comparison: dbd/common.c
dbd/common.c
- changeset 17
- 21c4feaeafe7
- child 28
- 44b1d78b50f5
equal
deleted
inserted
replaced
| 16:318e5dfd03b8 | 17:21c4feaeafe7 |
|---|---|
| 1 #include <dbd/common.h> | |
| 2 | |
| 3 const char *strlower(char *in) { | |
| 4 char *s = in; | |
| 5 | |
| 6 while(*s) { | |
| 7 *s= (*s <= 'Z' && *s >= 'A') ? (*s - 'A') + 'a' : *s; | |
| 8 s++; | |
| 9 } | |
| 10 | |
| 11 return in; | |
| 12 } | |
| 13 | |
| 14 /* | |
| 15 * replace '?' placeholders with $\d+ placeholders | |
| 16 * to be compatible with PSQL API | |
| 17 */ | |
| 18 char *replace_placeholders(lua_State *L, char native_prefix, const char *sql) { | |
| 19 size_t len = strlen(sql); | |
| 20 int num_placeholders = 0; | |
| 21 int extra_space = 0; | |
| 22 int i; | |
| 23 char *newsql; | |
| 24 int newpos = 1; | |
| 25 int ph_num = 1; | |
| 26 int in_quote = 0; | |
| 27 char format_str[4]; | |
| 28 | |
| 29 format_str[0] = native_prefix; | |
| 30 format_str[1] = '%'; | |
| 31 format_str[2] = 'u'; | |
| 32 format_str[3] = '\0'; | |
| 33 | |
| 34 /* | |
| 35 * dumb count of all '?' | |
| 36 * this will match more placeholders than necessesary | |
| 37 * but it's safer to allocate more placeholders at the | |
| 38 * cost of a few bytes than risk a buffer overflow | |
| 39 */ | |
| 40 for (i = 1; i < len; i++) { | |
| 41 if (sql[i] == '?') { | |
| 42 num_placeholders++; | |
| 43 } | |
| 44 } | |
| 45 | |
| 46 /* | |
| 47 * this is MAX_PLACEHOLDER_SIZE-1 because the '?' is | |
| 48 * replaced with '$' | |
| 49 */ | |
| 50 extra_space = num_placeholders * (MAX_PLACEHOLDER_SIZE-1); | |
| 51 | |
| 52 /* | |
| 53 * allocate a new string for the converted SQL statement | |
| 54 */ | |
| 55 newsql = malloc(sizeof(char) * (len+extra_space+1)); | |
| 56 memset(newsql, 0, sizeof(char) * (len+extra_space+1)); | |
| 57 | |
| 58 /* | |
| 59 * copy first char. In valid SQL this cannot be a placeholder | |
| 60 */ | |
| 61 newsql[0] = sql[0]; | |
| 62 | |
| 63 /* | |
| 64 * only replace '?' not in a single quoted string | |
| 65 */ | |
| 66 for (i = 1; i < len; i++) { | |
| 67 /* | |
| 68 * don't change the quote flag if the ''' is preceded | |
| 69 * by a '\' to account for escaping | |
| 70 */ | |
| 71 if (sql[i] == '\'' && sql[i-1] != '\\') { | |
| 72 in_quote = !in_quote; | |
| 73 } | |
| 74 | |
| 75 if (sql[i] == '?' && !in_quote) { | |
| 76 size_t n; | |
| 77 | |
| 78 if (ph_num > MAX_PLACEHOLDERS) { | |
| 79 luaL_error(L, "Sorry, you are using more than %d placeholders. Use ${num} format instead", MAX_PLACEHOLDERS); | |
| 80 } | |
| 81 | |
| 82 n = snprintf(&newsql[newpos], MAX_PLACEHOLDER_SIZE, format_str, ph_num++); | |
| 83 | |
| 84 newpos += n; | |
| 85 } else { | |
| 86 newsql[newpos] = sql[i]; | |
| 87 newpos++; | |
| 88 } | |
| 89 } | |
| 90 | |
| 91 /* | |
| 92 * terminate string on the last position | |
| 93 */ | |
| 94 newsql[newpos] = '\0'; | |
| 95 | |
| 96 /* fprintf(stderr, "[%s]\n", newsql); */ | |
| 97 return newsql; | |
| 98 } | |
| 99 |
