/*
* RE_compile_and_cache - compile a RE, caching if possible
*
* Returns regex_t *
*
* text_re --- the pattern, expressed as an *untoasted* TEXT object
* cflags --- compile options for the pattern
*
* Pattern is given in the database encoding. We internally convert to
* array of pg_wchar which is what Spencer's regex package wants.
*/
static regex_t *
RE_compile_and_cache(text *text_re, int cflags)
{
int text_re_len = VARSIZE(text_re);
pg_wchar *pattern;
size_t pattern_len;
int i;
int regcomp_result;
cached_re_str re_temp;
char errMsg[100];
/*
* Look for a match among previously compiled REs. Since the data
* structure is self-organizing with most-used entries at the front, our
* search strategy can just be to scan from the front.
*/
for (i = 0; i < num_res; i++)
{
if (VARSIZE(re_array[i].cre_pat) == text_re_len &&
memcmp(re_array[i].cre_pat, text_re, text_re_len) == 0 &&
re_array[i].cre_flags == cflags)
{
/*
* Found a match; move it to front if not there already.
*/
if (i > 0)
{
re_temp = re_array[i];
memmove(&re_array[1], &re_array[0], i * sizeof(cached_re_str));
re_array[0] = re_temp;
}
return &re_array[0].cre_re;
}
}
/*
* Couldn't find it, so try to compile the new RE. To avoid leaking
* resources on failure, we build into the re_temp local.
*/
/* Convert pattern string to wide characters */
pattern = (pg_wchar *) palloc((text_re_len - VARHDRSZ + 1) * sizeof(pg_wchar));
pattern_len = pg_mb2wchar_with_len(VARDATA(text_re),
pattern,
text_re_len - VARHDRSZ);
regcomp_result = pg_regcomp(&re_temp.cre_re,
pattern,
pattern_len,
cflags);
pfree(pattern);
if (regcomp_result != REG_OKAY)
{
/* re didn't compile */
pg_regerror(regcomp_result, &re_temp.cre_re, errMsg, sizeof(errMsg));
/* XXX should we pg_regfree here? */
ereport(ERROR,
(errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
errmsg("invalid regular expression: %s", errMsg)));
}
/*
* use malloc/free for the cre_pat field because the storage has to
* persist across transactions
*/
re_temp.cre_pat = malloc(text_re_len);
if (re_temp.cre_pat == NULL)
{
pg_regfree(&re_temp.cre_re);
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
}
memcpy(re_temp.cre_pat, text_re, text_re_len);
re_temp.cre_flags = cflags;
/*
* Okay, we have a valid new item in re_temp; insert it into the storage
* array. Discard last entry if needed.
*/
if (num_res >= MAX_CACHED_RES)
{
--num_res;
Assert(num_res < MAX_CACHED_RES);
pg_regfree(&re_array[num_res].cre_re);
free(re_array[num_res].cre_pat);
}
if (num_res > 0)
memmove(&re_array[1], &re_array[0], num_res * sizeof(cached_re_str));
re_array[0] = re_temp;
num_res++;
return &re_array[0].cre_re;
}
/*
* RE_compile_and_cache - compile a RE, caching if possible
*
* Returns regex_t *
*
* text_re --- the pattern, expressed as a TEXT object
* cflags --- compile options for the pattern
* collation --- collation to use for LC_CTYPE-dependent behavior
*
* Pattern is given in the database encoding. We internally convert to
* an array of pg_wchar, which is what Spencer's regex package wants.
*/
static regex_t *
RE_compile_and_cache(text *text_re, int cflags, Oid collation)
{
int text_re_len = VARSIZE_ANY_EXHDR(text_re);
char *text_re_val = VARDATA_ANY(text_re);
pg_wchar *pattern;
int pattern_len;
int i;
int regcomp_result;
cached_re_str re_temp;
char errMsg[100];
/*
* Look for a match among previously compiled REs. Since the data
* structure is self-organizing with most-used entries at the front, our
* search strategy can just be to scan from the front.
*/
for (i = 0; i < num_res; i++)
{
if (re_array[i].cre_pat_len == text_re_len &&
re_array[i].cre_flags == cflags &&
re_array[i].cre_collation == collation &&
memcmp(re_array[i].cre_pat, text_re_val, text_re_len) == 0)
{
/*
* Found a match; move it to front if not there already.
*/
if (i > 0)
{
re_temp = re_array[i];
memmove(&re_array[1], &re_array[0], i * sizeof(cached_re_str));
re_array[0] = re_temp;
}
return &re_array[0].cre_re;
}
}
/*
* Couldn't find it, so try to compile the new RE. To avoid leaking
* resources on failure, we build into the re_temp local.
*/
/* Convert pattern string to wide characters */
pattern = (pg_wchar *) palloc((text_re_len + 1) * sizeof(pg_wchar));
pattern_len = pg_mb2wchar_with_len(text_re_val,
pattern,
text_re_len);
regcomp_result = pg_regcomp(&re_temp.cre_re,
pattern,
pattern_len,
cflags,
collation);
pfree(pattern);
if (regcomp_result != REG_OKAY)
{
/* re didn't compile (no need for pg_regfree, if so) */
/*
* Here and in other places in this file, do CHECK_FOR_INTERRUPTS
* before reporting a regex error. This is so that if the regex
* library aborts and returns REG_CANCEL, we don't print an error
* message that implies the regex was invalid.
*/
CHECK_FOR_INTERRUPTS();
pg_regerror(regcomp_result, &re_temp.cre_re, errMsg, sizeof(errMsg));
ereport(ERROR,
(errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
errmsg("invalid regular expression: %s", errMsg)));
}
/*
* We use malloc/free for the cre_pat field because the storage has to
* persist across transactions, and because we want to get control back on
* out-of-memory. The Max() is because some malloc implementations return
* NULL for malloc(0).
*/
re_temp.cre_pat = malloc(Max(text_re_len, 1));
if (re_temp.cre_pat == NULL)
{
pg_regfree(&re_temp.cre_re);
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
}
memcpy(re_temp.cre_pat, text_re_val, text_re_len);
re_temp.cre_pat_len = text_re_len;
re_temp.cre_flags = cflags;
re_temp.cre_collation = collation;
/*
* Okay, we have a valid new item in re_temp; insert it into the storage
* array. Discard last entry if needed.
*/
if (num_res >= MAX_CACHED_RES)
{
--num_res;
Assert(num_res < MAX_CACHED_RES);
pg_regfree(&re_array[num_res].cre_re);
free(re_array[num_res].cre_pat);
}
if (num_res > 0)
memmove(&re_array[1], &re_array[0], num_res * sizeof(cached_re_str));
re_array[0] = re_temp;
num_res++;
return &re_array[0].cre_re;
}
