Lift 16kB limit of log message output
[git/git.git] / interpolate.c
1 /*
2 * Copyright 2006 Jon Loeliger
3 */
4
5 #include "git-compat-util.h"
6 #include "interpolate.h"
7
8
9 void interp_set_entry(struct interp *table, int slot, const char *value)
10 {
11 char *oldval = table[slot].value;
12 char *newval = NULL;
13
14 if (oldval)
15 free(oldval);
16
17 if (value)
18 newval = xstrdup(value);
19
20 table[slot].value = newval;
21 }
22
23
24 void interp_clear_table(struct interp *table, int ninterps)
25 {
26 int i;
27
28 for (i = 0; i < ninterps; i++) {
29 interp_set_entry(table, i, NULL);
30 }
31 }
32
33
34 /*
35 * Convert a NUL-terminated string in buffer orig
36 * into the supplied buffer, result, whose length is reslen,
37 * performing substitutions on %-named sub-strings from
38 * the table, interps, with ninterps entries.
39 *
40 * Example interps:
41 * {
42 * { "%H", "example.org"},
43 * { "%port", "123"},
44 * { "%%", "%"},
45 * }
46 *
47 * Returns 0 on a successful substitution pass that fits in result,
48 * Returns a number of bytes needed to hold the full substituted
49 * string otherwise.
50 */
51
52 unsigned long interpolate(char *result, unsigned long reslen,
53 const char *orig,
54 const struct interp *interps, int ninterps)
55 {
56 const char *src = orig;
57 char *dest = result;
58 unsigned long newlen = 0;
59 const char *name, *value;
60 unsigned long namelen, valuelen;
61 int i;
62 char c;
63
64 memset(result, 0, reslen);
65
66 while ((c = *src)) {
67 if (c == '%') {
68 /* Try to match an interpolation string. */
69 for (i = 0; i < ninterps; i++) {
70 name = interps[i].name;
71 namelen = strlen(name);
72 if (strncmp(src, name, namelen) == 0)
73 break;
74 }
75
76 /* Check for valid interpolation. */
77 if (i < ninterps) {
78 value = interps[i].value;
79 valuelen = strlen(value);
80
81 if (newlen + valuelen + 1 < reslen) {
82 /* Substitute. */
83 strncpy(dest, value, valuelen);
84 dest += valuelen;
85 }
86 newlen += valuelen;
87 src += namelen;
88 continue;
89 }
90 }
91 /* Straight copy one non-interpolation character. */
92 if (newlen + 1 < reslen)
93 *dest++ = *src;
94 src++;
95 newlen++;
96 }
97
98 if (newlen + 1 < reslen)
99 return 0;
100 else
101 return newlen + 2;
102 }