michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim:set ts=2 sw=2 sts=2 et cindent: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef EncodedBufferCache_h_
michael@0: #define EncodedBufferCache_h_
michael@0: 
michael@0: #include "nsCOMPtr.h"
michael@0: #include "nsTArray.h"
michael@0: #include "mozilla/Mutex.h"
michael@0: 
michael@0: struct PRFileDesc;
michael@0: class nsIDOMBlob;
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: class ReentrantMonitor;
michael@0: /**
michael@0:  * Data is moved into a temporary file when it grows beyond
michael@0:  * the maximal size passed in the Init function.
michael@0:  * The AppendBuffer and ExtractBlob methods are thread-safe and can be called on
michael@0:  * different threads at the same time.
michael@0:  */
michael@0: class EncodedBufferCache
michael@0: {
michael@0: public:
michael@0:   EncodedBufferCache(uint32_t aMaxMemoryStorage)
michael@0:   : mFD(nullptr),
michael@0:     mMutex("EncodedBufferCache.Data.Mutex"),
michael@0:     mDataSize(0),
michael@0:     mMaxMemoryStorage(aMaxMemoryStorage),
michael@0:     mTempFileEnabled(false) { }
michael@0:   ~EncodedBufferCache()
michael@0:   {
michael@0:   }
michael@0:   // Append buffers in cache, check if the queue is too large then switch to write buffer to file system
michael@0:   // aBuf will append to mEncodedBuffers or temporary File, aBuf also be cleared
michael@0:   void AppendBuffer(nsTArray<uint8_t> & aBuf);
michael@0:   // Read all buffer from memory or file System, also Remove the temporary file or clean the buffers in memory.
michael@0:   already_AddRefed<nsIDOMBlob> ExtractBlob(const nsAString &aContentType);
michael@0: 
michael@0: private:
michael@0:   //array for storing the encoded data.
michael@0:   nsTArray<nsTArray<uint8_t> > mEncodedBuffers;
michael@0:   // File handle for the temporary file
michael@0:   PRFileDesc* mFD;
michael@0:   // Used to protect the mEncodedBuffer for avoiding AppendBuffer/Consume on different thread at the same time.
michael@0:   Mutex mMutex;
michael@0:   // the current buffer size can be read
michael@0:   uint64_t mDataSize;
michael@0:   // The maximal buffer allowed in memory
michael@0:   uint32_t mMaxMemoryStorage;
michael@0:   // indicate the buffer is stored on temporary file or not
michael@0:   bool mTempFileEnabled;
michael@0: };
michael@0: 
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif