| // Copyright 2013 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef NET_WEBSOCKETS_WEBSOCKET_DEFLATE_PREDICTOR_H_ |
| #define NET_WEBSOCKETS_WEBSOCKET_DEFLATE_PREDICTOR_H_ |
| |
| #include "base/basictypes.h" |
| #include "base/memory/scoped_vector.h" |
| #include "net/base/net_export.h" |
| |
| namespace net { |
| |
| struct WebSocketFrame; |
| |
| // WebSocketDeflatePredictor is an interface class used for judging whether |
| // a WebSocketDeflateStream should compress a message or not. |
| class NET_EXPORT_PRIVATE WebSocketDeflatePredictor { |
| public: |
| enum Result { |
| // Deflate and send the message. |
| DEFLATE, |
| // Do not deflate and send the original message. |
| DO_NOT_DEFLATE, |
| // Try compressing the message and send the smaller one of the original |
| // and the compressed message. |
| // Returning this result implies that the deflater is running on |
| // DoNotTakeOverContext mode and the entire message is visible. |
| TRY_DEFLATE, |
| }; |
| |
| virtual ~WebSocketDeflatePredictor() {} |
| |
| // Predicts and returns whether the deflater should deflate the message |
| // which begins with |frames[frame_index]| or not. |
| // |frames[(frame_index + 1):]| consists of future frames if any. |
| // |frames[frame_index]| must be the first frame of a data message, |
| // but future frames may contain control message frames. |
| // |frames[frame_index]| cannot be recorded yet and all preceding |
| // data frames have to be already recorded when this method is called. |
| virtual Result Predict(const ScopedVector<WebSocketFrame>& frames, |
| size_t frame_index) = 0; |
| |
| // Records frame data for future prediction. |
| // Only data frames should be recorded. Do not pass control frames' data. |
| // All input data frames for the stream must be recorded in order. |
| virtual void RecordInputDataFrame(const WebSocketFrame* frame) = 0; |
| |
| // Records frame data for future prediction. |
| // Only data frames should be recorded. Do not pass control frames' data. |
| // All data frames written by the stream must be recorded in order |
| // regardless of whether they are compressed or not. |
| virtual void RecordWrittenDataFrame(const WebSocketFrame* frame) = 0; |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_WEBSOCKETS_WEBSOCKET_DEFLATE_PREDICTOR_H_ |