content: /*
   * 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;
      }
  }
  