Change QuicFramer so it accepts a QuicDataWriter rather than allocating

net/quic/quic_framer.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_framer.h"
 
 #include "base/containers/hash_tables.h"
 #include "base/stl_util.h"
 #include "net/quic/crypto/crypto_framer.h"
 #include "net/quic/crypto/crypto_handshake_message.h"
@@ skipping 300 matching lines @@
 QuicFramer::AckFrameInfo::~AckFrameInfo() {}
 
 // static
 QuicPacketEntropyHash QuicFramer::GetPacketEntropyHash(
     const QuicPacketHeader& header) {
   return header.entropy_flag << (header.packet_sequence_number % 8);
 }
 
 QuicPacket* QuicFramer::BuildDataPacket(const QuicPacketHeader& header,
                                         const QuicFrames& frames,
-                                        size_t packet_size) {
-  QuicDataWriter writer(packet_size);
+                                        char* buffer,
+                                        size_t packet_length) {
+  QuicDataWriter writer(packet_length, buffer);
   if (!AppendPacketHeader(header, &writer)) {
     LOG(DFATAL) << "AppendPacketHeader failed";
     return nullptr;
   }
 
   size_t i = 0;
   for (const QuicFrame& frame : frames) {
     // Determine if we should write stream frame length in header.
     const bool no_stream_frame_length =
         (header.is_in_fec_group == NOT_IN_FEC_GROUP) &&
@@ skipping 63 matching lines @@
         }
         break;
       default:
         RaiseError(QUIC_INVALID_FRAME_DATA);
         LOG(DFATAL) << "QUIC_INVALID_FRAME_DATA";
         return nullptr;
     }
     ++i;
   }
 
-  // Save the length before writing, because take clears it.
-  const size_t len = writer.length();
-  // Less than or equal because truncated acks end up with max_plaintex_size
-  // length, even though they're typically slightly shorter.
-  DCHECK_LE(len, packet_size);
-  QuicPacket* packet = new QuicPacket(
-      writer.take(), len, true, header.public_header.connection_id_length,
-      header.public_header.version_flag,
-      header.public_header.sequence_number_length);
+  QuicPacket* packet =
+      new QuicPacket(writer.data(), writer.length(), false,
+                     header.public_header.connection_id_length,
+                     header.public_header.version_flag,
+                     header.public_header.sequence_number_length);
 
   if (fec_builder_) {
     fec_builder_->OnBuiltFecProtectedPayload(header,
                                              packet->FecProtectedData());
   }
 
   return packet;
 }
 
 QuicPacket* QuicFramer::BuildFecPacket(const QuicPacketHeader& header,
                                        const QuicFecData& fec) {
   DCHECK_EQ(IN_FEC_GROUP, header.is_in_fec_group);
   DCHECK_NE(0u, header.fec_group);
   size_t len = GetPacketHeaderSize(header);
   len += fec.redundancy.length();
 
-  QuicDataWriter writer(len);
+  scoped_ptr<char[]> buffer(new char[len]);
+  QuicDataWriter writer(len, buffer.get());
   if (!AppendPacketHeader(header, &writer)) {
     LOG(DFATAL) << "AppendPacketHeader failed";
     return nullptr;
   }
 
   if (!writer.WriteBytes(fec.redundancy.data(), fec.redundancy.length())) {
     LOG(DFATAL) << "Failed to add FEC";
     return nullptr;
   }
 
-  return new QuicPacket(writer.take(), len, true,
+  return new QuicPacket(buffer.release(), len, true,
                         header.public_header.connection_id_length,
                         header.public_header.version_flag,
                         header.public_header.sequence_number_length);
 }
 
 // static
 QuicEncryptedPacket* QuicFramer::BuildPublicResetPacket(
     const QuicPublicResetPacket& packet) {
   DCHECK(packet.public_header.reset_flag);
 
