/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.handler.codec.http;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.TooLongFrameException;


Decodes ByteBufs into HttpRequests and HttpContents. 
Parameters that prevents excessive memory consumption


Name
Meaning


maxInitialLineLength
The maximum length of the initial line (e.g. "GET / HTTP/1.0") If the length of the initial line exceeds this value, a TooLongFrameException will be raised.


maxHeaderSize
The maximum length of all headers. If the sum of the length of each header exceeds this value, a TooLongFrameException will be raised.


maxChunkSize
The maximum length of the content or each chunk. If the content length exceeds this value, the transfer encoding of the decoded request will be converted to 'chunked' and the content will be split into multiple HttpContents. If the transfer encoding of the HTTP request is 'chunked' already, each chunk will be split into smaller chunks if the length of the chunk exceeds this value. If you prefer not to handle HttpContents in your handler, insert HttpObjectAggregator after this decoder in the ChannelPipeline.


/**
 * Decodes {@link ByteBuf}s into {@link HttpRequest}s and {@link HttpContent}s.
 *
 * <h3>Parameters that prevents excessive memory consumption</h3>
 * <table border="1">
 * <tr>
 * <th>Name</th><th>Meaning</th>
 * </tr>
 * <tr>
 * <td>{@code maxInitialLineLength}</td>
 * <td>The maximum length of the initial line (e.g. {@code "GET / HTTP/1.0"})
 *     If the length of the initial line exceeds this value, a
 *     {@link TooLongFrameException} will be raised.</td>
 * </tr>
 * <tr>
 * <td>{@code maxHeaderSize}</td>
 * <td>The maximum length of all headers.  If the sum of the length of each
 *     header exceeds this value, a {@link TooLongFrameException} will be raised.</td>
 * </tr>
 * <tr>
 * <td>{@code maxChunkSize}</td>
 * <td>The maximum length of the content or each chunk.  If the content length
 *     exceeds this value, the transfer encoding of the decoded request will be
 *     converted to 'chunked' and the content will be split into multiple
 *     {@link HttpContent}s.  If the transfer encoding of the HTTP request is
 *     'chunked' already, each chunk will be split into smaller chunks if the
 *     length of the chunk exceeds this value.  If you prefer not to handle
 *     {@link HttpContent}s in your handler, insert {@link HttpObjectAggregator}
 *     after this decoder in the {@link ChannelPipeline}.</td>
 * </tr>
 * </table>
 */
public class HttpRequestDecoder extends HttpObjectDecoder {

    
Creates a new instance with the default maxInitialLineLength (4096), maxHeaderSize (8192), and maxChunkSize (8192). /**
     * Creates a new instance with the default
     * {@code maxInitialLineLength (4096)}, {@code maxHeaderSize (8192)}, and
     * {@code maxChunkSize (8192)}.
     */
    public HttpRequestDecoder() {
    }

    
Creates a new instance with the specified parameters.
/**
     * Creates a new instance with the specified parameters.
     */
    public HttpRequestDecoder(
            int maxInitialLineLength, int maxHeaderSize, int maxChunkSize) {
        super(maxInitialLineLength, maxHeaderSize, maxChunkSize, true);
    }

    public HttpRequestDecoder(
            int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean validateHeaders) {
        super(maxInitialLineLength, maxHeaderSize, maxChunkSize, true, validateHeaders);
    }

    public HttpRequestDecoder(
            int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean validateHeaders,
            int initialBufferSize) {
        super(maxInitialLineLength, maxHeaderSize, maxChunkSize, true, validateHeaders, initialBufferSize);
    }

    @Override
    protected HttpMessage createMessage(String[] initialLine) throws Exception {
        return new DefaultHttpRequest(
                HttpVersion.valueOf(initialLine[2]),
                HttpMethod.valueOf(initialLine[0]), initialLine[1], validateHeaders);
    }

    @Override
    protected HttpMessage createInvalidMessage() {
        return new DefaultFullHttpRequest(HttpVersion.HTTP_1_0, HttpMethod.GET, "/bad-request", validateHeaders);
    }

    @Override
    protected boolean isDecodingRequest() {
        return true;
    }
}