nghttpx: Refactor Downstream::response_datalen_

src/shrpx_downstream.cc

@@ -116,9 +116,8 @@ Downstream::Downstream(Upstream *upstream, MemchunkPool *mcpool,
     : dlnext(nullptr), dlprev(nullptr),
       request_start_time_(std::chrono::high_resolution_clock::now()),
       request_buf_(mcpool), response_buf_(mcpool), response_sent_bodylen_(0),
-      upstream_(upstream), blocked_link_(nullptr), response_datalen_(0),
+      upstream_(upstream), blocked_link_(nullptr), num_retry_(0),
-      num_retry_(0), stream_id_(stream_id), priority_(priority),
+      stream_id_(stream_id), priority_(priority), downstream_stream_id_(-1),
-      downstream_stream_id_(-1),
       response_rst_stream_error_code_(NGHTTP2_NO_ERROR),
       request_state_(INITIAL), response_state_(INITIAL),
       dispatch_state_(DISPATCH_NONE), upgraded_(false), chunked_request_(false),
@@ -785,17 +784,6 @@ bool Downstream::get_expect_final_response() const {
   return expect_final_response_;
 }
 
-void Downstream::add_response_datalen(size_t len) { response_datalen_ += len; }
-
-void Downstream::dec_response_datalen(size_t len) {
-  assert(response_datalen_ >= len);
-  response_datalen_ -= len;
-}
-
-size_t Downstream::get_response_datalen() const { return response_datalen_; }
-
-void Downstream::reset_response_datalen() { response_datalen_ = 0; }
-
 bool Downstream::expect_response_body() const {
   return http2::expect_response_body(req_.method, resp_.http_status);
 }

src/shrpx_downstream.h

@@ -169,12 +169,20 @@ struct Request {
 
 struct Response {
   Response()
-      : fs(32), recv_body_length(0), http_status(0), http_major(1),
+      : fs(32), recv_body_length(0), unconsumed_body_length(0), http_status(0),
-        http_minor(1), connection_close(false) {}
+        http_major(1), http_minor(1), connection_close(false) {}
+
+  void consume(size_t len) {
+    assert(unconsumed_body_length >= len);
+    unconsumed_body_length -= len;
+  }
 
   FieldStore fs;
   // the length of response body received so far
   int64_t recv_body_length;
+  // The number of bytes not consumed by the application yet.  This is
+  // mainly for HTTP/2 backend.
+  size_t unconsumed_body_length;
   // HTTP status code
   unsigned int http_status;
   int http_major, http_minor;
@@ -305,10 +313,6 @@ public:
   bool get_non_final_response() const;
   void set_expect_final_response(bool f);
   bool get_expect_final_response() const;
-  void add_response_datalen(size_t len);
-  void dec_response_datalen(size_t len);
-  size_t get_response_datalen() const;
-  void reset_response_datalen();
 
   // Call this method when there is incoming data in downstream
   // connection.
@@ -406,9 +410,6 @@ private:
   // only used by HTTP/2 or SPDY upstream
   BlockedLink *blocked_link_;
 
-  // The number of bytes not consumed by the application yet.
-  size_t response_datalen_;
-
   size_t num_retry_;
 
   int32_t stream_id_;

src/shrpx_http2_downstream_connection.cc

@@ -71,10 +71,12 @@ Http2DownstreamConnection::~Http2DownstreamConnection() {
         downstream_->get_downstream_stream_id() != -1) {
       submit_rst_stream(downstream_, error_code);
 
-      http2session_->consume(downstream_->get_downstream_stream_id(),
+      auto &resp = downstream_->response();
-                             downstream_->get_response_datalen());
 
-      downstream_->reset_response_datalen();
+      http2session_->consume(downstream_->get_downstream_stream_id(),
+                             resp.unconsumed_body_length);
+
+      resp.unconsumed_body_length = 0;
 
       http2session_->signal_write();
     }
@@ -105,15 +107,18 @@ void Http2DownstreamConnection::detach_downstream(Downstream *downstream) {
   if (LOG_ENABLED(INFO)) {
     DCLOG(INFO, this) << "Detaching from DOWNSTREAM:" << downstream;
   }
+
+  auto &resp = downstream_->response();
+
   if (submit_rst_stream(downstream) == 0) {
     http2session_->signal_write();
   }
 
   if (downstream_->get_downstream_stream_id() != -1) {
     http2session_->consume(downstream_->get_downstream_stream_id(),
-                           downstream_->get_response_datalen());
+                           resp.unconsumed_body_length);
 
-    downstream_->reset_response_datalen();
+    resp.unconsumed_body_length = 0;
 
     http2session_->signal_write();
   }
@@ -449,8 +454,6 @@ int Http2DownstreamConnection::resume_read(IOCtrlReason reason,
   }
 
   if (consumed > 0) {
-    assert(downstream_->get_response_datalen() >= consumed);
-
     rv = http2session_->consume(downstream_->get_downstream_stream_id(),
                                 consumed);
 
@@ -458,7 +461,9 @@ int Http2DownstreamConnection::resume_read(IOCtrlReason reason,
       return -1;
     }
 
-    downstream_->dec_response_datalen(consumed);
+    auto &resp = downstream_->response();
+
+    resp.unconsumed_body_length -= consumed;
 
     http2session_->signal_write();
   }

src/shrpx_http2_session.cc

@@ -1180,6 +1180,7 @@ int on_data_chunk_recv_callback(nghttp2_session *session, uint8_t flags,
   auto &resp = downstream->response();
 
   resp.recv_body_length += len;
+  resp.unconsumed_body_length += len;
 
   auto upstream = downstream->get_upstream();
   rv = upstream->on_downstream_body(downstream, data, len, false);
@@ -1193,8 +1194,6 @@ int on_data_chunk_recv_callback(nghttp2_session *session, uint8_t flags,
     downstream->set_response_state(Downstream::MSG_RESET);
   }
 
-  downstream->add_response_datalen(len);
-
   call_downstream_readcb(http2session, downstream);
   return 0;
 }

src/shrpx_https_upstream.cc

@@ -563,8 +563,8 @@ int HttpsUpstream::on_write() {
 
   if (output->rleft() == 0 && dconn &&
       downstream->get_response_state() != Downstream::MSG_COMPLETE) {
-    if (downstream->resume_read(SHRPX_NO_BUFFER,
+    if (downstream->resume_read(SHRPX_NO_BUFFER, resp.unconsumed_body_length) !=
-                                downstream->get_response_datalen()) != 0) {
+        0) {
       return -1;
     }
 
@@ -601,8 +601,7 @@ int HttpsUpstream::on_write() {
     }
   }
 
-  return downstream->resume_read(SHRPX_NO_BUFFER,
+  return downstream->resume_read(SHRPX_NO_BUFFER, resp.unconsumed_body_length);
-                                 downstream->get_response_datalen());
 }
 
 int HttpsUpstream::on_event() { return 0; }