Track the number of "early" frames received in a QUIC stream.

net/quic/quic_stream_sequencer.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_stream_sequencer.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/logging.h"
 #include "base/metrics/sparse_histogram.h"
 #include "net/quic/reliable_quic_stream.h"
 
 using std::make_pair;
 using std::min;
 using std::numeric_limits;
 using std::string;
 
 namespace net {
 
 QuicStreamSequencer::QuicStreamSequencer(ReliableQuicStream* quic_stream)
     : stream_(quic_stream),
       num_bytes_consumed_(0),
       close_offset_(numeric_limits<QuicStreamOffset>::max()),
       blocked_(false),
       num_bytes_buffered_(0),
       num_frames_received_(0),
-      num_duplicate_frames_received_(0) {
+      num_duplicate_frames_received_(0),
+      num_early_frames_received_(0) {
 }
 
 QuicStreamSequencer::~QuicStreamSequencer() {
 }
 
 void QuicStreamSequencer::OnStreamFrame(const QuicStreamFrame& frame) {
   ++num_frames_received_;
   if (IsDuplicate(frame)) {
     ++num_duplicate_frames_received_;
     // Silently ignore duplicates.
@@ skipping 18 matching lines @@
   if (frame.fin) {
     CloseStreamAtOffset(frame.offset + data_len);
     if (data_len == 0) {
       return;
     }
   }
 
   IOVector data;
   data.AppendIovec(frame.data.iovec(), frame.data.Size());
 
+  if (byte_offset > num_bytes_consumed_) {
+    ++num_early_frames_received_;
+  }
+
   // If the frame has arrived in-order then we can process it immediately, only
   // buffering if the stream is unable to process it.
   if (!blocked_ && byte_offset == num_bytes_consumed_) {
     DVLOG(1) << "Processing byte offset " << byte_offset;
     size_t bytes_consumed = 0;
     for (size_t i = 0; i < data.Size(); ++i) {
       bytes_consumed += stream_->ProcessRawData(
           static_cast<char*>(data.iovec()[i].iov_base),
           data.iovec()[i].iov_len);
     }
@@ skipping 209 matching lines @@
 }
 
 void QuicStreamSequencer::RecordBytesConsumed(size_t bytes_consumed) {
   num_bytes_consumed_ += bytes_consumed;
   num_bytes_buffered_ -= bytes_consumed;
 
   stream_->AddBytesConsumed(bytes_consumed);
 }
 
 }  // namespace net