1 /* vim:set ts=2 sw=2 sts=2 et cindent: */ 2 /* This Source Code Form is subject to the terms of the Mozilla Public 3 * License, v. 2.0. If a copy of the MPL was not distributed with this 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 5 6 #if !defined(BufferMediaResource_h_) 7 # define BufferMediaResource_h_ 8 9 # include "MediaResource.h" 10 # include "nsISeekableStream.h" 11 # include <algorithm> 12 13 namespace mozilla { 14 15 DDLoggedTypeDeclNameAndBase(BufferMediaResource, MediaResource); 16 17 // A simple MediaResource based on an in memory buffer. This class accepts 18 // the address and the length of the buffer, and simulates a read/seek API 19 // on top of it. The Read implementation involves copying memory, which is 20 // unfortunate, but the MediaResource interface mandates that. 21 class BufferMediaResource 22 : public MediaResource, 23 public DecoderDoctorLifeLogger<BufferMediaResource> { 24 public: BufferMediaResource(const uint8_t * aBuffer,uint32_t aLength)25 BufferMediaResource(const uint8_t* aBuffer, uint32_t aLength) 26 : mBuffer(aBuffer), mLength(aLength) {} 27 28 protected: 29 virtual ~BufferMediaResource() = default; 30 31 private: 32 // These methods are called off the main thread. ReadAt(int64_t aOffset,char * aBuffer,uint32_t aCount,uint32_t * aBytes)33 nsresult ReadAt(int64_t aOffset, char* aBuffer, uint32_t aCount, 34 uint32_t* aBytes) override { 35 if (aOffset < 0 || aOffset > mLength) { 36 return NS_ERROR_FAILURE; 37 } 38 *aBytes = std::min(mLength - static_cast<uint32_t>(aOffset), aCount); 39 memcpy(aBuffer, mBuffer + aOffset, *aBytes); 40 return NS_OK; 41 } 42 // Memory-based and no locks, caching discouraged. ShouldCacheReads()43 bool ShouldCacheReads() override { return false; } 44 Pin()45 void Pin() override {} Unpin()46 void Unpin() override {} GetLength()47 int64_t GetLength() override { return mLength; } GetNextCachedData(int64_t aOffset)48 int64_t GetNextCachedData(int64_t aOffset) override { return aOffset; } GetCachedDataEnd(int64_t aOffset)49 int64_t GetCachedDataEnd(int64_t aOffset) override { 50 return std::max(aOffset, int64_t(mLength)); 51 } IsDataCachedToEndOfResource(int64_t aOffset)52 bool IsDataCachedToEndOfResource(int64_t aOffset) override { return true; } ReadFromCache(char * aBuffer,int64_t aOffset,uint32_t aCount)53 nsresult ReadFromCache(char* aBuffer, int64_t aOffset, 54 uint32_t aCount) override { 55 if (aOffset < 0) { 56 return NS_ERROR_FAILURE; 57 } 58 59 uint32_t bytes = std::min(mLength - static_cast<uint32_t>(aOffset), aCount); 60 memcpy(aBuffer, mBuffer + aOffset, bytes); 61 return NS_OK; 62 } 63 GetCachedRanges(MediaByteRangeSet & aRanges)64 nsresult GetCachedRanges(MediaByteRangeSet& aRanges) override { 65 aRanges += MediaByteRange(0, int64_t(mLength)); 66 return NS_OK; 67 } 68 69 private: 70 const uint8_t* mBuffer; 71 uint32_t mLength; 72 }; 73 74 } // namespace mozilla 75 76 #endif 77