From: Ruediger Pluem <rpluem@apache.org>
Date: Sun, 28 Aug 2011 17:52:44 +0000 (+0000)
Subject: * Do a better estimation on how elements we should allocate:
X-Git-Tag: 2.3.15~324
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=884647f59483bd647fbc0a5b468da4785cd9ba4f;p=thirdparty%2Fapache%2Fhttpd.git

* Do a better estimation on how elements we should allocate:

  Preallocate the number of ranges as number of elements as this works good
  for well behaving clients which we assume to be the most cases, but do
  cut this at the arbitrary number of 100 to avoid too large preallocations.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1162565 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/modules/http/byterange_filter.c b/modules/http/byterange_filter.c
index 52c9b03aa84..a1a5b9408ca 100644
--- a/modules/http/byterange_filter.c
+++ b/modules/http/byterange_filter.c
@@ -62,7 +62,7 @@
 APLOG_USE_MODULE(http);
 
 static int ap_set_byterange(request_rec *r, apr_off_t clength,
-                            apr_array_header_t *indexes);
+                            apr_array_header_t **indexes);
 
 /*
  * Here we try to be compatible with clients that want multipart/x-byteranges
@@ -80,6 +80,7 @@ static int use_range_x(request_rec *r)
 }
 
 #define BYTERANGE_FMT "%" APR_OFF_T_FMT "-%" APR_OFF_T_FMT "/%" APR_OFF_T_FMT
+#define MAX_PREALLOC_RANGES 100
 
 static apr_status_t copy_brigade_range(apr_bucket_brigade *bb,
                                        apr_bucket_brigade *bbout,
@@ -274,8 +275,6 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_byterange_filter(ap_filter_t *f,
     indexes_t *idx;
     int i;
 
-    indexes = apr_array_make(r->pool, 10, sizeof(indexes_t));
-
     /*
      * Iterate through the brigade until reaching EOS or a bucket with
      * unknown length.
@@ -298,7 +297,7 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_byterange_filter(ap_filter_t *f,
         return ap_pass_brigade(f->next, bb);
     }
 
-    num_ranges = ap_set_byterange(r, clength, indexes);
+    num_ranges = ap_set_byterange(r, clength, &indexes);
 
     /* We have nothing to do, get out of the way. */
     if (num_ranges == 0) {
@@ -415,7 +414,7 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_byterange_filter(ap_filter_t *f,
 }
 
 static int ap_set_byterange(request_rec *r, apr_off_t clength,
-                            apr_array_header_t *indexes)
+                            apr_array_header_t **indexes)
 {
     const char *range, *or;
     const char *if_range;
@@ -428,6 +427,8 @@ static int ap_set_byterange(request_rec *r, apr_off_t clength,
     int in_merge = 0;
     indexes_t *idx;
     int overlaps = 0, reversals = 0;
+    int i, ranges = 1;
+    const char *it;
 
     if (r->assbackwards) {
         return 0;
@@ -484,7 +485,17 @@ static int ap_set_byterange(request_rec *r, apr_off_t clength,
 
     range += 6;
     or = apr_pstrdup(r->pool, range);
-    merged = apr_array_make(r->pool, 10, sizeof(char *));
+    it = range;
+    for (i = 0; i < strlen(it); i++) {
+        if (*it == ',') {
+            ranges++;
+        }
+    }
+    if (ranges > MAX_PREALLOC_RANGES) {
+        ranges = MAX_PREALLOC_RANGES;
+    }
+    *indexes = apr_array_make(r->pool, ranges, sizeof(indexes_t));
+    merged = apr_array_make(r->pool, ranges, sizeof(char *));
     while ((cur = ap_getword(r->pool, &range, ','))) {
         char *dash;
         char *errp;
@@ -560,7 +571,7 @@ static int ap_set_byterange(request_rec *r, apr_off_t clength,
             new = (char **)apr_array_push(merged);
             *new = apr_psprintf(r->pool, "%" APR_OFF_T_FMT "-%" APR_OFF_T_FMT,
                                     ostart, oend);
-            idx = (indexes_t *)apr_array_push(indexes);
+            idx = (indexes_t *)apr_array_push(*indexes);
             idx->start = ostart;
             idx->end = oend;
             sum_lengths += oend - ostart + 1;
@@ -576,7 +587,7 @@ static int ap_set_byterange(request_rec *r, apr_off_t clength,
         new = (char **)apr_array_push(merged);
         *new = apr_psprintf(r->pool, "%" APR_OFF_T_FMT "-%" APR_OFF_T_FMT,
                             ostart, oend);
-        idx = (indexes_t *)apr_array_push(indexes);
+        idx = (indexes_t *)apr_array_push(*indexes);
         idx->start = ostart;
         idx->end = oend;
         sum_lengths += oend - ostart + 1;