From 0dec04921d929c1e36c85983d0d6481ace307f6a Mon Sep 17 00:00:00 2001
From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Fri, 9 Aug 2013 21:21:14 +0900
Subject: [PATCH] Remove priority adjustment for a DATA frame

Simply it does not work as expected.
---
 lib/nghttp2_outbound_item.h | 16 ----------------
 lib/nghttp2_session.c       | 25 -------------------------
 2 files changed, 41 deletions(-)

diff --git a/lib/nghttp2_outbound_item.h b/lib/nghttp2_outbound_item.h
index 55597b85..24929efb 100644
--- a/lib/nghttp2_outbound_item.h
+++ b/lib/nghttp2_outbound_item.h
@@ -34,10 +34,6 @@
 
 /* Priority for PING */
 #define NGHTTP2_OB_PRI_PING -10
-/* Priority for CREDENTIAL */
-#define NGHTTP2_OB_PRI_CREDENTIAL -2
-/* Priority for the frame which must be sent after CREDENTIAL */
-#define NGHTTP2_OB_PRI_AFTER_CREDENTIAL -1
 
 typedef struct {
   nghttp2_data_provider *data_prd;
@@ -50,19 +46,7 @@ typedef struct {
   nghttp2_frame_category frame_cat;
   void *frame;
   void *aux_data;
-  /* Initial priority of this item */
-  int inipri;
-  /* The current priority of this item. Initially, pri equals to
-     inipri. The item is chosen from the queue based on pri and
-     seq. For control frames, they consist of just 1 frame and pri
-     does not change. For DATA frame, they could split up to several
-     frames. After sending a frame, the pri becomes |inipri| +
-     |pridecay| and |pridecay| is multiplied by 2. If it becomes more
-     than lowest priority, then it returns back to |inipri| and do the
-     same sequence again and again. By doing this, the higher priority
-     long DATA frames don't starve the lower prioritized streams. */
   int pri;
-  uint32_t pridecay;
   int64_t seq;
 } nghttp2_outbound_item;
 
diff --git a/lib/nghttp2_session.c b/lib/nghttp2_session.c
index a50a2fd9..3bed0fe9 100644
--- a/lib/nghttp2_session.c
+++ b/lib/nghttp2_session.c
@@ -415,8 +415,6 @@ int nghttp2_session_add_frame(nghttp2_session *session,
     free(item);
     return r;
   }
-  item->inipri = item->pri;
-  item->pridecay = 1;
   return 0;
 }
 
@@ -1193,28 +1191,6 @@ nghttp2_outbound_item* nghttp2_session_pop_next_ob_item
   }
 }
 
-/*
- * Adjust priority of item so that the higher priority long DATA
- * frames don't starve lower priority streams.
- */
-static void nghttp2_outbound_item_adjust_pri(nghttp2_session *session,
-                                             nghttp2_outbound_item *item)
-{
-  if(item->pri == NGHTTP2_PRI_LOWEST) {
-    nghttp2_stream *stream;
-    stream = nghttp2_session_get_stream
-      (session, nghttp2_outbound_item_get_data_frame(item)->hd.stream_id);
-    assert(stream);
-    item->pri = item->inipri = stream->pri;
-    item->pridecay = 1;
-  } else if(item->pri + item->pridecay > NGHTTP2_PRI_LOWEST) {
-    item->pri = NGHTTP2_PRI_LOWEST;
-  } else {
-    item->pri = item->inipri + item->pridecay;
-    item->pridecay *= 2;
-  }
-}
-
 /*
  * Called after a frame is sent.
  *
@@ -1368,7 +1344,6 @@ static int nghttp2_session_after_frame_sent(nghttp2_session *session)
     } else {
       nghttp2_outbound_item* next_item;
       next_item = nghttp2_session_get_next_ob_item(session);
-      nghttp2_outbound_item_adjust_pri(session, session->aob.item);
       /* If priority of this stream is higher or equal to other stream
          waiting at the top of the queue, we continue to send this
          data. */