面向对象 suite

Python 的面向对象设计特性允许我们在设计和构建 suite definition 时考虑灵活性。 设计每个 suite 有不同的准则。让我们考虑如何以一种更面向对象的方式设计本教程的例子。我们以一些设计准则开始。

  • 默认变量（例如 ECF_HOME 等）必须设置，并与 suite 独立
  • 新的 suite 必须开启自动检测 job 生成。
  • 需要将 definition 保存到单独的文件。
  • 新的 suite 应该能够复用为上面要求而设计的代码

下面是一种可行的设计，使用单例模式和模板模式。

  1. import os
  2. import ecflow  
  4. class DefaultVariables(object):
  5.     """Provide the setup variables for each suite"""
  6.     def add_to(self, node):
  7.         """Adds ECF_INCLUDE,ECF_HOME to the input node"""
  8.         node.add_variable("ECF_INCLUDE", os.path.join(os.getenv("HOME"),  "course"))
  9.         node.add_variable("ECF_HOME", os.path.join(os.getenv("HOME"),  "course"))
  12. class BaseSuiteBuilder(object):
  13.     """Abstract class. Add default variables to suite and enable job creation 
  14.  checking for any derived suite
  15.  """
  16.     def __init__(self, default_variables):
  17.         self.defs = ecflow.Defs()
  18.         # use derived class name as suite name
  19.         self.suite = self.defs.add_suite(type(self).__name__) 
  20.         default_variables.add_to(self.suite)
  22.     def _build_definition_hook(self):
  23.         """Derived suite should override this function to build the suite
  24.  Should not be called explicitly. How could we enforce this ?
  25.  """
  26.         pass
  28.     def setup(self):
  29.         """Template/skeleton function. 
  30.  Provides common algorithm for *all* derivatives
  31.  Uses Hollywood principle.
  32.  """
  34.         # Build the suite
  35.         self._build_definition_hook()
  37.         # check job creation. Could use an assert
  38.         job_check_result = self.defs.check_job_creation()
  39.         if len(job_check_result) != 0:
  40.             print "Job creation failed\n" + job_check_result
  42.         # Check trigger expressions and limit references"
  43.         print self.defs.check()
  45.         # Allows definition creation to be separated from the load
  46.         # Use the class name as the name of the definition file
  47.         self.defs.save_as_defs( type(self).__name__ + ".def")
  50. class SuiteBuilder(BaseSuiteBuilder):
  51.     """My example suite. Generates SuiteBuilder.def"""
  52.     def __init__(self, default_variables):
  53.         BaseSuiteBuilder.__init__(self, default_variables)
  55.     def _build_definition_hook(self):
  56.         f1 = self.suite.add_family("family")
  57.         f1.add_task("task1")           
  58.         f1.add_task("task2") 
  61. class TestSuite(BaseSuiteBuilder):
  62.     """My test suite. Generates TestSuite.def"""
  63.     def __init__(self, default_variables):
  64.         BaseSuiteBuilder.__init__(self, default_variables)
  66.     def _build_definition_hook(self):
  67.         self.suite.add_task("task1")
  70. if __name__ == "__main__":
  72.     my_suite = SuiteBuilder(DefaultVariables())
  73.     my_suite.setup()
  75.     my_test_suite = TestSuite(DefaultVariables())
  76.     my_test_suite.setup()