| /* |
| * Copyright (C) 2007 The Guava Authors |
| * |
| * Licensed 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 com.google.common.io; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| import com.google.common.annotations.Beta; |
| import com.google.common.annotations.GwtIncompatible; |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * An {@link InputStream} that counts the number of bytes read. |
| * |
| * @author Chris Nokleberg |
| * @since 1.0 |
| */ |
| @Beta |
| @GwtIncompatible |
| public final class CountingInputStream extends FilterInputStream { |
| |
| private long count; |
| private long mark = -1; |
| |
| /** |
| * Wraps another input stream, counting the number of bytes read. |
| * |
| * @param in the input stream to be wrapped |
| */ |
| public CountingInputStream(InputStream in) { |
| super(checkNotNull(in)); |
| } |
| |
| /** Returns the number of bytes read. */ |
| public long getCount() { |
| return count; |
| } |
| |
| @Override |
| public int read() throws IOException { |
| int result = in.read(); |
| if (result != -1) { |
| count++; |
| } |
| return result; |
| } |
| |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException { |
| int result = in.read(b, off, len); |
| if (result != -1) { |
| count += result; |
| } |
| return result; |
| } |
| |
| @Override |
| public long skip(long n) throws IOException { |
| long result = in.skip(n); |
| count += result; |
| return result; |
| } |
| |
| @Override |
| public synchronized void mark(int readlimit) { |
| in.mark(readlimit); |
| mark = count; |
| // it's okay to mark even if mark isn't supported, as reset won't work |
| } |
| |
| @Override |
| public synchronized void reset() throws IOException { |
| if (!in.markSupported()) { |
| throw new IOException("Mark not supported"); |
| } |
| if (mark == -1) { |
| throw new IOException("Mark not set"); |
| } |
| |
| in.reset(); |
| count = mark; |
| } |
| } |