| // Copyright 2015 The Bazel Authors. All rights reserved. |
| // |
| // 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.devtools.build.zip; |
| |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * An {@link InputStream} that counts the number of bytes read. |
| */ |
| public final class CountingInputStream extends FilterInputStream { |
| |
| private static <T> T checkNotNull(T reference) { |
| if (reference == null) { |
| throw new NullPointerException(); |
| } |
| return reference; |
| } |
| |
| 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(); |
| count += result == -1 ? 0 : 1; |
| return result; |
| } |
| |
| @Override public int read(byte[] b, int off, int len) throws IOException { |
| int result = in.read(b, off, len); |
| count += result == -1 ? 0 : 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; |
| } |
| } |