michael@0: 
michael@0: /*
michael@0:  * Copyright 2011 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: #include "SkImageRefPool.h"
michael@0: #include "SkImageRef.h"
michael@0: #include "SkThread.h"
michael@0: 
michael@0: SkImageRefPool::SkImageRefPool() {
michael@0:     fRAMBudget = 0; // means no explicit limit
michael@0:     fRAMUsed = 0;
michael@0:     fCount = 0;
michael@0:     fHead = fTail = NULL;
michael@0: }
michael@0: 
michael@0: SkImageRefPool::~SkImageRefPool() {
michael@0:     //    SkASSERT(NULL == fHead);
michael@0: }
michael@0: 
michael@0: void SkImageRefPool::setRAMBudget(size_t size) {
michael@0:     if (fRAMBudget != size) {
michael@0:         fRAMBudget = size;
michael@0:         this->purgeIfNeeded();
michael@0:     }
michael@0: }
michael@0: 
michael@0: void SkImageRefPool::justAddedPixels(SkImageRef* ref) {
michael@0: #ifdef DUMP_IMAGEREF_LIFECYCLE
michael@0:     SkDebugf("=== ImagePool: add pixels %s [%d %d %d] bytes=%d heap=%d\n",
michael@0:              ref->getURI(),
michael@0:              ref->fBitmap.width(), ref->fBitmap.height(),
michael@0:              ref->fBitmap.bytesPerPixel(),
michael@0:              ref->fBitmap.getSize(), (int)fRAMUsed);
michael@0: #endif
michael@0:     fRAMUsed += ref->ramUsed();
michael@0:     this->purgeIfNeeded();
michael@0: }
michael@0: 
michael@0: void SkImageRefPool::canLosePixels(SkImageRef* ref) {
michael@0:     // the refs near fHead have recently been released (used)
michael@0:     // if we purge, we purge from the tail
michael@0:     this->detach(ref);
michael@0:     this->addToHead(ref);
michael@0:     this->purgeIfNeeded();
michael@0: }
michael@0: 
michael@0: void SkImageRefPool::purgeIfNeeded() {
michael@0:     // do nothing if we have a zero-budget (i.e. unlimited)
michael@0:     if (fRAMBudget != 0) {
michael@0:         this->setRAMUsed(fRAMBudget);
michael@0:     }
michael@0: }
michael@0: 
michael@0: void SkImageRefPool::setRAMUsed(size_t limit) {
michael@0:     SkImageRef* ref = fTail;
michael@0: 
michael@0:     while (NULL != ref && fRAMUsed > limit) {
michael@0:         // only purge it if its pixels are unlocked
michael@0:         if (!ref->isLocked() && ref->fBitmap.getPixels()) {
michael@0:             size_t size = ref->ramUsed();
michael@0:             SkASSERT(size <= fRAMUsed);
michael@0:             fRAMUsed -= size;
michael@0: 
michael@0: #ifdef DUMP_IMAGEREF_LIFECYCLE
michael@0:             SkDebugf("=== ImagePool: purge %s [%d %d %d] bytes=%d heap=%d\n",
michael@0:                      ref->getURI(),
michael@0:                      ref->fBitmap.width(), ref->fBitmap.height(),
michael@0:                      ref->fBitmap.bytesPerPixel(),
michael@0:                      (int)size, (int)fRAMUsed);
michael@0: #endif
michael@0: 
michael@0:             // remember the bitmap config (don't call reset),
michael@0:             // just clear the pixel memory
michael@0:             ref->fBitmap.setPixels(NULL);
michael@0:             SkASSERT(NULL == ref->fBitmap.getPixels());
michael@0:         }
michael@0:         ref = ref->fPrev;
michael@0:     }
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: void SkImageRefPool::addToHead(SkImageRef* ref) {
michael@0:     ref->fNext = fHead;
