XA Txn with Driver

# 模拟数据库驱动，提供 XA 的回调接口
class DatabaseDriver:
    def __init__(self, name):
        self.name = name

    def xa_prepare(self, transaction_id):
        print(f"{self.name}: Preparing transaction {transaction_id}")
        return "ready"

    def xa_commit(self, transaction_id):
        print(f"{self.name}: Committing transaction {transaction_id}")

    def xa_rollback(self, transaction_id):
        print(f"{self.name}: Rolling back transaction {transaction_id}")


# 模拟协调者
class Coordinator:
    def __init__(self):
        self.participants = []  # 记录所有参与者

    def add_participant(self, driver):
        self.participants.append(driver)

    def execute_transaction(self, transaction_id):
        # 第一阶段：准备阶段
        prepare_status = []
        for participant in self.participants:
            status = participant.xa_prepare(transaction_id)
            prepare_status.append(status)

        # 检查所有参与者是否准备就绪
        if all(status == "ready" for status in prepare_status):
            # 第二阶段：提交
            print(f"All participants ready. Committing transaction {transaction_id}.")
            for participant in self.participants:
                participant.xa_commit(transaction_id)
        else:
            # 回滚
            print(f"Some participants not ready. Rolling back transaction {transaction_id}.")
            for participant in self.participants:
                participant.xa_rollback(transaction_id)


# 模拟应用程序
class Application:
    def __init__(self, coordinator):
        self.coordinator = coordinator

    def run(self):
        transaction_id = "txn_123"
        print(f"Starting transaction {transaction_id}")
        self.coordinator.execute_transaction(transaction_id)


########################################################################################

# 模拟场景
driver1 = DatabaseDriver("Database1")
driver2 = DatabaseDriver("Database2")

coordinator = Coordinator()
coordinator.add_participant(driver1)
coordinator.add_participant(driver2)

app = Application(coordinator)
app.run()

########################################################################################
# Starting transaction txn_123
# Database1: Preparing transaction txn_123
# Database2: Preparing transaction txn_123
# All participants ready. Committing transaction txn_123.
# Database1: Committing transaction txn_123
# Database2: Committing transaction txn_123