test_ok2/py/_com.py

143 lines
4.5 KiB
Python

"""
py lib plugins and plugin call management
"""
import py
class MultiCall:
""" Manage a specific call into many python functions/methods.
Simple example:
MultiCall([list1.append, list2.append], 42).execute()
"""
NONEASRESULT = object()
def __init__(self, methods, *args, **kwargs):
self.methods = methods[:]
self.args = args
self.kwargs = kwargs
self.results = []
def execute(self, firstresult=False):
while self.methods:
currentmethod = self.methods.pop()
res = self.execute_method(currentmethod)
if hasattr(self, '_ex1'):
self.results = [res]
break
if res is not None:
if res is self.NONEASRESULT:
res = None
self.results.append(res)
if firstresult:
break
if not firstresult:
return self.results
if self.results:
return self.results[-1]
def execute_method(self, currentmethod):
self.currentmethod = currentmethod
# provide call introspection if "__call__" is the first positional argument
if hasattr(currentmethod, 'im_self'):
varnames = currentmethod.im_func.func_code.co_varnames
needscall = varnames[1:2] == ('__call__',)
else:
try:
varnames = currentmethod.func_code.co_varnames
except AttributeError:
# builtin function
varnames = ()
needscall = varnames[:1] == ('__call__',)
if needscall:
return currentmethod(self, *self.args, **self.kwargs)
else:
#try:
return currentmethod(*self.args, **self.kwargs)
#except TypeError:
# print currentmethod.__module__, currentmethod.__name__, self.args, self.kwargs
# raise
def exclude_other_results(self):
self._ex1 = True
class Registry:
"""
Manage Plugins: Load plugins and manage calls to plugins.
"""
MultiCall = MultiCall
def __init__(self, plugins=None):
if plugins is None:
plugins = []
self._plugins = plugins
def register(self, plugin):
assert not isinstance(plugin, str)
self._plugins.append(plugin)
def unregister(self, plugin):
self._plugins.remove(plugin)
def isregistered(self, plugin):
return plugin in self._plugins
def __iter__(self):
return iter(self._plugins)
def listattr(self, attrname, plugins=None, extra=(), reverse=False):
l = []
if plugins is None:
plugins = self._plugins
for plugin in list(plugins) + list(extra):
try:
l.append(getattr(plugin, attrname))
except AttributeError:
continue
if reverse:
l.reverse()
return l
def call_firstresult(self, methname, *args, **kwargs):
""" return first non-None result of a plugin method. """
return MultiCall(self.listattr(methname), *args, **kwargs).execute(firstresult=True)
def call_plugin(self, plugin, methname, *args, **kwargs):
return MultiCall(self.listattr(methname, plugins=[plugin]),
*args, **kwargs).execute(firstresult=True)
class PluginAPI:
def __init__(self, apiclass, registry=None):
self._apiclass = apiclass
if registry is None:
registry = comregistry
self.registry = registry
for name, method in vars(apiclass).items():
if name[:2] != "__":
firstresult = getattr(method, 'firstresult', False)
mm = ApiCall(registry, name, firstresult=firstresult)
setattr(self, name, mm)
def __repr__(self):
return "<PluginAPI %r %r>" %(self._apiclass, self._plugins)
class ApiCall:
def __init__(self, registry, name, firstresult):
self.registry = registry
self.name = name
self.firstresult = firstresult
def __repr__(self):
mode = self.firstresult and "firstresult" or "each"
return "<ApiCall %r mode=%s %s>" %(self.name, mode, self.registry)
def __call__(self, *args, **kwargs):
if args:
raise TypeError("only keyword arguments allowed "
"for api call to %r" % self.name)
mc = MultiCall(self.registry.listattr(self.name), **kwargs)
return mc.execute(firstresult=self.firstresult)
comregistry = Registry()