##############################################################################
#
# Copyright (c) 2001 Zope Corporation and Contributors. All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################
__doc__='''Standard routines for handling extensions.
Extensions currently include external methods and pluggable brains.
$Id: Extensions.py,v 1.19 2002/08/14 21:31:40 mj Exp $'''
__version__='$Revision: 1.19 $'[11:-2]
import os, zlib, rotor, imp
import Products
path_split=os.path.split
path_join=os.path.join
exists=os.path.exists
class FuncCode:
def __init__(self, f, im=0):
self.co_varnames=f.func_code.co_varnames[im:]
self.co_argcount=f.func_code.co_argcount-im
def __cmp__(self,other):
if other is None: return 1
try: return cmp((self.co_argcount, self.co_varnames),
(other.co_argcount, other.co_varnames))
except: return 1
def _getPath(home, prefix, name, suffixes):
d=path_join(home, prefix)
if d==prefix: raise ValueError, (
'The prefix, %s, should be a relative path' % prefix)
d=path_join(d,name)
if d==name: raise ValueError, ( # Paranoia
'The file name, %s, should be a simple file name' % name)
for s in suffixes:
if s: s="%s.%s" % (d, s)
else: s=d
if exists(s): return s
def getPath(prefix, name, checkProduct=1, suffixes=('',)):
"""Find a file in one of several relative locations
Arguments:
prefix -- The location, relative to some home, to look for the
file
name -- The name of the file. This must not be a path.
checkProduct -- a flag indicating whether product directories
should be used as additional hope ares to be searched. This
defaults to a true value.
If this is true and the name contains a dot, then the
text before the dot is treated as a product name and
the product package directory is used as anothe rhome.
suffixes -- a sequences of file suffixes to check.
By default, the name is used without a suffix.
The search takes on multiple homes which are INSTANCE_HOME,
the directory containing the directory containing SOFTWARE_HOME, and
possibly product areas.
"""
d,n = path_split(name)
if d: raise ValueError, (
'The file name, %s, should be a simple file name' % name)
if checkProduct:
l = name.find('.')
if l > 0:
p = name[:l]
n = name[l + 1:]
for product_dir in Products.__path__:
r = _getPath(product_dir, os.path.join(p, prefix), n, suffixes)
if r is not None: return r
sw=path_split(path_split(SOFTWARE_HOME)[0])[0]
for home in (INSTANCE_HOME, sw):
r=_getPath(home, prefix, name, suffixes)
if r is not None: return r
def getObject(module, name, reload=0,
# The use of a mutable default is intentional here,
# because modules is a module cache.
modules={}
):
# The use of modules here is not thread safe, however, there is
# no real harm in a rece condition here. If two threads
# update the cache, then one will have simply worked a little
# harder than need be. So, in this case, we won't incur
# the expense of a lock.
if modules.has_key(module):
old=modules[module]
if old.has_key(name) and not reload: return old[name]
else:
old=None
if module[-3:]=='.py': p=module[:-3]
elif module[-4:]=='.pyp': p=module[:-4]
elif module[-4:]=='.pyc': p=module[:-4]
else: p=module
p=getPath('Extensions', p, suffixes=('','py','pyp','pyc'))
if p is None:
raise "Module Error", (
"The specified module, <em>%s</em>, couldn't be found." % module)
__traceback_info__=p, module
if p[-4:]=='.pyc':
file = open(p, 'rb')
binmod=imp.load_compiled('Extension', p, file)
file.close()
m=binmod.__dict__
elif p[-4:]=='.pyp':
prod_id=module.split('.')[0]
data=zlib.decompress(
rotor.newrotor(prod_id +' shshsh').decrypt(open(p,'rb').read())
)
execsrc=compile(data, module, 'exec')
m={}
exec execsrc in m
else:
try: execsrc=open(p)
except: raise "Module Error", (
"The specified module, <em>%s</em>, couldn't be opened."
% module)
m={}
exec execsrc in m
try: r=m[name]
except KeyError:
raise 'Invalid Object Name', (
"The specified object, <em>%s</em>, was not found in module, "
"<em>%s</em>." % (name, module))
if old:
for k, v in m.items(): old[k]=v
modules[module]=m
return r
class NoBrains: pass
def getBrain(module, class_name, reload=0):
'Check/load a class'
if not module and not class_name: return NoBrains
try: c=getObject(module, class_name, reload)
except KeyError, v:
if v == class_name: raise ValueError, (
'The class, %s, is not defined in file, %s' % (class_name, module))
if not hasattr(c,'__bases__'): raise ValueError, (
'%s, is not a class' % class_name)
return c
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