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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * 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:
 *
 *   https://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.buffer.ByteBufUtil;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import io.netty.channel.FileRegion;
import io.netty.handler.codec.EncoderException;
import io.netty.handler.codec.MessageToMessageEncoder;
import io.netty.util.CharsetUtil;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.concurrent.PromiseCombiner;
import io.netty.util.internal.StringUtil;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;

import static io.netty.buffer.Unpooled.directBuffer;
import static io.netty.buffer.Unpooled.unreleasableBuffer;
import static io.netty.handler.codec.http.HttpConstants.CR;
import static io.netty.handler.codec.http.HttpConstants.LF;

/**
 * Encodes an {@link HttpMessage} or an {@link HttpContent} into
 * a {@link ByteBuf}.
 *
 * 
Extensibility

 *
 * Please note that this encoder is designed to be extended to implement
 * a protocol derived from HTTP, such as
 * RTSP and
 * ICAP.
 * To implement the encoder of such a derived protocol, extend this class and
 * implement all abstract methods properly.
 */
public abstract class HttpObjectEncoder extends MessageToMessageEncoder {

    // this is a constant to decide when it is appropriate to copy the data content into the header buffer
    private static final int COPY_CONTENT_THRESHOLD = 128;
    static final int CRLF_SHORT = (CR << 8) | LF;
    private static final int ZERO_CRLF_MEDIUM = ('0' << 16) | CRLF_SHORT;
    private static final byte[] ZERO_CRLF_CRLF = { '0', CR, LF, CR, LF };
    private static final ByteBuf CRLF_BUF = unreleasableBuffer(
            directBuffer(2).writeByte(CR).writeByte(LF)).asReadOnly();
    private static final ByteBuf ZERO_CRLF_CRLF_BUF = unreleasableBuffer(
            directBuffer(ZERO_CRLF_CRLF.length).writeBytes(ZERO_CRLF_CRLF)).asReadOnly();
    private static final float HEADERS_WEIGHT_NEW = 1 / 5f;
    private static final float HEADERS_WEIGHT_HISTORICAL = 1 - HEADERS_WEIGHT_NEW;
    private static final float TRAILERS_WEIGHT_NEW = HEADERS_WEIGHT_NEW;
    private static final float TRAILERS_WEIGHT_HISTORICAL = HEADERS_WEIGHT_HISTORICAL;

    private static final int ST_INIT = 0;
    private static final int ST_CONTENT_NON_CHUNK = 1;
    private static final int ST_CONTENT_CHUNK = 2;
    private static final int ST_CONTENT_ALWAYS_EMPTY = 3;

    @SuppressWarnings("RedundantFieldInitialization")
    private int state = ST_INIT;

    /**
     * Used to calculate an exponential moving average of the encoded size of the initial line and the headers for
     * a guess for future buffer allocations.
     */
    private float headersEncodedSizeAccumulator = 256;

    /**
     * Used to calculate an exponential moving average of the encoded size of the trailers for
     * a guess for future buffer allocations.
     */
    private float trailersEncodedSizeAccumulator = 256;

    private final List out = new ArrayList();

    private static boolean checkContentState(int state) {
        return state == ST_CONTENT_CHUNK || state == ST_CONTENT_NON_CHUNK || state == ST_CONTENT_ALWAYS_EMPTY;
    }

    @Override
    public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
        try {
            if (acceptOutboundMessage(msg)) {
                encode(ctx, msg, out);
                if (out.isEmpty()) {
                    throw new EncoderException(
                            StringUtil.simpleClassName(this) + " must produce at least one message.");
                }
            } else {
                ctx.write(msg, promise);
            }
        } catch (EncoderException e) {
            throw e;
        } catch (Throwable t) {
            throw new EncoderException(t);
        } finally {
            writeOutList(ctx, out, promise);
        }
    }

    private static void writeOutList(ChannelHandlerContext ctx, List out, ChannelPromise promise) {
        final int size = out.size();
        try {
            if (size == 1) {
                ctx.write(out.get(0), promise);
            } else if (size > 1) {
                // Check if we can use a voidPromise for our extra writes to reduce GC-Pressure
                // See https://github.com/netty/netty/issues/2525
                if (promise == ctx.voidPromise()) {
                    writeVoidPromise(ctx, out);
                } else {
                    writePromiseCombiner(ctx, out, promise);
                }
            }
        } finally {
            out.clear();
        }
    }

    private static void writeVoidPromise(ChannelHandlerContext ctx, List out) {
        final ChannelPromise voidPromise = ctx.voidPromise();
        for (int i = 0; i < out.size(); i++) {
            ctx.write(out.get(i), voidPromise);
        }
    }

    private static void writePromiseCombiner(ChannelHandlerContext ctx, List out, ChannelPromise promise) {
        final PromiseCombiner combiner = new PromiseCombiner(ctx.executor());
        for (int i = 0; i < out.size(); i++) {
            combiner.add(ctx.write(out.get(i)));
        }
        combiner.finish(promise);
    }

