/*
* RE_execute - execute a RE
*
* Returns TRUE on match, FALSE on no match
*
* re --- the compiled pattern as returned by RE_compile_and_cache
* dat --- the data to match against (need not be null-terminated)
* dat_len --- the length of the data string
* nmatch, pmatch --- optional return area for match details
*
* Data is given in the database encoding. We internally
* convert to array of pg_wchar which is what Spencer's regex package wants.
*/
static bool
RE_execute(regex_t* re, char *dat, int dat_len, int nmatch, regmatch_t* pmatch)
{
pg_wchar *data;
int data_len;
bool match;
/* Convert data string to wide characters */
data = (pg_wchar *) palloc((dat_len + 1) * sizeof(pg_wchar));
data_len = pg_mb2wchar_with_len(dat, data, dat_len);
/* Perform RE match and return result */
match = RE_wchar_execute(re, data, data_len, 0, nmatch, pmatch);
pfree(data);
return match;
}
/*
* RE_compile_and_execute - compile and execute a RE
*
* Returns TRUE on match, FALSE on no match
*
* text_re --- the pattern, expressed as an *untoasted* TEXT object
* dat --- the data to match against (need not be null-terminated)
* dat_len --- the length of the data string
* cflags --- compile options for the pattern
* nmatch, pmatch --- optional return area for match details
*
* Both pattern and data are given in the database encoding. We internally
* convert to array of pg_wchar which is what Spencer's regex package wants.
*/
static bool
RE_compile_and_execute(text *text_re, char *dat, int dat_len,
int cflags, int nmatch, regmatch_t *pmatch)
{
pg_wchar *data;
size_t data_len;
int regexec_result;
regex_t *re;
char errMsg[100];
/* Convert data string to wide characters */
data = (pg_wchar *) palloc((dat_len + 1) * sizeof(pg_wchar));
data_len = pg_mb2wchar_with_len(dat, data, dat_len);
/* Compile RE */
re = RE_compile_and_cache(text_re, cflags);
/* Perform RE match and return result */
regexec_result = pg_regexec(re,
data,
data_len,
0,
NULL, /* no details */
nmatch,
pmatch,
0);
pfree(data);
if (regexec_result != REG_OKAY && regexec_result != REG_NOMATCH)
{
/* re failed??? */
pg_regerror(regexec_result, re, errMsg, sizeof(errMsg));
ereport(ERROR,
(errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
errmsg("regular expression failed: %s", errMsg)));
}
return (regexec_result == REG_OKAY);
}
size_t
char2wchar(wchar_t *to, const char *from, size_t len)
{
if (len == 0)
return 0;
#ifdef WIN32
if (GetDatabaseEncoding() == PG_UTF8)
{
int r;
r = MultiByteToWideChar(CP_UTF8, 0, from, len, to, len);
if (!r)
{
pg_verifymbstr(from, strlen(from), false);
ereport(ERROR,
(errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
errmsg("invalid multibyte character for locale"),
errhint("The server's LC_CTYPE locale is probably incompatible with the database encoding.")));
}
Assert(r <= len);
return r;
}
else
#endif /* WIN32 */
if ( lc_ctype_is_c() )
{
/*
* pg_mb2wchar_with_len always adds trailing '\0', so
* 'to' should be allocated with sufficient space
*/
return pg_mb2wchar_with_len(from, (pg_wchar *)to, len);
}
return mbstowcs(to, from, len);
}
/*
* 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;
}
/*
* setup_regexp_matches --- do the initial matching for regexp_matches()
* or regexp_split()
*
* To avoid having to re-find the compiled pattern on each call, we do
* all the matching in one swoop. The returned regexp_matches_ctx contains
* the locations of all the substrings matching the pattern.
*
* The three bool parameters have only two patterns (one for each caller)
* but it seems clearer to distinguish the functionality this way than to
* key it all off one "is_split" flag.
