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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and Jakarta Messaging 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 2015 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.
 */

/*
 * Copyright 2014 Twitter, Inc.
 *
 * 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 io.netty.handler.codec.http2;

import io.netty.buffer.ByteBuf;
import io.netty.util.AsciiString;
import io.netty.util.ByteProcessor;
import io.netty.util.internal.ObjectUtil;
import io.netty.util.internal.PlatformDependent;

final class HpackHuffmanEncoder {

    private final int[] codes;
    private final byte[] lengths;
    private final EncodedLengthProcessor encodedLengthProcessor = new EncodedLengthProcessor();
    private final EncodeProcessor encodeProcessor = new EncodeProcessor();

    HpackHuffmanEncoder() {
        this(HpackUtil.HUFFMAN_CODES, HpackUtil.HUFFMAN_CODE_LENGTHS);
    }

    /**
     * Creates a new Huffman encoder with the specified Huffman coding.
     *
     * @param codes the Huffman codes indexed by symbol
     * @param lengths the length of each Huffman code
     */
    private HpackHuffmanEncoder(int[] codes, byte[] lengths) {
        this.codes = codes;
        this.lengths = lengths;
    }

    /**
     * Compresses the input string literal using the Huffman coding.
     *
     * @param out the output stream for the compressed data
     * @param data the string literal to be Huffman encoded
     */
    public void encode(ByteBuf out, CharSequence data) {
        ObjectUtil.checkNotNull(out, "out");
        if (data instanceof AsciiString) {
            AsciiString string = (AsciiString) data;
            try {
                encodeProcessor.out = out;
                string.forEachByte(encodeProcessor);
            } catch (Exception e) {
                PlatformDependent.throwException(e);
            } finally {
                encodeProcessor.end();
            }
        } else {
            encodeSlowPath(out, data);
        }
    }

    private void encodeSlowPath(ByteBuf out, CharSequence data) {
        long current = 0;
        int n = 0;

        for (int i = 0; i < data.length(); i++) {
            int b = data.charAt(i) & 0xFF;
            int code = codes[b];
            int nbits = lengths[b];

            current <<= nbits;
            current |= code;
            n += nbits;

            while (n >= 8) {
                n -= 8;
                out.writeByte((int) (current >> n));
            }
        }

        if (n > 0) {
            current <<= 8 - n;
            current |= 0xFF >>> n; // this should be EOS symbol
            out.writeByte((int) current);
        }
    }

    /**
     * Returns the number of bytes required to Huffman encode the input string literal.
     *
     * @param data the string literal to be Huffman encoded
     * @return the number of bytes required to Huffman encode {@code data}
     */
    int getEncodedLength(CharSequence data) {
        if (data instanceof AsciiString) {
            AsciiString string = (AsciiString) data;
            try {
                encodedLengthProcessor.reset();
                string.forEachByte(encodedLengthProcessor);
                return encodedLengthProcessor.length();
            } catch (Exception e) {
                PlatformDependent.throwException(e);
                return -1;
            }
        } else {
            return getEncodedLengthSlowPath(data);
        }
    }

    private int getEncodedLengthSlowPath(CharSequence data) {
        long len = 0;
        for (int i = 0; i < data.length(); i++) {
            len += lengths[data.charAt(i) & 0xFF];
        }
        return (int) ((len + 7) >> 3);
    }

    private final class EncodeProcessor implements ByteProcessor {
        ByteBuf out;
        private long current;
        private int n;

        @Override
        public boolean process(byte value) {
            int b = value & 0xFF;
            int nbits = lengths[b];

            current <<= nbits;
            current |= codes[b];
            n += nbits;

            while (n >= 8) {
                n -= 8;
                out.writeByte((int) (current >> n));
            }
            return true;
        }

        void end() {
            try {
                if (n > 0) {
                    current <<= 8 - n;
                    current |= 0xFF >>> n; // this should be EOS symbol
                    out.writeByte((int) current);
                }
            } finally {
                out = null;
                current = 0;
                n = 0;
            }
        }
    }

    private final class EncodedLengthProcessor implements ByteProcessor {
        private long len;

        @Override
        public boolean process(byte value) {
            len += lengths[value & 0xFF];
            return true;
        }

        void reset() {
            len = 0;
        }

        int length() {
            return (int) ((len + 7) >> 3);
        }
    }
}