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
020import java.io.IOException;
021import java.io.InputStream;
022
023import org.apache.commons.compress.compressors.CompressorInputStream;
024import org.apache.commons.compress.utils.InputStreamStatistics;
025import org.apache.commons.io.input.CountingInputStream;
026
027import com.github.luben.zstd.BufferPool;
028import com.github.luben.zstd.ZstdInputStream;
029
030/**
031 * {@link CompressorInputStream} implementation to decode Zstandard encoded stream. Library relies on <a href="https://github.com/luben/zstd-jni/">Zstandard
032 * JNI</a>
033 *
034 * @since 1.16
035 */
036public class ZstdCompressorInputStream extends CompressorInputStream implements InputStreamStatistics {
037
038    private final CountingInputStream countingStream;
039    private final ZstdInputStream decIS;
040
041    public ZstdCompressorInputStream(final InputStream in) throws IOException {
042        this.decIS = new ZstdInputStream(countingStream = new CountingInputStream(in));
043    }
044
045    /**
046     * Creates a new input stream that decompresses zstd-compressed data from the specific input stream
047     *
048     * @param in         the input stream of compressed data
049     * @param bufferPool a configuration of zstd-jni that allows users to customize how buffers are recycled. Either a {@link com.github.luben.zstd.NoPool} or a
050     *                   {@link com.github.luben.zstd.RecyclingBufferPool} is allowed here.
051     * @throws IOException if an IO error occurs.
052     */
053    public ZstdCompressorInputStream(final InputStream in, final BufferPool bufferPool) throws IOException {
054        this.decIS = new ZstdInputStream(countingStream = new CountingInputStream(in), bufferPool);
055    }
056
057    @Override
058    public int available() throws IOException {
059        return decIS.available();
060    }
061
062    @Override
063    public void close() throws IOException {
064        decIS.close();
065    }
066
067    /**
068     * @since 1.17
069     */
070    @Override
071    public long getCompressedCount() {
072        return countingStream.getByteCount();
073    }
074
075    @Override
076    public synchronized void mark(final int readLimit) {
077        decIS.mark(readLimit);
078    }
079
080    @Override
081    public boolean markSupported() {
082        return decIS.markSupported();
083    }
084
085    @Override
086    public int read() throws IOException {
087        final int ret = decIS.read();
088        count(ret == -1 ? 0 : 1);
089        return ret;
090    }
091
092    @Override
093    public int read(final byte[] b) throws IOException {
094        return read(b, 0, b.length);
095    }
096
097    @Override
098    public int read(final byte[] buf, final int off, final int len) throws IOException {
099        if (len == 0) {
100            return 0;
101        }
102        final int ret = decIS.read(buf, off, len);
103        count(ret);
104        return ret;
105    }
106
107    @Override
108    public synchronized void reset() throws IOException {
109        decIS.reset();
110    }
111
112    @Override
113    public long skip(final long n) throws IOException {
114        return org.apache.commons.io.IOUtils.skip(decIS, n);
115    }
116
117    @Override
118    public String toString() {
119        return decIS.toString();
120    }
121}