*/
static regexp_matches_ctx *
setup_regexp_matches(text *orig_str, text *pattern, text *flags,
Oid collation,
bool force_glob, bool use_subpatterns,
bool ignore_degenerate)
{
regexp_matches_ctx *matchctx = palloc0(sizeof(regexp_matches_ctx));
int orig_len;
pg_wchar *wide_str;
int wide_len;
pg_re_flags re_flags;
regex_t *cpattern;
regmatch_t *pmatch;
int pmatch_len;
int array_len;
int array_idx;
int prev_match_end;
int start_search;
/* save original string --- we'll extract result substrings from it */
matchctx->orig_str = orig_str;
/* convert string to pg_wchar form for matching */
orig_len = VARSIZE_ANY_EXHDR(orig_str);
wide_str = (pg_wchar *) palloc(sizeof(pg_wchar) * (orig_len + 1));
wide_len = pg_mb2wchar_with_len(VARDATA_ANY(orig_str), wide_str, orig_len);
/* determine options */
parse_re_flags(&re_flags, flags);
if (force_glob)
{
/* user mustn't specify 'g' for regexp_split */
if (re_flags.glob)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("regexp_split does not support the global option")));
/* but we find all the matches anyway */
re_flags.glob = true;
}
/* set up the compiled pattern */
cpattern = RE_compile_and_cache(pattern, re_flags.cflags, collation);
/* do we want to remember subpatterns? */
if (use_subpatterns && cpattern->re_nsub > 0)
{
matchctx->npatterns = cpattern->re_nsub;
pmatch_len = cpattern->re_nsub + 1;
}
else
{
use_subpatterns = false;
matchctx->npatterns = 1;
pmatch_len = 1;
}
/* temporary output space for RE package */
pmatch = palloc(sizeof(regmatch_t) * pmatch_len);
/* the real output space (grown dynamically if needed) */
array_len = re_flags.glob ? 256 : 32;
matchctx->match_locs = (int *) palloc(sizeof(int) * array_len);
array_idx = 0;
/* search for the pattern, perhaps repeatedly */
prev_match_end = 0;
start_search = 0;
while (RE_wchar_execute(cpattern, wide_str, wide_len, start_search,
pmatch_len, pmatch))
{
/*
* If requested, ignore degenerate matches, which are zero-length
* matches occurring at the start or end of a string or just after a
* previous match.
*/
if (!ignore_degenerate ||
(pmatch[0].rm_so < wide_len &&
pmatch[0].rm_eo > prev_match_end))
{
/* enlarge output space if needed */
while (array_idx + matchctx->npatterns * 2 > array_len)
{
array_len *= 2;
matchctx->match_locs = (int *) repalloc(matchctx->match_locs,
sizeof(int) * array_len);
}
/* save this match's locations */
if (use_subpatterns)
{
int i;
for (i = 1; i <= matchctx->npatterns; i++)
{
matchctx->match_locs[array_idx++] = pmatch[i].rm_so;
matchctx->match_locs[array_idx++] = pmatch[i].rm_eo;
}
}
else
{
matchctx->match_locs[array_idx++] = pmatch[0].rm_so;
matchctx->match_locs[array_idx++] = pmatch[0].rm_eo;
}
matchctx->nmatches++;
}
prev_match_end = pmatch[0].rm_eo;
/* if not glob, stop after one match */
if (!re_flags.glob)
break;
/*
* Advance search position. Normally we start the next search at the
* end of the previous match; but if the match was of zero length, we
* have to advance by one character, or we'd just find the same match
* again.
*/
start_search = prev_match_end;
if (pmatch[0].rm_so == pmatch[0].rm_eo)
start_search++;
if (start_search > wide_len)
break;
}
/* Clean up temp storage */
pfree(wide_str);
pfree(pmatch);
return matchctx;
}
/*
* 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;
}
/*
* setup_regexp_matches --- do the initial matching for regexp_matches()
* or regexp_split()
*
* To avoid having to re-find the compiled pattern on each call, we do
* all the matching in one swoop. The returned regexp_matches_ctx contains
* the locations of all the substrings matching the pattern.
*
* The four bool parameters have only two patterns (one for matching, one for
* splitting) but it seems clearer to distinguish the functionality this way
* than to key it all off one "is_split" flag. We don't currently assume that
* fetching_unmatched is exclusive of fetching the matched text too; if it's
* set, the conversion buffer is large enough to fetch any single matched or
* unmatched string, but not any larger substring. (In practice, when splitting
* the matches are usually small anyway, and it didn't seem worth complicating
* the code further.)
*/
static regexp_matches_ctx *
setup_regexp_matches(text *orig_str, text *pattern, text *flags,
Oid collation,
bool force_glob,
bool use_subpatterns,
bool ignore_degenerate,
bool fetching_unmatched)
{
regexp_matches_ctx *matchctx = palloc0(sizeof(regexp_matches_ctx));
int eml = pg_database_encoding_max_length();
int orig_len;
pg_wchar *wide_str;
int wide_len;
pg_re_flags re_flags;
regex_t *cpattern;
regmatch_t *pmatch;
int pmatch_len;
int array_len;
int array_idx;
int prev_match_end;
int prev_valid_match_end;
int start_search;
int maxlen = 0; /* largest fetch length in characters */
/* save original string --- we'll extract result substrings from it */
matchctx->orig_str = orig_str;
/* convert string to pg_wchar form for matching */
orig_len = VARSIZE_ANY_EXHDR(orig_str);
wide_str = (pg_wchar *) palloc(sizeof(pg_wchar) * (orig_len + 1));
wide_len = pg_mb2wchar_with_len(VARDATA_ANY(orig_str), wide_str, orig_len);
/* determine options */
parse_re_flags(&re_flags, flags);
if (force_glob)
{
/* user mustn't specify 'g' for regexp_split */
if (re_flags.glob)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("regexp_split does not support the global option")));
/* but we find all the matches anyway */
re_flags.glob = true;
}
/* set up the compiled pattern */
cpattern = RE_compile_and_cache(pattern, re_flags.cflags, collation);
/* do we want to remember subpatterns? */
if (use_subpatterns && cpattern->re_nsub > 0)
{
matchctx->npatterns = cpattern->re_nsub;
pmatch_len = cpattern->re_nsub + 1;
}
else
{
use_subpatterns = false;
matchctx->npatterns = 1;
pmatch_len = 1;
}
/* temporary output space for RE package */
pmatch = palloc(sizeof(regmatch_t) * pmatch_len);
/*
* the real output space (grown dynamically if needed)
*
* use values 2^n-1, not 2^n, so that we hit the limit at 2^28-1 rather
* than at 2^27
*/
array_len = re_flags.glob ? 255 : 31;
matchctx->match_locs = (int *) palloc(sizeof(int) * array_len);
array_idx = 0;
/* search for the pattern, perhaps repeatedly */
prev_match_end = 0;
prev_valid_match_end = 0;
start_search = 0;
while (RE_wchar_execute(cpattern, wide_str, wide_len, start_search,
pmatch_len, pmatch))
{
/*
* If requested, ignore degenerate matches, which are zero-length
* matches occurring at the start or end of a string or just after a
* previous match.
