1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
|
/*
* ParseBuffer.java February 2001
*
* Copyright (C) 2001, Niall Gallagher <niallg@users.sf.net>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package org.simpleframework.common.parse;
/**
* This is primarily used to replace the <code>StringBuffer</code>
* class, as a way for the <code>Parser</code> to store the char's
* for a specific region within the parse data that constitutes a
* desired value. The methods are not synchronized so it enables
* the <code>char</code>'s to be taken quicker than the
* <code>StringBuffer</code> class.
*
* @author Niall Gallagher
*/
public class ParseBuffer {
/**
* This is used to quicken <code>toString</code>.
*/
protected String cache;
/**
* The <code>char</code>'s this buffer accumulated.
*/
protected char[] buf;
/**
* This is the number of <code>char</code>'s stored.
*/
protected int count;
/**
* Constructor for <code>ParseBuffer</code>. The default
* <code>ParseBuffer</code> stores 16 <code>char</code>'s
* before a <code>resize</code> is needed to accommodate
* extra characters.
*/
public ParseBuffer(){
this(16);
}
/**
* This creates a <code>ParseBuffer</code> with a specific
* default size. The buffer will be created the with the
* length specified. The <code>ParseBuffer</code> can grow
* to accommodate a collection of <code>char</code>'s larger
* the the size specified.
*
* @param size initial size of this <code>ParseBuffer</code>
*/
public ParseBuffer(int size){
this.buf = new char[size];
}
/**
* This will add a <code>char</code> to the end of the buffer.
* The buffer will not overflow with repeated uses of the
* <code>append</code>, it uses an <code>ensureCapacity</code>
* method which will allow the buffer to dynamically grow in
* size to accommodate more <code>char</code>'s.
*
* @param c the <code>char</code> to be appended
*/
public void append(char c){
ensureCapacity(count+ 1);
buf[count++] = c;
}
/**
* This will add a <code>String</code> to the end of the buffer.
* The buffer will not overflow with repeated uses of the
* <code>append</code>, it uses an <code>ensureCapacity</code>
* method which will allow the buffer to dynamically grow in
* size to accommodate large <code>String</code> objects.
*
* @param text the <code>String</code> to be appended to this
*/
public void append(String text){
ensureCapacity(count+ text.length());
text.getChars(0,text.length(),buf,count);
count += text.length();
}
/**
* This will reset the buffer in such a way that the buffer is
* cleared of all contents and then has the given string appended.
* This is used when a value is to be set into the buffer value.
* See the <code>append(String)</code> method for reference.
*
* @param text this is the text that is to be appended to this
*/
public void reset(String text) {
clear();
append(text);
}
/**
* This will add a <code>ParseBuffer</code> to the end of this.
* The buffer will not overflow with repeated uses of the
* <code>append</code>, it uses an <code>ensureCapacity</code>
* method which will allow the buffer to dynamically grow in
* size to accommodate large <code>ParseBuffer</code> objects.
*
* @param text the <code>ParseBuffer</code> to be appended
*/
public void append(ParseBuffer text){
append(text.buf, 0, text.count);
}
/**
* This will reset the buffer in such a way that the buffer is
* cleared of all contents and then has the given string appended.
* This is used when a value is to be set into the buffer value.
* See the <code>append(ParseBuffer)</code> method for reference.
*
* @param text this is the text that is to be appended to this
*/
public void reset(ParseBuffer text) {
clear();
append(text);
}
/**
* This will add a <code>char</code> to the end of the buffer.
* The buffer will not overflow with repeated uses of the
* <code>append</code>, it uses an <code>ensureCapacity</code>
* method which will allow the buffer to dynamically grow in
* size to accommodate large <code>char</code> arrays.
*
* @param c the <code>char</code> array to be appended to this
* @param off the read offset for the array
* @param len the number of <code>char</code>'s to add
*/
public void append(char[] c, int off, int len){
ensureCapacity(count+ len);
System.arraycopy(c,off,buf,count,len);
count+=len;
}
/**
* This will add a <code>String</code> to the end of the buffer.
* The buffer will not overflow with repeated uses of the
* <code>append</code>, it uses an <code>ensureCapacity</code>
* method which will allow the buffer to dynamically grow in
* size to accommodate large <code>String</code> objects.
*
* @param str the <code>String</code> to be appended to this
* @param off the read offset for the <code>String</code>
* @param len the number of <code>char</code>'s to add
*/
public void append(String str, int off, int len){
ensureCapacity(count+ len);
str.getChars(off,len,buf,count);
count += len;
}
/**
* This will add a <code>ParseBuffer</code> to the end of this.
* The buffer will not overflow with repeated uses of the
* <code>append</code>, it uses an <code>ensureCapacity</code>
* method which will allow the buffer to dynamically grow in
* size to accommodate large <code>ParseBuffer</code> objects.
*
* @param text the <code>ParseBuffer</code> to be appended
* @param off the read offset for the <code>ParseBuffer</code>
* @param len the number of <code>char</code>'s to add
*/
public void append(ParseBuffer text, int off, int len){
append(text.buf, off, len);
}
/**
* This ensure that there is enough space in the buffer to
* allow for more <code>char</code>'s to be added. If
* the buffer is already larger than min then the buffer
* will not be expanded at all.
*
* @param min the minimum size needed
*/
protected void ensureCapacity(int min) {
if(buf.length < min) {
int size = buf.length * 2;
int max = Math.max(min, size);
char[] temp = new char[max];
System.arraycopy(buf, 0, temp, 0, count);
buf = temp;
}
}
/**
* This will empty the <code>ParseBuffer</code> so that the
* <code>toString</code> parameter will return <code>null</code>.
* This is used so that the same <code>ParseBuffer</code> can be
* recycled for different tokens.
*/
public void clear(){
cache = null;
count = 0;
}
/**
* This will return the number of bytes that have been appended
* to the <code>ParseBuffer</code>. This will return zero after
* the clear method has been invoked.
*
* @return the number of <code>char</code>'s within the buffer
*/
public int length(){
return count;
}
/**
* This will return the characters that have been appended to the
* <code>ParseBuffer</code> as a <code>String</code> object.
* If the <code>String</code> object has been created before then
* a cached <code>String</code> object will be returned. This
* method will return <code>null</code> after clear is invoked.
*
* @return the <code>char</code>'s appended as a <code>String</code>
*/
public String toString(){
if(count <= 0) {
return null;
}
if(cache != null) {
return cache;
}
cache = new String(buf,0,count);
return cache;
}
}
|
