| /* |
| * 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.cassandra.io.util; |
| |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * a FilterInputStream that returns the remaining bytes to read from available() |
| * regardless of whether the device is ready to provide them. |
| */ |
| public class LengthAvailableInputStream extends FilterInputStream |
| { |
| private long remainingBytes; |
| |
| public LengthAvailableInputStream(InputStream in, long totalLength) |
| { |
| super(in); |
| remainingBytes = totalLength; |
| } |
| |
| @Override |
| public int read() throws IOException |
| { |
| int b = in.read(); |
| --remainingBytes; |
| return b; |
| } |
| |
| @Override |
| public int read(byte[] b) throws IOException |
| { |
| int length = in.read(b); |
| remainingBytes -= length; |
| return length; |
| } |
| |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException |
| { |
| int length = in.read(b, off, len); |
| remainingBytes -= length; |
| return length; |
| } |
| |
| @Override |
| public long skip(long n) throws IOException |
| { |
| long length = in.skip(n); |
| remainingBytes -= length; |
| return length; |
| } |
| |
| @Override |
| public int available() throws IOException |
| { |
| return (remainingBytes <= 0) ? 0 : ((remainingBytes > Integer.MAX_VALUE) ? Integer.MAX_VALUE : (int)remainingBytes); |
| } |
| |
| @Override |
| public void close() throws IOException |
| { |
| in.close(); |
| } |
| |
| @Override |
| public synchronized void mark(int readlimit) |
| { |
| } |
| |
| @Override |
| public synchronized void reset() throws IOException |
| { |
| throw new IOException("Mark/Reset not supported"); |
| } |
| |
| @Override |
| public boolean markSupported() |
| { |
| return false; |
| } |
| } |