Current File : //usr/share/rhn/up2date_client/getMethod.py
# Retrieve action method name given queued action information.
#
# Client code for Update Agent
# Copyright (c) 1999--2012 Red Hat, Inc. Distributed under GPLv2.
#
# An allowable xmlrpc method is retrieved given a base location, a
# hierarchical route to the class/module, and method name.
#
# $Id$
import os
import string
import sys
from types import ClassType
class GetMethodException(Exception):
"""Exception class"""
pass
def sanity(methodNameComps):
#"""
# Verifies if all the components have proper names
#"""
# Allowed characters in each string
alpha = string.ascii_lowercase + string.ascii_uppercase
allowedChars = alpha + string.digits + '_'
for comp in methodNameComps:
if not len(comp):
raise GetMethodException("Empty method component")
for c in comp:
if c not in allowedChars:
raise GetMethodException(
"Invalid character '%s' in the method name" % c)
# Can only begin with a letter
if comp[0] not in alpha:
raise GetMethodException(
"Method names should start with an alphabetic character")
def getMethod(methodName, abspath, baseClass):
#"""
#Retreive method given methodName, path to base of tree, and class/module
#route/label.
#"""
# First split the method name
methodNameComps = string.split(baseClass, '.') + string.split(methodName, '.')
# Sanity checks
sanity(methodNameComps)
# Build the path to the file
path = abspath
for index in range(len(methodNameComps)):
comp = methodNameComps[index]
path = "%s/%s" % (path, comp)
# If this is a directory, fine...
if os.path.isdir(path):
# Okay, go on
continue
# Try to load this as a file
for extension in ['py', 'pyc', 'pyo']:
if os.path.isfile("%s.%s" % (path, extension)):
# Yes, this is a file
break
else:
# No dir and no file. Die
raise GetMethodException("Action %s could not be found" % methodName)
break
else:
# Only directories. This can't happen
raise GetMethodException("Very wrong")
# The position of the file
fIndex = index + 1
# Now build the module name
modulename = string.join(methodNameComps[:fIndex], '.')
# And try to import it
try:
actions = __import__(modulename)
except ImportError:
raise GetMethodException("Could not import module %s" % modulename), None, sys.exc_info()[2]
className = actions
# Iterate through the list of components and try to load that specific
# module/method
for index in range(1, len(methodNameComps)):
comp = methodNameComps[index]
if index < fIndex:
# This is a directory or a file we have to load
if not hasattr(className, comp):
# Hmmm... Not there
raise GetMethodException("Class %s has no attribute %s" % (
string.join(methodNameComps[:index], '.'), comp))
className = getattr(className, comp)
#print type(className)
continue
# A file or method
# We look for the special __rhnexport__ array
if not hasattr(className, '__rhnexport__'):
raise GetMethodException("Class %s is not RHN-compliant" % \
string.join(methodNameComps[:index], '.'))
export = getattr(className, '__rhnexport__')
if comp not in export:
raise GetMethodException("Class %s does not export '%s'" % (
string.join(methodNameComps[:index], '.'), comp))
className = getattr(className, comp)
if type(className) is ClassType:
# Try to instantiate it
className = className()
#print type(className)
return className
#-----------------------------------------------------------------------------
if __name__ == '__main__':
# Two valid ones and a bogus one
methods = [
'a.b.c.d.e.f',
'a.b.c.d.e.foo.h',
'a.b.c.d.e.g.h',
'a.b.d.d.e.g.h',
'a.b.d.d._e.g.h',
'a.b.d.d.e_.g.h',
'a.b.d.d.e-.g.h',
'a.b.d.d..g.h',
]
for m in methods:
print "----Running method %s: " % m
try:
method = getMethod(m, '.', 'Actions')
except GetMethodException, e:
print "Error getting the method %s: %s" % (m,
string.join(map(str, e.args)))
else:
method()
#-----------------------------------------------------------------------------
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