Builder for Saga pattern transactions. More...

#include <async_operations.h>

Collaboration diagram for database::async::saga_builder:

Classes
struct	saga_step

Public Member Functions
	saga_builder (transaction_coordinator &coordinator)

template<concepts::TransactionAction Action, concepts::CompensationAction Compensation>
saga_builder &	add_step (Action &&action, Compensation &&compensation)

saga_builder &	add_step (std::function< async_result< bool >()> action, std::function< async_result< bool >()> compensation)

async_result< bool >	execute ()

Private Attributes
transaction_coordinator &	coordinator_

std::vector< saga_step >	steps_

Detailed Description

Builder for Saga pattern transactions.

Definition at line 707 of file async_operations.h.

Constructor & Destructor Documentation

◆ saga_builder()

database::async::saga_builder::saga_builder ( transaction_coordinator & coordinator )

inline

Examples: /home/runner/work/database_system/database_system/database/async/async_operations.h.

Definition at line 1084 of file async_operations.h.

        : coordinator_(coordinator)
    {
    }

Member Function Documentation

◆ add_step() [1/2]

template<concepts::TransactionAction Action, concepts::CompensationAction Compensation>

saga_builder & database::async::saga_builder::add_step	(	Action &&	action,
		Compensation &&	compensation )

Examples: /home/runner/work/database_system/database_system/database/async/async_operations.h.

Definition at line 1099 of file async_operations.h.

    {
        steps_.push_back({
            std::function<async_result<bool>()>(std::forward<Action>(action)),
            std::function<async_result<bool>()>(std::forward<Compensation>(compensation))
        });
        return *this;
    }

References steps_.

◆ add_step() [2/2]

saga_builder & database::async::saga_builder::add_step	(	std::function< async_result< bool >()>	action,
		std::function< async_result< bool >()>	compensation )

inline

Definition at line 1089 of file async_operations.h.

    {
        steps_.push_back({std::move(action), std::move(compensation)});
        return *this;
    }

References steps_.

◆ execute()

async_result< bool > database::async::saga_builder::execute ( )

inline

Examples: /home/runner/work/database_system/database_system/database/async/async_operations.h.

Definition at line 1109 of file async_operations.h.

    {
        std::vector<size_t> completed;
 
        for (size_t i = 0; i < steps_.size(); ++i) {
            try {
                bool success = steps_[i].action().get();
                if (!success) {
                    for (auto it = completed.rbegin();
                         it != completed.rend(); ++it) {
                        try { steps_[*it].compensation().get(); }
                        catch (...) {}
                    }
                    return make_ready_result(false);
                }
                completed.push_back(i);
            } catch (...) {
                for (auto it = completed.rbegin();
                     it != completed.rend(); ++it) {
                    try { steps_[*it].compensation().get(); }
                    catch (...) {}
                }
                return make_ready_result(false);
            }
        }
 
        return make_ready_result(true);
    }