Maybe a little optimization - Yes?

[胡聪 (hucc)]

Hi,

Maybe a little optimization. I am not sure whether nginx intends to do it.

And this his is the result of nginx-tests:
All tests successful.
Files=270, Tests=3328, 259 wallclock secs ( 1.35 usr  0.69 sys + 39.76 cusr  9.54 csys = 51.34 CPU)
Result: PASS

# HG changeset patch
# User hucongcong <hucong.c at foxmail.com>
# Date 1478615841 -28800
#      Tue Nov 08 22:37:21 2016 +0800
# Node ID 4eb871095d2703fbc4ef55edd918bfd9a4011610
# Parent  92ad1c92bcf93310bf59447dd581cac37af87adb
Optimize some code.

*) It is not necessary to traverse *busy and link the *out when *out == NULL.
*) Only call ngx_array_init() in main request to avoid extra initialization in subrequest.

diff -r 92ad1c92bcf9 -r 4eb871095d27 src/core/ngx_buf.c
--- a/src/core/ngx_buf.c	Fri Nov 04 19:12:19 2016 +0300
+++ b/src/core/ngx_buf.c	Tue Nov 08 22:37:21 2016 +0800
@@ -189,7 +189,7 @@
     if (*busy == NULL) {
         *busy = *out;
 
-    } else {
+    } else if (*out != NULL) {
         for (cl = *busy; cl->next; cl = cl->next) { /* void */ }
 
         cl->next = *out;
diff -r 92ad1c92bcf9 -r 4eb871095d27 src/http/modules/ngx_http_range_filter_module.c
--- a/src/http/modules/ngx_http_range_filter_module.c	Fri Nov 04 19:12:19 2016 +0300
+++ b/src/http/modules/ngx_http_range_filter_module.c	Tue Nov 08 22:37:21 2016 +0800
@@ -224,12 +224,6 @@
 
     ctx->offset = r->headers_out.content_offset;
 
-    if (ngx_array_init(&ctx->ranges, r->pool, 1, sizeof(ngx_http_range_t))
-        != NGX_OK)
-    {
-        return NGX_ERROR;
-    }
-
     ranges = r->single_range ? 1 : clcf->max_ranges;
 
     switch (ngx_http_range_parse(r, ctx, ranges)) {
@@ -291,6 +285,12 @@
         }
     }
 
+    if (ngx_array_init(&ctx->ranges, r->pool, 1, sizeof(ngx_http_range_t))
+        != NGX_OK)
+    {
+        return NGX_ERROR;
+    }
+
     p = r->headers_in.range->value.data + 6;
     size = 0;
     content_length = r->headers_out.content_length_n;