| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.commons.io.input; |
| |
| import static org.apache.commons.io.IOUtils.EOF; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * A decorating input stream that counts the number of bytes that have passed |
| * through the stream so far. |
| * <p> |
| * A typical use case would be during debugging, to ensure that data is being |
| * read as expected. |
| * </p> |
| */ |
| public class CountingInputStream extends ProxyInputStream { |
| |
| /** The count of bytes that have passed. */ |
| private long count; |
| |
| /** |
| * Constructs a new CountingInputStream. |
| * |
| * @param in the InputStream to delegate to |
| */ |
| public CountingInputStream(final InputStream in) { |
| super(in); |
| } |
| |
| //----------------------------------------------------------------------- |
| |
| /** |
| * Skips the stream over the specified number of bytes, adding the skipped |
| * amount to the count. |
| * |
| * @param length the number of bytes to skip |
| * @return the actual number of bytes skipped |
| * @throws IOException if an I/O error occurs. |
| * @see java.io.InputStream#skip(long) |
| */ |
| @Override |
| public synchronized long skip(final long length) throws IOException { |
| final long skip = super.skip(length); |
| this.count += skip; |
| return skip; |
| } |
| |
| /** |
| * Adds the number of read bytes to the count. |
| * |
| * @param n number of bytes read, or -1 if no more bytes are available |
| * @since 2.0 |
| */ |
| @Override |
| protected synchronized void afterRead(final int n) { |
| if (n != EOF) { |
| this.count += n; |
| } |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * The number of bytes that have passed through this stream. |
| * <p> |
| * NOTE: From v1.3 this method throws an ArithmeticException if the |
| * count is greater than can be expressed by an {@code int}. |
| * See {@link #getByteCount()} for a method using a {@code long}. |
| * |
| * @return the number of bytes accumulated |
| * @throws ArithmeticException if the byte count is too large |
| */ |
| public int getCount() { |
| final long result = getByteCount(); |
| if (result > Integer.MAX_VALUE) { |
| throw new ArithmeticException("The byte count " + result + " is too large to be converted to an int"); |
| } |
| return (int) result; |
| } |
| |
| /** |
| * Set the byte count back to 0. |
| * <p> |
| * NOTE: From v1.3 this method throws an ArithmeticException if the |
| * count is greater than can be expressed by an {@code int}. |
| * See {@link #resetByteCount()} for a method using a {@code long}. |
| * |
| * @return the count previous to resetting |
| * @throws ArithmeticException if the byte count is too large |
| */ |
| public int resetCount() { |
| final long result = resetByteCount(); |
| if (result > Integer.MAX_VALUE) { |
| throw new ArithmeticException("The byte count " + result + " is too large to be converted to an int"); |
| } |
| return (int) result; |
| } |
| |
| /** |
| * The number of bytes that have passed through this stream. |
| * <p> |
| * NOTE: This method is an alternative for {@code getCount()} |
| * and was added because that method returns an integer which will |
| * result in incorrect count for files over 2GB. |
| * |
| * @return the number of bytes accumulated |
| * @since 1.3 |
| */ |
| public synchronized long getByteCount() { |
| return this.count; |
| } |
| |
| /** |
| * Set the byte count back to 0. |
| * <p> |
| * NOTE: This method is an alternative for {@code resetCount()} |
| * and was added because that method returns an integer which will |
| * result in incorrect count for files over 2GB. |
| * |
| * @return the count previous to resetting |
| * @since 1.3 |
| */ |
| public synchronized long resetByteCount() { |
| final long tmp = this.count; |
| this.count = 0; |
| return tmp; |
| } |
| |
| } |