com.spotify.netty4.handler.codec.zmtp.ZMTPFramingDecoder.java Source code

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Here is the source code for com.spotify.netty4.handler.codec.zmtp.ZMTPFramingDecoder.java

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/*
 * Copyright (c) 2012-2013 Spotify AB
 *
 * Licensed 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 com.spotify.netty4.handler.codec.zmtp;

import java.util.List;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;

import static java.lang.Math.min;

/**
 * Netty ZMTP decoder.
 */
class ZMTPFramingDecoder extends ByteToMessageDecoder {

    private final ZMTPDecoder decoder;
    private final ZMTPWireFormat.Header header;

    private long remaining;
    private boolean headerParsed;

    public ZMTPFramingDecoder(final ZMTPWireFormat wireFormat, final ZMTPDecoder decoder) {
        this.header = wireFormat.header();
        this.decoder = decoder;
    }

    @Override
    protected void handlerRemoved0(final ChannelHandlerContext ctx) {
        decoder.close();
    }

    @Override
    protected void decode(final ChannelHandlerContext ctx, final ByteBuf in, final List<Object> out)
            throws ZMTPParsingException {
        while (in.isReadable()) {
            if (!headerParsed) {
                final int mark = in.readerIndex();
                headerParsed = header.read(in);
                if (!headerParsed) {
                    // Wait for more data
                    in.readerIndex(mark);
                    return;
                }
                decoder.header(ctx, header.length(), header.more(), out);
                remaining = header.length();
            }

            final int writerMark = in.writerIndex();
            final int n = (int) min(remaining, in.readableBytes());
            final int readerMark = in.readerIndex();
            in.writerIndex(readerMark + n);
            decoder.content(ctx, in, out);
            in.writerIndex(writerMark);
            final int read = in.readerIndex() - readerMark;
            remaining -= read;
            if (remaining > 0) {
                // Wait for more data
                return;
            }
            if (!header.more()) {
                decoder.finish(ctx, out);
            }
            headerParsed = false;
        }
    }
}