dynamic_config::Source Class Reference

A client for easy dynamic config fetching in components. More...

#include <userver/dynamic_config/source.hpp>

Public Types
using	EventSource = concurrent::AsyncEventSource< const Snapshot & >

Public Member Functions
	Source (impl::StorageData &storage)
	Source (const Source &)=default
Source &	operator= (const Source &)=default
Snapshot	GetSnapshot () const
template<typename Key >
VariableSnapshotPtr< Key >	GetSnapshot (Key key) const
template<typename Key >
VariableOfKey< Key >	GetCopy (Key key) const
template<typename Class >
concurrent::AsyncEventSubscriberScope	UpdateAndListen (Class *obj, std::string_view name, void(Class::*func)(const dynamic_config::Snapshot &config))
EventSource &	GetEventChannel ()

Detailed Description

A client for easy dynamic config fetching in components.

After construction, dynamic_config::Source can be copied around and passed to clients or child helper classes.

Usually retrieved from components::DynamicConfig component.

Typical usage:

namespace myservice::smth {
 
namespace {
int ParseRuntimeCfg(const dynamic_config::DocsMap& docs_map) {
  return docs_map.Get("SAMPLE_INTEGER_FROM_RUNTIME_CONFIG").As<int>();
}
constexpr dynamic_config::Key<ParseRuntimeCfg> kMyConfig{};
}  // namespace
 
int Component::DoSomething() const {
  // Getting a snapshot of dynamic config.
  const auto runtime_config = config_.GetSnapshot();
  return runtime_config[kMyConfig];
}
 
}  // namespace myservice::smth

Examples

components/component_sample_test.hpp.

Definition at line 64 of file source.hpp.

Member Typedef Documentation

EventSource

using dynamic_config::Source::EventSource = concurrent::AsyncEventSource<const Snapshot&>

Definition at line 66 of file source.hpp.

Constructor & Destructor Documentation

Source()

dynamic_config::Source::Source ( impl::StorageData &  storage )

explicit

For internal use only. Obtain using components::DynamicConfig or dynamic_config::StorageMock instead.

Member Function Documentation

GetCopy()

template<typename Key >

VariableOfKey< Key > dynamic_config::Source::GetCopy ( Key  key ) const

inline

Definition at line 84 of file source.hpp.

GetSnapshot()

template<typename Key >

VariableSnapshotPtr< Key > dynamic_config::Source::GetSnapshot ( Key  key ) const

inline

Definition at line 79 of file source.hpp.

UpdateAndListen()

template<typename Class >

concurrent::AsyncEventSubscriberScope dynamic_config::Source::UpdateAndListen ( Class *  obj, std::string_view  name, void(Class::*)(const dynamic_config::Snapshot &config)  func  )

inline

Subscribes to dynamic-config updates using a member function, named OnConfigUpdate by convention. Also immediately invokes the function with the current config snapshot.

Definition at line 93 of file source.hpp.

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The documentation for this class was generated from the following file:

• userver/dynamic_config/source.hpp