    @Override
    @SuppressWarnings("ConditionCoveredByFurtherCondition")
    protected void encode(ChannelHandlerContext ctx, Object msg, List out) throws Exception {
        // fast-path for common idiom that doesn't require class-checks
        if (msg == Unpooled.EMPTY_BUFFER) {
            out.add(Unpooled.EMPTY_BUFFER);
            return;
        }
        // The reason why we perform instanceof checks in this order,
        // by duplicating some code and without relying on ReferenceCountUtil::release as a generic release
        // mechanism, is https://bugs.openjdk.org/browse/JDK-8180450.
        // https://github.com/netty/netty/issues/12708 contains more detail re how the previous version of this
        // code was interacting with the JIT instanceof optimizations.
        if (msg instanceof FullHttpMessage) {
            encodeFullHttpMessage(ctx, msg, out);
            return;
        }
        if (msg instanceof HttpMessage) {
            final H m;
            try {
                m = (H) msg;
            } catch (Exception rethrow) {
                ReferenceCountUtil.release(msg);
                throw rethrow;
            }
            if (m instanceof LastHttpContent) {
                encodeHttpMessageLastContent(ctx, m, out);
            } else if (m instanceof HttpContent) {
                encodeHttpMessageNotLastContent(ctx, m, out);
            } else {
                encodeJustHttpMessage(ctx, m, out);
            }
        } else {
            encodeNotHttpMessageContentTypes(ctx, msg, out);
        }
    }

    private void encodeJustHttpMessage(ChannelHandlerContext ctx, H m, List out) throws Exception {
        assert !(m instanceof HttpContent);
        try {
            if (state != ST_INIT) {
                throwUnexpectedMessageTypeEx(m, state);
            }
            final ByteBuf buf = encodeInitHttpMessage(ctx, m);

            assert checkContentState(state);

            out.add(buf);
        } finally {
            ReferenceCountUtil.release(m);
        }
    }

    private void encodeByteBufHttpContent(int state, ChannelHandlerContext ctx, ByteBuf buf, ByteBuf content,
                                          HttpHeaders trailingHeaders, List out) {
        switch (state) {
            case ST_CONTENT_NON_CHUNK:
                if (encodeContentNonChunk(out, buf, content)) {
                    break;
                }
                // fall-through!
            case ST_CONTENT_ALWAYS_EMPTY:
                // We allocated a buffer so add it now.
                out.add(buf);
                break;
            case ST_CONTENT_CHUNK:
                // We allocated a buffer so add it now.
                out.add(buf);
                encodeChunkedHttpContent(ctx, content, trailingHeaders, out);
                break;
            default:
                throw new Error();
        }
    }

    private void encodeHttpMessageNotLastContent(ChannelHandlerContext ctx, H m, List out) throws Exception {
        assert m instanceof HttpContent;
        assert !(m instanceof LastHttpContent);
        final HttpContent httpContent = (HttpContent) m;
        try {
            if (state != ST_INIT) {
                throwUnexpectedMessageTypeEx(m, state);
            }
            final ByteBuf buf = encodeInitHttpMessage(ctx, m);

            assert checkContentState(state);

            encodeByteBufHttpContent(state, ctx, buf, httpContent.content(), null, out);
        } finally {
            httpContent.release();
        }
    }

    private void encodeHttpMessageLastContent(ChannelHandlerContext ctx, H m, List out) throws Exception {
        assert m instanceof LastHttpContent;
        final LastHttpContent httpContent = (LastHttpContent) m;
        try {
            if (state != ST_INIT) {
                throwUnexpectedMessageTypeEx(m, state);
            }
            final ByteBuf buf = encodeInitHttpMessage(ctx, m);

            assert checkContentState(state);

            encodeByteBufHttpContent(state, ctx, buf, httpContent.content(), httpContent.trailingHeaders(), out);

