diff options
Diffstat (limited to 'remoting/client/decoder.h')
| -rw-r--r-- | remoting/client/decoder.h | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/remoting/client/decoder.h b/remoting/client/decoder.h index ac2fe4d..4d083bd 100644 --- a/remoting/client/decoder.h +++ b/remoting/client/decoder.h @@ -57,9 +57,20 @@ class Decoder { // Give a HostMessage that contains the update stream packet that contains // the encoded data to the decoder. // The decoder will own |message| and is responsible for deleting it. + // // If the decoder has written something into |frame|, // |partial_decode_done_| is called with |frame| and updated regions. // Return true if the decoder can accept |message| and decode it. + // + // HostMessage returned by this method will contain a + // UpdateStreamPacketMessage. + // This message will contain either: + // 1. UpdateStreamBeginRect + // 2. UpdateStreamRectData + // 3. UpdateStreamEndRect + // + // See remoting/base/protocol/chromotocol.proto for more information about + // these messages. virtual bool PartialDecode(HostMessage* message) = 0; // Notify the decoder that we have received the last update stream packet. @@ -68,6 +79,34 @@ class Decoder { // If the update stream is not received fully and this method is called the // decoder should also call |decode_done_| as soon as possible. virtual void EndDecode() = 0; + + protected: + // Every decoder will have two internal states because there are three + // kinds of messages send to PartialDecode(). + // + // Here's a state diagram: + // + // UpdateStreamBeginRect UpdateStreamRectData + // .............. ............ + // . . . . + // . v . . + // kWaitingForBeginRect kWaitingForRectData . + // ^ . ^ . + // . . . . + // .............. ............ + // UpdateStreaEndRect + enum State { + // In this state the decoder is waiting for UpdateStreamBeginRect. + // After receiving UpdateStreaBeginRect, the encoder will transit to + // to kWaitingForRectData state. + kWaitingForBeginRect, + + // In this state the decoder is waiting for UpdateStreamRectData. + // The decode remains in this state if UpdateStreamRectData is received. + // The decoder will transit to kWaitingForBeginRect if UpdateStreamEndRect + // is received. + kWaitingForRectData, + }; }; } // namespace remoting |