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
|
//
//
#include "utils/encoding.h"
#include "mod_table/mod_table.h"
namespace util {
Encoding guess_encoding(const SCP_string& content, bool assume_utf8) {
if (content.size()>= 3 && !strncmp(content.c_str(), "\xEF\xBB\xBF", 3)) { // UTF-8
return Encoding::UTF8;
}
if (content.size()>= 4 && !strncmp(content.c_str(), "\x00\x00\xFE\xFF", 4)) { // UTF-32 big-endian
return Encoding::UTF32BE;
}
if (content.size()>= 4 && !strncmp(content.c_str(), "\xFF\xFE\x00\x00", 4)) { // UTF-32 little-endian
return Encoding::UTF32LE;
}
if (content.size()>= 2 && !strncmp(content.c_str(), "\xFE\xFF", 2)) { // UTF-16 big-endian
return Encoding::UTF16BE;
}
if (content.size()>= 2 && !strncmp(content.c_str(), "\xFF\xFE", 2)) { // UTF-16 little-endian
return Encoding::UTF16LE;
}
return assume_utf8 ? Encoding::UTF8 : Encoding::ASCII;
}
bool has_bom(const SCP_string& content) {
if (content.size()>= 3 && !strncmp(content.c_str(), "\xEF\xBB\xBF", 3)) { // UTF-8
return true;
}
if (content.size()>= 4 && !strncmp(content.c_str(), "\x00\x00\xFE\xFF", 4)) { // UTF-32 big-endian
return true;
}
if (content.size()>= 4 && !strncmp(content.c_str(), "\xFF\xFE\x00\x00", 4)) { // UTF-32 little-endian
return true;
}
if (content.size()>= 2 && !strncmp(content.c_str(), "\xFE\xFF", 2)) { // UTF-16 big-endian
return true;
}
if (content.size()>= 2 && !strncmp(content.c_str(), "\xFF\xFE", 2)) { // UTF-16 little-endian
return true;
}
return false;
}
int check_encoding_and_skip_bom(CFILE* file, const char* filename, int* start_offset) {
cfseek(file, 0, CF_SEEK_SET);
// Read up to 10 bytes from the file to check if there is a BOM
SCP_string probe;
auto probe_size = (size_t)std::min(10, cfilelength(file));
probe.resize(probe_size);
cfread(&probe[0], 1, (int) probe_size, file);
cfseek(file, 0, CF_SEEK_SET);
auto filelength = cfilelength(file);
if (start_offset) {
*start_offset = 0;
}
// Determine encoding. Assume UTF-8 if we are in unicode text mode
auto encoding = util::guess_encoding(probe, Unicode_text_mode);
if (Unicode_text_mode) {
if (encoding != util::Encoding::UTF8) {
//This is probably fatal, so let's abort right here and now.
Error(LOCATION,
"%s is in an Unicode/UTF format that cannot be read by FreeSpace Open. Please convert it to UTF-8\n",
filename);
}
if (util::has_bom(probe)) {
// The encoding has to be UTF-8 here so we know that the BOM is 3 Bytes long
// This makes sure that the first byte we read will be the first actual text byte.
cfseek(file, 3, SEEK_SET);
filelength -= 3;
if (start_offset) {
*start_offset = 3;
}
}
} else {
if (encoding != util::Encoding::ASCII) {
//This is probably fatal, so let's abort right here and now.
