98 lines
2.1 KiB
Java
98 lines
2.1 KiB
Java
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/*
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* Copyright (C) 2007 The Guava Authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.google.common.io;
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import java.io.FilterInputStream;
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import java.io.IOException;
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import java.io.InputStream;
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import javax.annotation.Nullable;
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import com.google.common.annotations.Beta;
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/**
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* An {@link InputStream} that counts the number of bytes read.
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*
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* @author Chris Nokleberg
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* @since 1.0
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*/
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@Beta
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public final class CountingInputStream extends FilterInputStream {
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private long count;
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private long mark = -1;
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/**
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* Wraps another input stream, counting the number of bytes read.
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*
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* @param in the input stream to be wrapped
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*/
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public CountingInputStream(@Nullable InputStream in) {
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super(in);
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}
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/** Returns the number of bytes read. */
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public long getCount() {
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return count;
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}
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@Override
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public int read() throws IOException {
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int result = in.read();
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if (result != -1) {
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count++;
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}
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return result;
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}
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@Override
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public int read(byte[] b, int off, int len) throws IOException {
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int result = in.read(b, off, len);
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if (result != -1) {
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count += result;
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}
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return result;
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}
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@Override
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public long skip(long n) throws IOException {
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long result = in.skip(n);
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count += result;
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return result;
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}
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@Override
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public synchronized void mark(int readlimit) {
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in.mark(readlimit);
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mark = count;
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// it's okay to mark even if mark isn't supported, as reset won't work
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}
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@Override
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public synchronized void reset() throws IOException {
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if (!in.markSupported()) {
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throw new IOException("Mark not supported");
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}
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if (mark == -1) {
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throw new IOException("Mark not set");
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}
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in.reset();
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count = mark;
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}
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}
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