From 9f9c0cbcd1805458963101be9a4483fd2afd074f Mon Sep 17 00:00:00 2001
From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Sun, 28 Jul 2013 19:28:41 +0900
Subject: [PATCH] nghttpd: Add -F and -f option to disable connection/stream
 level flow control

---
 src/HttpServer.cc | 30 ++++++++++++++++++++++++++----
 src/HttpServer.h  |  2 ++
 src/nghttpd.cc    | 16 ++++++++++++++--
 3 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/src/HttpServer.cc b/src/HttpServer.cc
index 1dcaaa18..28135267 100644
--- a/src/HttpServer.cc
+++ b/src/HttpServer.cc
@@ -72,6 +72,8 @@ Config::Config()
     data_ptr(nullptr),
     verify_client(false),
     no_tls(false),
+    no_connection_flow_control(false),
+    no_stream_flow_control(false),
     output_upper_thres(1024*1024)
 {}
 
@@ -346,13 +348,28 @@ int Http2Handler::on_connect()
   if(r != 0) {
     return r;
   }
-  nghttp2_settings_entry entry;
-  entry.settings_id = NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS;
-  entry.value = NGHTTP2_INITIAL_MAX_CONCURRENT_STREAMS;
-  r = nghttp2_submit_settings(session_, &entry, 1);
+  nghttp2_settings_entry entry[2];
+  size_t niv = 1;
+  entry[0].settings_id = NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS;
+  entry[0].value = NGHTTP2_INITIAL_MAX_CONCURRENT_STREAMS;
+  if(sessions_->get_config()->no_connection_flow_control &&
+     sessions_->get_config()->no_stream_flow_control) {
+    entry[niv].settings_id = NGHTTP2_SETTINGS_FLOW_CONTROL_OPTIONS;
+    entry[niv].value = 1;
+    ++niv;
+  }
+  r = nghttp2_submit_settings(session_, entry, niv);
   if(r != 0) {
     return r;
   }
+  if(sessions_->get_config()->no_connection_flow_control &&
+     !sessions_->get_config()->no_stream_flow_control) {
+    r = nghttp2_submit_window_update(session_, NGHTTP2_FLAG_END_FLOW_CONTROL,
+                                     0, 0);
+    if(r != 0) {
+      return r;
+    }
+  }
   return on_write();
 }
 
@@ -698,6 +715,11 @@ void hd_on_frame_recv_callback
       auto req = util::make_unique<Request>(stream_id);
       append_nv(req.get(), frame->headers.nva, frame->headers.nvlen);
       hd->add_stream(stream_id, std::move(req));
+      if(!hd->get_config()->no_connection_flow_control &&
+         hd->get_config()->no_stream_flow_control) {
+        nghttp2_submit_window_update(session, NGHTTP2_FLAG_END_FLOW_CONTROL,
+                                     stream_id, 0);
+      }
       break;
     }
     case NGHTTP2_HCAT_HEADERS:
diff --git a/src/HttpServer.h b/src/HttpServer.h
index 216ab971..a27974e2 100644
--- a/src/HttpServer.h
+++ b/src/HttpServer.h
@@ -57,6 +57,8 @@ struct Config {
   void *data_ptr;
   bool verify_client;
   bool no_tls;
+  bool no_connection_flow_control;
+  bool no_stream_flow_control;
   size_t output_upper_thres;
   Config();
 };
diff --git a/src/nghttpd.cc b/src/nghttpd.cc
index 1e5420f2..28ab2c12 100644
--- a/src/nghttpd.cc
+++ b/src/nghttpd.cc
@@ -45,7 +45,7 @@ namespace nghttp2 {
 namespace {
 void print_usage(std::ostream& out)
 {
-  out << "Usage: nghttpd [-DVhv] [-d <PATH>] [--no-tls] <PORT> [<PRIVATE_KEY> <CERT>]"
+  out << "Usage: nghttpd [-FDVfhv] [-d <PATH>] [--no-tls] <PORT> [<PRIVATE_KEY> <CERT>]"
       << std::endl;
 }
 } // namespace
@@ -73,6 +73,10 @@ void print_help(std::ostream& out)
       << "    -v, --verbose      Print debug information such as reception/\n"
       << "                       transmission of frames and name/value pairs.\n"
       << "    --no-tls           Disable SSL/TLS.\n"
+      << "    -F, --no-connection-flow-control\n"
+      << "                       Disables connection level flow control.\n"
+      << "    -f, --no-stream-flow-control\n"
+      << "                       Disables stream level flow control.\n"
       << "    -h, --help         Print this help.\n"
       << std::endl;
 }
@@ -90,14 +94,19 @@ int main(int argc, char **argv)
       {"verbose", no_argument, 0, 'v' },
       {"verify-client", no_argument, 0, 'V' },
       {"no-tls", no_argument, &flag, 1 },
+      {"no-connection-flow-control", no_argument, 0, 'F'},
+      {"no-stream-flow-control", no_argument, 0, 'f'},
       {0, 0, 0, 0 }
     };
     int option_index = 0;
-    int c = getopt_long(argc, argv, "DVd:hv", long_options, &option_index);
+    int c = getopt_long(argc, argv, "FDVd:fhv", long_options, &option_index);
     if(c == -1) {
       break;
     }
     switch(c) {
+    case 'F':
+      config.no_connection_flow_control = true;
+      break;
     case 'D':
       config.daemon = true;
       break;
@@ -107,6 +116,9 @@ int main(int argc, char **argv)
     case 'd':
       config.htdocs = optarg;
       break;
+    case 'f':
+      config.no_stream_flow_control = true;
+      break;
     case 'h':
       print_help(std::cout);
       exit(EXIT_SUCCESS);