1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
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 mozilla_RemoteLazyInputStream_h
8 #define mozilla_RemoteLazyInputStream_h
9 
10 #include "mozilla/Mutex.h"
11 #include "mozIRemoteLazyInputStream.h"
12 #include "nsIAsyncInputStream.h"
13 #include "nsICloneableInputStream.h"
14 #include "nsIFileStreams.h"
15 #include "nsIIPCSerializableInputStream.h"
16 #include "nsIInputStreamLength.h"
17 #include "nsCOMPtr.h"
18 
19 namespace mozilla {
20 
21 class RemoteLazyInputStreamChild;
22 
23 class RemoteLazyInputStream final : public nsIAsyncInputStream,
24                                     public nsIInputStreamCallback,
25                                     public nsICloneableInputStreamWithRange,
26                                     public nsIIPCSerializableInputStream,
27                                     public nsIAsyncFileMetadata,
28                                     public nsIInputStreamLength,
29                                     public nsIAsyncInputStreamLength,
30                                     public mozIRemoteLazyInputStream {
31  public:
32   NS_DECL_THREADSAFE_ISUPPORTS
33   NS_DECL_NSIINPUTSTREAM
34   NS_DECL_NSIASYNCINPUTSTREAM
35   NS_DECL_NSIINPUTSTREAMCALLBACK
36   NS_DECL_NSICLONEABLEINPUTSTREAM
37   NS_DECL_NSICLONEABLEINPUTSTREAMWITHRANGE
38   NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
39   NS_DECL_NSIFILEMETADATA
40   NS_DECL_NSIASYNCFILEMETADATA
41   NS_DECL_NSIINPUTSTREAMLENGTH
42   NS_DECL_NSIASYNCINPUTSTREAMLENGTH
43 
44   explicit RemoteLazyInputStream(RemoteLazyInputStreamChild* aActor);
45 
46   void StreamReady(already_AddRefed<nsIInputStream> aInputStream);
47 
48   void LengthReady(int64_t aLength);
49 
50   // mozIRemoteLazyInputStream
GetInternalStream()51   NS_IMETHOD_(nsIInputStream*) GetInternalStream() override {
52     if (mRemoteStream) {
53       return mRemoteStream;
54     }
55 
56     if (mAsyncRemoteStream) {
57       return mAsyncRemoteStream;
58     }
59 
60     return nullptr;
61   }
62 
63  private:
64   ~RemoteLazyInputStream();
65 
66   nsresult EnsureAsyncRemoteStream(const MutexAutoLock& aProofOfLock);
67 
68   void InitWithExistingRange(uint64_t aStart, uint64_t aLength,
69                              const MutexAutoLock& aProofOfLock);
70 
71   RefPtr<RemoteLazyInputStreamChild> mActor;
72 
73   // This is the list of possible states.
74   enum {
75     // The initial state. Only ::Available() can be used without receiving an
76     // error. The available size is known by the actor.
77     eInit,
78 
79     // AsyncWait() has been called for the first time. SendStreamNeeded() has
80     // been called and we are waiting for the 'real' inputStream.
81     ePending,
82 
83     // When the child receives the stream from the parent, we move to this
84     // state. The received stream is stored in mRemoteStream. From now on, any
85     // method call will be forwared to mRemoteStream.
86     eRunning,
87 
88     // If Close() or CloseWithStatus() is called, we move to this state.
89     // mRemoveStream is released and any method will return
90     // NS_BASE_STREAM_CLOSED.
91     eClosed,
92   } mState;
93 
94   uint64_t mStart;
95   uint64_t mLength;
96 
97   // Set to true if the stream is used via Read/ReadSegments or Close.
98   bool mConsumed;
99 
100   nsCOMPtr<nsIInputStream> mRemoteStream;
101   nsCOMPtr<nsIAsyncInputStream> mAsyncRemoteStream;
102 
103   // These 2 values are set only if mState is ePending.
104   nsCOMPtr<nsIInputStreamCallback> mInputStreamCallback;
105   nsCOMPtr<nsIEventTarget> mInputStreamCallbackEventTarget;
106 
107   // These 2 values are set only if mState is ePending.
108   nsCOMPtr<nsIFileMetadataCallback> mFileMetadataCallback;
109   nsCOMPtr<nsIEventTarget> mFileMetadataCallbackEventTarget;
110 
111   // These 2 values are set only when nsIAsyncInputStreamLength::asyncWait() is
112   // called.
113   nsCOMPtr<nsIInputStreamLengthCallback> mLengthCallback;
114   nsCOMPtr<nsIEventTarget> mLengthCallbackEventTarget;
115 
116   // Any member of this class is protected by mutex because touched on
117   // multiple threads.
118   Mutex mMutex;
119 };
120 
121 }  // namespace mozilla
122 
123 #endif  // mozilla_RemoteLazyInputStream_h
124