ceph/src/pybind/mgr/dashboard/controllers/_task.py

   1 from functools import wraps
   2
   3 import cherrypy
   4
   5 from ..tools import TaskManager
   6 from ._helpers import _get_function_params
   7
   8
   9 class Task:
  10     def __init__(self, name, metadata, wait_for=5.0, exception_handler=None):
  11         self.name = name
  12         if isinstance(metadata, list):
  13             self.metadata = {e[1:-1]: e for e in metadata}
  14         else:
  15             self.metadata = metadata
  16         self.wait_for = wait_for
  17         self.exception_handler = exception_handler
  18
  19     def _gen_arg_map(self, func, args, kwargs):
  20         arg_map = {}
  21         params = _get_function_params(func)
  22
  23         args = args[1:]  # exclude self
  24         for idx, param in enumerate(params):
  25             if idx < len(args):
  26                 arg_map[param['name']] = args[idx]
  27             else:
  28                 if param['name'] in kwargs:
  29                     arg_map[param['name']] = kwargs[param['name']]
  30                 else:
  31                     assert not param['required'], "{0} is required".format(param['name'])
  32                     arg_map[param['name']] = param['default']
  33
  34             if param['name'] in arg_map:
  35                 # This is not a type error. We are using the index here.
  36                 arg_map[idx+1] = arg_map[param['name']]
  37
  38         return arg_map
  39
  40     def __call__(self, func):
  41         @wraps(func)
  42         def wrapper(*args, **kwargs):
  43             arg_map = self._gen_arg_map(func, args, kwargs)
  44             metadata = {}
  45             for k, v in self.metadata.items():
  46                 if isinstance(v, str) and v and v[0] == '{' and v[-1] == '}':
  47                     param = v[1:-1]
  48                     try:
  49                         pos = int(param)
  50                         metadata[k] = arg_map[pos]
  51                     except ValueError:
  52                         if param.find('.') == -1:
  53                             metadata[k] = arg_map[param]
  54                         else:
  55                             path = param.split('.')
  56                             metadata[k] = arg_map[path[0]]
  57                             for i in range(1, len(path)):
  58                                 metadata[k] = metadata[k][path[i]]
  59                 else:
  60                     metadata[k] = v
  61             task = TaskManager.run(self.name, metadata, func, args, kwargs,
  62                                    exception_handler=self.exception_handler)
  63             try:
  64                 status, value = task.wait(self.wait_for)
  65             except Exception as ex:
  66                 if task.ret_value:
  67                     # exception was handled by task.exception_handler
  68                     if 'status' in task.ret_value:
  69                         status = task.ret_value['status']
  70                     else:
  71                         status = getattr(ex, 'status', 500)
  72                     cherrypy.response.status = status
  73                     return task.ret_value
  74                 raise ex
  75             if status == TaskManager.VALUE_EXECUTING:
  76                 cherrypy.response.status = 202
  77                 return {'name': self.name, 'metadata': metadata}
  78             return value
  79         return wrapper