Hand optimisatinos for strrchr_m using the properties we know about MB

character sets and how we use this call.
Jeremy.

diff --git a/source/lib/util_str.c b/source/lib/util_str.c
index 34fdf75f635e43a79da501aac428e86bd781641a..4556405b040a2d1a293cf39a08a5a476a05bb373 100644 (file)
--- a/source/lib/util_str.c
+++ b/source/lib/util_str.c
@@ -1115,7 +1115,7 @@ char *strchr_m(const char *s, char c)
           supported multi-byte character sets are ascii-compatible
           (ie. they match for the first 128 chars) */
 
-       while (*s && !(((unsigned char)s[0]) & 0x7F)) {
+       while (*s && (((unsigned char)s[0]) & 0x80)) {
                if (*s == c)
                        return s;
        }
@@ -1134,17 +1134,53 @@ char *strchr_m(const char *s, char c)
 
 char *strrchr_m(const char *s, char c)
 {
-       wpstring ws;
-       pstring s2;
-       smb_ucs2_t *p;
+       /* this is quite a common operation, so we want it to be
+          fast. We optimise for the ascii case, knowing that all our
+          supported multi-byte character sets are ascii-compatible
+          (ie. they match for the first 128 chars). Also, in Samba
+          we only search for ascii characters in 'c' and that
+          in all mb character sets with a compound character
+          containing c, if 'c' is not a match at position
+          p, then p[-1] > 0x7f. JRA. */
 
-       push_ucs2(NULL, ws, s, sizeof(ws), STR_TERMINATE);
-       p = strrchr_w(ws, UCS2_CHAR(c));
-       if (!p)
-               return NULL;
-       *p = 0;
-       pull_ucs2_pstring(s2, ws);
-       return (char *)(s+strlen(s2));
+       {
+               size_t len = strlen(s);
+               const char *cp = s;
+               BOOL got_mb = False;
+
+               if (len == 0)
+                       return NULL;
+               cp += (len - 1);
+               do {
+                       if (c == *cp) {
+                               /* Could be a match. Part of a multibyte ? */
+                               if ((cp > s) && (((unsigned char)cp[-1]) & 0x80)) {
+                                       /* Yep - go slow :-( */
+                                       got_mb = True;
+                                       break;
+                               }
+                               /* No - we have a match ! */
+                               return cp;
+                       }
+               } while (cp-- != s);
+               if (!got_mb)
+                       return NULL;
+       }
+
+       /* String contained a non-ascii char. Slow path. */
+       {
+               wpstring ws;
+               pstring s2;
+               smb_ucs2_t *p;
+
+               push_ucs2(NULL, ws, s, sizeof(ws), STR_TERMINATE);
+               p = strrchr_w(ws, UCS2_CHAR(c));
+               if (!p)
+                       return NULL;
+               *p = 0;
+               pull_ucs2_pstring(s2, ws);
+               return (char *)(s+strlen(s2));
+       }
 }
 
 /***********************************************************************