Persist server's crypto config data to disk cache for 0-RTT

net/quic/crypto/quic_crypto_client_config.cc

Index: net/quic/crypto/quic_crypto_client_config.cc
diff --git a/net/quic/crypto/quic_crypto_client_config.cc b/net/quic/crypto/quic_crypto_client_config.cc
index 876391065330cd78b1259d34c45a63a7994ee870..c1485919be7b458069b2b2495dbac338fb8e6442 100644
--- a/net/quic/crypto/quic_crypto_client_config.cc
+++ b/net/quic/crypto/quic_crypto_client_config.cc
@@ -38,11 +38,13 @@ QuicCryptoClientConfig::~QuicCryptoClientConfig() {
 
 QuicCryptoClientConfig::CachedState::CachedState()
     : server_config_valid_(false),
+      need_to_persist_(false),
       generation_counter_(0) {}
 
 QuicCryptoClientConfig::CachedState::CachedState(
     scoped_ptr<QuicServerInfo> quic_server_info)
     : server_config_valid_(false),
+      need_to_persist_(false),
       generation_counter_(0),
       quic_server_info_(quic_server_info.Pass()) {}
 
@@ -118,6 +120,7 @@ QuicErrorCode QuicCryptoClientConfig::CachedState::SetServerConfig(
     server_config_ = server_config.as_string();
     SetProofInvalid();
     scfg_.reset(new_scfg_storage.release());
+    need_to_persist_ = true;
   }
   return QUIC_NO_ERROR;
 }
@@ -160,6 +163,7 @@ void QuicCryptoClientConfig::CachedState::ClearProof() {
 
 void QuicCryptoClientConfig::CachedState::SetProofValid() {
   server_config_valid_ = true;
+  SaveQuicServerInfo();
 }
 
 void QuicCryptoClientConfig::CachedState::SetProofInvalid() {
@@ -197,6 +201,10 @@ QuicCryptoClientConfig::CachedState::proof_verify_details() const {
   return proof_verify_details_.get();
 }
 
+QuicServerInfo* QuicCryptoClientConfig::CachedState::quic_server_info() const {
+  return quic_server_info_.get();
+}
+
 void QuicCryptoClientConfig::CachedState::set_source_address_token(
     StringPiece token) {
   source_address_token_ = token.as_string();
@@ -218,6 +226,55 @@ void QuicCryptoClientConfig::CachedState::InitializeFrom(
   server_config_valid_ = other.server_config_valid_;
 }
 
+// TODO(rtenneti): LoadQuicServerInfo and SaveQuicServerInfo have duplication of
+// data in CachedState and QuicServerInfo. We should eliminate the duplication
+// of data.
+// An issue to be solved: while we are loading the data from disk cache, it is
+// possible for another request for the same hostname update the CachedState
+// because that request has sent FillInchoateClientHello and got REJ message.
+// Loading of data from disk cache shouldn't blindly overwrite what is in
+// CachedState.
+void QuicCryptoClientConfig::CachedState::LoadQuicServerInfo() {

[wtc, 2014/02/14 01:46:13]

This method needs to return a bool status.

[ramant (doing other things), 2014/02/15 00:36:12]

Done.

+  if (!server_config_.empty()) {

[wtc, 2014/02/14 01:46:13]

This should become a DCHECK:
  DCHECK(server_config_.empty());

Also DCHECK(quic_server_info_->IsDataReady()).

[ramant (doing other things), 2014/02/15 00:36:12]

Done.

+    return;
+  }
+  DCHECK(quic_server_info_.get());
+
+  const QuicServerInfo::State& state(quic_server_info_->state());
+  if (state.server_config.empty()) {
+    return;

[wtc, 2014/02/14 01:46:13]

We should return false.

[ramant (doing other things), 2014/02/15 00:36:12]

Done.

+  }
+
+  server_config_ = state.server_config;

[wtc, 2014/02/13 23:48:43]

I now think we should call SetServerConfig() to set server_config_ rather than
setting server_config_ directly. SetServerConfig() will check for expiry and
call SetProofInvalid(), which increments the generation counter.

We'll need to make sure that need_to_persist_ should be set to false here, but
for the other call to SetServerConfig() we need to set need_to_persist_ to true.
Perhaps we need to add a new method for setting need_to_persist_

[wtc, 2014/02/14 01:46:13]

If SetServerConfig() fails, we should return false.

[ramant (doing other things), 2014/02/15 00:36:12]

Done.

[ramant (doing other things), 2014/02/15 00:36:12]

Done.

+  source_address_token_ = state.source_address_token;
+  server_config_sig_ = state.server_config_sig;
+  certs_ = state.certs;
+  need_to_persist_ = false;
+}
+
+void QuicCryptoClientConfig::CachedState::SaveQuicServerInfo() {
+  if (!quic_server_info_.get() || !need_to_persist_) {
+    return;
+  }
+  DCHECK(server_config_valid_);
+
+  // If the QuicServerInfo hasn't managed to load from disk yet then we can't
+  // save anything.
+  if (!quic_server_info_->IsDataReady()) {
+    return;
+  }
+
+  QuicServerInfo::State* state = quic_server_info_->mutable_state();
+
+  state->server_config = server_config_;
+  state->source_address_token = source_address_token_;
+  state->server_config_sig = server_config_sig_;
+  state->certs = certs_;
+
+  quic_server_info_->Persist();
+  need_to_persist_ = false;
+}
+
 void QuicCryptoClientConfig::SetDefaults() {
   // Key exchange methods.
   kexs.resize(2);