   CryptoHandshakeMessage reset;
   reset.set_tag(kPRST);
   reset.SetValue(kRNON, packet.nonce_proof);
   reset.SetValue(kRSEQ, packet.rejected_sequence_number);
   if (!packet.client_address.address().empty()) {
     // packet.client_address is non-empty.
     QuicSocketAddressCoder address_coder(packet.client_address);
     string serialized_address = address_coder.Encode();
     if (serialized_address.empty()) {
       return nullptr;
     }
     reset.SetStringPiece(kCADR, serialized_address);
   }
   const QuicData& reset_serialized = reset.GetSerialized();
 
   size_t len =
       kPublicFlagsSize + PACKET_8BYTE_CONNECTION_ID + reset_serialized.length();
-  QuicDataWriter writer(len);
+  scoped_ptr<char[]> buffer(new char[len]);
+  QuicDataWriter writer(len, buffer.get());
 
   uint8 flags = static_cast<uint8>(PACKET_PUBLIC_FLAGS_RST |
                                    PACKET_PUBLIC_FLAGS_8BYTE_CONNECTION_ID);
   if (!writer.WriteUInt8(flags)) {
     return nullptr;
   }
 
   if (!writer.WriteUInt64(packet.public_header.connection_id)) {
     return nullptr;
   }
 
   if (!writer.WriteBytes(reset_serialized.data(), reset_serialized.length())) {
     return nullptr;
   }
 
-  return new QuicEncryptedPacket(writer.take(), len, true);
+  return new QuicEncryptedPacket(buffer.release(), len, true);
 }
 
 QuicEncryptedPacket* QuicFramer::BuildVersionNegotiationPacket(
     const QuicPacketPublicHeader& header,
     const QuicVersionVector& supported_versions) {
   DCHECK(header.version_flag);
   size_t len = GetVersionNegotiationPacketSize(supported_versions.size());
-  QuicDataWriter writer(len);
+  scoped_ptr<char[]> buffer(new char[len]);
+  QuicDataWriter writer(len, buffer.get());
 
   uint8 flags = static_cast<uint8>(PACKET_PUBLIC_FLAGS_VERSION |
                                    PACKET_PUBLIC_FLAGS_8BYTE_CONNECTION_ID);
   if (!writer.WriteUInt8(flags)) {
     return nullptr;
   }
 
   if (!writer.WriteUInt64(header.connection_id)) {
     return nullptr;
   }
 
   for (size_t i = 0; i < supported_versions.size(); ++i) {
     if (!writer.WriteUInt32(QuicVersionToQuicTag(supported_versions[i]))) {
       return nullptr;
     }
   }
 
-  return new QuicEncryptedPacket(writer.take(), len, true);
+  return new QuicEncryptedPacket(buffer.release(), len, true);
 }
 
 bool QuicFramer::ProcessPacket(const QuicEncryptedPacket& packet) {
   DCHECK(!reader_.get());
   reader_.reset(new QuicDataReader(packet.data(), packet.length()));
 
   visitor_->OnPacket();
 
   // First parse the public header.
   QuicPacketPublicHeader public_header;
@@ skipping 15 matching lines @@
       reader_.reset(nullptr);
       return true;
     }
   }
 
   bool rv;
   if (!is_server_ && public_header.version_flag) {
     rv = ProcessVersionNegotiationPacket(&public_header);
   } else if (public_header.reset_flag) {
     rv = ProcessPublicResetPacket(public_header);
+  } else if (packet.length() <= kMaxPacketSize) {
+    char buffer[kMaxPacketSize];
+    rv = ProcessDataPacket(public_header, packet, buffer, kMaxPacketSize);
   } else {
-    if (packet.length() <= kMaxPacketSize) {
-      char buffer[kMaxPacketSize];
-      rv = ProcessDataPacket(public_header, packet, buffer, kMaxPacketSize);
-    } else {
-      scoped_ptr<char[]> buffer(new char[packet.length()]);
-      rv = ProcessDataPacket(public_header, packet, buffer.get(),
-                             packet.length());
-      LOG_IF(DFATAL, rv) << "QUIC should never successfully process packets "
-                         << "larger than kMaxPacketSize. packet size:"
-                         << packet.length();
-    }
+    scoped_ptr<char[]> large_buffer(new char[packet.length()]);
+    rv = ProcessDataPacket(public_header, packet, large_buffer.get(),
+                           packet.length());
+    LOG_IF(DFATAL, rv) << "QUIC should never successfully process packets "
+                       << "larger than kMaxPacketSize. packet size:"
+                       << packet.length();
   }
 
   reader_.reset(nullptr);
   return rv;
 }
 
 bool QuicFramer::ProcessVersionNegotiationPacket(
     QuicPacketPublicHeader* public_header) {
   DCHECK(!is_server_);
   // Try reading at least once to raise error if the packet is invalid.
@@ skipping 1646 matching lines @@
 
 bool QuicFramer::RaiseError(QuicErrorCode error) {
   DVLOG(1) << "Error detail: " << detailed_error_;
   set_error(error);
   visitor_->OnError(this);
   reader_.reset(nullptr);
   return false;
 }
 
 }  // namespace net