diff options
Diffstat (limited to 'versioncmp.c')
| -rw-r--r-- | versioncmp.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/versioncmp.c b/versioncmp.c new file mode 100644 index 0000000000..80bfd109fa --- /dev/null +++ b/versioncmp.c @@ -0,0 +1,143 @@ +#include "cache.h" +#include "string-list.h" + +/* + * versioncmp(): copied from string/strverscmp.c in glibc commit + * ee9247c38a8def24a59eb5cfb7196a98bef8cfdc, reformatted to Git coding + * style. The implementation is under LGPL-2.1 and Git relicenses it + * to GPLv2. + */ + +/* + * states: S_N: normal, S_I: comparing integral part, S_F: comparing + * fractionnal parts, S_Z: idem but with leading Zeroes only + */ +#define S_N 0x0 +#define S_I 0x3 +#define S_F 0x6 +#define S_Z 0x9 + +/* result_type: CMP: return diff; LEN: compare using len_diff/diff */ +#define CMP 2 +#define LEN 3 + +static const struct string_list *prereleases; +static int initialized; + +/* + * p1 and p2 point to the first different character in two strings. If + * either p1 or p2 starts with a prerelease suffix, it will be forced + * to be on top. + * + * If both p1 and p2 start with (different) suffix, the order is + * determined by config file. + * + * Note that we don't have to deal with the situation when both p1 and + * p2 start with the same suffix because the common part is already + * consumed by the caller. + * + * Return non-zero if *diff contains the return value for versioncmp() + */ +static int swap_prereleases(const void *p1_, + const void *p2_, + int *diff) +{ + const char *p1 = p1_; + const char *p2 = p2_; + int i, i1 = -1, i2 = -1; + + for (i = 0; i < prereleases->nr; i++) { + const char *suffix = prereleases->items[i].string; + if (i1 == -1 && starts_with(p1, suffix)) + i1 = i; + if (i2 == -1 && starts_with(p2, suffix)) + i2 = i; + } + if (i1 == -1 && i2 == -1) + return 0; + if (i1 >= 0 && i2 >= 0) + *diff = i1 - i2; + else if (i1 >= 0) + *diff = -1; + else /* if (i2 >= 0) */ + *diff = 1; + return 1; +} + +/* + * 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 versioncmp(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, diff; + + /* + * Symbol(s) 0 [1-9] others + * Transition (10) 0 (01) d (00) x + */ + static const uint8_t next_state[] = { + /* state x d 0 */ + /* S_N */ S_N, S_I, S_Z, + /* S_I */ S_N, S_I, S_I, + /* S_F */ S_N, S_F, S_F, + /* S_Z */ S_N, S_F, S_Z + }; + + static const int8_t result_type[] = { + /* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */ + + /* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP, + /* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN, + /* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, + /* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, 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) { + if (c1 == '\0') + return diff; + + state = next_state[state]; + c1 = *p1++; + c2 = *p2++; + state += (c1 == '0') + (isdigit (c1) != 0); + } + + if (!initialized) { + initialized = 1; + prereleases = git_config_get_value_multi("versionsort.prereleasesuffix"); + } + if (prereleases && swap_prereleases(p1 - 1, p2 - 1, &diff)) + return diff; + + state = result_type[state * 3 + (((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; + } +} |