Optimized away some string scans and copies in analyze_ct()

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@92363 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/modules/http/mod_mime.c b/modules/http/mod_mime.c
index c776371936efa16b4d351f945000d22575ffd40c..416b1a127bb8931c1d954d66f8fea3da52c5c4ca 100644 (file)
--- a/modules/http/mod_mime.c
+++ b/modules/http/mod_mime.c
@@ -465,10 +465,8 @@ static int mime_post_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp,
     return OK;
 }
 
-static char *zap_sp(char *s)
+static const char *zap_sp(const char *s)
 {
-    char *tp;
-
     if (s == NULL) {
        return (NULL);
     }
@@ -476,17 +474,27 @@ static char *zap_sp(char *s)
        return (s);
     }
 
-    /* delete prefixed white space */
+    /* skip prefixed white space */
     for (; *s == ' ' || *s == '\t' || *s == '\n'; s++);
 
-    /* delete postfixed white space */
-    for (tp = s; *tp != '\0'; tp++);
-    for (tp--; tp != s && (*tp == ' ' || *tp == '\t' || *tp == '\n'); tp--) {
-       *tp = '\0';
-    }
     return (s);
 }
 
+static char *zap_sp_and_dup(apr_pool_t *p, const char *start,
+                            const char *end, apr_size_t *len)
+{
+    while ((start < end) && apr_isspace(*start)) {
+        start++;
+    }
+    while ((end > start) && apr_isspace(*(end - 1))) {
+        end--;
+    }
+    if (len) {
+        *len = end - start;
+    }
+    return apr_pstrmemdup(p, start, end - start);
+}
+
 static int is_token(char c)
 {
     int res;
@@ -505,7 +513,7 @@ static int is_qtext(char c)
     return res;
 }
 
-static int is_quoted_pair(char *s)
+static int is_quoted_pair(const char *s)
 {
     int res = -1;
     int c;
@@ -519,9 +527,10 @@ static int is_quoted_pair(char *s)
     return (res);
 }
 
-static content_type *analyze_ct(request_rec *r, char *s)
+static content_type *analyze_ct(request_rec *r, const char *s)
 {
-    char *tp, *mp, *cp;
+    const char *cp;
+    const char *mp;
     char *attribute, *value;
     int quoted = 0;
     server_rec * ss = r->server;
@@ -536,10 +545,7 @@ static content_type *analyze_ct(request_rec *r, char *s)
     ctp->subtype = NULL;
     ctp->param = NULL;
 
-    tp = apr_pstrdup(p, s);
-
-    mp = tp;
-    cp = mp;
+    mp = s;
 
     /* getting a type */
     if (!(cp = strchr(mp, '/'))) {
@@ -548,8 +554,7 @@ static content_type *analyze_ct(request_rec *r, char *s)
                     (const char *) mp);
        return (NULL);
     }
-    ctp->type = apr_pstrmemdup(p, mp, cp - mp);
-    ctp->type = zap_sp(ctp->type);
+    ctp->type = zap_sp_and_dup(p, mp, cp, NULL);
     if (ctp->type == NULL || *(ctp->type) == '\0' ||
        strchr(ctp->type, ';') || strchr(ctp->type, ' ') ||
        strchr(ctp->type, '\t')) {
@@ -564,17 +569,15 @@ static content_type *analyze_ct(request_rec *r, char *s)
 
     for (; *cp != ';' && *cp != '\0'; cp++)
         continue;
-    ctp->subtype = apr_pstrndup(p, mp, cp - mp);
-    ctp->subtype = zap_sp(ctp->subtype);
+    ctp->subtype = zap_sp_and_dup(p, mp, cp, NULL);
     if ((ctp->subtype == NULL) || (*(ctp->subtype) == '\0') ||
        strchr(ctp->subtype, ' ') || strchr(ctp->subtype, '\t')) {
        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ss,
                     "Cannot get media subtype.");
        return (NULL);
     }
-    cp = zap_sp(cp);
-    if (cp == NULL || *cp == '\0') {
-       return (ctp);
+    if (*cp == '\0') {
+        return (ctp);
     }
 
     /* getting parameters */
@@ -600,8 +603,7 @@ static content_type *analyze_ct(request_rec *r, char *s)
                continue;
            }
            else if (*cp == '=') {
-               attribute = apr_pstrndup(p, mp, cp - mp);
-               attribute = zap_sp(attribute);
+               attribute = zap_sp_and_dup(p, mp, cp, NULL);
                if (attribute == NULL || *attribute == '\0') {
                    ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ss,
                                 "Cannot get media parameter.");
@@ -675,8 +677,7 @@ static content_type *analyze_ct(request_rec *r, char *s)
                    }
                }
            }
-           value = apr_pstrndup(p, mp, cp - mp);
-           value = zap_sp(value);
+           value = zap_sp_and_dup(p, mp, cp, NULL);
            if (value == NULL || *value == '\0') {
                ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ss,
                             "Cannot get media parameter.");