michael@0:     ref->fPrev = NULL;
michael@0: 
michael@0:     if (fHead) {
michael@0:         SkASSERT(NULL == fHead->fPrev);
michael@0:         fHead->fPrev = ref;
michael@0:     }
michael@0:     fHead = ref;
michael@0: 
michael@0:     if (NULL == fTail) {
michael@0:         fTail = ref;
michael@0:     }
michael@0:     fCount += 1;
michael@0:     SkASSERT(computeCount() == fCount);
michael@0: 
michael@0:     fRAMUsed += ref->ramUsed();
michael@0: }
michael@0: 
michael@0: void SkImageRefPool::addToTail(SkImageRef* ref) {
michael@0:     ref->fNext = NULL;
michael@0:     ref->fPrev = fTail;
michael@0: 
michael@0:     if (fTail) {
michael@0:         SkASSERT(NULL == fTail->fNext);
michael@0:         fTail->fNext = ref;
michael@0:     }
michael@0:     fTail = ref;
michael@0: 
michael@0:     if (NULL == fHead) {
michael@0:         fHead = ref;
michael@0:     }
michael@0:     fCount += 1;
michael@0:     SkASSERT(computeCount() == fCount);
michael@0: 
michael@0:     fRAMUsed += ref->ramUsed();
michael@0: }
michael@0: 
michael@0: void SkImageRefPool::detach(SkImageRef* ref) {
michael@0:     SkASSERT(fCount > 0);
michael@0: 
michael@0:     if (fHead == ref) {
michael@0:         fHead = ref->fNext;
michael@0:     }
michael@0:     if (fTail == ref) {
michael@0:         fTail = ref->fPrev;
michael@0:     }
michael@0:     if (ref->fPrev) {
michael@0:         ref->fPrev->fNext = ref->fNext;
michael@0:     }
michael@0:     if (ref->fNext) {
michael@0:         ref->fNext->fPrev = ref->fPrev;
michael@0:     }
michael@0: 
michael@0:     ref->fNext = ref->fPrev = NULL;
michael@0: 
michael@0:     fCount -= 1;
michael@0:     SkASSERT(computeCount() == fCount);
michael@0: 
michael@0:     SkASSERT(fRAMUsed >= ref->ramUsed());
michael@0:     fRAMUsed -= ref->ramUsed();
michael@0: }
michael@0: 
michael@0: int SkImageRefPool::computeCount() const {
michael@0:     SkImageRef* ref = fHead;
michael@0:     int count = 0;
michael@0: 
michael@0:     while (ref != NULL) {
michael@0:         count += 1;
michael@0:         ref = ref->fNext;
michael@0:     }
michael@0: 
michael@0: #ifdef SK_DEBUG
michael@0:     ref = fTail;
michael@0:     int count2 = 0;
michael@0: 
michael@0:     while (ref != NULL) {
michael@0:         count2 += 1;
michael@0:         ref = ref->fPrev;
michael@0:     }
michael@0:     SkASSERT(count2 == count);
michael@0: #endif
michael@0: 
michael@0:     return count;
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: #include "SkStream.h"
michael@0: 
michael@0: void SkImageRefPool::dump() const {
michael@0: #if defined(SK_DEBUG) || defined(DUMP_IMAGEREF_LIFECYCLE)
michael@0:     SkDebugf("ImagePool dump: bugdet: %d used: %d count: %d\n",
michael@0:              (int)fRAMBudget, (int)fRAMUsed, fCount);
michael@0: 
michael@0:     SkImageRef* ref = fHead;
michael@0: 
michael@0:     while (ref != NULL) {
michael@0:         SkDebugf("  [%3d %3d %d] ram=%d data=%d locked=%d %s\n", ref->fBitmap.width(),
michael@0:                  ref->fBitmap.height(), ref->fBitmap.config(),
michael@0:                  ref->ramUsed(), (int)ref->fStream->getLength(),
michael@0:                  ref->isLocked(), ref->getURI());
michael@0: 
michael@0:         ref = ref->fNext;
michael@0:     }
michael@0: #endif
michael@0: }