httpd: speed up httpd.conf at the cost of 49 bytes of code

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/networking/httpd.c b/networking/httpd.c
index b8aa02f..52b2b2a 100644 (file)
--- a/networking/httpd.c
+++ b/networking/httpd.c
@@ -530,27 +530,39 @@ static void parse_conf(const char *path, int flag)
        while (fgets(buf, sizeof(buf), f) != NULL) {
                unsigned strlen_buf;
                unsigned char ch;
-               char *after_colon = NULL;
+               char *after_colon;
 
                { /* remove all whitespace, and # comments */
                        char *p, *p0;
 
-                       p = p0 = buf;
-                       while ((ch = *p0++) != '\0' && ch != '#') {
-                               if (!isspace(ch)) {
+                       p0 = buf;
+                       /* skip non-whitespace beginning. Often the whole line
+                        * is non-whitespace. We want this case to work fast,
+                        * without needless copying, therefore we don't merge
+                        * this operation into next while loop. */
+                       while ((ch = *p0) != '\0' && ch != '\n' && ch != '#'
+                        && ch != ' ' && ch != '\t'
+                       ) {
+                               p0++;
+                       }
+                       p = p0;
+                       /* if we enter this loop, we have some whitespace.
+                        * discard it */
+                       while (ch != '\0' && ch != '\n' && ch != '#') {
+                               if (ch != ' ' && ch != '\t') {
                                        *p++ = ch;
-                                       if (ch == ':' && after_colon == NULL)
-                                               after_colon = p;
                                }
+                               ch = *++p0;
                        }
                        *p = '\0';
                        strlen_buf = p - buf;
                        if (strlen_buf == 0)
-                               continue;
+                               continue; /* empty line */
                }
 
+               after_colon = strchr(buf, ':');
                /* strange line? */
-               if (after_colon == NULL || *after_colon == '\0')
+               if (after_colon == NULL || *++after_colon == '\0')
                        goto config_error;
 
                ch = (buf[0] & ~0x20); /* toupper if it's a letter */