Bzip2BitReader.java — netty Source File

Source Code

/*
 * Copyright 2014 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.compression;

import io.netty.buffer.ByteBuf;

/**
 * An bit reader that allows the reading of single bit booleans, bit strings of
 * arbitrary length (up to 32 bits), and bit aligned 32-bit integers. A single byte
 * at a time is read from the {@link ByteBuf} when more bits are required.
 */
class Bzip2BitReader {
    /**
     * Maximum count of possible readable bytes to check.
     */
    private static final int MAX_COUNT_OF_READABLE_BYTES = Integer.MAX_VALUE >>> 3;

    /**
     * The {@link ByteBuf} from which to read data.
     */
    private ByteBuf in;

    /**
     * A buffer of bits read from the input stream that have not yet been returned.
     */
    private long bitBuffer;

    /**
     * The number of bits currently buffered in {@link #bitBuffer}.
     */
    private int bitCount;

    /**
     * Set the {@link ByteBuf} from which to read data.
     */
    void setByteBuf(ByteBuf in) {
        this.in = in;
    }

    /**
     * Reads up to 32 bits from the {@link ByteBuf}.
     * @param count The number of bits to read (maximum {@code 32} as a size of {@code int})
     * @return The bits requested, right-aligned within the integer
     */
    int readBits(final int count) {
        if (count < 0 || count > 32) {
            throw new IllegalArgumentException("count: " + count + " (expected: 0-32 )");
// ... (98 more lines)