gecko-dev/content/media/EncodedBufferCache.h

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1.9 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
#ifndef EncodedBufferCache_h_
#define EncodedBufferCache_h_
#include "nsTArray.h"
#include "mozilla/Mutex.h"
#include "prio.h"
#include "nsDOMFile.h"
namespace mozilla {
class ReentrantMonitor;
/**
* Data is moved into a temporary file when it grows beyond
* the maximal size passed in the Init function.
* The AppendBuffer and ExtractBlob methods are thread-safe and can be called on
* different threads at the same time.
*/
class EncodedBufferCache
{
public:
EncodedBufferCache(uint32_t aMaxMemoryStorage)
: mFD(nullptr),
mMutex("EncodedBufferCache.Data.Mutex"),
mDataSize(0),
mMaxMemoryStorage(aMaxMemoryStorage),
mTempFileEnabled(false) { }
~EncodedBufferCache()
{
}
// Append buffers in cache, check if the queue is too large then switch to write buffer to file system
// aBuf will append to mEncodedBuffers or temporary File, aBuf also be cleared
void AppendBuffer(nsTArray<uint8_t> & aBuf);
// Read all buffer from memory or file System, also Remove the temporary file or clean the buffers in memory.
already_AddRefed<nsIDOMBlob> ExtractBlob(const nsAString &aContentType);
private:
//array for storing the encoded data.
nsTArray<nsTArray<uint8_t> > mEncodedBuffers;
// File handle for the temporary file
PRFileDesc* mFD;
// Used to protect the mEncodedBuffer for avoiding AppendBuffer/Consume on different thread at the same time.
Mutex mMutex;;
// the current buffer size can be read
uint64_t mDataSize;
// The maximal buffer allowed in memory
uint32_t mMaxMemoryStorage;
// indicate the buffer is stored on temporary file or not
bool mTempFileEnabled;
};
} // namespace mozilla
#endif