From 3fea604ed8b92a0284cae1a490afdb1a8830b6a0 Mon Sep 17 00:00:00 2001
From: Tony Han <h.bing612@gmail.com>
Date: Tue, 30 Jul 2019 14:19:56 +0800
Subject: [PATCH] Use cal_increasing_window to calculate new window

---
 Makefile             |  2 +-
 src/cowboy_http2.erl | 22 +++++++++++++++++++---
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 039bf2e3..b5958fb9 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,7 @@ CT_OPTS += -ct_hooks cowboy_ct_hook [] # -boot start_sasl
 LOCAL_DEPS = crypto
 
 DEPS = cowlib ranch
-dep_cowlib = git https://github.com/ninenines/cowlib 2.7.3
+dep_cowlib = git https://github.com/elixir-grpc/cowlib add-new-update-window
 dep_ranch = git https://github.com/ninenines/ranch 1.7.1
 
 DOC_DEPS = asciideck
diff --git a/src/cowboy_http2.erl b/src/cowboy_http2.erl
index 3f456702..deb57ce6 100644
--- a/src/cowboy_http2.erl
+++ b/src/cowboy_http2.erl
@@ -311,7 +311,7 @@ data_frame(State=#state{opts=Opts, streams=Streams}, StreamID, IsFin, Data) ->
 lingering_data_frame(State=#state{socket=Socket, transport=Transport,
 		http2_machine=HTTP2Machine0}, DataLen) ->
 	Transport:send(Socket, cow_http2:window_update(DataLen)),
-	HTTP2Machine1 = cow_http2_machine:update_window(DataLen, HTTP2Machine0),
+	HTTP2Machine1 = cal_and_update_window(DataLen, HTTP2Machine0),
 	State#state{http2_machine=HTTP2Machine1}.
 
 headers_frame(State, StreamID, IsFin, Headers,
@@ -586,8 +586,8 @@ commands(State=#state{socket=Socket, transport=Transport, http2_machine=HTTP2Mac
 		cow_http2:window_update(Size),
 		cow_http2:window_update(StreamID, Size)
 	]),
-	HTTP2Machine1 = cow_http2_machine:update_window(Size, HTTP2Machine0),
-	HTTP2Machine = cow_http2_machine:update_window(StreamID, Size, HTTP2Machine1),
+	HTTP2Machine1 = cal_and_update_window(Size, HTTP2Machine0),
+	HTTP2Machine = cal_and_update_window(StreamID, Size, HTTP2Machine1),
 	commands(State#state{http2_machine=HTTP2Machine}, StreamID, Tail);
 %% Supervise a child process.
 commands(State=#state{children=Children}, StreamID, [{spawn, Pid, Shutdown}|Tail]) ->
@@ -666,6 +666,22 @@ maybe_send_data(State=#state{http2_machine=HTTP2Machine0}, StreamID, IsFin, Data
 			send_data(State#state{http2_machine=HTTP2Machine}, SendData)
 	end.
 
+cal_and_update_window(DataLen, HTTP2Machine) ->
+	case cow_http2_machine:cal_increasing_window(DataLen, HTTP2Machine) of
+		0 ->
+			HTTP2Machine;
+		NewSize ->
+			cow_http2_machine:update_window(NewSize, HTTP2Machine)
+	end.
+
+cal_and_update_window(StreamID, _DataLen, HTTP2Machine) ->
+	case cow_http2_machine:cal_increasing_window(StreamID, HTTP2Machine) of
+		0 ->
+			HTTP2Machine;
+		NewSize ->
+			cow_http2_machine:update_window(StreamID, NewSize, HTTP2Machine)
+	end.
+
 send_data(State, []) ->
 	State;
 send_data(State0, [{StreamID, IsFin, SendData}|Tail]) ->