This patch optimizes away some strlen and strcat calls in
ap_directory_walk. The strlen calls, in particular, had
ranked as a top bottleneck in the usr-space code in recent
performance profiling.
--Brian
Index: server/request.c
===================================================================
RCS file: /home/cvspublic/httpd-2.0/server/request.c,v
retrieving revision 1.79
diff -u -r1.79 request.c
--- server/request.c 2001/11/01 20:14:16 1.79
+++ server/request.c 2001/11/04 21:00:31
@@ -545,6 +545,11 @@
char *buf;
unsigned int seg, startseg;
+ /* Invariant: from the first time filename_len is set until
+ * it goes out of scope, filename_len==strlen(r->filename)
+ */
+ size_t filename_len;
+
/*
* We must play our own mimi-merge game here, for the few
* running dir_config values we care about within dir_walk.
@@ -569,10 +574,11 @@
rv = apr_filepath_root((const char **)&r->filename,
(const char **)&r->path_info,
APR_FILEPATH_TRUENAME, r->pool);
+ filename_len = strlen(r->filename);
/* Space for terminating null and an extra / is required. */
- buflen = strlen(r->filename) + strlen(r->path_info) + 2;
+ buflen = filename_len + strlen(r->path_info) + 2;
buf = apr_palloc(r->pool, buflen);
- strcpy (buf, r->filename);
+ memcpy(buf, r->filename, filename_len + 1);
r->filename = buf;
r->finfo.valid = APR_FINFO_TYPE;
r->finfo.filetype = APR_DIR; /* It's the root, of course it's a dir */
@@ -591,8 +597,9 @@
/* We have no trailing slash, but we sure would appreciate one...
*/
- if (sec_idx && r->filename[strlen(r->filename)-1] != '/') {
- strcat(r->filename, "/");
+ if (sec_idx && r->filename[filename_len-1] != '/') {
+ r->filename[filename_len++] = '/';
+ r->filename[filename_len] = 0;
}
/* Begin *this* level by looking for matching <Directory> sections
@@ -761,7 +768,7 @@
/* That temporary trailing slash was useful, now drop it.
*/
if (seg > startseg) {
- r->filename[strlen(r->filename) - 1] = '\0';
+ r->filename[--filename_len] = '\0';
}
/* Time for all good things to come to an end?
@@ -775,17 +782,21 @@
* below as necessary...
*/
- seg_name = strchr(r->filename, '\0');
+ seg_name = r->filename + filename_len;
delim = strchr(r->path_info + (*r->path_info == '/' ? 1 : 0), '/');
if (delim) {
+ size_t path_info_len = delim - r->path_info;
*delim = '\0';
- strcpy(seg_name, r->path_info);
+ memcpy(seg_name, r->path_info, path_info_len + 1);
+ filename_len += path_info_len;
r->path_info = delim;
*delim = '/';
}
else {
- strcpy(seg_name, r->path_info);
- r->path_info = strchr(r->path_info, '\0');
+ size_t path_info_len = strlen(r->path_info);
+ memcpy(seg_name, r->path_info, path_info_len + 1);
+ filename_len += path_info_len;
+ r->path_info += path_info_len;
}
if (*seg_name == '/')
++seg_name;
@@ -850,6 +861,7 @@
* filename in tandem to properly correlate these.
*/
strcpy(seg_name, r->finfo.name);
+ filename_len = strlen(r->filename);
}
if (r->finfo.filetype == APR_LNK) {
