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       1             : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* vim:set ts=2 sw=2 sts=2 et cindent: */
       3             : /* This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : #ifndef EncodedBufferCache_h_
       8             : #define EncodedBufferCache_h_
       9             : 
      10             : #include "nsCOMPtr.h"
      11             : #include "nsTArray.h"
      12             : #include "mozilla/Mutex.h"
      13             : 
      14             : struct PRFileDesc;
      15             : 
      16             : namespace mozilla {
      17             : 
      18             : namespace dom {
      19             : class Blob;
      20             : } // namespace dom
      21             : 
      22             : /**
      23             :  * Data is moved into a temporary file when it grows beyond
      24             :  * the maximal size passed in the Init function.
      25             :  * The AppendBuffer and ExtractBlob methods are thread-safe and can be called on
      26             :  * different threads at the same time.
      27             :  */
      28             : class EncodedBufferCache
      29             : {
      30             : public:
      31           0 :   explicit EncodedBufferCache(uint32_t aMaxMemoryStorage)
      32           0 :   : mFD(nullptr),
      33             :     mMutex("EncodedBufferCache.Data.Mutex"),
      34             :     mDataSize(0),
      35             :     mMaxMemoryStorage(aMaxMemoryStorage),
      36           0 :     mTempFileEnabled(false) { }
      37           0 :   ~EncodedBufferCache()
      38           0 :   {
      39           0 :   }
      40             :   // Append buffers in cache, check if the queue is too large then switch to write buffer to file system
      41             :   // aBuf will append to mEncodedBuffers or temporary File, aBuf also be cleared
      42             :   void AppendBuffer(nsTArray<uint8_t> & aBuf);
      43             :   // Read all buffer from memory or file System, also Remove the temporary file or clean the buffers in memory.
      44             :   already_AddRefed<dom::Blob> ExtractBlob(nsISupports* aParent, const nsAString &aContentType);
      45             : 
      46             : private:
      47             :   //array for storing the encoded data.
      48             :   nsTArray<nsTArray<uint8_t> > mEncodedBuffers;
      49             :   // File handle for the temporary file
      50             :   PRFileDesc* mFD;
      51             :   // Used to protect the mEncodedBuffer for avoiding AppendBuffer/Consume on different thread at the same time.
      52             :   Mutex mMutex;
      53             :   // the current buffer size can be read
      54             :   uint64_t mDataSize;
      55             :   // The maximal buffer allowed in memory
      56             :   uint32_t mMaxMemoryStorage;
      57             :   // indicate the buffer is stored on temporary file or not
      58             :   bool mTempFileEnabled;
      59             : };
      60             : 
      61             : } // namespace mozilla
      62             : 
      63             : #endif