Java example source code file (SpdyHeaderBlockRawEncoder.java)

This example Java source code file (SpdyHeaderBlockRawEncoder.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bytebuf, charsequence, illegalargumentexception, nullpointerexception, override, set, spdy_max_nv_length, spdyheaderblockencoder, spdyheaderblockrawencoder, spdyheadersframe, util

The SpdyHeaderBlockRawEncoder.java Java example source code

/*
 * Copyright 2013 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.spdy;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.buffer.ByteBufUtil;
import io.netty.buffer.Unpooled;

import java.util.Set;

import static io.netty.handler.codec.spdy.SpdyCodecUtil.SPDY_MAX_NV_LENGTH;

public class SpdyHeaderBlockRawEncoder extends SpdyHeaderBlockEncoder {

    private final int version;

    public SpdyHeaderBlockRawEncoder(SpdyVersion version) {
        if (version == null) {
            throw new NullPointerException("version");
        }
        this.version = version.getVersion();
    }

    private static void setLengthField(ByteBuf buffer, int writerIndex, int length) {
        buffer.setInt(writerIndex, length);
    }

    private static void writeLengthField(ByteBuf buffer, int length) {
        buffer.writeInt(length);
    }

    @Override
    public ByteBuf encode(ByteBufAllocator alloc, SpdyHeadersFrame frame) throws Exception {
        Set<CharSequence> names = frame.headers().names();
        int numHeaders = names.size();
        if (numHeaders == 0) {
            return Unpooled.EMPTY_BUFFER;
        }
        if (numHeaders > SPDY_MAX_NV_LENGTH) {
            throw new IllegalArgumentException(
                    "header block contains too many headers");
        }
        ByteBuf headerBlock = alloc.heapBuffer();
        writeLengthField(headerBlock, numHeaders);
        for (CharSequence name: names) {
            writeLengthField(headerBlock, name.length());
            ByteBufUtil.writeAscii(headerBlock, name);
            int savedIndex = headerBlock.writerIndex();
            int valueLength = 0;
            writeLengthField(headerBlock, valueLength);
            for (CharSequence value: frame.headers().getAll(name)) {
                int length = value.length();
                if (length > 0) {
                    ByteBufUtil.writeAscii(headerBlock, value);
                    headerBlock.writeByte(0);
                    valueLength += length + 1;
                }
            }
            if (valueLength != 0) {
                valueLength --;
            }
            if (valueLength > SPDY_MAX_NV_LENGTH) {
                throw new IllegalArgumentException(
                        "header exceeds allowable length: " + name);
            }
            if (valueLength > 0) {
                setLengthField(headerBlock, savedIndex, valueLength);
                headerBlock.writerIndex(headerBlock.writerIndex() - 1);
            }
        }
        return headerBlock;
    }

    @Override
    void end() {
    }
}