PatchCache.cpp revision 36fad8f6fcfbc2087b910600ed5a6f9741177d00 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "OpenGLRenderer"
18
19#include <utils/JenkinsHash.h>
20#include <utils/Log.h>
21
22#include "Caches.h"
23#include "PatchCache.h"
24#include "Properties.h"
25
26namespace android {
27namespace uirenderer {
28
29///////////////////////////////////////////////////////////////////////////////
30// Constructors/destructor
31///////////////////////////////////////////////////////////////////////////////
32
33PatchCache::PatchCache():
34        mSize(0), mCache(LruCache<PatchDescription, Patch*>::kUnlimitedCapacity),
35        mMeshBuffer(0), mFreeBlocks(NULL), mGenerationId(0) {
36    char property[PROPERTY_VALUE_MAX];
37    if (property_get(PROPERTY_PATCH_CACHE_SIZE, property, NULL) > 0) {
38        INIT_LOGD("  Setting patch cache size to %skB", property);
39        mMaxSize = KB(atoi(property));
40    } else {
41        INIT_LOGD("  Using default patch cache size of %.2fkB", DEFAULT_PATCH_CACHE_SIZE);
42        mMaxSize = KB(DEFAULT_PATCH_CACHE_SIZE);
43    }
44}
45
46PatchCache::~PatchCache() {
47    clear();
48}
49
50void PatchCache::init(Caches& caches) {
51    bool created = false;
52    if (!mMeshBuffer) {
53        glGenBuffers(1, &mMeshBuffer);
54        created = true;
55    }
56
57    caches.bindMeshBuffer(mMeshBuffer);
58    caches.resetVertexPointers();
59
60    if (created) {
61        createVertexBuffer();
62    }
63}
64
65///////////////////////////////////////////////////////////////////////////////
66// Caching
67///////////////////////////////////////////////////////////////////////////////
68
69hash_t PatchCache::PatchDescription::hash() const {
70    uint32_t hash = JenkinsHashMix(0, android::hash_type(mPatch));
71    hash = JenkinsHashMix(hash, mBitmapWidth);
72    hash = JenkinsHashMix(hash, mBitmapHeight);
73    hash = JenkinsHashMix(hash, mPixelWidth);
74    hash = JenkinsHashMix(hash, mPixelHeight);
75    return JenkinsHashWhiten(hash);
76}
77
78int PatchCache::PatchDescription::compare(const PatchCache::PatchDescription& lhs,
79            const PatchCache::PatchDescription& rhs) {
80    return memcmp(&lhs, &rhs, sizeof(PatchDescription));
81}
82
83void PatchCache::clear() {
84    clearCache();
85
86    if (mMeshBuffer) {
87        Caches::getInstance().unbindMeshBuffer();
88        glDeleteBuffers(1, &mMeshBuffer);
89        mMeshBuffer = 0;
90        mSize = 0;
91    }
92}
93
94void PatchCache::clearCache() {
95    LruCache<PatchDescription, Patch*>::Iterator i(mCache);
96    while (i.next()) {
97        delete i.value();
98    }
99    mCache.clear();
100
101    BufferBlock* block = mFreeBlocks;
102    while (block) {
103        BufferBlock* next = block->next;
104        delete block;
105        block = next;
106    }
107    mFreeBlocks = NULL;
108}
109
110void PatchCache::remove(Vector<patch_pair_t>& patchesToRemove, Res_png_9patch* patch) {
111    LruCache<PatchDescription, Patch*>::Iterator i(mCache);
112    while (i.next()) {
113        const PatchDescription& key = i.key();
114        if (key.getPatch() == patch) {
115            patchesToRemove.push(patch_pair_t(&key, i.value()));
116        }
117    }
118}
119
120void PatchCache::removeDeferred(Res_png_9patch* patch) {
121    Mutex::Autolock _l(mLock);
122    mGarbage.push(patch);
123}
124
125void PatchCache::clearGarbage() {
126    Vector<patch_pair_t> patchesToRemove;
127
128    { // scope for the mutex
129        Mutex::Autolock _l(mLock);
130        size_t count = mGarbage.size();
131        for (size_t i = 0; i < count; i++) {
132            Res_png_9patch* patch = mGarbage[i];
133            remove(patchesToRemove, patch);
134            // A Res_png_9patch is actually an array of byte that's larger
135            // than sizeof(Res_png_9patch). It must be freed as an array.
