Improve loggging to debug invalid acks. No functional change.

net/quic/quic_connection.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/quic_connection.h"
 
 #include <string.h>
 #include <sys/types.h>
 
 #include <algorithm>
@@ skipping 772 matching lines @@
   DCHECK(connected_);
   if (debug_visitor_ != nullptr) {
     debug_visitor_->OnPingFrame(frame);
   }
   should_last_packet_instigate_acks_ = true;
   return true;
 }
 
 const char* QuicConnection::ValidateAckFrame(const QuicAckFrame& incoming_ack) {
   if (incoming_ack.largest_observed > packet_generator_.packet_number()) {
-    LOG(WARNING) << ENDPOINT << "Peer's observed unsent packet:"
-                 << incoming_ack.largest_observed << " vs "
-                 << packet_generator_.packet_number();
+    // clang-format off

[Ryan Hamilton, 2016/02/02 04:33:19]

Why clang-format off?

[ramant (doing other things), 2016/02/02 05:08:25]

Added it to keep code in sync with internal code. Thought merging becomes easier
(internally LOG_FIRST_N and the intention to keep name: value on the same line
results in the following format). Chrome tries
to optimize for # of lines and formatting changes and results in conflicts. 

What do you think of using clang-format off/on to keep chromium code similar to
internal code.

    LOG_FIRST_N(WARNING, 10)
        << ENDPOINT
        << "Peer's observed unsent packet:" << incoming_ack.largest_observed
        << " vs " << packet_generator_.packet_number();

[Ryan Hamilton, 2016/02/02 05:23:26]

Hm. I'm not in love with that. We could define LOG_FIRST_N if we wanted to?

[ramant (doing other things), 2016/02/02 06:42:10]

Reverted the clang-format statements.

+1 to adding LOG_FIRST_N macro (will work on it in a separate CL).

+    LOG(WARNING)
+        << ENDPOINT
+        << "Peer's observed unsent packet:" << incoming_ack.largest_observed
+        << " vs " << packet_generator_.packet_number();
+    // clang-format on
     // We got an error for data we have not sent.  Error out.
     return "Largest observed too high";
   }
 
   if (incoming_ack.largest_observed < sent_packet_manager_.largest_observed()) {
     LOG(WARNING) << ENDPOINT << "Peer's largest_observed packet decreased:"
                  << incoming_ack.largest_observed << " vs "
                  << sent_packet_manager_.largest_observed();
     // A new ack has a diminished largest_observed value.  Error out.
     // If this was an old packet, we wouldn't even have checked.
     return "Largest observed too low";
   }
 
   if (!incoming_ack.missing_packets.Empty() &&
       incoming_ack.missing_packets.Max() > incoming_ack.largest_observed) {
-    LOG(WARNING) << ENDPOINT << "Peer sent missing packet: "
-                 << incoming_ack.missing_packets.Max()
-                 << " which is greater than largest observed: "
-                 << incoming_ack.largest_observed;
+    // clang-format off
+    LOG(WARNING)
+        << ENDPOINT
+        << "Peer sent missing packet: " << incoming_ack.missing_packets.Max()
+        << " which is greater than largest observed: "
+        << incoming_ack.largest_observed;
+    // clang-format on
     return "Missing packet higher than largest observed";
   }
 
   if (!incoming_ack.missing_packets.Empty() &&
       incoming_ack.missing_packets.Min() <
           sent_packet_manager_.least_packet_awaited_by_peer()) {
-    LOG(WARNING) << ENDPOINT << "Peer sent missing packet: "
-                 << incoming_ack.missing_packets.Min()
-                 << " which is smaller than least_packet_awaited_by_peer_: "
-                 << sent_packet_manager_.least_packet_awaited_by_peer();
+    // clang-format off
+    LOG(WARNING)
+        << ENDPOINT
+        << "Peer sent missing packet: " << incoming_ack.missing_packets.Min()
+        << " which is smaller than least_packet_awaited_by_peer_: "
+        << sent_packet_manager_.least_packet_awaited_by_peer();
+    // clang-format on
     return "Missing packet smaller than least awaited";
   }
 
   if (!sent_entropy_manager_.IsValidEntropy(incoming_ack.largest_observed,
                                             incoming_ack.missing_packets,
                                             incoming_ack.entropy_hash)) {
-    LOG(WARNING) << ENDPOINT << "Peer sent invalid entropy.";
+    // clang-format off
+    LOG(WARNING)
+        << ENDPOINT << "Peer sent invalid entropy."
+        << " largest_observed:" << incoming_ack.largest_observed
+        << " last_received:" << last_header_.packet_number;
+    // clang-format on
     return "Invalid entropy";
   }
 
   if (incoming_ack.latest_revived_packet != 0 &&
       !incoming_ack.missing_packets.Contains(
           incoming_ack.latest_revived_packet)) {
-    LOG(WARNING) << ENDPOINT
-                 << "Peer specified revived packet which was not missing.";
+    // clang-format off
+    LOG(WARNING)
+        << ENDPOINT << "Peer specified revived packet which was not missing."
+        << " revived_packet:" << incoming_ack.latest_revived_packet;
+    // clang-format on
     return "Invalid revived packet";
   }
   return nullptr;
 }
 
 const char* QuicConnection::ValidateStopWaitingFrame(
     const QuicStopWaitingFrame& stop_waiting) {
   if (stop_waiting.least_unacked <
       received_packet_manager_.peer_least_packet_awaiting_ack()) {
     DLOG(ERROR) << ENDPOINT << "Peer's sent low least_unacked: "
@@ skipping 1594 matching lines @@
 void QuicConnection::OnPathClosed(QuicPathId path_id) {
   // Stop receiving packets on this path.
   framer_.OnPathClosed(path_id);
 }
 
 bool QuicConnection::ack_frame_updated() const {
   return received_packet_manager_.ack_frame_updated();
 }
 
 }  // namespace net