80 lines
2.3 KiB
C++
80 lines
2.3 KiB
C++
/*
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* Copyright (C) 2012 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#define LOG_TAG "MonoPipeReader"
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//#define LOG_NDEBUG 0
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#include <cutils/compiler.h>
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#include <utils/Log.h>
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#include <media/nbaio/MonoPipeReader.h>
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namespace android {
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MonoPipeReader::MonoPipeReader(MonoPipe* pipe) :
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NBAIO_Source(pipe->mFormat),
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mPipe(pipe)
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{
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}
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MonoPipeReader::~MonoPipeReader()
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{
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}
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ssize_t MonoPipeReader::availableToRead()
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{
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if (CC_UNLIKELY(!mNegotiated)) {
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return NEGOTIATE;
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}
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ssize_t ret = android_atomic_acquire_load(&mPipe->mRear) - mPipe->mFront;
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ALOG_ASSERT((0 <= ret) && ((size_t) ret <= mPipe->mMaxFrames));
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return ret;
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}
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ssize_t MonoPipeReader::read(void *buffer, size_t count)
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{
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// count == 0 is unlikely and not worth checking for explicitly; will be handled automatically
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ssize_t red = availableToRead();
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if (CC_UNLIKELY(red <= 0)) {
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return red;
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}
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if (CC_LIKELY((size_t) red > count)) {
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red = count;
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}
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size_t front = mPipe->mFront & (mPipe->mMaxFrames - 1);
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size_t part1 = mPipe->mMaxFrames - front;
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if (part1 > (size_t) red) {
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part1 = red;
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}
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if (CC_LIKELY(part1 > 0)) {
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memcpy(buffer, (char *) mPipe->mBuffer + (front * mFrameSize), part1 * mFrameSize);
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if (CC_UNLIKELY(front + part1 == mPipe->mMaxFrames)) {
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size_t part2 = red - part1;
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if (CC_LIKELY(part2 > 0)) {
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memcpy((char *) buffer + (part1 * mFrameSize), mPipe->mBuffer, part2 * mFrameSize);
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}
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}
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android_atomic_release_store(red + mPipe->mFront, &mPipe->mFront);
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mFramesRead += red;
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}
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return red;
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}
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void MonoPipeReader::onTimestamp(const ExtendedTimestamp ×tamp)
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{
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mPipe->mTimestampMutator.push(timestamp);
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}
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} // namespace android
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