            state = ST_INIT;
        } finally {
            httpContent.release();
        }
    }
    @SuppressWarnings("ConditionCoveredByFurtherCondition")
    private void encodeNotHttpMessageContentTypes(ChannelHandlerContext ctx, Object msg, List out) {
        assert !(msg instanceof HttpMessage);
        if (state == ST_INIT) {
            try {
                if (msg instanceof ByteBuf && bypassEncoderIfEmpty((ByteBuf) msg, out)) {
                    return;
                }
                throwUnexpectedMessageTypeEx(msg, ST_INIT);
            } finally {
                ReferenceCountUtil.release(msg);
            }
        }
        if (msg == LastHttpContent.EMPTY_LAST_CONTENT) {
            state = encodeEmptyLastHttpContent(state, out);
            return;
        }
        if (msg instanceof LastHttpContent) {
            encodeLastHttpContent(ctx, (LastHttpContent) msg, out);
            return;
        }
        if (msg instanceof HttpContent) {
            encodeHttpContent(ctx, (HttpContent) msg, out);
            return;
        }
        if (msg instanceof ByteBuf) {
            encodeByteBufContent(ctx, (ByteBuf) msg, out);
            return;
        }
        if (msg instanceof FileRegion) {
            encodeFileRegionContent(ctx, (FileRegion) msg, out);
            return;
        }
        try {
            throwUnexpectedMessageTypeEx(msg, state);
        } finally {
            ReferenceCountUtil.release(msg);
        }
    }

    private void encodeFullHttpMessage(ChannelHandlerContext ctx, Object o, List out)
            throws Exception {
        assert o instanceof FullHttpMessage;
        final FullHttpMessage msg = (FullHttpMessage) o;
        try {
            if (state != ST_INIT) {
                throwUnexpectedMessageTypeEx(o, state);
            }

            final H m = (H) o;

            final int state = isContentAlwaysEmpty(m) ? ST_CONTENT_ALWAYS_EMPTY :
                    HttpUtil.isTransferEncodingChunked(m) ? ST_CONTENT_CHUNK : ST_CONTENT_NON_CHUNK;

            ByteBuf content = msg.content();

            final boolean accountForContentSize = content.readableBytes() > 0 &&
                                        state == ST_CONTENT_NON_CHUNK &&
                                        // try embed the content if less or equals than
                                        // the biggest of ~12.5% of the header estimated size and COPY_DATA_THRESHOLD:
                                        // it limits a wrong estimation to waste too much memory
                                        content.readableBytes() <=
                                        Math.max(COPY_CONTENT_THRESHOLD, ((int) headersEncodedSizeAccumulator) / 8);

            final int headersAndContentSize = (int) headersEncodedSizeAccumulator +
                                                  (accountForContentSize? content.readableBytes() : 0);
            final ByteBuf buf = ctx.alloc().buffer(headersAndContentSize);

            encodeInitialLine(buf, m);

            sanitizeHeadersBeforeEncode(m, state == ST_CONTENT_ALWAYS_EMPTY);

            encodeHeaders(m.headers(), buf);
            ByteBufUtil.writeShortBE(buf, CRLF_SHORT);

            // don't consider the copyContent case here: the statistics is just related the headers
            headersEncodedSizeAccumulator = HEADERS_WEIGHT_NEW * padSizeForAccumulation(buf.readableBytes()) +
                    HEADERS_WEIGHT_HISTORICAL * headersEncodedSizeAccumulator;

            encodeByteBufHttpContent(state, ctx, buf, content, msg.trailingHeaders(), out);
        } finally {
            msg.release();
        }
    }

    private static boolean encodeContentNonChunk(List out, ByteBuf buf, ByteBuf content) {
        final int contentLength = content.readableBytes();
        if (contentLength > 0) {
            if (buf.maxFastWritableBytes() >= contentLength) {
                // merge into other buffer for performance reasons
                buf.writeBytes(content);
                out.add(buf);
            } else {
                out.add(buf);
                out.add(content.retain());
            }
            return true;
        }
        return false;
    }

    private static void throwUnexpectedMessageTypeEx(Object msg, int state) {
        throw new IllegalStateException("unexpected message type: " + StringUtil.simpleClassName(msg)
                + ", state: " + state);
    }

    private void encodeFileRegionContent(ChannelHandlerContext ctx, FileRegion msg, List out) {
        try {
            assert state != ST_INIT;
            switch (state) {
                case ST_CONTENT_NON_CHUNK:
                    if (msg.count() > 0) {
                        out.add(msg.retain());
                        break;
                    }

