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/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#if !defined(BufferMediaResource_h_)
# define BufferMediaResource_h_
# include "MediaResource.h"
# include "nsISeekableStream.h"
# include <algorithm>
namespace mozilla {
DDLoggedTypeDeclNameAndBase(BufferMediaResource, MediaResource);
// A simple MediaResource based on an in memory buffer. This class accepts
// the address and the length of the buffer, and simulates a read/seek API
// on top of it. The Read implementation involves copying memory, which is
// unfortunate, but the MediaResource interface mandates that.
class BufferMediaResource
: public MediaResource,
public DecoderDoctorLifeLogger<BufferMediaResource> {
public:
BufferMediaResource(const uint8_t* aBuffer, uint32_t aLength)
: mBuffer(aBuffer), mLength(aLength) {}
protected:
virtual ~BufferMediaResource() = default;
private:
// These methods are called off the main thread.
nsresult ReadAt(int64_t aOffset, char* aBuffer, uint32_t aCount,
uint32_t* aBytes) override {
if (aOffset < 0 || aOffset > mLength) {
return NS_ERROR_FAILURE;
}
*aBytes = std::min(mLength - static_cast<uint32_t>(aOffset), aCount);
memcpy(aBuffer, mBuffer + aOffset, *aBytes);
return NS_OK;
}
// Memory-based and no locks, caching discouraged.
bool ShouldCacheReads() override { return false; }
void Pin() override {}
void Unpin() override {}
int64_t GetLength() override { return mLength; }
int64_t GetNextCachedData(int64_t aOffset) override { return aOffset; }
int64_t GetCachedDataEnd(int64_t aOffset) override {
return std::max(aOffset, int64_t(mLength));
}
bool IsDataCachedToEndOfResource(int64_t aOffset) override { return true; }
nsresult ReadFromCache(char* aBuffer, int64_t aOffset,
uint32_t aCount) override {
if (aOffset < 0) {
return NS_ERROR_FAILURE;
}
uint32_t bytes = std::min(mLength - static_cast<uint32_t>(aOffset), aCount);
memcpy(aBuffer, mBuffer + aOffset, bytes);
return NS_OK;
}
nsresult GetCachedRanges(MediaByteRangeSet& aRanges) override {
aRanges += MediaByteRange(0, int64_t(mLength));
return NS_OK;
}
private:
const uint8_t* mBuffer;
uint32_t mLength;
};
} // namespace mozilla
#endif