98 lines
2.1 KiB
Java
98 lines
2.1 KiB
Java
/*
|
|
* 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 java.io.FilterInputStream;
|
|
import java.io.IOException;
|
|
import java.io.InputStream;
|
|
|
|
import javax.annotation.Nullable;
|
|
|
|
import com.google.common.annotations.Beta;
|
|
|
|
/**
|
|
* An {@link InputStream} that counts the number of bytes read.
|
|
*
|
|
* @author Chris Nokleberg
|
|
* @since 1.0
|
|
*/
|
|
@Beta
|
|
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(@Nullable InputStream in) {
|
|
super(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;
|
|
}
|
|
}
|