                    // fall-through!
                case ST_CONTENT_ALWAYS_EMPTY:
                    // Need to produce some output otherwise an
                    // IllegalStateException will be thrown as we did not write anything
                    // Its ok to just write an EMPTY_BUFFER as if there are reference count issues these will be
                    // propagated as the caller of the encode(...) method will release the original
                    // buffer.
                    // Writing an empty buffer will not actually write anything on the wire, so if there is a user
                    // error with msg it will not be visible externally
                    out.add(Unpooled.EMPTY_BUFFER);
                    break;
                case ST_CONTENT_CHUNK:
                    encodedChunkedFileRegionContent(ctx, msg, out);
                    break;
                default:
                    throw new Error();
            }
        } finally {
            msg.release();
        }
    }

    // Bypass the encoder in case of an empty buffer, so that the following idiom works:
    //
    //     ch.write(Unpooled.EMPTY_BUFFER).addListener(ChannelFutureListener.CLOSE);
    //
    // See https://github.com/netty/netty/issues/2983 for more information.
    private static boolean bypassEncoderIfEmpty(ByteBuf msg, List out) {
        if (!msg.isReadable()) {
            out.add(msg.retain());
            return true;
        }
        return false;
    }

    private void encodeByteBufContent(ChannelHandlerContext ctx, ByteBuf content, List out) {
        try {
            assert state != ST_INIT;
            if (bypassEncoderIfEmpty(content, out)) {
                return;
            }
            encodeByteBufAndTrailers(state, ctx, out, content, null);
        } finally {
            content.release();
        }
    }

    private static int encodeEmptyLastHttpContent(int state, List out) {
        assert state != ST_INIT;

        switch (state) {
            case ST_CONTENT_NON_CHUNK:
            case ST_CONTENT_ALWAYS_EMPTY:
                out.add(Unpooled.EMPTY_BUFFER);
                break;
            case ST_CONTENT_CHUNK:
                out.add(ZERO_CRLF_CRLF_BUF.duplicate());
                break;
            default:
                throw new Error();
        }
        return ST_INIT;
    }

    private void encodeLastHttpContent(ChannelHandlerContext ctx, LastHttpContent msg, List out) {
        assert state != ST_INIT;
        assert !(msg instanceof HttpMessage);
        try {
            encodeByteBufAndTrailers(state, ctx, out, msg.content(), msg.trailingHeaders());
            state = ST_INIT;
        } finally {
            msg.release();
        }
    }

    private void encodeHttpContent(ChannelHandlerContext ctx, HttpContent msg, List out) {
        assert state != ST_INIT;
        assert !(msg instanceof HttpMessage);
        assert !(msg instanceof LastHttpContent);
        try {
            this.encodeByteBufAndTrailers(state, ctx, out, msg.content(), null);
        } finally {
            msg.release();
        }
    }

    private void encodeByteBufAndTrailers(int state, ChannelHandlerContext ctx, List out, ByteBuf content,
                                          HttpHeaders trailingHeaders) {
        switch (state) {
            case ST_CONTENT_NON_CHUNK:
                if (content.isReadable()) {
                    out.add(content.retain());
                    break;
                }
                // fall-through!
            case ST_CONTENT_ALWAYS_EMPTY:
                out.add(Unpooled.EMPTY_BUFFER);
                break;
            case ST_CONTENT_CHUNK:
                encodeChunkedHttpContent(ctx, content, trailingHeaders, out);
                break;
            default:
                throw new Error();
        }
    }

    private void encodeChunkedHttpContent(ChannelHandlerContext ctx, ByteBuf content, HttpHeaders trailingHeaders,
                                          List out) {
        final int contentLength = content.readableBytes();
        if (contentLength > 0) {
            addEncodedLengthHex(ctx, contentLength, out);
            out.add(content.retain());
            out.add(CRLF_BUF.duplicate());
        }
        if (trailingHeaders != null) {
            encodeTrailingHeaders(ctx, trailingHeaders, out);
        } else if (contentLength == 0) {
            // Need to produce some output otherwise an
            // IllegalStateException will be thrown
            out.add(content.retain());
        }
    }

    private void encodeTrailingHeaders(ChannelHandlerContext ctx, HttpHeaders trailingHeaders, List out) {
        if (trailingHeaders.isEmpty()) {
            out.add(ZERO_CRLF_CRLF_BUF.duplicate());
        } else {
            ByteBuf buf = ctx.alloc().buffer((int) trailersEncodedSizeAccumulator);
            ByteBufUtil.writeMediumBE(buf, ZERO_CRLF_MEDIUM);
            encodeHeaders(trailingHeaders, buf);
            ByteBufUtil.writeShortBE(buf, CRLF_SHORT);
            trailersEncodedSizeAccumulator = TRAILERS_WEIGHT_NEW * padSizeForAccumulation(buf.readableBytes()) +
                    TRAILERS_WEIGHT_HISTORICAL * trailersEncodedSizeAccumulator;
            out.add(buf);
        }
    }

    private ByteBuf encodeInitHttpMessage(ChannelHandlerContext ctx, H m) throws Exception {
        assert state == ST_INIT;

