--- themer/main.c.orig 2009-10-13 20:56:23.000000000 -0400 +++ themer/main.c 2010-11-24 15:45:57.000000000 -0500 @@ -7,6 +7,103 @@ #include #include +/* states: S_N: normal, S_I: comparing integral part, S_F: comparing + fractional parts, S_Z: idem but with leading Zeroes only */ +#define S_N 0x0 +#define S_I 0x4 +#define S_F 0x8 +#define S_Z 0xC + +/* result_type: CMP: return diff; LEN: compare using len_diff/diff */ +#define CMP 2 +#define LEN 3 + + +/* ISDIGIT differs from isdigit, as follows: + - Its arg may be any int or unsigned int; it need not be an unsigned char. + - It's guaranteed to evaluate its argument exactly once. + - It's typically faster. + Posix 1003.2-1992 section 2.5.2.1 page 50 lines 1556-1558 says that + only '0' through '9' are digits. Prefer ISDIGIT to isdigit unless + it's important to use the locale's definition of `digit' even when the + host does not conform to Posix. */ +#define ISDIGIT(c) ((unsigned) (c) - '0' <= 9) + +/* Compare S1 and S2 as strings holding indices/version numbers, + returning less than, equal to or greater than zero if S1 is less than, + equal to or greater than S2 (for more info, see the texinfo doc). +*/ + +int +strverscmp (const char *s1, const char *s2) +{ + const unsigned char *p1 = (const unsigned char *) s1; + const unsigned char *p2 = (const unsigned char *) s2; + unsigned char c1, c2; + int state; + int diff; + + /* Symbol(s) 0 [1-9] others (padding) + Transition (10) 0 (01) d (00) x (11) - */ + static const unsigned int next_state[] = + { + /* state x d 0 - */ + /* S_N */ S_N, S_I, S_Z, S_N, + /* S_I */ S_N, S_I, S_I, S_I, + /* S_F */ S_N, S_F, S_F, S_F, + /* S_Z */ S_N, S_F, S_Z, S_Z + }; + + static const int result_type[] = + { + /* state x/x x/d x/0 x/- d/x d/d d/0 d/- + 0/x 0/d 0/0 0/- -/x -/d -/0 -/- */ + + /* S_N */ CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP, + CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, + /* S_I */ CMP, -1, -1, CMP, 1, LEN, LEN, CMP, + 1, LEN, LEN, CMP, CMP, CMP, CMP, CMP, + /* S_F */ CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP, + CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, + /* S_Z */ CMP, 1, 1, CMP, -1, CMP, CMP, CMP, + -1, CMP, CMP, CMP + }; + + if (p1 == p2) + return 0; + + c1 = *p1++; + c2 = *p2++; + /* Hint: '0' is a digit too. */ + state = S_N | ((c1 == '0') + (ISDIGIT (c1) != 0)); + + while ((diff = c1 - c2) == 0 && c1 != '\0') + { + state = next_state[state]; + c1 = *p1++; + c2 = *p2++; + state |= (c1 == '0') + (ISDIGIT (c1) != 0); + } + + state = result_type[state << 2 | ((c2 == '0') + (ISDIGIT (c2) != 0))]; + + switch (state) + { + case CMP: + return diff; + + case LEN: + while (ISDIGIT (*p1++)) + if (!ISDIGIT (*p2++)) + return 1; + + return ISDIGIT (*p2) ? -1 : diff; + + default: + return state; + } +} + #define LAST_COMPAT_VER "0.1.0" typedef struct _FetcherInfo