001 /*
002 * Copyright 1999-2008 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package com.sun.tools.javac.util;
027
028 /** An abstraction for internal compiler strings. They are stored in
029 * Utf8 format. Names are stored in a Name.Table, and are unique within
030 * that table.
031 *
032 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
033 * you write code that depends on this, you do so at your own risk.
034 * This code and its internal interfaces are subject to change or
035 * deletion without notice.</b>
036 */
037 public abstract class Name implements javax.lang.model.element.Name {
038
039 public final Table table;
040
041 protected Name(Table table) {
042 this.table = table;
043 }
044
045 /**
046 * @inheritDoc
047 */
048 public boolean contentEquals(CharSequence cs) {
049 return toString().equals(cs.toString());
050 }
051
052 /**
053 * @inheritDoc
054 */
055 public int length() {
056 return toString().length();
057 }
058
059 /**
060 * @inheritDoc
061 */
062 public char charAt(int index) {
063 return toString().charAt(index);
064 }
065
066 /**
067 * @inheritDoc
068 */
069 public CharSequence subSequence(int start, int end) {
070 return toString().subSequence(start, end);
071 }
072
073 /** Return the concatenation of this name and name `n'.
074 */
075 public Name append(Name n) {
076 int len = getByteLength();
077 byte[] bs = new byte[len + n.getByteLength()];
078 getBytes(bs, 0);
079 n.getBytes(bs, len);
080 return table.fromUtf(bs, 0, bs.length);
081 }
082
083 /** Return the concatenation of this name, the given ASCII
084 * character, and name `n'.
085 */
086 public Name append(char c, Name n) {
087 int len = getByteLength();
088 byte[] bs = new byte[len + 1 + n.getByteLength()];
089 getBytes(bs, 0);
090 bs[len] = (byte) c;
091 n.getBytes(bs, len+1);
092 return table.fromUtf(bs, 0, bs.length);
093 }
094
095 /** An arbitrary but consistent complete order among all Names.
096 */
097 public int compareTo(Name other) {
098 return other.getIndex() - this.getIndex();
099 }
100
101 /** Return true if this is the empty name.
102 */
103 public boolean isEmpty() {
104 return getByteLength() == 0;
105 }
106
107 /** Returns last occurrence of byte b in this name, -1 if not found.
108 */
109 public int lastIndexOf(byte b) {
110 byte[] bytes = getByteArray();
111 int offset = getByteOffset();
112 int i = getByteLength() - 1;
113 while (i >= 0 && bytes[offset + i] != b) i--;
114 return i;
115 }
116
117 /** Does this name start with prefix?
118 */
119 public boolean startsWith(Name prefix) {
120 byte[] thisBytes = this.getByteArray();
121 int thisOffset = this.getByteOffset();
122 int thisLength = this.getByteLength();
123 byte[] prefixBytes = prefix.getByteArray();
124 int prefixOffset = prefix.getByteOffset();
125 int prefixLength = prefix.getByteLength();
126
127 int i = 0;
128 while (i < prefixLength &&
129 i < thisLength &&
130 thisBytes[thisOffset + i] == prefixBytes[prefixOffset + i])
131 i++;
132 return i == prefixLength;
133 }
134
135 /** Returns the sub-name starting at position start, up to and
136 * excluding position end.
137 */
138 public Name subName(int start, int end) {
139 if (end < start) end = start;
140 return table.fromUtf(getByteArray(), getByteOffset() + start, end - start);
141 }
142
143 /** Return the string representation of this name.
144 */
145 public String toString() {
146 return Convert.utf2string(getByteArray(), getByteOffset(), getByteLength());
147 }
148
149 /** Return the Utf8 representation of this name.
150 */
151 public byte[] toUtf() {
152 byte[] bs = new byte[getByteLength()];
153 getBytes(bs, 0);
154 return bs;
155 }
156
157 /* Get a "reasonably small" value that uniquely identifies this name
158 * within its name table.
159 */
160 public abstract int getIndex();
161
162 /** Get the length (in bytes) of this name.
163 */
164 public abstract int getByteLength();
165
166 /** Returns i'th byte of this name.
167 */
168 public abstract byte getByteAt(int i);
169
170 /** Copy all bytes of this name to buffer cs, starting at start.
171 */
172 public void getBytes(byte cs[], int start) {
173 System.arraycopy(getByteArray(), getByteOffset(), cs, start, getByteLength());
174 }
175
176 /** Get the underlying byte array for this name. The contents of the
177 * array must not be modified.
178 */
179 public abstract byte[] getByteArray();
180
181 /** Get the start offset of this name within its byte array.
182 */
183 public abstract int getByteOffset();
184
185 /** An abstraction for the hash table used to create unique Name instances.
186 */
187 public static abstract class Table {
188 /** Standard name table.
189 */
190 public final Names names;
191
192 Table(Names names) {
193 this.names = names;
194 }
195
196 /** Get the name from the characters in cs[start..start+len-1].
197 */
198 public abstract Name fromChars(char[] cs, int start, int len);
199
200 /** Get the name for the characters in string s.
201 */
202 public Name fromString(String s) {
203 char[] cs = s.toCharArray();
204 return fromChars(cs, 0, cs.length);
205 }
206
207 /** Get the name for the bytes in array cs.
208 * Assume that bytes are in utf8 format.
209 */
210 public Name fromUtf(byte[] cs) {
211 return fromUtf(cs, 0, cs.length);
212 }
213
214 /** get the name for the bytes in cs[start..start+len-1].
215 * Assume that bytes are in utf8 format.
216 */
217 public abstract Name fromUtf(byte[] cs, int start, int len);
218
219 /** Release any resources used by this table.
220 */
221 public abstract void dispose();
222
223 /** The hashcode of a name.
224 */
225 protected static int hashValue(byte bytes[], int offset, int length) {
226 int h = 0;
227 int off = offset;
228
229 for (int i = 0; i < length; i++) {
230 h = (h << 5) - h + bytes[off++];
231 }
232 return h;
233 }
234
235 /** Compare two subarrays
236 */
237 protected static boolean equals(byte[] bytes1, int offset1,
238 byte[] bytes2, int offset2, int length) {
239 int i = 0;
240 while (i < length && bytes1[offset1 + i] == bytes2[offset2 + i]) {
241 i++;
242 }
243 return i == length;
244 }
245 }
246 }