    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.compress.compressors.zstandard;
    019
    020
    021import java.io.IOException;
    022import java.io.InputStream;
    023
    024import com.github.luben.zstd.BufferPool;
    025import com.github.luben.zstd.ZstdInputStream;
    026import org.apache.commons.compress.compressors.CompressorInputStream;
    027import org.apache.commons.compress.utils.CountingInputStream;
    028import org.apache.commons.compress.utils.IOUtils;
    029import org.apache.commons.compress.utils.InputStreamStatistics;
    030
    031/**
    032 * {@link CompressorInputStream} implementation to decode Zstandard encoded stream.
    033 * Library relies on <a href="https://github.com/luben/zstd-jni/">Zstandard JNI</a>
    034 *
    035 * @since 1.16
    036 */
    037public class ZstdCompressorInputStream extends CompressorInputStream
    038    implements InputStreamStatistics {
    039
    040    private final CountingInputStream countingStream;
    041    private final ZstdInputStream decIS;
    042
    043    public ZstdCompressorInputStream(final InputStream in) throws IOException {
    044        this.decIS = new ZstdInputStream(countingStream = new CountingInputStream(in));
    045    }
    046
    047    /**
    048     * Creates a new input stream that decompresses zstd-compressed data from
    049     * the specific input stream
    050     *
    051     * @param in the input stream of compressed data
    052     * @param bufferPool a configuration of zstd-jni that allows users to customize
    053     *                   how buffers are recycled. Either a
    054     *                   {@link com.github.luben.zstd.NoPool} or a
    055     *                   {@link com.github.luben.zstd.RecyclingBufferPool} is
    056     *                   allowed here.
    057     * @throws IOException if an IO error occurs.
    058     */
    059    public ZstdCompressorInputStream(final InputStream in, final BufferPool bufferPool) throws IOException {
    060        this.decIS = new ZstdInputStream(countingStream = new CountingInputStream(in), bufferPool);
    061    }
    062
    063    @Override
    064    public int available() throws IOException {
    065        return decIS.available();
    066    }
    067
    068    @Override
    069    public void close() throws IOException {
    070        decIS.close();
    071    }
    072
    073    @Override
    074    public int read(final byte[] b) throws IOException {
    075        return read(b, 0, b.length);
    076    }
    077
    078    @Override
    079    public long skip(final long n) throws IOException {
    080        return IOUtils.skip(decIS, n);
    081    }
    082
    083    @Override
    084    public synchronized void mark(final int readlimit) {
    085        decIS.mark(readlimit);
    086    }
    087
    088    @Override
    089    public boolean markSupported() {
    090        return decIS.markSupported();
    091    }
    092
    093    @Override
    094    public int read() throws IOException {
    095        final int ret = decIS.read();
    096        count(ret == -1 ? 0 : 1);
    097        return ret;
    098    }
    099
    100    @Override
    101    public int read(final byte[] buf, final int off, final int len) throws IOException {
    102        if (len == 0) {
    103            return 0;
    104        }
    105        final int ret = decIS.read(buf, off, len);
    106        count(ret);
    107        return ret;
    108    }
    109
    110    @Override
    111    public String toString() {
    112        return decIS.toString();
    113    }
    114
    115    @Override
    116    public synchronized void reset() throws IOException {
    117        decIS.reset();
    118    }
    119
    120    /**
    121     * @since 1.17
    122     */
    123    @Override
    124    public long getCompressedCount() {
    125        return countingStream.getBytesRead();
    126    }
    127}