1 /*
2 * Copyright (c) 2000, 2003, 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,
20 * CA 94065 USA or visit www.oracle.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 package sun.jvm.hotspot.debugger;
26
27 /** A class representing an arbitrary-sized page which can be linked
28 into a list. Used by the PageCache. */
29
30 public class Page {
31 private long baseAddress;
32 private byte[] data;
33 private Page prev;
34 private Page next;
35 private long unmappedPageLength;
36
37 /** The length of the data[] array implicitly defines the size of the
38 page. */
39 public Page(long baseAddress, byte[] data) {
40 this.baseAddress = baseAddress;
41 this.data = data;
42 }
43
44 /** This constructor creates an "unmapped" page of the specified
45 length. Fetches from this page will cause -1 to be inserted into
46 the destination buffer. */
47 public Page(long baseAddress, long unmappedPageLength) {
48 this.baseAddress = baseAddress;
49 this.unmappedPageLength = unmappedPageLength;
50 }
51
52 public long getBaseAddress() {
53 return baseAddress;
54 }
55
56 public long getSize() {
57 if (data != null) {
58 return data.length;
59 } else {
60 return unmappedPageLength;
61 }
62 }
63
64 /** Indicates whether this page is mapped in the remote process's
65 address space */
66 public boolean isMapped() {
67 return (data != null);
68 }
69
70 public Page getPrev() {
71 return prev;
72 }
73
74 public void setPrev(Page prev) {
75 this.prev = prev;
76 }
77
78 public Page getNext() {
79 return next;
80 }
81
82 public void setNext(Page next) {
83 this.next = next;
84 }
85
86 /** Throws IndexOutOfBoundsException if the number of bytes
87 requested is greater than the page size, or if the start address
88 doesn't fall within the page. There are no guarantees on whether
89 any data was actually fetched if an IndexOutOfBoundsException is
90 thrown. If this page is unmapped, -1 is returned for all
91 addresses on this page. */
92 public void getData(long startAddress, long numBytes,
93 int[] destBuf, long destBufOffset)
94 throws IndexOutOfBoundsException {
95 int startOffset = (int) (startAddress - baseAddress);
96 if ((data == null) &&
97 ((startOffset < 0) || ((startOffset + numBytes) > (baseAddress + unmappedPageLength)))) {
98 throw new IndexOutOfBoundsException("startAddress = " + startAddress +
99 ", baseAddress = " + baseAddress +
100 ", unmappedPageLength = " + unmappedPageLength);
101 }
102 for (int i = 0; i < (int) numBytes; ++i) {
103 if (data != null) {
104 destBuf[i + (int) destBufOffset] = ((int) (data[i + startOffset]) & 0x000000FF);
105 } else {
106 destBuf[i + (int) destBufOffset] = -1;
107 }
108 }
109 }
110
111 /** Throws IndexOutOfBoundsException if the number of bytes
112 requested is greater than the page size, or if the start address
113 doesn't fall within the page. There are no guarantees on whether
114 any data was actually fetched if an IndexOutOfBoundsException is
115 thrown. If this page is unmapped, throws a RuntimeException;
116 this should be watched for at higher levels. */
117 public void getDataAsBytes(long startAddress, long numBytes,
118 byte[] destBuf, long destBufOffset)
119 throws IndexOutOfBoundsException {
120 long startOffset = startAddress - baseAddress;
121 if (data == null) {
122 throw new RuntimeException("Bug in PageCache; should not fetch from unmapped pages using getDataAsBytes");
123 }
124 System.arraycopy(data, (int) startOffset, destBuf, (int) destBufOffset, (int) numBytes);
125 }
126
127 public boolean getBoolean(long address) {
128 return (getByte(address) != 0);
129 }
130
131 public byte getByte(long address) {
132 return data[(int) address - (int) baseAddress];
133 }
134
135 public short getShort(long address, boolean bigEndian) {
136 int start = (int) address - (int) baseAddress;
137 if (bigEndian) {
138 return (short)
139 (((data[start + 1] & 0xFF)) |
140 ((data[start] & 0xFF) << 8));
141 } else {
142 return (short)
143 (((data[start + 1] & 0xFF) << 8) |
144 ((data[start] & 0xFF)));
145 }
146 }
147
148 public char getChar(long address, boolean bigEndian) {
149 return (char) getShort(address, bigEndian);
150 }
151
152 public int getInt(long address, boolean bigEndian) {
153 int start = (int) address - (int) baseAddress;
154 if (bigEndian) {
155 return
156 ((data[start + 3] & 0xFF)) |
157 ((data[start + 2] & 0xFF) << 8) |
158 ((data[start + 1] & 0xFF) << 16) |
159 ((data[start] & 0xFF) << 24);
160 } else {
161 return
162 ((data[start + 3] & 0xFF) << 24) |
163 ((data[start + 2] & 0xFF) << 16) |
164 ((data[start + 1] & 0xFF) << 8) |
165 ((data[start] & 0xFF));
166 }
167 }
168
169 public long getLong(long address, boolean bigEndian) {
170 int start = (int) address - (int) baseAddress;
171 if (bigEndian) {
172 return
173 ((data[start + 7] & 0xFFL)) |
174 ((data[start + 6] & 0xFFL) << 8) |
175 ((data[start + 5] & 0xFFL) << 16) |
176 ((data[start + 4] & 0xFFL) << 24) |
177 ((data[start + 3] & 0xFFL) << 32) |
178 ((data[start + 2] & 0xFFL) << 40) |
179 ((data[start + 1] & 0xFFL) << 48) |
180 ((data[start] & 0xFFL) << 56);
181 } else {
182 return
183 ((data[start + 7] & 0xFFL) << 56) |
184 ((data[start + 6] & 0xFFL) << 48) |
185 ((data[start + 5] & 0xFFL) << 40) |
186 ((data[start + 4] & 0xFFL) << 32) |
187 ((data[start + 3] & 0xFFL) << 24) |
188 ((data[start + 2] & 0xFFL) << 16) |
189 ((data[start + 1] & 0xFFL) << 8) |
190 ((data[start] & 0xFFL));
191 }
192 }
193
194 public float getFloat(long address, boolean bigEndian) {
195 return Float.intBitsToFloat(getInt(address, bigEndian));
196 }
197
198 public double getDouble(long address, boolean bigEndian) {
199 return Double.longBitsToDouble(getLong(address, bigEndian));
200 }
201 }