content/media/EncodedBufferCache.h@97036ab72558
content/media/EncodedBufferCache.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
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/. */
7 #ifndef EncodedBufferCache_h_
8 #define EncodedBufferCache_h_
10 #include "nsCOMPtr.h"
11 #include "nsTArray.h"
12 #include "mozilla/Mutex.h"
14 struct PRFileDesc;
15 class nsIDOMBlob;
17 namespace mozilla {
19 class ReentrantMonitor;
20 /**
21 * Data is moved into a temporary file when it grows beyond
22 * the maximal size passed in the Init function.
23 * The AppendBuffer and ExtractBlob methods are thread-safe and can be called on
24 * different threads at the same time.
25 */
26 class EncodedBufferCache
27 {
28 public:
29 EncodedBufferCache(uint32_t aMaxMemoryStorage)
30 : mFD(nullptr),
31 mMutex("EncodedBufferCache.Data.Mutex"),
32 mDataSize(0),
33 mMaxMemoryStorage(aMaxMemoryStorage),
34 mTempFileEnabled(false) { }
35 ~EncodedBufferCache()
36 {
37 }
38 // Append buffers in cache, check if the queue is too large then switch to write buffer to file system
39 // aBuf will append to mEncodedBuffers or temporary File, aBuf also be cleared
40 void AppendBuffer(nsTArray<uint8_t> & aBuf);
41 // Read all buffer from memory or file System, also Remove the temporary file or clean the buffers in memory.
42 already_AddRefed<nsIDOMBlob> ExtractBlob(const nsAString &aContentType);
44 private:
45 //array for storing the encoded data.
46 nsTArray<nsTArray<uint8_t> > mEncodedBuffers;
47 // File handle for the temporary file
48 PRFileDesc* mFD;
49 // Used to protect the mEncodedBuffer for avoiding AppendBuffer/Consume on different thread at the same time.
50 Mutex mMutex;
51 // the current buffer size can be read
52 uint64_t mDataSize;
53 // The maximal buffer allowed in memory
54 uint32_t mMaxMemoryStorage;
55 // indicate the buffer is stored on temporary file or not
56 bool mTempFileEnabled;
57 };
59 } // namespace mozilla
61 #endif
