QUIC - Allow cronet apps to specify how many server configs are to be

net/http/http_server_properties_impl.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/http/http_server_properties_impl.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 15 matching lines @@
 const uint64_t kBrokenAlternativeProtocolDelaySecs = 300;
 
 }  // namespace
 
 HttpServerPropertiesImpl::HttpServerPropertiesImpl()
     : spdy_servers_map_(SpdyServerHostPortMap::NO_AUTO_EVICT),
       alternative_service_map_(AlternativeServiceMap::NO_AUTO_EVICT),
       spdy_settings_map_(SpdySettingsMap::NO_AUTO_EVICT),
       server_network_stats_map_(ServerNetworkStatsMap::NO_AUTO_EVICT),
       alternative_service_probability_threshold_(1.0),
-      quic_server_info_map_(kMaxQuicServersToPersist),
+      quic_server_info_map_(QuicServerInfoMap::NO_AUTO_EVICT),
+      max_server_configs_stored_in_properties_(kMaxQuicServersToPersist),
       weak_ptr_factory_(this) {
   canonical_suffixes_.push_back(".c.youtube.com");
   canonical_suffixes_.push_back(".googlevideo.com");
   canonical_suffixes_.push_back(".googleusercontent.com");
 }
 
 HttpServerPropertiesImpl::~HttpServerPropertiesImpl() {
 }
 
 void HttpServerPropertiesImpl::InitializeSpdyServers(
@@ skipping 130 matching lines @@
     if (server_network_stats_map_.Get(it->first) ==
         server_network_stats_map_.end()) {
       server_network_stats_map_.Put(it->first, it->second);
     }
   }
 }
 
 void HttpServerPropertiesImpl::InitializeQuicServerInfoMap(
     QuicServerInfoMap* quic_server_info_map) {
   // Add the entries from persisted data.
-  QuicServerInfoMap temp_map(kMaxQuicServersToPersist);
+  QuicServerInfoMap temp_map(QuicServerInfoMap::NO_AUTO_EVICT);
   for (QuicServerInfoMap::reverse_iterator it = quic_server_info_map->rbegin();
        it != quic_server_info_map->rend(); ++it) {
     temp_map.Put(it->first, it->second);
   }
 
   quic_server_info_map_.Swap(temp_map);
 
   // Add the entries from the memory cache.
   for (QuicServerInfoMap::reverse_iterator it = temp_map.rbegin();
        it != temp_map.rend(); ++it) {
@@ skipping 471 matching lines @@
   if (it == quic_server_info_map_.end())
     return nullptr;
   return &it->second;
 }
 
 const QuicServerInfoMap& HttpServerPropertiesImpl::quic_server_info_map()
     const {
   return quic_server_info_map_;
 }
 
+int HttpServerPropertiesImpl::max_server_configs_stored_in_properties() const {
+  return max_server_configs_stored_in_properties_;
+}
+
+void HttpServerPropertiesImpl::set_max_server_configs_stored_in_properties(

[mef, 2016/01/15 16:12:32]

Should this be SetMaxServerConfigsStoredInProperties given that it is not just a
setter, but has a considerable side effect?

[ramant (doing other things), 2016/01/15 18:57:01]

Good point.

Done.

+    int max_server_configs_stored_in_properties) {
+  max_server_configs_stored_in_properties_ =
+      max_server_configs_stored_in_properties;
+
+  // MRUCache doesn't allow the size of the cache to be changed. Thus create a
+  // new map with the new size and add current elements and swap the new map.
+  QuicServerInfoMap temp_map(max_server_configs_stored_in_properties_);
+  for (QuicServerInfoMap::reverse_iterator it = quic_server_info_map_.rbegin();

[mef, 2016/01/15 16:12:32]

Microoptimization: quic_server_info_map_.ShrinkToSize first, and than copy
everything into new map. This will avoid copy-and-delete of entries that don't
fit into new map.

[ramant (doing other things), 2016/01/15 18:57:01]

+1. Thanks for the above optimization.

Done.

+       it != quic_server_info_map_.rend(); ++it) {
+    temp_map.Put(it->first, it->second);
+  }
+
+  quic_server_info_map_.Swap(temp_map);
+}
+
 void HttpServerPropertiesImpl::SetAlternativeServiceProbabilityThreshold(
     double threshold) {
   alternative_service_probability_threshold_ = threshold;
 }
 
 AlternativeServiceMap::const_iterator
 HttpServerPropertiesImpl::GetAlternateProtocolIterator(
     const HostPortPair& server) {
   AlternativeServiceMap::const_iterator it =
       alternative_service_map_.Get(server);
@@ skipping 107 matching lines @@
   base::TimeDelta delay = when > now ? when - now : base::TimeDelta();
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE,
       base::Bind(
           &HttpServerPropertiesImpl::ExpireBrokenAlternateProtocolMappings,
           weak_ptr_factory_.GetWeakPtr()),
       delay);
 }
 
 }  // namespace net