1 /*
2 * Copyright (c) 2016, 2019, 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
25 package gc.stress.gcbasher;
26
27 class ByteCursor {
28 private int offset;
29 private byte[] data;
30
31 public ByteCursor(byte[] data) {
32 this.offset = 0;
33 this.data = data;
34 }
35
36 public int getOffset() {
37 return offset;
38 }
39
40 public void skipBytes(int n) {
41 offset += n;
42 }
43
44 public int readUnsignedByte() {
45 int val = readUnsignedByteAt(offset);
46 offset += 1;
47 return val;
48 }
49
50 public int readUnsignedByteAt(int offset) {
51 return data[offset++] & 0xff;
52 }
53
54 public int readUnsignedShort() {
55 int val = readUnsignedShortAt(offset);
56 offset += 2;
57 return val;
58 }
59
60 public int readInt() {
61 int val = readIntAt(offset);
62 offset += 4;
63 return val;
64 }
65
66 public int readUnsignedShortAt(int offset) {
67 int b1 = data[offset++] & 0xff;
68 int b2 = data[offset] & 0xff;
69
70 return (b1 << 8) + b2;
71 }
72
73 public int readIntAt(int offset) {
74 int s1 = readUnsignedShortAt(offset);
75 int s2 = readUnsignedShortAt(offset + 2);
76 return (s1 << 16) + s2;
77 }
78
79 public String readUtf8(int length) throws IllegalStateException {
80 char str[] = new char[length];
81 int count = 0;
82 int pos = 0;
83 while (count < length) {
84 int c = readUnsignedByte();
85 switch (c >> 4) {
86 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: {
87 // 0xxxxxxx
88 count++;
89 if(c == '/') {
90 str[pos++] = '.';
91 } else {
92 str[pos++] = (char) c;
93 }
94 break;
95 } case 12: case 13: {
96 // 110x xxxx 10xx xxxx
97 count += 2;
98 int c2 = readUnsignedByte();
99 if ((c2 & 0xC0) != 0x80) {
100 throw new IllegalStateException();
101 }
102 str[pos++] = (char) (((c & 0x1F) << 6) | (c2 & 0x3F));
103 break;
104 } case 14: {
105 // 1110 xxxx 10xx xxxx 10xx xxxx
106 count += 3;
107 int c2 = readUnsignedByte();
108 int c3 = readUnsignedByte();
109 if ((c2 & 0xC0) != 0x80 || (c3 & 0xC0) != 0x80) {
110 throw new IllegalStateException();
111 }
112 str[pos++] = (char)(((c & 0x0F) << 12) |
113 ((c2 & 0x3F) << 6) |
114 ((c3 & 0x3F) << 0));
115 break;
116 } default:
117 // 10xx xxxx, 1111 xxxx
118 throw new IllegalStateException();
119 }
120 }
121 return new String(str);
122 }
123 }