diff --git a/src/backend/regex/regc_nfa.c b/src/backend/regex/regc_nfa.c
index ae2dbe43fe8cfe2db1a1448ea4ee464c44e9b859..f6dad013b544d7a432ccba348011445ba763d328 100644
--- a/src/backend/regex/regc_nfa.c
+++ b/src/backend/regex/regc_nfa.c
@@ -174,11 +174,23 @@ newstate(struct nfa * nfa)
{
struct state *s;
+ /*
+ * This is a handy place to check for operation cancel during regex
+ * compilation, since no code path will go very long without making a new
+ * state.
+ */
+ if (CANCEL_REQUESTED(nfa->v->re))
+ {
+ NERR(REG_CANCEL);
+ return NULL;
+ }
+
if (TooManyStates(nfa))
{
NERR(REG_ETOOBIG);
return NULL;
}
+
if (nfa->free != NULL)
{
s = nfa->free;
diff --git a/src/backend/regex/regcomp.c b/src/backend/regex/regcomp.c
index ca1ccc520238ab914407b4478d16f9f0c27d769e..d31d7f7b72786dae608d0ee1232f1f8631215ee9 100644
--- a/src/backend/regex/regcomp.c
+++ b/src/backend/regex/regcomp.c
@@ -34,6 +34,8 @@
#include "regex/regguts.h"
+#include "miscadmin.h" /* needed by rcancelrequested() */
+
/*
* forward declarations, up here so forward datatypes etc. are defined early
*/
@@ -67,6 +69,7 @@ static long nfanode(struct vars *, struct subre *, FILE *);
static int newlacon(struct vars *, struct state *, struct state *, int);
static void freelacons(struct subre *, int);
static void rfree(regex_t *);
+static int rcancelrequested(void);
#ifdef REG_DEBUG
static void dump(regex_t *, FILE *);
@@ -276,6 +279,7 @@ struct vars
/* static function list */
static const struct fns functions = {
rfree, /* regfree insides */
+ rcancelrequested /* check for cancel request */
};
@@ -1893,6 +1897,22 @@ rfree(regex_t *re)
}
}
+/*
+ * rcancelrequested - check for external request to cancel regex operation
+ *
+ * Return nonzero to fail the operation with error code REG_CANCEL,
+ * zero to keep going
+ *
+ * The current implementation is Postgres-specific. If we ever get around
+ * to splitting the regex code out as a standalone library, there will need
+ * to be some API to let applications define a callback function for this.
+ */
+static int
+rcancelrequested(void)
+{
+ return InterruptPending && (QueryCancelPending || ProcDiePending);
+}
+
#ifdef REG_DEBUG
/*
diff --git a/src/backend/regex/regexec.c b/src/backend/regex/regexec.c
index 78ebdee39e443dc89a211d8439e5513330ae4d92..0edb83c1099f9fb99f38e8c1e7df6761a1d1b693 100644
--- a/src/backend/regex/regexec.c
+++ b/src/backend/regex/regexec.c
@@ -595,6 +595,10 @@ cdissect(struct vars * v,
assert(t != NULL);
MDEBUG(("cdissect %ld-%ld %c\n", LOFF(begin), LOFF(end), t->op));
+ /* handy place to check for operation cancel */
+ if (CANCEL_REQUESTED(v->re))
+ return REG_CANCEL;
+
switch (t->op)
{
case '=': /* terminal node */
diff --git a/src/backend/utils/adt/regexp.c b/src/backend/utils/adt/regexp.c
index 588052c7a0144e2a5bca641590dbec513c44ca04..7c5b0d53bcfb809b0d62054f9102419523fb8b9a 100644
--- a/src/backend/utils/adt/regexp.c
+++ b/src/backend/utils/adt/regexp.c
@@ -31,6 +31,7 @@
#include "catalog/pg_type.h"
#include "funcapi.h"
+#include "miscadmin.h"
#include "regex/regex.h"
#include "utils/array.h"
#include "utils/builtins.h"
@@ -188,6 +189,15 @@ RE_compile_and_cache(text *text_re, int cflags, Oid collation)
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),
@@ -268,6 +278,7 @@ RE_wchar_execute(regex_t *re, pg_wchar *data, int data_len,
if (regexec_result != REG_OKAY && regexec_result != REG_NOMATCH)
{
/* re failed??? */
+ CHECK_FOR_INTERRUPTS();
pg_regerror(regexec_result, re, errMsg, sizeof(errMsg));
ereport(ERROR,
(errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
@@ -1216,6 +1227,7 @@ regexp_fixed_prefix(text *text_re, bool case_insensitive, Oid collation,
default:
/* re failed??? */
+ CHECK_FOR_INTERRUPTS();
pg_regerror(re_result, re, errMsg, sizeof(errMsg));
ereport(ERROR,
(errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index 8ac402b1740e6e82f5bc7fca835800fe62afac1a..cb07a066ef1054fc011ce503461ab9b62b8bf4c7 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -3035,6 +3035,7 @@ replace_text_regexp(text *src_text, void *regexp,
{
char errMsg[100];
+ CHECK_FOR_INTERRUPTS();
pg_regerror(regexec_result, re, errMsg, sizeof(errMsg));
ereport(ERROR,
(errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
diff --git a/src/include/regex/regerrs.h b/src/include/regex/regerrs.h
index f02711ee1762604dee60ce2b99a3858dded91ccf..809b511266047a32b403ac05f0f3b22d3437b5dc 100644
--- a/src/include/regex/regerrs.h
+++ b/src/include/regex/regerrs.h
@@ -81,3 +81,7 @@
{
REG_ECOLORS, "REG_ECOLORS", "too many colors"
},
+
+{
+ REG_CANCEL, "REG_CANCEL", "operation cancelled"
+},
diff --git a/src/include/regex/regex.h b/src/include/regex/regex.h
index 3e87dff17b27f6c622a9e9278a64ea7a2bc8abad..2c7fa4df46f818f1e139f0eae1b50e0a5fe78524 100644
--- a/src/include/regex/regex.h
+++ b/src/include/regex/regex.h
@@ -154,6 +154,7 @@ typedef struct
#define REG_BADOPT 18 /* invalid embedded option */
#define REG_ETOOBIG 19 /* nfa has too many states */
#define REG_ECOLORS 20 /* too many colors */
+#define REG_CANCEL 21 /* operation cancelled */
/* two specials for debugging and testing */
#define REG_ATOI 101 /* convert error-code name to number */
#define REG_ITOA 102 /* convert error-code number to name */
diff --git a/src/include/regex/regguts.h b/src/include/regex/regguts.h
index 3a397551d5e3dff2154ed92ab069d91ee5234801..5361411481dfe320d8c57a2e8a9ce17a192ee63e 100644
--- a/src/include/regex/regguts.h
+++ b/src/include/regex/regguts.h
@@ -446,8 +446,11 @@ struct subre
struct fns
{
void FUNCPTR(free, (regex_t *));
+ int FUNCPTR(cancel_requested, (void));
};
+#define CANCEL_REQUESTED(re) \
+ ((*((struct fns *) (re)->re_fns)->cancel_requested) ())
/*