001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019
020package org.apache.commons.compress.compressors.zstandard;
021
022import java.io.IOException;
023import java.io.InputStream;
024
025import org.apache.commons.compress.compressors.CompressorInputStream;
026import org.apache.commons.compress.utils.InputStreamStatistics;
027import org.apache.commons.io.input.BoundedInputStream;
028
029import com.github.luben.zstd.BufferPool;
030import com.github.luben.zstd.ZstdInputStream;
031
032/**
033 * {@link CompressorInputStream} implementation to decode Zstandard encoded stream.
034 *
035 * <p>
036 * This class avoids making the underlying {@code zstd} classes part of the public or protected API. The underlying implementation is provided through the
037 * <a href="https://github.com/luben/zstd-jni/">Zstandard JNI</a> library which is based on <a href="https://github.com/facebook/zstd/">zstd</a>.
038 * </p>
039 *
040 * @see <a href="https://github.com/luben/zstd-jni/">Zstandard JNI</a>
041 * @see <a href="https://github.com/facebook/zstd/">zstd</a>
042 * @since 1.16
043 */
044public class ZstdCompressorInputStream extends CompressorInputStream implements InputStreamStatistics {
045
046    private final BoundedInputStream countingStream;
047    private final ZstdInputStream decIS;
048
049    /**
050     * Constructs a new input stream that decompresses zstd-compressed data from the specific input stream.
051     *
052     * @param in         the input stream of compressed data.
053     * @throws IOException if an I/O error occurs.
054     */
055    public ZstdCompressorInputStream(final InputStream in) throws IOException {
056        this.decIS = new ZstdInputStream(countingStream = BoundedInputStream.builder().setInputStream(in).get());
057    }
058
059    /**
060     * Constructs a new input stream that decompresses zstd-compressed data from the specific input stream.
061     *
062     * @param in         the input stream of compressed data.
063     * @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
064     *                   {@link com.github.luben.zstd.RecyclingBufferPool} is allowed here.
065     * @throws IOException if an I/O error occurs.
066     */
067    public ZstdCompressorInputStream(final InputStream in, final BufferPool bufferPool) throws IOException {
068        this.decIS = new ZstdInputStream(countingStream = BoundedInputStream.builder().setInputStream(in).get(), bufferPool);
069    }
070
071    @Override
072    public int available() throws IOException {
073        return decIS.available();
074    }
075
076    @Override
077    public void close() throws IOException {
078        decIS.close();
079    }
080
081    /**
082     *
083     * {@inheritDoc}
084     *
085     * @since 1.17
086     */
087    @Override
088    public long getCompressedCount() {
089        return countingStream.getCount();
090    }
091
092    @Override
093    public synchronized void mark(final int readLimit) {
094        decIS.mark(readLimit);
095    }
096
097    @Override
098    public boolean markSupported() {
099        return decIS.markSupported();
100    }
101
102    @Override
103    public int read() throws IOException {
104        final int ret = decIS.read();
105        count(ret == -1 ? 0 : 1);
106        return ret;
107    }
108
109    @Override
110    public int read(final byte[] b) throws IOException {
111        return read(b, 0, b.length);
112    }
113
114    @Override
115    public int read(final byte[] buf, final int off, final int len) throws IOException {
116        if (len == 0) {
117            return 0;
118        }
119        final int ret = decIS.read(buf, off, len);
120        count(ret);
121        return ret;
122    }
123
124    @Override
125    public synchronized void reset() throws IOException {
126        decIS.reset();
127    }
128
129    @Override
130    public long skip(final long n) throws IOException {
131        return org.apache.commons.io.IOUtils.skip(decIS, n);
132    }
133
134    @Override
135    public String toString() {
136        return decIS.toString();
137    }
138}