summaryrefslogtreecommitdiff
path: root/fitz/base_string.c
blob: 76748e20fedc7ff2411b006ef8519dbcfad931db (plain)
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
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
#include "fitz.h"

int
fz_is_big_endian(void)
{
	static const int one = 1;
	return *(char*)&one == 0;
}

char *
fz_strsep(char **stringp, const char *delim)
{
	char *ret = *stringp;
	if (ret == NULL) return NULL;
	if ((*stringp = strpbrk(*stringp, delim)) != NULL)
		*((*stringp)++) = '\0';
	return ret;
}

int
fz_strlcpy(char *dst, const char *src, int siz)
{
	register char *d = dst;
	register const char *s = src;
	register int n = siz;

	/* Copy as many bytes as will fit */
	if (n != 0 && --n != 0) {
		do {
			if ((*d++ = *s++) == 0)
				break;
		} while (--n != 0);
	}

	/* Not enough room in dst, add NUL and traverse rest of src */
	if (n == 0) {
		if (siz != 0)
			*d = '\0';		/* NUL-terminate dst */
			while (*s++)
				;
	}

	return(s - src - 1);	/* count does not include NUL */
}

int
fz_strlcat(char *dst, const char *src, int siz)
{
	register char *d = dst;
	register const char *s = src;
	register int n = siz;
	int dlen;

	/* Find the end of dst and adjust bytes left but don't go past end */
	while (*d != '\0' && n-- != 0)
		d++;
	dlen = d - dst;
	n = siz - dlen;

	if (n == 0)
		return dlen + strlen(s);
	while (*s != '\0') {
		if (n != 1) {
			*d++ = *s;
			n--;
		}
		s++;
	}
	*d = '\0';

	return dlen + (s - src);	/* count does not include NUL */
}

enum
{
	UTFmax = 4, /* maximum bytes per rune */
	Runesync = 0x80, /* cannot represent part of a UTF sequence (<) */
	Runeself = 0x80, /* rune and UTF sequences are the same (<) */
	Runeerror = 0xFFFD, /* decoding error in UTF */
	Runemax = 0x10FFFF, /* maximum rune value */
};

enum
{
	Bit1 = 7,
	Bitx = 6,
	Bit2 = 5,
	Bit3 = 4,
	Bit4 = 3,
	Bit5 = 2,

	T1 = ((1<<(Bit1+1))-1) ^ 0xFF, /* 0000 0000 */
	Tx = ((1<<(Bitx+1))-1) ^ 0xFF, /* 1000 0000 */
	T2 = ((1<<(Bit2+1))-1) ^ 0xFF, /* 1100 0000 */
	T3 = ((1<<(Bit3+1))-1) ^ 0xFF, /* 1110 0000 */
	T4 = ((1<<(Bit4+1))-1) ^ 0xFF, /* 1111 0000 */
	T5 = ((1<<(Bit5+1))-1) ^ 0xFF, /* 1111 1000 */

	Rune1 = (1<<(Bit1+0*Bitx))-1, /* 0000 0000 0111 1111 */
	Rune2 = (1<<(Bit2+1*Bitx))-1, /* 0000 0111 1111 1111 */
	Rune3 = (1<<(Bit3+2*Bitx))-1, /* 1111 1111 1111 1111 */
	Rune4 = (1<<(Bit4+3*Bitx))-1, /* 0001 1111 1111 1111 1111 1111 */

	Maskx = (1<<Bitx)-1,	/* 0011 1111 */
	Testx = Maskx ^ 0xFF,	/* 1100 0000 */

	Bad = Runeerror,
};

int
chartorune(int *rune, char *str)
{
	int c, c1, c2, c3;
	long l;

	/*
	 * one character sequence
	 *	00000-0007F => T1
	 */
	c = *(unsigned char*)str;
	if(c < Tx) {
		*rune = c;
		return 1;
	}

	/*
	 * two character sequence
	 *	0080-07FF => T2 Tx
	 */
	c1 = *(unsigned char*)(str+1) ^ Tx;
	if(c1 & Testx)
		goto bad;
	if(c < T3) {
		if(c < T2)
			goto bad;
		l = ((c << Bitx) | c1) & Rune2;
		if(l <= Rune1)
			goto bad;
		*rune = l;
		return 2;
	}

	/*
	 * three character sequence
	 *	0800-FFFF => T3 Tx Tx
	 */
	c2 = *(unsigned char*)(str+2) ^ Tx;
	if(c2 & Testx)
		goto bad;
	if(c < T4) {
		l = ((((c << Bitx) | c1) << Bitx) | c2) & Rune3;
		if(l <= Rune2)
			goto bad;
		*rune = l;
		return 3;
	}

	/*
	 * four character sequence (21-bit value)
	 *	10000-1FFFFF => T4 Tx Tx Tx
	 */
	c3 = *(unsigned char*)(str+3) ^ Tx;
	if (c3 & Testx)
		goto bad;
	if (c < T5) {
		l = ((((((c << Bitx) | c1) << Bitx) | c2) << Bitx) | c3) & Rune4;
		if (l <= Rune3)
			goto bad;
		*rune = l;
		return 4;
	}
	/*
	 * Support for 5-byte or longer UTF-8 would go here, but
	 * since we don't have that, we'll just fall through to bad.
	 */

	/*
	 * bad decoding
	 */
bad:
	*rune = Bad;
	return 1;
}

int
runetochar(char *str, int *rune)
{
	/* Runes are signed, so convert to unsigned for range check. */
	unsigned long c;

	/*
	 * one character sequence
	 *	00000-0007F => 00-7F
	 */
	c = *rune;
	if(c <= Rune1) {
		str[0] = c;
		return 1;
	}

	/*
	 * two character sequence
	 *	0080-07FF => T2 Tx
	 */
	if(c <= Rune2) {
		str[0] = T2 | (c >> 1*Bitx);
		str[1] = Tx | (c & Maskx);
		return 2;
	}

	/*
	 * If the Rune is out of range, convert it to the error rune.
	 * Do this test here because the error rune encodes to three bytes.
	 * Doing it earlier would duplicate work, since an out of range
	 * Rune wouldn't have fit in one or two bytes.
	 */
	if (c > Runemax)
		c = Runeerror;

	/*
	 * three character sequence
	 *	0800-FFFF => T3 Tx Tx
	 */
	if (c <= Rune3) {
		str[0] = T3 | (c >> 2*Bitx);
		str[1] = Tx | ((c >> 1*Bitx) & Maskx);
		str[2] = Tx | (c & Maskx);
		return 3;
	}

	/*
	 * four character sequence (21-bit value)
	 *	10000-1FFFFF => T4 Tx Tx Tx
	 */
	str[0] = T4 | (c >> 3*Bitx);
	str[1] = Tx | ((c >> 2*Bitx) & Maskx);
	str[2] = Tx | ((c >> 1*Bitx) & Maskx);
	str[3] = Tx | (c & Maskx);
	return 4;
}

int
runelen(int c)
{
	char str[10];
	return runetochar(str, &c);
}

float fz_atof(const char *s)
{
	double d;

	/* The errno voodoo here checks for us reading numbers that are too
	 * big to fit into a double. The checks for FLT_MAX ensure that we
	 * don't read a number that's OK as a double and then become invalid
	 * as we convert to a float. */
	errno = 0;
	d = strtod(s, NULL);
	if (errno == ERANGE || d > FLT_MAX || d < -FLT_MAX) {
		/* Return 1.0, as it's a small known value that won't cause a
		 * divide by 0. */
		return 1.0;
	}
	return (float)d;
}