        ByteBuf buf = ctx.alloc().buffer((int) headersEncodedSizeAccumulator);
        // Encode the message.
        encodeInitialLine(buf, m);
        state = isContentAlwaysEmpty(m) ? ST_CONTENT_ALWAYS_EMPTY :
                HttpUtil.isTransferEncodingChunked(m) ? ST_CONTENT_CHUNK : ST_CONTENT_NON_CHUNK;

        sanitizeHeadersBeforeEncode(m, state == ST_CONTENT_ALWAYS_EMPTY);

        encodeHeaders(m.headers(), buf);
        ByteBufUtil.writeShortBE(buf, CRLF_SHORT);

        headersEncodedSizeAccumulator = HEADERS_WEIGHT_NEW * padSizeForAccumulation(buf.readableBytes()) +
                HEADERS_WEIGHT_HISTORICAL * headersEncodedSizeAccumulator;
        return buf;
    }

    /**
     * Encode the {@link HttpHeaders} into a {@link ByteBuf}.
     */
    protected void encodeHeaders(HttpHeaders headers, ByteBuf buf) {
        Iterator> iter = headers.iteratorCharSequence();
        while (iter.hasNext()) {
            Entry header = iter.next();
            HttpHeadersEncoder.encoderHeader(header.getKey(), header.getValue(), buf);
        }
    }

    private static void encodedChunkedFileRegionContent(ChannelHandlerContext ctx, FileRegion msg, List out) {
        final long contentLength = msg.count();
        if (contentLength > 0) {
            addEncodedLengthHex(ctx, contentLength, out);
            out.add(msg.retain());
            out.add(CRLF_BUF.duplicate());
        } else if (contentLength == 0) {
            // Need to produce some output otherwise an
            // IllegalStateException will be thrown
            out.add(msg.retain());
        }
    }

    private static void addEncodedLengthHex(ChannelHandlerContext ctx, long contentLength, List out) {
        String lengthHex = Long.toHexString(contentLength);
        ByteBuf buf = ctx.alloc().buffer(lengthHex.length() + 2);
        buf.writeCharSequence(lengthHex, CharsetUtil.US_ASCII);
        ByteBufUtil.writeShortBE(buf, CRLF_SHORT);
        out.add(buf);
    }

    /**
     * Allows to sanitize headers of the message before encoding these.
     */
    protected void sanitizeHeadersBeforeEncode(@SuppressWarnings("unused") H msg, boolean isAlwaysEmpty) {
        // noop
    }

    /**
     * Determine whether a message has a content or not. Some message may have headers indicating
     * a content without having an actual content, e.g the response to an HEAD or CONNECT request.
     *
     * @param msg the message to test
     * @return {@code true} to signal the message has no content
     */
    protected boolean isContentAlwaysEmpty(@SuppressWarnings("unused") H msg) {
        return false;
    }

    @Override
    @SuppressWarnings("ConditionCoveredByFurtherCondition")
    public boolean acceptOutboundMessage(Object msg) throws Exception {
        return msg == Unpooled.EMPTY_BUFFER ||
                msg == LastHttpContent.EMPTY_LAST_CONTENT ||
                msg instanceof FullHttpMessage ||
                msg instanceof HttpMessage ||
                msg instanceof LastHttpContent ||
                msg instanceof HttpContent ||
                msg instanceof ByteBuf || msg instanceof FileRegion;
    }

    /**
     * Add some additional overhead to the buffer. The rational is that it is better to slightly over allocate and waste
     * some memory, rather than under allocate and require a resize/copy.
     *
     * @param readableBytes The readable bytes in the buffer.
     * @return The {@code readableBytes} with some additional padding.
     */
    private static int padSizeForAccumulation(int readableBytes) {
        return (readableBytes << 2) / 3;
    }

    @Deprecated
    protected static void encodeAscii(String s, ByteBuf buf) {
        buf.writeCharSequence(s, CharsetUtil.US_ASCII);
    }

    protected abstract void encodeInitialLine(ByteBuf buf, H message) throws Exception;
}
    

    

    

            

    

            



    
    






    
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