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
|
/*
* Copyright (C) 2020 The Android Open Source Project
*
* 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 com.android.build.config;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/**
* A CSV parser.
*/
public class CsvParser {
/**
* Internal string buffer grows by this amount.
*/
private static final int CHUNK_SIZE = 64 * 1024;
/**
* Error parsing.
*/
public static class ParseException extends Exception {
private int mLine;
private int mColumn;
public ParseException(int line, int column, String message) {
super(message);
mLine = line;
mColumn = column;
}
/**
* Line number in source file.
*/
public int getLine() {
return mLine;
}
/**
* Column in source file.
*/
public int getColumn() {
return mColumn;
}
}
public static class Line {
private final int mLineNumber;
private final List<String> mFields;
Line(int lineno, List<String> fields) {
mLineNumber = lineno;
mFields = fields;
}
public int getLine() {
return mLineNumber;
}
public List<String> getFields() {
return mFields;
}
}
// Parser States
private static final int STATE_START_LINE = 0;
private static final int STATE_START_FIELD = 1;
private static final int STATE_INSIDE_QUOTED_FIELD = 2;
private static final int STATE_FIRST_QUOTATION_MARK = 3;
private static final int STATE_INSIDE_UNQUOTED_FIELD = 4;
private static final int STATE_DONE = 5;
// Parser Actions
private static final int ACTION_APPEND_CHAR = 1;
private static final int ACTION_FIELD_COMPLETE = 2;
private static final int ACTION_LINE_COMPLETE = 4;
/**
* Constructor.
*/
private CsvParser() {
}
/**
* Reads CSV and returns a list of Line objects.
*
* Handles newlines inside fields quoted with double quotes (").
*
* Doesn't report blank lines, but does include empty fields.
*/
public static List<Line> parse(Reader reader)
throws ParseException, IOException {
ArrayList<Line> result = new ArrayList();
int line = 1;
int column = 1;
int pos = 0;
char[] buf = new char[CHUNK_SIZE];
HashMap<String,String> stringPool = new HashMap();
ArrayList<String> fields = new ArrayList();
int state = STATE_START_LINE;
while (state != STATE_DONE) {
int c = reader.read();
int action = 0;
if (state == STATE_START_LINE) {
if (c <= 0) {
// No data, skip ACTION_LINE_COMPLETE.
state = STATE_DONE;
} else if (c == '"') {
state = STATE_INSIDE_QUOTED_FIELD;
} else if (c == ',') {
action = ACTION_FIELD_COMPLETE;
state = STATE_START_FIELD;
} else if (c == '\n') {
// Consume the newline, state stays STATE_START_LINE.
} else {
action = ACTION_APPEND_CHAR;
state = STATE_INSIDE_UNQUOTED_FIELD;
}
} else if (state == STATE_START_FIELD) {
if (c <= 0) {
// Field will be empty
action = ACTION_FIELD_COMPLETE | ACTION_LINE_COMPLETE;
state = STATE_DONE;
} else if (c == '"') {
state = STATE_INSIDE_QUOTED_FIELD;
} else if (c == ',') {
action = ACTION_FIELD_COMPLETE;
state = STATE_START_FIELD;
} else if (c == '\n') {
action = ACTION_FIELD_COMPLETE | ACTION_LINE_COMPLETE;
state = STATE_START_LINE;
} else {
action = ACTION_APPEND_CHAR;
state = STATE_INSIDE_UNQUOTED_FIELD;
}
} else if (state == STATE_INSIDE_QUOTED_FIELD) {
if (c <= 0) {
throw new ParseException(line, column,
"Bad input: End of input inside quoted field.");
} else if (c == '"') {
state = STATE_FIRST_QUOTATION_MARK;
} else {
action = ACTION_APPEND_CHAR;
}
} else if (state == STATE_FIRST_QUOTATION_MARK) {
if (c <= 0) {
action = ACTION_FIELD_COMPLETE | ACTION_LINE_COMPLETE;
state = STATE_DONE;
} else if (c == '"') {
action = ACTION_APPEND_CHAR;
state = STATE_INSIDE_QUOTED_FIELD;
} else if (c == ',') {
action = ACTION_FIELD_COMPLETE;
state = STATE_START_FIELD;
} else if (c == '\n') {
action = ACTION_FIELD_COMPLETE | ACTION_LINE_COMPLETE;
state = STATE_START_LINE;
} else {
throw new ParseException(line, column,
"Bad input: Character after field ended or unquoted '\"'.");
}
} else if (state == STATE_INSIDE_UNQUOTED_FIELD) {
if (c <= 0) {
action = ACTION_FIELD_COMPLETE | ACTION_LINE_COMPLETE;
state = STATE_DONE;
} else if (c == ',') {
action = ACTION_FIELD_COMPLETE;
state = STATE_START_FIELD;
} else if (c == '\n') {
action = ACTION_FIELD_COMPLETE | ACTION_LINE_COMPLETE;
state = STATE_START_LINE;
} else {
action = ACTION_APPEND_CHAR;
}
}
if ((action & ACTION_APPEND_CHAR) != 0) {
// Reallocate buffer if necessary. Hopefully not often because CHUNK_SIZE is big.
if (pos >= buf.length) {
char[] old = buf;
buf = new char[old.length + CHUNK_SIZE];
System.arraycopy(old, 0, buf, 0, old.length);
}
// Store the character
buf[pos] = (char)c;
pos++;
}
if ((action & ACTION_FIELD_COMPLETE) != 0) {
// A lot of the strings are duplicated, so pool them to reduce peak memory
// usage. This could be made slightly better by having a custom key class
// that does the lookup without making a new String that gets immediately
// thrown away.
String field = new String(buf, 0, pos);
final String cached = stringPool.get(field);
if (cached == null) {
stringPool.put(field, field);
} else {
field = cached;
}
fields.add(field);
pos = 0;
}
if ((action & ACTION_LINE_COMPLETE) != 0) {
// Only report lines with any contents
if (fields.size() > 0) {
result.add(new Line(line, fields));
fields = new ArrayList();
}
}
if (c == '\n') {
line++;
column = 1;
} else {
column++;
}
}
return result;
}
}
|
