Re: [Nano-devel] WIP: Use caching for regex

[Devin Hussey]

I'm sorry, I got carried away. I guess this isn't the right solution.

And yeah, I did exaggerate about the strlen stuff.

Anyways, I did get a benefit from this, as it does reduce the constant
freeing and reallocating.

Regex is still compiled twice, though, as nregcomp is stupid. I
considered storing the result from nregcomp, but memory usage went way
up.

diff --git a/src/color.c b/src/color.c
index 6605a713..0c5cea62 100644
--- a/src/color.c
+++ b/src/color.c
@@ -141,17 +141,16 @@ void color_init(void)
 bool found_in_list(regexlisttype *head, const char *shibboleth)
 {
        regexlisttype *item;
-       regex_t rgx;

        for (item = head; item != NULL; item = item->next) {
-               regcomp(&rgx, fixbounds(item->full_regex), NANO_REG_EXTENDED);
+               if (item->regex == NULL) {
+                       item->regex = (regex_t *)nmalloc(sizeof(regex_t));
+                       regcomp(item->regex, fixbounds(item->full_regex), NANO_R
EG_EXTENDED);
+               }

-               if (regexec(&rgx, shibboleth, 0, NULL, 0) == 0) {
-                       regfree(&rgx);
+               if (regexec(item->regex, shibboleth, 0, NULL, 0) == 0) {
                        return TRUE;
                }
-
-               regfree(&rgx);
        }

        return FALSE;
diff --git a/src/nano.h b/src/nano.h
index 3007881d..5fb770ca 100644
--- a/src/nano.h
+++ b/src/nano.h
@@ -214,6 +219,8 @@ typedef struct regexlisttype {
                /* A regex string to match things that imply a certain
syntax. */
        struct regexlisttype *next;
                /* The next regex. */
+       regex_t *regex;
+               /* The compiled regex. Will be NULL if not initialized. */
 } regexlisttype;
diff --git a/src/rcfile.c b/src/rcfile.c
index d8a2d1fe..c09b8ea9 100644
--- a/src/rcfile.c
+++ b/src/rcfile.c
@@ -831,6 +831,7 @@ void grab_and_store(const char *kind, char *ptr,
regexlisttype **storage)
                newthing = (regexlisttype *)nmalloc(sizeof(regexlisttype));
                newthing->full_regex = mallocstrcpy(NULL, regexstring);
                newthing->next = NULL;
+               newthing->regex = NULL;

                if (lastthing == NULL)
                        *storage = newthing;