/* $Id$ */
/**
* 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.manifoldcf.connectorcommon.fuzzyml;
import org.apache.manifoldcf.core.interfaces.*;
import java.io.*;
import java.nio.*;
/** This class represents a Reader that begins with characters
* passed to it through the constructor, and then continues with the characters
* from a wrapped Reader. It's basically used when
* we've read past where we want to be in a Reader and need to back up.
*/
public class PrefixedReader extends Reader
{
protected final CharacterBuffer chars;
protected final Reader remainderStream;
protected int charPosition = 0;
protected int charMax;
/** Constructor */
public PrefixedReader(CharacterBuffer chars, Reader remainderStream)
{
this.chars = chars;
this.remainderStream = remainderStream;
charMax = chars.size();
}
@Override
public int read(CharBuffer target)
throws IOException
{
if (charPosition < charMax)
return super.read(target);
return remainderStream.read(target);
}
@Override
public int read()
throws IOException
{
if (charPosition < charMax)
return super.read();
return remainderStream.read();
}
@Override
public int read(char[] cbuf)
throws IOException
{
if (charPosition < charMax)
return super.read(cbuf);
return remainderStream.read(cbuf);
}
@Override
public int read(char[] cbuf, int off, int len)
throws IOException
{
int amt = 0;
while (charPosition < charMax)
{
cbuf[off++] = chars.readChar(charPosition++);
len--;
amt++;
}
if (len > 0)
{
int rem = remainderStream.read(cbuf,off,len);
if (rem == -1)
{
if (amt > 0)
return amt;
return rem;
}
amt += rem;
}
return amt;
}
@Override
public long skip(long n)
throws IOException
{
if (charPosition < charMax)
return super.skip(n);
return remainderStream.skip(n);
}
@Override
public void close()
throws IOException
{
// Since the wrapped reader will be closed by someone else,
// we NEVER close it through the wrapper.
}
}