1 /*
2 * Copyright 2014 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty.handler.codec.http.websocketx.extensions.compression;
17
18 import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
19 import io.netty.handler.codec.http.websocketx.ContinuationWebSocketFrame;
20 import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
21 import io.netty.handler.codec.http.websocketx.WebSocketFrame;
22 import io.netty.handler.codec.http.websocketx.extensions.WebSocketExtension;
23 import io.netty.handler.codec.http.websocketx.extensions.WebSocketExtensionFilter;
24
25 /**
26 * Per-frame implementation of deflate compressor.
27 */
28 class PerFrameDeflateEncoder extends DeflateEncoder {
29
30 /**
31 * Constructor
32 *
33 * @param compressionLevel compression level of the compressor.
34 * @param windowSize maximum size of the window compressor buffer.
35 * @param noContext true to disable context takeover.
36 */
37 PerFrameDeflateEncoder(int compressionLevel, int windowSize, boolean noContext) {
38 super(compressionLevel, windowSize, noContext, WebSocketExtensionFilter.NEVER_SKIP);
39 }
40
41 /**
42 * Constructor
43 *
44 * @param compressionLevel compression level of the compressor.
45 * @param windowSize maximum size of the window compressor buffer.
46 * @param noContext true to disable context takeover.
47 * @param extensionEncoderFilter extension encoder filter for per frame deflate encoder.
48 */
49 PerFrameDeflateEncoder(int compressionLevel, int windowSize, boolean noContext,
50 WebSocketExtensionFilter extensionEncoderFilter) {
51 super(compressionLevel, windowSize, noContext, extensionEncoderFilter);
52 }
53
54 /**
55 * Constructor
56 *
57 * @param compressionLevel compression level of the compressor.
58 * @param windowSize maximum size of the window compressor buffer.
59 * @param memLevel internal compression state memory level (1..9).
60 * @param noContext true to disable context takeover.
61 * @param extensionEncoderFilter extension encoder filter for per frame deflate encoder.
62 */
63 PerFrameDeflateEncoder(int compressionLevel, int windowSize, int memLevel, boolean noContext,
64 WebSocketExtensionFilter extensionEncoderFilter) {
65 super(compressionLevel, windowSize, memLevel, noContext, extensionEncoderFilter);
66 }
67
68 @Override
69 public boolean acceptOutboundMessage(Object msg) throws Exception {
70 if (!super.acceptOutboundMessage(msg)) {
71 return false;
72 }
73
74 WebSocketFrame wsFrame = (WebSocketFrame) msg;
75 if (extensionEncoderFilter().mustSkip(wsFrame)) {
76 return false;
77 }
78
79 return (msg instanceof TextWebSocketFrame || msg instanceof BinaryWebSocketFrame ||
80 msg instanceof ContinuationWebSocketFrame) &&
81 wsFrame.content().readableBytes() > 0 &&
82 (wsFrame.rsv() & WebSocketExtension.RSV1) == 0;
83 }
84
85 @Override
86 protected int rsv(WebSocketFrame msg) {
87 return msg.rsv() | WebSocketExtension.RSV1;
88 }
89
90 @Override
91 protected boolean removeFrameTail(WebSocketFrame msg) {
92 return true;
93 }
94
95 }