136            delete[] (int8_t*) patch;
137        }
138        mGarbage.clear();
139    }
140
141    // TODO: We could sort patchesToRemove by offset to merge
142    // adjacent free blocks
143    for (size_t i = 0; i < patchesToRemove.size(); i++) {
144        const patch_pair_t& pair = patchesToRemove[i];
145
146        // Add a new free block to the list
147        const Patch* patch = pair.getSecond();
148        BufferBlock* block = new BufferBlock(patch->offset, patch->getSize());
149        block->next = mFreeBlocks;
150        mFreeBlocks = block;
151
152        mSize -= patch->getSize();
153
154        mCache.remove(*pair.getFirst());
155    }
156
157#if DEBUG_PATCHES
158    if (patchesToRemove.size() > 0) {
159        dumpFreeBlocks("Removed garbage");
160    }
161#endif
162}
163
164void PatchCache::createVertexBuffer() {
165    glBufferData(GL_ARRAY_BUFFER, mMaxSize, NULL, GL_DYNAMIC_DRAW);
166    mSize = 0;
167    mFreeBlocks = new BufferBlock(0, mMaxSize);
168    mGenerationId++;
169}
170
171/**
172 * Sets the mesh's offsets and copies its associated vertices into
173 * the mesh buffer (VBO).
174 */
175void PatchCache::setupMesh(Patch* newMesh, TextureVertex* vertices) {
176    // This call ensures the VBO exists and that it is bound
177    init(Caches::getInstance());
178
179    // If we're running out of space, let's clear the entire cache
180    uint32_t size = newMesh->getSize();
181    if (mSize + size > mMaxSize) {
182        clearCache();
183        createVertexBuffer();
184    }
185
186    // Find a block where we can fit the mesh
187    BufferBlock* previous = NULL;
188    BufferBlock* block = mFreeBlocks;
189    while (block) {
190        // The mesh fits
191        if (block->size >= size) {
192            break;
193        }
194        previous = block;
195        block = block->next;
196    }
197
198    // We have enough space left in the buffer, but it's
199    // too fragmented, let's clear the cache
200    if (!block) {
201        clearCache();
202        createVertexBuffer();
203        previous = NULL;
204        block = mFreeBlocks;
205    }
206
207    // Copy the 9patch mesh in the VBO
208    newMesh->offset = (GLintptr) (block->offset);
209    newMesh->textureOffset = newMesh->offset + gMeshTextureOffset;
210    glBufferSubData(GL_ARRAY_BUFFER, newMesh->offset, size, vertices);
211
212    // Remove the block since we've used it entirely
213    if (block->size == size) {
214        if (previous) {
215            previous->next = block->next;
216        } else {
217            mFreeBlocks = block->next;
218        }
219    } else {
220        // Resize the block now that it's occupied
221        block->offset += size;
222        block->size -= size;
223    }
224
225    mSize += size;
226}
227
228const Patch* PatchCache::get(const AssetAtlas::Entry* entry,
229        const uint32_t bitmapWidth, const uint32_t bitmapHeight,
230        const float pixelWidth, const float pixelHeight, const Res_png_9patch* patch) {
231
232    const PatchDescription description(bitmapWidth, bitmapHeight, pixelWidth, pixelHeight, patch);
233    const Patch* mesh = mCache.get(description);
234
235    if (!mesh) {
236        Patch* newMesh = new Patch();
237        TextureVertex* vertices;
238
239        if (entry) {
240            // An atlas entry has a UV mapper
241            vertices = newMesh->createMesh(bitmapWidth, bitmapHeight,
242                    pixelWidth, pixelHeight, entry->uvMapper, patch);
243        } else {
244            vertices = newMesh->createMesh(bitmapWidth, bitmapHeight,
245                    pixelWidth, pixelHeight, patch);
246        }
247
248        if (vertices) {
249            setupMesh(newMesh, vertices);
250        }
251
252#if DEBUG_PATCHES
253        dumpFreeBlocks("Adding patch");
254#endif
255
256        mCache.put(description, newMesh);
257        return newMesh;
258    }
259
260    return mesh;
261}
262
263#if DEBUG_PATCHES
264void PatchCache::dumpFreeBlocks(const char* prefix) {
265    String8 dump;
266    BufferBlock* block = mFreeBlocks;
267    while (block) {
268        dump.appendFormat("->(%d, %d)", block->offset, block->size);
269        block = block->next;
270    }
271    ALOGD("%s: Free blocks%s", prefix, dump.string());
272}
273#endif
274
275}; // namespace uirenderer
276}; // namespace android
277