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/*
* Copyright 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//#define LOG_NDEBUG 0
#define LOG_TAG "CallbackDataSource"
#include <utils/Log.h>
#include "include/CallbackDataSource.h"
#include <binder/IMemory.h>
#include <media/IDataSource.h>
#include <media/stagefright/foundation/ADebug.h>
#include <algorithm>
namespace android {
CallbackDataSource::CallbackDataSource(
const sp<IDataSource>& binderDataSource)
: mIDataSource(binderDataSource) {
// Set up the buffer to read into.
mMemory = mIDataSource->getIMemory();
}
CallbackDataSource::~CallbackDataSource() {
ALOGV("~CallbackDataSource");
mIDataSource->close();
}
status_t CallbackDataSource::initCheck() const {
if (mMemory == NULL) {
return UNKNOWN_ERROR;
}
return OK;
}
ssize_t CallbackDataSource::readAt(off64_t offset, void* data, size_t size) {
if (mMemory == NULL) {
return -1;
}
// IDataSource can only read up to mMemory->size() bytes at a time, but this
// method should be able to read any number of bytes, so read in a loop.
size_t totalNumRead = 0;
size_t numLeft = size;
const size_t bufferSize = mMemory->size();
while (numLeft > 0) {
size_t numToRead = std::min(numLeft, bufferSize);
ssize_t numRead =
mIDataSource->readAt(offset + totalNumRead, numToRead);
// A negative return value represents an error. Pass it on.
if (numRead < 0) {
return numRead;
}
// A zero return value signals EOS. Return the bytes read so far.
if (numRead == 0) {
return totalNumRead;
}
if ((size_t)numRead > numToRead) {
return ERROR_OUT_OF_RANGE;
}
CHECK(numRead >= 0 && (size_t)numRead <= bufferSize);
memcpy(((uint8_t*)data) + totalNumRead, mMemory->pointer(), numRead);
numLeft -= numRead;
totalNumRead += numRead;
}
return totalNumRead;
}
status_t CallbackDataSource::getSize(off64_t *size) {
status_t err = mIDataSource->getSize(size);
if (err != OK) {
return err;
}
if (*size < 0) {
// IDataSource will set size to -1 to indicate unknown size, but
// DataSource returns ERROR_UNSUPPORTED for that.
return ERROR_UNSUPPORTED;
}
return OK;
}
TinyCacheSource::TinyCacheSource(const sp<DataSource>& source)
: mSource(source), mCachedOffset(0), mCachedSize(0) {
}
status_t TinyCacheSource::initCheck() const {
return mSource->initCheck();
}
ssize_t TinyCacheSource::readAt(off64_t offset, void* data, size_t size) {
if (size >= kCacheSize) {
return mSource->readAt(offset, data, size);
}
// Check if the cache satisfies the read.
if (mCachedOffset <= offset
&& offset < (off64_t) (mCachedOffset + mCachedSize)) {
if (offset + size <= mCachedOffset + mCachedSize) {
memcpy(data, &mCache[offset - mCachedOffset], size);
return size;
} else {
// If the cache hits only partially, flush the cache and read the
// remainder.
// This value is guaranteed to be greater than 0 because of the
// enclosing if statement.
const ssize_t remaining = mCachedOffset + mCachedSize - offset;
memcpy(data, &mCache[offset - mCachedOffset], remaining);
const ssize_t readMore = readAt(offset + remaining,
(uint8_t*)data + remaining, size - remaining);
if (readMore < 0) {
return readMore;
}
return remaining + readMore;
}
}
// Fill the cache and copy to the caller.
const ssize_t numRead = mSource->readAt(offset, mCache, kCacheSize);
if (numRead <= 0) {
return numRead;
}
if ((size_t)numRead > kCacheSize) {
return ERROR_OUT_OF_RANGE;
}
mCachedSize = numRead;
mCachedOffset = offset;
CHECK(mCachedSize <= kCacheSize && mCachedOffset >= 0);
const size_t numToReturn = std::min(size, (size_t)numRead);
memcpy(data, mCache, numToReturn);
return numToReturn;
}
status_t TinyCacheSource::getSize(off64_t *size) {
return mSource->getSize(size);
}
uint32_t TinyCacheSource::flags() {
return mSource->flags();
}
} // namespace android
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