Error(LOCATION,
"%s is in Unicode/UTF format and cannot be read by FreeSpace Open without turning on Unicode mode. Please convert it to ASCII/ANSI\n",
filename);
}
}
return filelength;
}
// The following code is adapted from the uchardet library, the original licence of the file has been kept
/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Universal charset detector code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 2001
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Shy Shalom <shooshX@gmail.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include <cstdio>
#define UDF 0 // undefined
#define OTH 1 //other
#define ASC 2 // ascii capital letter
#define ASS 3 // ascii small letter
#define ACV 4 // accent capital vowel
#define ACO 5 // accent capital other
#define ASV 6 // accent small vowel
#define ASO 7 // accent small other
#define CLASS_NUM 8 // total classes
#define FREQ_CAT_NUM 4
static const unsigned char Latin1_CharToClass[] = { OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 00 - 07
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 08 - 0F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 10 - 17
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 18 - 1F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 20 - 27
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 28 - 2F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 30 - 37
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 38 - 3F
OTH, ASC, ASC, ASC, ASC, ASC, ASC, ASC, // 40 - 47
ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC, // 48 - 4F
ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC, // 50 - 57
ASC, ASC, ASC, OTH, OTH, OTH, OTH, OTH, // 58 - 5F
OTH, ASS, ASS, ASS, ASS, ASS, ASS, ASS, // 60 - 67
ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS, // 68 - 6F
ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS, // 70 - 77
ASS, ASS, ASS, OTH, OTH, OTH, OTH, OTH, // 78 - 7F
OTH, UDF, OTH, ASO, OTH, OTH, OTH, OTH, // 80 - 87
OTH, OTH, ACO, OTH, ACO, UDF, ACO, UDF, // 88 - 8F
UDF, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 90 - 97
OTH, OTH, ASO, OTH, ASO, UDF, ASO, ACO, // 98 - 9F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // A0 - A7
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // A8 - AF
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // B0 - B7
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // B8 - BF
ACV, ACV, ACV, ACV, ACV, ACV, ACO, ACO, // C0 - C7
ACV, ACV, ACV, ACV, ACV, ACV, ACV, ACV, // C8 - CF
ACO, ACO, ACV, ACV, ACV, ACV, ACV, OTH, // D0 - D7
ACV, ACV, ACV, ACV, ACV, ACO, ACO, ACO, // D8 - DF
ASV, ASV, ASV, ASV, ASV, ASV, ASO, ASO, // E0 - E7
ASV, ASV, ASV, ASV, ASV, ASV, ASV, ASV, // E8 - EF
ASO, ASO, ASV, ASV, ASV, ASV, ASV, OTH, // F0 - F7
ASV, ASV, ASV, ASV, ASV, ASO, ASO, ASO, // F8 - FF
};
/* 0 : illegal
1 : very unlikely
2 : normal
3 : very likely
*/
static const unsigned char Latin1ClassModel[] = {
/* UDF OTH ASC ASS ACV ACO ASV ASO */
/*UDF*/ 0, 0, 0, 0, 0, 0, 0, 0,
/*OTH*/ 0, 3, 3, 3, 3, 3, 3, 3,
/*ASC*/ 0, 3, 3, 3, 3, 3, 3, 3,
/*ASS*/ 0, 3, 3, 3, 1, 1, 3, 3,
/*ACV*/ 0, 3, 3, 3, 1, 2, 1, 2,
/*ACO*/ 0, 3, 3, 3, 3, 3, 3, 3,
/*ASV*/ 0, 3, 1, 3, 1, 1, 1, 3,
/*ASO*/ 0, 3, 1, 3, 1, 1, 3, 3, };
bool guessLatin1Encoding(const char* aBuf, size_t aLen) {
char mLastCharClass = OTH;
uint32_t mFreqCounter[FREQ_CAT_NUM];
for (int i = 0; i < FREQ_CAT_NUM; i++) {
mFreqCounter[i] = 0;
}
unsigned char charClass;
unsigned char freq;
for (size_t i = 0; i < aLen; i++) {
charClass = Latin1_CharToClass[(unsigned char) aBuf[i]];
freq = Latin1ClassModel[mLastCharClass * CLASS_NUM + charClass];
if (freq == 0) {
return false;
}
mFreqCounter[freq]++;
mLastCharClass = charClass;
}
float confidence;
uint32_t total = 0;
for (int32_t i = 0; i < FREQ_CAT_NUM; i++) {
total += mFreqCounter[i];
}
if (!total) {
confidence = 0.0f;
} else {
confidence = mFreqCounter[3] * 1.0f / total;
confidence -= mFreqCounter[1] * 20.0f / total;
}
if (confidence < 0.0f) {
confidence = 0.0f;
}
return confidence > .5f;
}
}
|
