1 /**************************************************************
2  *
3  * Licensed to the Apache Software Foundation (ASF) under one
4  * or more contributor license agreements.  See the NOTICE file
5  * distributed with this work for additional information
6  * regarding copyright ownership.  The ASF licenses this file
7  * to you under the Apache License, Version 2.0 (the
8  * "License"); you may not use this file except in compliance
9  * with the License.  You may obtain a copy of the License at
10  *
11  *   http://www.apache.org/licenses/LICENSE-2.0
12  *
13  * Unless required by applicable law or agreed to in writing,
14  * software distributed under the License is distributed on an
15  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16  * KIND, either express or implied.  See the License for the
17  * specific language governing permissions and limitations
18  * under the License.
19  *
20  *************************************************************/
21 package com.sun.star.comp.sdbc;
22 
23 import java.io.IOException;
24 import java.io.InputStream;
25 
26 public class BoundedInputStream extends InputStream {
27     private final InputStream is;
28     private long remaining;
29 
BoundedInputStream(InputStream is, long max)30     public BoundedInputStream(InputStream is, long max) {
31         this.is = is;
32         this.remaining = max;
33     }
34 
35     @Override
available()36     public int available() throws IOException {
37         return is.available();
38     }
39 
40     @Override
close()41     public void close() throws IOException {
42         is.close();
43     }
44 
45     @Override
read()46     public int read() throws IOException {
47         if (remaining <= 0) {
48             return -1;
49         }
50         int ret = is.read();
51         if (ret >= 0) {
52             --remaining;
53         }
54         return ret;
55     }
56 
57     @Override
read(byte[] b, int off, int len)58     public int read(byte[] b, int off, int len) throws IOException {
59         if (remaining <= 0) {
60             return -1;
61         }
62         long max = Math.max(remaining, len);
63         int bytesRead = is.read(b, off, (int)max);
64         if (bytesRead > 0) {
65             remaining -= bytesRead;
66         }
67         return bytesRead;
68     }
69 }
70