From 5cf11ab2e0e27a4289ac7a69174c90fc7306f805 Mon Sep 17 00:00:00 2001
From: Valentin Bartenev <vbart@nginx.com>
Date: Mon, 7 Apr 2014 23:35:33 +0400
Subject: SPDY: avoid creating flush frames.

Previously, an empty frame object was created for an output chain that contains
only sync or flush empty buffers.  But since 39d7eef2e332 every DATA frame has
the flush flag set on its last buffer, so there's no need any more in additional
flush buffers in the output queue and they can be skipped.

Note that such flush frames caused an incorrect $body_bytes_sent value.
---
 src/http/ngx_http_spdy_filter_module.c | 75 +++++++++++++++++++---------------
 1 file changed, 42 insertions(+), 33 deletions(-)

(limited to 'src')

diff --git a/src/http/ngx_http_spdy_filter_module.c b/src/http/ngx_http_spdy_filter_module.c
index 92c760243..559fb4aab 100644
--- a/src/http/ngx_http_spdy_filter_module.c
+++ b/src/http/ngx_http_spdy_filter_module.c
@@ -625,6 +625,20 @@ ngx_http_spdy_send_chain(ngx_connection_t *fc, ngx_chain_t *in, off_t limit)
     r = fc->data;
     stream = r->spdy_stream;
 
+#if (NGX_SUPPRESS_WARN)
+    size = 0;
+#endif
+
+    while (in) {
+        size = ngx_buf_size(in->buf);
+
+        if (size || in->buf->last_buf) {
+            break;
+        }
+
+        in = in->next;
+    }
+
     if (in == NULL) {
 
         if (stream->queued) {
@@ -638,8 +652,6 @@ ngx_http_spdy_send_chain(ngx_connection_t *fc, ngx_chain_t *in, off_t limit)
 
     sc = stream->connection;
 
-    size = ngx_buf_size(in->buf);
-
     if (size && ngx_http_spdy_flow_control(sc, stream) == NGX_DECLINED) {
         fc->write->delayed = 1;
         return in;
@@ -850,48 +862,45 @@ ngx_http_spdy_filter_get_data_frame(ngx_http_spdy_stream_t *stream,
                    "spdy:%ui create DATA frame %p: len:%uz flags:%ui",
                    stream->id, frame, len, flags);
 
-    if (len || flags) {
-
-        cl = ngx_chain_get_free_buf(stream->request->pool,
-                                    &stream->free_data_headers);
-        if (cl == NULL) {
-            return NULL;
-        }
+    cl = ngx_chain_get_free_buf(stream->request->pool,
+                                &stream->free_data_headers);
+    if (cl == NULL) {
+        return NULL;
+    }
 
-        buf = cl->buf;
+    buf = cl->buf;
 
-        if (buf->start) {
-            p = buf->start;
-            buf->pos = p;
+    if (buf->start) {
+        p = buf->start;
+        buf->pos = p;
 
-            p += NGX_SPDY_SID_SIZE;
+        p += NGX_SPDY_SID_SIZE;
 
-            (void) ngx_spdy_frame_write_flags_and_len(p, flags, len);
+        (void) ngx_spdy_frame_write_flags_and_len(p, flags, len);
 
-        } else {
-            p = ngx_palloc(stream->request->pool, NGX_SPDY_FRAME_HEADER_SIZE);
-            if (p == NULL) {
-                return NULL;
-            }
+    } else {
+        p = ngx_palloc(stream->request->pool, NGX_SPDY_FRAME_HEADER_SIZE);
+        if (p == NULL) {
+            return NULL;
+        }
 
-            buf->pos = p;
-            buf->start = p;
+        buf->pos = p;
+        buf->start = p;
 
-            p = ngx_spdy_frame_write_sid(p, stream->id);
-            p = ngx_spdy_frame_write_flags_and_len(p, flags, len);
+        p = ngx_spdy_frame_write_sid(p, stream->id);
+        p = ngx_spdy_frame_write_flags_and_len(p, flags, len);
 
-            buf->last = p;
-            buf->end = p;
+        buf->last = p;
+        buf->end = p;
 
-            buf->tag = (ngx_buf_tag_t) &ngx_http_spdy_filter_get_data_frame;
-            buf->memory = 1;
-        }
+        buf->tag = (ngx_buf_tag_t) &ngx_http_spdy_filter_get_data_frame;
+        buf->memory = 1;
+    }
 
-        cl->next = first;
-        first = cl;
+    cl->next = first;
+    first = cl;
 
-        last->buf->flush = 1;
-    }
+    last->buf->flush = 1;
 
     frame->first = first;
     frame->last = last;
-- 
cgit