1/*
2 * Copyright (c) 1998, 2006, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24/* @test
25   @bug 4090383
26   @summary Ensure that BufferedInputStream's read method will fill the target
27            array whenever possible
28 */
29
30
31import java.io.IOException;
32import java.io.InputStream;
33import java.io.BufferedInputStream;
34
35
36public class Fill {
37
38    /**
39     * A simple InputStream that is always ready but may read fewer than the
40     * requested number of bytes
41     */
42    static class Source extends InputStream {
43
44        int shortFall;
45        byte next = 0;
46
47        Source(int shortFall) {
48            this.shortFall = shortFall;
49        }
50
51        public int read() throws IOException {
52            return next++;
53        }
54
55        public int read(byte[] buf, int off, int len) throws IOException {
56            int n = len - shortFall;
57            for (int i = off; i < n; i++)
58                buf[i] = next++;
59            return n;
60        }
61
62        public int available() {
63            return Integer.MAX_VALUE;
64        }
65
66        public void close() throws IOException {
67        }
68
69    }
70
71    /**
72     * Test BufferedInputStream with an underlying source that always reads
73     * shortFall fewer bytes than requested
74     */
75    static void go(int shortFall) throws Exception {
76
77        InputStream r = new BufferedInputStream(new Source(shortFall), 10);
78        byte[] buf = new byte[8];
79
80        int n1 = r.read(buf);
81        int n2 = r.read(buf);
82        System.err.println("Shortfall " + shortFall
83                           + ": Read " + n1 + ", then " + n2 + " bytes");
84        if (n1 != buf.length)
85            throw new Exception("First read returned " + n1);
86        if (n2 != buf.length)
87            throw new Exception("Second read returned " + n2);
88
89    }
90
91    public static void main(String[] args) throws Exception {
92        for (int i = 0; i < 8; i++) go(i);
93    }
94
95}
96