svn commit: r1510044 - in /httpd/httpd/branches/2.2.x: ./ STATUS server/util.c

[sf...@apache.org]

Author: sf
Date: Sat Aug  3 17:35:21 2013
New Revision: 1510044

URL: http://svn.apache.org/r1510044
Log:
Merge r1485409:

  Be more clever when allocating memory for log item to be escaped.
  This should be faster and save about 70-100 bytes in the request pool with the default config.

Reviewed by: minfrin, rjung, rpluem

Modified:
    httpd/httpd/branches/2.2.x/   (props changed)
    httpd/httpd/branches/2.2.x/STATUS
    httpd/httpd/branches/2.2.x/server/util.c

Propchange: httpd/httpd/branches/2.2.x/
------------------------------------------------------------------------------
  Merged /httpd/httpd/trunk:r1485409

Modified: httpd/httpd/branches/2.2.x/STATUS
URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.2.x/STATUS?rev=1510044&r1=1510043&r2=1510044&view=diff
==============================================================================
--- httpd/httpd/branches/2.2.x/STATUS (original)
+++ httpd/httpd/branches/2.2.x/STATUS Sat Aug  3 17:35:21 2013
@@ -97,19 +97,6 @@ RELEASE SHOWSTOPPERS:
 PATCHES ACCEPTED TO BACKPORT FROM TRUNK:
   [ start all new proposals below, under PATCHES PROPOSED. ]
   
-  * core: speed up (for common cases) and reduce memory usage of ap_escape_logitem
-    This should save 70-100 bytes in the request pool for a default config.
-    trunk patch: http://svn.apache.org/r1485409
-    2.4.x patch: http://svn.apache.org/r1485723
-    2.2.x patch: trunk works
-    +1: minfrin, rjung, rpluem
-    wrowe wonders why we copy and don't simply return the identity on no-change
-    rjung: From an API point of view the function - as well as the html escape functions
-           - takes a const char* and returns a plain char *. So a consumer would be free
-           to write to the returned string. There's no such place in httpd code I can
-           find but we can't rule it out for foreign modules. We could fix the signature
-           (returning const char *) in trunk but not for 2.2 ad 2.4. 
-
   * mod_dav; Teeny patch to fix #55304
     trunk: http://svn.apache.org/r1506714
     +1: gstein, wrowe, rpluem

Modified: httpd/httpd/branches/2.2.x/server/util.c
URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.2.x/server/util.c?rev=1510044&r1=1510043&r2=1510044&view=diff
==============================================================================
--- httpd/httpd/branches/2.2.x/server/util.c (original)
+++ httpd/httpd/branches/2.2.x/server/util.c Sat Aug  3 17:35:21 2013
@@ -1845,16 +1845,33 @@ AP_DECLARE(char *) ap_escape_logitem(apr
     char *ret;
     unsigned char *d;
     const unsigned char *s;
+    apr_size_t length, escapes = 0;
 
     if (!str) {
         return NULL;
     }
 
-    ret = apr_palloc(p, 4 * strlen(str) + 1); /* Be safe */
+    /* Compute how many characters need to be escaped */
+    s = (const unsigned char *)str;
+    for (; *s; ++s) {
+        if (TEST_CHAR(*s, T_ESCAPE_LOGITEM)) {
+            escapes++;
+        }
+    }
+    
+    /* Compute the length of the input string, including NULL */
+    length = s - (const unsigned char *)str + 1;
+    
+    /* Fast path: nothing to escape */
+    if (escapes == 0) {
+        return apr_pmemdup(p, str, length);
+    }
+    
+    /* Each escaped character needs up to 3 extra bytes (0 --> \x00) */
+    ret = apr_palloc(p, length + 3 * escapes);
     d = (unsigned char *)ret;
     s = (const unsigned char *)str;
     for (; *s; ++s) {
-
         if (TEST_CHAR(*s, T_ESCAPE_LOGITEM)) {
             *d++ = '\\';
             switch(*s) {