    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 */
    017package org.apache.commons.io.input;
    018
    019import static org.apache.commons.io.IOUtils.EOF;
    020
    021import java.io.IOException;
    022import java.io.InputStream;
    023
    024/**
    025 * A decorating input stream that counts the number of bytes that have passed
    026 * through the stream so far.
    027 * <p>
    028 * A typical use case would be during debugging, to ensure that data is being
    029 * read as expected.
    030 * </p>
    031 * @deprecated Use {@link BoundedInputStream} (unbounded by default).
    032 */
    033@Deprecated
    034public class CountingInputStream extends ProxyInputStream {
    035
    036    /** The count of bytes read. */
    037    private long count;
    038
    039    /**
    040     * Constructs a new CountingInputStream.
    041     *
    042     * @param in  the InputStream to delegate to
    043     */
    044    public CountingInputStream(final InputStream in) {
    045        super(in);
    046    }
    047
    048    CountingInputStream(final InputStream in, final ProxyInputStream.AbstractBuilder<?, ?> builder) {
    049        super(in, builder);
    050    }
    051
    052    CountingInputStream(final ProxyInputStream.AbstractBuilder<?, ?> builder) throws IOException {
    053        super(builder);
    054    }
    055
    056    /**
    057     * Adds the number of read bytes to the count.
    058     *
    059     * @param n number of bytes read, or -1 if no more bytes are available
    060     * @throws IOException Not thrown here but subclasses may throw.
    061     * @since 2.0
    062     */
    063    @Override
    064    protected synchronized void afterRead(final int n) throws IOException {
    065        if (n != EOF) {
    066            count += n;
    067        }
    068        super.afterRead(n);
    069    }
    070
    071    /**
    072     * Gets number of bytes that have passed through this stream.
    073     * <p>
    074     * NOTE: This method is an alternative for {@code getCount()}
    075     * and was added because that method returns an integer which will
    076     * result in incorrect count for files over 2GB.
    077     * </p>
    078     *
    079     * @return the number of bytes accumulated
    080     * @since 1.3
    081     */
    082    public synchronized long getByteCount() {
    083        return count;
    084    }
    085
    086    /**
    087     * Gets number of bytes that have passed through this stream.
    088     * <p>
    089     * This method throws an ArithmeticException if the
    090     * count is greater than can be expressed by an {@code int}.
    091     * See {@link #getByteCount()} for a method using a {@code long}.
    092     * </p>
    093     *
    094     * @return the number of bytes accumulated
    095     * @throws ArithmeticException if the byte count is too large
    096     * @deprecated Use {@link #getByteCount()}.
    097     */
    098    @Deprecated
    099    public int getCount() {
    100        final long result = getByteCount();
    101        if (result > Integer.MAX_VALUE) {
    102            throw new ArithmeticException("The byte count " + result + " is too large to be converted to an int");
    103        }
    104        return (int) result;
    105    }
    106
    107    /**
    108     * Resets the byte count back to 0.
    109     * <p>
    110     * NOTE: This method is an alternative for {@code resetCount()}
    111     * and was added because that method returns an integer which will
    112     * result in incorrect count for files over 2GB.
    113     * </p>
    114     *
    115     * @return the count previous to resetting
    116     * @since 1.3
    117     */
    118    public synchronized long resetByteCount() {
    119        final long tmp = count;
    120        count = 0;
    121        return tmp;
    122    }
    123
    124    /**
    125     * Resets the byte count back to 0.
    126     * <p>
    127     * This method throws an ArithmeticException if the
    128     * count is greater than can be expressed by an {@code int}.
    129     * See {@link #resetByteCount()} for a method using a {@code long}.
    130     * </p>
    131     *
    132     * @return the count previous to resetting
    133     * @throws ArithmeticException if the byte count is too large
    134     * @deprecated Use {@link #resetByteCount()}.
    135     */
    136    @Deprecated
    137    public int resetCount() {
    138        final long result = resetByteCount();
    139        if (result > Integer.MAX_VALUE) {
    140            throw new ArithmeticException("The byte count " + result + " is too large to be converted to an int");
    141        }
    142        return (int) result;
    143    }
    144
    145    /**
    146     * Skips the stream over the specified number of bytes, adding the skipped
    147     * amount to the count.
    148     *
    149     * @param length  the number of bytes to skip
    150     * @return the actual number of bytes skipped
    151     * @throws IOException if an I/O error occurs.
    152     * @see java.io.InputStream#skip(long)
    153     */
    154    @Override
    155    public synchronized long skip(final long length) throws IOException {
    156        final long skip = super.skip(length);
    157        count += skip;
    158        return skip;
    159    }
    160
    161}