| /* |
| * |
| * 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.hadoop.util; |
| |
| import static org.apache.hadoop.thirdparty.com.google.common.base.Preconditions.checkArgument; |
| import static org.apache.hadoop.thirdparty.com.google.common.base.Preconditions.checkNotNull; |
| |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| import org.apache.hadoop.classification.InterfaceStability.Unstable; |
| |
| /** |
| * Copied from guava source code v15 (LimitedInputStream) |
| * Guava deprecated LimitInputStream in v14 and removed it in v15. Copying this class here |
| * allows to be compatible with guava 11 to 15+. |
| * |
| * Originally: org.apache.hadoop.hbase.io.LimitInputStream |
| */ |
| @Unstable |
| public final class LimitInputStream extends FilterInputStream { |
| private long left; |
| private long mark = -1; |
| |
| public LimitInputStream(InputStream in, long limit) { |
| super(in); |
| checkNotNull(in); |
| checkArgument(limit >= 0, "limit must be non-negative"); |
| left = limit; |
| } |
| |
| @Override |
| public int available() throws IOException { |
| return (int) Math.min(in.available(), left); |
| } |
| |
| // it's okay to mark even if mark isn't supported, as reset won't work |
| @Override |
| public synchronized void mark(int readLimit) { |
| in.mark(readLimit); |
| mark = left; |
| } |
| |
| @Override |
| public int read() throws IOException { |
| if (left == 0) { |
| return -1; |
| } |
| |
| int result = in.read(); |
| if (result != -1) { |
| --left; |
| } |
| return result; |
| } |
| |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException { |
| if (len == 0) { |
| return 0; |
| } |
| if (left == 0) { |
| return -1; |
| } |
| |
| len = (int) Math.min(len, left); |
| int result = in.read(b, off, len); |
| if (result != -1) { |
| left -= result; |
| } |
| return result; |
| } |
| |
| @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(); |
| left = mark; |
| } |
| |
| @Override |
| public long skip(long n) throws IOException { |
| n = Math.min(n, left); |
| long skipped = in.skip(n); |
| left -= skipped; |
| return skipped; |
| } |
| } |