HWComposerBufferCache.cpp revision 5b3cf0576d91358cb850945d89382938ff8dc5ed 
1/*
2 * Copyright (C) 2017 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#include "HWComposerBufferCache.h"
18
19#include <gui/BufferQueue.h>
20
21namespace android {
22
23HWComposerBufferCache::HWComposerBufferCache()
24{
25    mBuffers.reserve(BufferQueue::NUM_BUFFER_SLOTS);
26}
27
28void HWComposerBufferCache::getHwcBuffer(int slot,
29        const sp<GraphicBuffer>& buffer,
30        uint32_t* outSlot, sp<GraphicBuffer>* outBuffer)
31{
32    if (slot == BufferQueue::INVALID_BUFFER_SLOT || slot < 0) {
33        // default to slot 0
34        slot = 0;
35    }
36
37    if (static_cast<size_t>(slot) >= mBuffers.size()) {
38        mBuffers.resize(slot + 1);
39    }
40
41    *outSlot = slot;
42
43    if (mBuffers[slot] == buffer) {
44        // already cached in HWC, skip sending the buffer
45        *outBuffer = nullptr;
46    } else {
47        *outBuffer = buffer;
48
49        // update cache
50        mBuffers[slot] = buffer;
51    }
52}
53
54} // namespace android
55