state.hpp

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#pragma once
 
/// @file userver/components/state.hpp
/// @brief @copybrief components::State
 
#include <string>
#include <string_view>
#include <unordered_set>
 
USERVER_NAMESPACE_BEGIN
 
namespace components {
 
class ComponentContext;
 
namespace impl {
class ComponentContextImpl;
}
 
/// State of components that is usable after the components constructor and
/// until all the components were not destroyed.
///
/// @see components::ComponentContext
class State final {
public:
    explicit State(const ComponentContext& cc) noexcept;
 
    /// @returns true if one of the components is in fatal state and can not
    /// work. A component is in fatal state if the
    /// components::ComponentHealth::kFatal value is returned from the overridden
    /// components::ComponentBase::GetComponentHealth().
    bool IsAnyComponentInFatalState() const;
 
    /// @returns true if component with name `component_name` depends
    /// (directly or transitively) on a component with name `dependency`.
    ///
    /// Component with name `component_name` should be loaded.
    /// Components construction should finish before any call to this function
    /// is made.
    ///
    /// Note that GetAllDependencies usually is more effective, if you are
    /// planning multiple calls for the same component name.
    bool HasDependencyOn(std::string_view component_name, std::string_view dependency) const;
 
    /// @returns all the components that `component_name` depends on directly or
    /// transitively.
    ///
    /// Component with name `component_name` should be loaded.
    /// Components construction should finish before any call to this function
    /// is made. The result should now outlive the all the components
    /// destruction.
    std::unordered_set<std::string_view> GetAllDependencies(std::string_view component_name) const;
 
private:
    const impl::ComponentContextImpl& impl_;
};
 
}  // namespace components
 
USERVER_NAMESPACE_END