Release read buffer of QuicCryptoStream when incoming message become less frequent. Protected by --…

net/quic/core/quic_crypto_stream.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/core/quic_crypto_stream.h"
 
 #include <string>
 
 #include "base/strings/string_piece.h"
 #include "net/quic/core/crypto/crypto_handshake.h"
@@ skipping 51 matching lines @@
       // No more data to read.
       break;
     }
     StringPiece data(static_cast<char*>(iov.iov_base), iov.iov_len);
     if (!crypto_framer_.ProcessInput(data)) {
       CloseConnectionWithDetails(crypto_framer_.error(),
                                  crypto_framer_.error_detail());
       return;
     }
     sequencer()->MarkConsumed(iov.iov_len);
+    if (handshake_confirmed_ && crypto_framer_.InputBytesRemaining() == 0) {
+      // If the handshake is complete and the current message has been fully
+      // processed then no more handshake messages are likely to arrive soon
+      // so release the memory in the stream sequencer.
+      sequencer()->ReleaseBufferIfEmpty();
+    }
   }
 }
 
 void QuicCryptoStream::SendHandshakeMessage(
     const CryptoHandshakeMessage& message) {
   DVLOG(1) << ENDPOINT << "Sending " << message.DebugString();
   session()->connection()->NeuterUnencryptedPackets();
   session()->OnCryptoHandshakeMessageSent(message);
   const QuicData& data = message.GetSerialized();
   WriteOrBufferData(StringPiece(data.data(), data.length()), false, nullptr);
@@ skipping 23 matching lines @@
       crypto_negotiated_params_.initial_subkey_secret, "EXPORTER-Token-Binding",
       /* context= */ "", 32, result);
 }
 
 const QuicCryptoNegotiatedParameters&
 QuicCryptoStream::crypto_negotiated_params() const {
   return crypto_negotiated_params_;
 }
 
 }  // namespace net