaches() {
-    SkAutoMutexAcquire ac(&fMutex);
-    this->purgeTilAtOrBelow(0);
-}
-#endif
-
-size_t SkLruImageCache::setImageCacheLimit(size_t newLimit) {
-    size_t oldLimit = fRamBudget;
-    SkAutoMutexAcquire ac(&fMutex);
-    fRamBudget = newLimit;
-    this->purgeIfNeeded();
-    return oldLimit;
-}
-
-void* SkLruImageCache::allocAndPinCache(size_t bytes, intptr_t* ID) {
-    SkAutoMutexAcquire ac(&fMutex);
-    CachedPixels* pixels = SkNEW_ARGS(CachedPixels, (bytes));
-    if (ID != NULL) {
-        *ID = pixels->getID();
-    }
-    pixels->lock();
-    fRamUsed += bytes;
-    fLRU.addToHead(pixels);
-    this->purgeIfNeeded();
-    return pixels->getData();
-}
-
-void* SkLruImageCache::pinCache(intptr_t ID, SkImageCache::DataStatus* status) {
-    SkASSERT(ID != SkImageCache::UNINITIALIZED_ID);
-    SkAutoMutexAcquire ac(&fMutex);
-    CachedPixels* pixels = this->findByID(ID);
-    if (NULL == pixels) {
-        return NULL;
-    }
-    if (pixels != fLRU.head()) {
-        fLRU.remove(pixels);
-        fLRU.addToHead(pixels);
-    }
-    SkASSERT(status != NULL);
-    // This cache will never return pinned memory whose data has been overwritten.
-    *status = SkImageCache::kRetained_DataStatus;
-    pixels->lock();
-    return pixels->getData();
-}
-
-void SkLruImageCache::releaseCache(intptr_t ID) {
-    SkASSERT(ID != SkImageCache::UNINITIALIZED_ID);
-    SkAutoMutexAcquire ac(&fMutex);
-    CachedPixels* pixels = this->findByID(ID);
-    SkASSERT(pixels != NULL);
-    pixels->unlock();
-    this->purgeIfNeeded();
-}
-
-void SkLruImageCache::throwAwayCache(intptr_t ID) {
-    SkASSERT(ID != SkImageCache::UNINITIALIZED_ID);
-    SkAutoMutexAcquire ac(&fMutex);
-    CachedPixels* pixels = this->findByID(ID);
-    if (pixels != NULL) {
-        if (pixels->isLocked()) {
-            pixels->unlock();
-        }
-        this->removePixels(pixels);
-    }
-}
-
-void SkLruImageCache::removePixels(CachedPixels* pixels) {
-    // Mutex is already locked.
-    SkASSERT(!pixels->isLocked());
-    const size_t size = pixels->getLength();
-    SkASSERT(size <= fRamUsed);
-    fLRU.remove(pixels);
-    SkDELETE(pixels);
-    fRamUsed -= size;
-}
-
-CachedPixels* SkLruImageCache::findByID(intptr_t ID) const {
-    // Mutex is already locked.
-    Iter iter;
-    // Start from the head, most recently used.
-    CachedPixels* pixels = iter.init(fLRU, Iter::kHead_IterStart);
-    while (pixels != NULL) {
-        if (pixels->getID() == ID) {
-            return pixels;
-        }
-        pixels = iter.next();
-    }
-    return NULL;
-}
-
-void SkLruImageCache::purgeIfNeeded() {
-    // Mutex is already locked.
-    if (fRamBudget > 0) {
-        this->purgeTilAtOrBelow(fRamBudget);
-    }
-}
-
-void SkLruImageCache::purgeTilAtOrBelow(size_t limit) {
-    // Mutex is already locked.
-    if (fRamUsed > limit) {
-        Iter iter;
-        // Start from the tail, least recently used.
-        CachedPixels* pixels = iter.init(fLRU, Iter::kTail_IterStart);
-        while (pixels != NULL && fRamUsed > limit) {
-            CachedPixels* prev = iter.prev();
-            if (!pixels->isLocked()) {
-                this->removePixels(pixels);
-            }
-            pixels = prev;
-        }
-    }
-}