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 */
019package org.apache.commons.compress.compressors;
020
021import java.io.InputStream;
022
023/**
024 * Abstracts services for all compressor input streams.
025 */
026public abstract class CompressorInputStream extends InputStream {
027
028    private long bytesRead;
029
030    /**
031     * Constructs a new instance.
032     */
033    public CompressorInputStream() {
034        // empty
035    }
036
037    /**
038     * Increments the counter of already read bytes. Doesn't increment if the EOF has been hit (read == -1)
039     *
040     * @param read the number of bytes read
041     * @since 1.1
042     */
043    protected void count(final int read) {
044        count((long) read);
045    }
046
047    /**
048     * Increments the counter of already read bytes. Doesn't increment if the EOF has been hit (read == -1)
049     *
050     * @param read the number of bytes read
051     */
052    protected void count(final long read) {
053        if (read != -1) {
054            bytesRead += read;
055        }
056    }
057
058    /**
059     * Gets the current number of bytes read from this stream.
060     *
061     * @return the number of read bytes
062     * @since 1.1
063     */
064    public long getBytesRead() {
065        return bytesRead;
066    }
067
068    /**
069     * Gets the current number of bytes read from this stream.
070     *
071     * @return the number of read bytes
072     * @deprecated this method may yield wrong results for large archives, use #getBytesRead instead
073     */
074    @Deprecated
075    public int getCount() {
076        return (int) bytesRead;
077    }
078
079    /**
080     * Gets the amount of raw or compressed bytes read by the stream.
081     *
082     * <p>
083     * This implementation invokes {@link #getBytesRead}.
084     * </p>
085     *
086     * <p>
087     * Provides half of {@link org.apache.commons.compress.utils.InputStreamStatistics} without forcing subclasses to implement the other half.
088     * </p>
089     *
090     * @return the amount of decompressed bytes returned by the stream
091     * @since 1.17
092     */
093    public long getUncompressedCount() {
094        return getBytesRead();
095    }
096
097    /**
098     * Decrements the counter of already read bytes.
099     *
100     * @param pushedBack the number of bytes pushed back.
101     * @since 1.7
102     */
103    protected void pushedBackBytes(final long pushedBack) {
104        bytesRead -= pushedBack;
105    }
106}