*/
if (!ignore_degenerate ||
(pmatch[0].rm_so < wide_len &&
pmatch[0].rm_eo > prev_match_end))
{
/* enlarge output space if needed */
while (array_idx + matchctx->npatterns * 2 + 1 > array_len)
{
array_len += array_len + 1; /* 2^n-1 => 2^(n+1)-1 */
if (array_len > MaxAllocSize/sizeof(int))
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("too many regular expression matches")));
matchctx->match_locs = (int *) repalloc(matchctx->match_locs,
sizeof(int) * array_len);
}
/* save this match's locations */
if (use_subpatterns)
{
int i;
for (i = 1; i <= matchctx->npatterns; i++)
{
int so = pmatch[i].rm_so;
int eo = pmatch[i].rm_eo;
matchctx->match_locs[array_idx++] = so;
matchctx->match_locs[array_idx++] = eo;
if (so >= 0 && eo >= 0 && (eo - so) > maxlen)
maxlen = (eo - so);
}
}
else
{
int so = pmatch[0].rm_so;
int eo = pmatch[0].rm_eo;
matchctx->match_locs[array_idx++] = so;
matchctx->match_locs[array_idx++] = eo;
if (so >= 0 && eo >= 0 && (eo - so) > maxlen)
maxlen = (eo - so);
}
matchctx->nmatches++;
/*
* check length of unmatched portion between end of previous valid
* (nondegenerate, or degenerate but not ignored) match and start
* of current one
*/
if (fetching_unmatched &&
pmatch[0].rm_so >= 0 &&
(pmatch[0].rm_so - prev_valid_match_end) > maxlen)
maxlen = (pmatch[0].rm_so - prev_valid_match_end);
prev_valid_match_end = pmatch[0].rm_eo;
}
prev_match_end = pmatch[0].rm_eo;
/* if not glob, stop after one match */
if (!re_flags.glob)
break;
/*
* Advance search position. Normally we start the next search at the
* end of the previous match; but if the match was of zero length, we
* have to advance by one character, or we'd just find the same match
* again.
*/
start_search = prev_match_end;
if (pmatch[0].rm_so == pmatch[0].rm_eo)
start_search++;
if (start_search > wide_len)
break;
}
/*
* check length of unmatched portion between end of last match and end of
* input string
*/
if (fetching_unmatched &&
(wide_len - prev_valid_match_end) > maxlen)
maxlen = (wide_len - prev_valid_match_end);
/*
* Keep a note of the end position of the string for the benefit of
* splitting code.
*/
matchctx->match_locs[array_idx] = wide_len;
if (eml > 1)
{
int64 maxsiz = eml * (int64) maxlen;
int conv_bufsiz;
/*
* Make the conversion buffer large enough for any substring of
* interest.
*
* Worst case: assume we need the maximum size (maxlen*eml), but take
* advantage of the fact that the original string length in bytes is an
* upper bound on the byte length of any fetched substring (and we know
* that len+1 is safe to allocate because the varlena header is longer
* than 1 byte).
*/
if (maxsiz > orig_len)
conv_bufsiz = orig_len + 1;
else
conv_bufsiz = maxsiz + 1; /* safe since maxsiz < 2^30 */
matchctx->conv_buf = palloc(conv_bufsiz);
matchctx->conv_bufsiz = conv_bufsiz;
matchctx->wide_str = wide_str;
}
else
{
/* No need to keep the wide string if we're in a single-byte charset. */
pfree(wide_str);
matchctx->wide_str = NULL;
matchctx->conv_buf = NULL;
matchctx->conv_bufsiz = 0;
}
/* Clean up temp storage */
pfree(pmatch);
return matchctx;
}
