/**************************************************************
 * 
 * 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 com.sun.star.comp.sdbc;

import java.io.IOException;
import java.io.InputStream;

public class BoundedInputStream extends InputStream {
    private final InputStream is;
    private long remaining;
    
    public BoundedInputStream(InputStream is, long max) {
        this.is = is;
        this.remaining = max;
    }

    @Override
    public int available() throws IOException {
        return is.available();
    }
    
    @Override
    public void close() throws IOException {
        is.close(); 
    }
    
    @Override
    public int read() throws IOException {
        if (remaining <= 0) {
            return -1;
        }
        int ret = is.read();
        if (ret >= 0) {
            --remaining;
        }
        return ret;
    }
    
    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        if (remaining <= 0) {
            return -1;
        }
        long max = Math.max(remaining, len);
        int bytesRead = is.read(b, off, (int)max);
        if (bytesRead > 0) {
            remaining -= bytesRead;
        }
        return bytesRead;
    }
}