Improve time complexity of removal of callback handle.

source/common/common/callback_impl.h

@@ -24,6 +24,7 @@ template <typename... CallbackArgs> class CallbackManager {
  */
  CallbackHandle* add(Callback callback) {
  callbacks_.emplace_back(*this, callback);
+ callbacks_.back().it_ = (--callbacks_.end());
  return &callbacks_.back();
  }
 
@@ -46,24 +47,21 @@ template <typename... CallbackArgs> class CallbackManager {
  CallbackHolder(CallbackManager& parent, Callback cb) : parent_(parent), cb_(cb) {}
 
  // CallbackHandle
- void remove() override { parent_.remove(this); }
+ void remove() override { parent_.remove(it_); }
 
  CallbackManager& parent_;
  Callback cb_;
+
+ // the iterator of this callback holder inside callbacks_ list
+ // upon removal, use this iterator to delete callback holder in O(1)
+ typename std::list<CallbackHolder>::iterator it_;
  };
 
  /**
  * Remove a member update callback added via add().
  * @param handle supplies the callback handle to remove.
  */
- void remove(CallbackHandle* handle) {
- ASSERT(std::find_if(callbacks_.begin(), callbacks_.end(),
- [handle](const CallbackHolder& holder) -> bool {
- return handle == &holder;
- }) != callbacks_.end());
- callbacks_.remove_if(
- [handle](const CallbackHolder& holder) -> bool { return handle == &holder; });
- }
+ void remove(typename std::list<CallbackHolder>::iterator& it) { callbacks_.erase(it); }
 
  std::list<CallbackHolder> callbacks_;
 };

source/common/router/scoped_rds.cc

@@ -84,9 +84,7 @@ InlineScopedRoutesConfigProvider::InlineScopedRoutesConfigProvider(
  ConfigProvider::ApiType::Delta),
  name_(std::move(name)),
  config_(std::make_shared<ScopedConfigImpl>(std::move(scope_key_builder))),
- config_protos_(std::make_move_iterator(config_protos.begin()),
- std::make_move_iterator(config_protos.end())),
- rds_config_source_(std::move(rds_config_source)) {}
+ config_protos_(move(config_protos)), rds_config_source_(std::move(rds_config_source)) {}
 
 ScopedRdsConfigSubscription::ScopedRdsConfigSubscription(
  const envoy::extensions::filters::network::http_connection_manager::v3::ScopedRds& scoped_rds,

source/common/router/scoped_rds.h

@@ -54,6 +54,7 @@ class InlineScopedRoutesConfigProvider : public Envoy::Config::ImmutableConfigPr
  // Envoy::Config::ConfigProvider
  Envoy::Config::ConfigProvider::ConfigProtoVector getConfigProtos() const override {
  Envoy::Config::ConfigProvider::ConfigProtoVector out_protos;
+ out_protos.reserve(config_protos_.size());
  std::for_each(config_protos_.begin(), config_protos_.end(),
  [&out_protos](const std::unique_ptr<const Protobuf::Message>& message) {
  out_protos.push_back(message.get());

test/integration/stats_integration_test.cc

@@ -286,7 +286,7 @@ TEST_P(ClusterMemoryTestRunner, MemoryLargeClusterSizeWithFakeSymbolTable) {
  // If you encounter a failure here, please see
  // https://github.com/envoyproxy/envoy/blob/master/source/docs/stats.md#stats-memory-tests
  // for details on how to fix.
- EXPECT_MEMORY_EQ(m_per_cluster, 44491);
+ EXPECT_MEMORY_EQ(m_per_cluster, 44715);
  EXPECT_MEMORY_LE(m_per_cluster, 46000); // Round up to allow platform variations.
 }
 
@@ -349,7 +349,7 @@ TEST_P(ClusterMemoryTestRunner, MemoryLargeClusterSizeWithRealSymbolTable) {
  // If you encounter a failure here, please see
  // https://github.com/envoyproxy/envoy/blob/master/source/docs/stats.md#stats-memory-tests
  // for details on how to fix.
- EXPECT_MEMORY_EQ(m_per_cluster, 36603);
+ EXPECT_MEMORY_EQ(m_per_cluster, 36827);
  EXPECT_MEMORY_LE(m_per_cluster, 38000); // Round up to allow platform variations.
 }