104 lines
3.6 KiB
Java
104 lines
3.6 KiB
Java
/*
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* Copyright 2014 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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package io.netty.handler.codec.http.websocketx.extensions.compression;
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import io.netty.handler.codec.http.websocketx.extensions.WebSocketExtensionData;
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import io.netty.handler.codec.http.websocketx.extensions.WebSocketExtensionDecoder;
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import io.netty.handler.codec.http.websocketx.extensions.WebSocketExtensionEncoder;
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import io.netty.handler.codec.http.websocketx.extensions.WebSocketServerExtension;
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import io.netty.handler.codec.http.websocketx.extensions.WebSocketServerExtensionHandshaker;
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import java.util.Collections;
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/**
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* <a href="https://tools.ietf.org/id/draft-tyoshino-hybi-websocket-perframe-deflate-06.txt">perframe-deflate</a>
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* handshake implementation.
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*/
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public final class DeflateFrameServerExtensionHandshaker implements WebSocketServerExtensionHandshaker {
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static final String X_WEBKIT_DEFLATE_FRAME_EXTENSION = "x-webkit-deflate-frame";
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static final String DEFLATE_FRAME_EXTENSION = "deflate-frame";
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private final int compressionLevel;
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/**
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* Constructor with default configuration.
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*/
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public DeflateFrameServerExtensionHandshaker() {
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this(6);
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}
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/**
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* Constructor with custom configuration.
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*
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* @param compressionLevel
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* Compression level between 0 and 9 (default is 6).
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*/
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public DeflateFrameServerExtensionHandshaker(int compressionLevel) {
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if (compressionLevel < 0 || compressionLevel > 9) {
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throw new IllegalArgumentException(
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"compressionLevel: " + compressionLevel + " (expected: 0-9)");
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}
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this.compressionLevel = compressionLevel;
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}
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@Override
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public WebSocketServerExtension handshakeExtension(WebSocketExtensionData extensionData) {
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if (!X_WEBKIT_DEFLATE_FRAME_EXTENSION.equals(extensionData.name()) &&
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!DEFLATE_FRAME_EXTENSION.equals(extensionData.name())) {
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return null;
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}
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if (extensionData.parameters().isEmpty()) {
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return new DeflateFrameServerExtension(compressionLevel, extensionData.name());
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} else {
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return null;
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}
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}
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private static class DeflateFrameServerExtension implements WebSocketServerExtension {
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private final String extensionName;
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private final int compressionLevel;
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DeflateFrameServerExtension(int compressionLevel, String extensionName) {
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this.extensionName = extensionName;
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this.compressionLevel = compressionLevel;
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}
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@Override
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public int rsv() {
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return RSV1;
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}
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@Override
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public WebSocketExtensionEncoder newExtensionEncoder() {
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return new PerFrameDeflateEncoder(compressionLevel, 15, false);
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}
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@Override
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public WebSocketExtensionDecoder newExtensionDecoder() {
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return new PerFrameDeflateDecoder(false);
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}
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@Override
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public WebSocketExtensionData newReponseData() {
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return new WebSocketExtensionData(extensionName, Collections.<String, String>emptyMap());
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}
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}
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}
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