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9ef176b5 NTND |
1 | #include "cache.h" |
2 | ||
3 | /* | |
4 | * versioncmp(): copied from string/strverscmp.c in glibc commit | |
5 | * ee9247c38a8def24a59eb5cfb7196a98bef8cfdc, reformatted to Git coding | |
6 | * style. The implementation is under LGPL-2.1 and Git relicenses it | |
7 | * to GPLv2. | |
8 | */ | |
9 | ||
10 | /* | |
11 | * states: S_N: normal, S_I: comparing integral part, S_F: comparing | |
12 | * fractionnal parts, S_Z: idem but with leading Zeroes only | |
13 | */ | |
14 | #define S_N 0x0 | |
15 | #define S_I 0x3 | |
16 | #define S_F 0x6 | |
17 | #define S_Z 0x9 | |
18 | ||
19 | /* result_type: CMP: return diff; LEN: compare using len_diff/diff */ | |
20 | #define CMP 2 | |
21 | #define LEN 3 | |
22 | ||
23 | ||
24 | /* | |
25 | * Compare S1 and S2 as strings holding indices/version numbers, | |
26 | * returning less than, equal to or greater than zero if S1 is less | |
27 | * than, equal to or greater than S2 (for more info, see the texinfo | |
28 | * doc). | |
29 | */ | |
30 | ||
31 | int versioncmp(const char *s1, const char *s2) | |
32 | { | |
33 | const unsigned char *p1 = (const unsigned char *) s1; | |
34 | const unsigned char *p2 = (const unsigned char *) s2; | |
35 | unsigned char c1, c2; | |
36 | int state, diff; | |
37 | ||
38 | /* | |
39 | * Symbol(s) 0 [1-9] others | |
40 | * Transition (10) 0 (01) d (00) x | |
41 | */ | |
42 | static const uint8_t next_state[] = { | |
43 | /* state x d 0 */ | |
44 | /* S_N */ S_N, S_I, S_Z, | |
45 | /* S_I */ S_N, S_I, S_I, | |
46 | /* S_F */ S_N, S_F, S_F, | |
47 | /* S_Z */ S_N, S_F, S_Z | |
48 | }; | |
49 | ||
50 | static const int8_t result_type[] = { | |
51 | /* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */ | |
52 | ||
53 | /* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP, | |
54 | /* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN, | |
55 | /* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, | |
56 | /* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, CMP, CMP | |
57 | }; | |
58 | ||
59 | if (p1 == p2) | |
60 | return 0; | |
61 | ||
62 | c1 = *p1++; | |
63 | c2 = *p2++; | |
64 | /* Hint: '0' is a digit too. */ | |
65 | state = S_N + ((c1 == '0') + (isdigit (c1) != 0)); | |
66 | ||
67 | while ((diff = c1 - c2) == 0) { | |
68 | if (c1 == '\0') | |
69 | return diff; | |
70 | ||
71 | state = next_state[state]; | |
72 | c1 = *p1++; | |
73 | c2 = *p2++; | |
74 | state += (c1 == '0') + (isdigit (c1) != 0); | |
75 | } | |
76 | ||
77 | state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))]; | |
78 | ||
79 | switch (state) { | |
80 | case CMP: | |
81 | return diff; | |
82 | ||
83 | case LEN: | |
84 | while (isdigit (*p1++)) | |
85 | if (!isdigit (*p2++)) | |
86 | return 1; | |
87 | ||
88 | return isdigit (*p2) ? -1 : diff; | |
89 | ||
90 | default: | |
91 | return state; | |
92 | } | |
93 | } |