1//
2// UTF8Encoding.cpp
3//
4// Library: Foundation
5// Package: Text
6// Module: UTF8Encoding
7//
8// Copyright (c) 2004-2007, Applied Informatics Software Engineering GmbH.
9// and Contributors.
10//
11// SPDX-License-Identifier: BSL-1.0
12//
13
14
15#include "Poco/UTF8Encoding.h"
16#include "Poco/String.h"
17
18
19namespace Poco {
20
21
22const char* UTF8Encoding::_names[] =
23{
24 "UTF-8",
25 "UTF8",
26 NULL
27};
28
29
30const TextEncoding::CharacterMap UTF8Encoding::_charMap =
31{
32 /* 00 */ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
33 /* 10 */ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
34 /* 20 */ 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
35 /* 30 */ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
36 /* 40 */ 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
37 /* 50 */ 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
38 /* 60 */ 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
39 /* 70 */ 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
40 /* 80 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
41 /* 90 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
42 /* a0 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
43 /* b0 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
44 /* c0 */ -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
45 /* d0 */ -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
46 /* e0 */ -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3,
47 /* f0 */ -4, -4, -4, -4, -4, -4, -4, -4, -5, -5, -5, -5, -6, -6, -1, -1,
48};
49
50
51UTF8Encoding::UTF8Encoding()
52{
53}
54
55
56UTF8Encoding::~UTF8Encoding()
57{
58}
59
60
61const char* UTF8Encoding::canonicalName() const
62{
63 return _names[0];
64}
65
66
67bool UTF8Encoding::isA(const std::string& encodingName) const
68{
69 for (const char** name = _names; *name; ++name)
70 {
71 if (Poco::icompare(encodingName, *name) == 0)
72 return true;
73 }
74 return false;
75}
76
77
78const TextEncoding::CharacterMap& UTF8Encoding::characterMap() const
79{
80 return _charMap;
81}
82
83
84int UTF8Encoding::convert(const unsigned char* bytes) const
85{
86 int n = _charMap[*bytes];
87 int uc;
88
89 switch (n)
90 {
91 case -6:
92 case -5:
93 case -1:
94 return -1;
95 case -4:
96 case -3:
97 case -2:
98 if (!isLegal(bytes, -n)) return -1;
99 uc = *bytes & ((0x07 << (n + 4)) | 0x03);
100 break;
101 default:
102 return n;
103 }
104
105 while (n++ < -1)
106 {
107 uc <<= 6;
108 uc |= (*++bytes & 0x3F);
109 }
110 return uc;
111}
112
113
114int UTF8Encoding::convert(int ch, unsigned char* bytes, int length) const
115{
116 if (ch <= 0x7F)
117 {
118 if (bytes && length >= 1)
119 *bytes = (unsigned char) ch;
120 return 1;
121 }
122 else if (ch <= 0x7FF)
123 {
124 if (bytes && length >= 2)
125 {
126 *bytes++ = (unsigned char) (((ch >> 6) & 0x1F) | 0xC0);
127 *bytes = (unsigned char) ((ch & 0x3F) | 0x80);
128 }
129 return 2;
130 }
131 else if (ch <= 0xFFFF)
132 {
133 if (bytes && length >= 3)
134 {
135 *bytes++ = (unsigned char) (((ch >> 12) & 0x0F) | 0xE0);
136 *bytes++ = (unsigned char) (((ch >> 6) & 0x3F) | 0x80);
137 *bytes = (unsigned char) ((ch & 0x3F) | 0x80);
138 }
139 return 3;
140 }
141 else if (ch <= 0x10FFFF)
142 {
143 if (bytes && length >= 4)
144 {
145 *bytes++ = (unsigned char) (((ch >> 18) & 0x07) | 0xF0);
146 *bytes++ = (unsigned char) (((ch >> 12) & 0x3F) | 0x80);
147 *bytes++ = (unsigned char) (((ch >> 6) & 0x3F) | 0x80);
148 *bytes = (unsigned char) ((ch & 0x3F) | 0x80);
149 }
150 return 4;
151 }
152 else return 0;
153}
154
155
156int UTF8Encoding::queryConvert(const unsigned char* bytes, int length) const
157{
158 int n = _charMap[*bytes];
159 int uc;
160 if (-n > length)
161 {
162 return n;
163 }
164 else
165 {
166 switch (n)
167 {
168 case -6:
169 case -5:
170 case -1:
171 return -1;
172 case -4:
173 case -3:
174 case -2:
175 if (!isLegal(bytes, -n)) return -1;
176 uc = *bytes & ((0x07 << (n + 4)) | 0x03);
177 break;
178 default:
179 return n;
180 }
181 while (n++ < -1)
182 {
183 uc <<= 6;
184 uc |= (*++bytes & 0x3F);
185 }
186 return uc;
187 }
188}
189
190
191int UTF8Encoding::sequenceLength(const unsigned char* bytes, int length) const
192{
193 if (1 <= length)
194 {
195 int cc = _charMap[*bytes];
196 if (cc >= 0)
197 return 1;
198 else
199 return -cc;
200 }
201 else return -1;
202}
203
204
205bool UTF8Encoding::isLegal(const unsigned char *bytes, int length)
206{
207 if (0 == bytes || 0 == length) return false;
208
209 unsigned char a;
210 const unsigned char* srcptr = bytes + length;
211 switch (length)
212 {
213 default:
214 return false;
215 // Everything else falls through when true.
216 case 4:
217 if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
218 case 3:
219 if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
220 case 2:
221 a = (*--srcptr);
222 switch (*bytes)
223 {
224 case 0xE0:
225 if (a < 0xA0 || a > 0xBF) return false;
226 break;
227 case 0xED:
228 if (a < 0x80 || a > 0x9F) return false;
229 break;
230 case 0xF0:
231 if (a < 0x90 || a > 0xBF) return false;
232 break;
233 case 0xF4:
234 if (a < 0x80 || a > 0x8F) return false;
235 break;
236 default:
237 if (a < 0x80 || a > 0xBF) return false;
238 }
239 case 1:
240 if (*bytes >= 0x80 && *bytes < 0xC2) return false;
241 }
242 return *bytes <= 0xF4;
243}
244
245
246} // namespace Poco
247