#!/usr/bin/env python
# encoding: utf-8
# Thomas Nagy, 2005 (ita)
"""Environment representation
There is one gotcha: getitem returns [] if the contents evals to False
This means env['foo'] = {}; print env['foo'] will print [] not {}
"""
import os, copy, re
import Logs, Options, Utils
from Constants import *
re_imp = re.compile('^(#)*?([^#=]*?)\ =\ (.*?)$', re.M)
class Environment(object):
"""A safe-to-use dictionary, but do not attach functions to it please (break cPickle)
An environment instance can be stored into a file and loaded easily
"""
__slots__ = ("table", "parent")
def __init__(self, filename=None):
self.table = {}
#self.parent = None
if filename:
self.load(filename)
def __contains__(self, key):
if key in self.table: return True
try: return self.parent.__contains__(key)
except AttributeError: return False # parent may not exist
def __str__(self):
keys = set()
cur = self
while cur:
keys.update(cur.table.keys())
cur = getattr(cur, 'parent', None)
keys = list(keys)
keys.sort()
return "\n".join(["%r %r" % (x, self.__getitem__(x)) for x in keys])
def __getitem__(self, key):
try:
while 1:
x = self.table.get(key, None)
if not x is None:
return x
self = self.parent
except AttributeError:
return []
def __setitem__(self, key, value):
self.table[key] = value
def __delitem__(self, key):
del self.table[key]
def pop(self, key, *args):
if len(args):
return self.table.pop(key, *args)
return self.table.pop(key)
def set_variant(self, name):
self.table[VARIANT] = name
def variant(self):
try:
while 1:
x = self.table.get(VARIANT, None)
if not x is None:
return x
self = self.parent
except AttributeError:
return DEFAULT
def copy(self):
# TODO waf 1.6 rename this method derive, #368
newenv = Environment()
newenv.parent = self
return newenv
def detach(self):
"""TODO try it
modifying the original env will not change the copy"""
tbl = self.get_merged_dict()
try:
delattr(self, 'parent')
except AttributeError:
pass
else:
keys = tbl.keys()
for x in keys:
tbl[x] = copy.deepcopy(tbl[x])
self.table = tbl
def get_flat(self, key):
s = self[key]
if isinstance(s, str): return s
return ' '.join(s)
def _get_list_value_for_modification(self, key):
"""Gets a value that must be a list for further modification. The
list may be modified inplace and there is no need to
"self.table[var] = value" afterwards.
"""
try:
value = self.table[key]
except KeyError:
try: value = self.parent[key]
except AttributeError: value = []
if isinstance(value, list):
value = value[:]
else:
value = [value]
else:
if not isinstance(value, list):
value = [value]
self.table[key] = value
return value
def append_value(self, var, value):
current_value = self._get_list_value_for_modification(var)
if isinstance(value, list):
current_value.extend(value)
else:
current_value.append(value)
def prepend_value(self, var, value):
current_value = self._get_list_value_for_modification(var)
if isinstance(value, list):
current_value = value + current_value
# a new list: update the dictionary entry
self.table[var] = current_value
else:
current_value.insert(0, value)
# prepend unique would be ambiguous
def append_unique(self, var, value):
current_value = self._get_list_value_for_modification(var)
if isinstance(value, list):
for value_item in value:
if value_item not in current_value:
current_value.append(value_item)
else:
if value not in current_value:
current_value.append(value)
def get_merged_dict(self):
"""compute a merged table"""
table_list = []
env = self
while 1:
table_list.insert(0, env.table)
try: env = env.parent
except AttributeError: break
merged_table = {}
for table in table_list:
merged_table.update(table)
return merged_table
def store(self, filename):
"Write the variables into a file"
file = open(filename, 'w')
merged_table = self.get_merged_dict()
keys = list(merged_table.keys())
keys.sort()
for k in keys: file.write('%s = %r\n' % (k, merged_table[k]))
file.close()
def load(self, filename):
"Retrieve the variables from a file"
tbl = self.table
code = Utils.readf(filename)
for m in re_imp.finditer(code):
g = m.group
tbl[g(2)] = eval(g(3))
Logs.debug('env: %s', self.table)
def get_destdir(self):
"return the destdir, useful for installing"
if self.__getitem__('NOINSTALL'): return ''
return Options.options.destdir
def update(self, d):
for k, v in d.iteritems():
self[k] = v
def __getattr__(self, name):
if name in self.__slots__:
return object.__getattr__(self, name)
else:
return self[name]
def __setattr__(self, name, value):
if name in self.__slots__:
object.__setattr__(self, name, value)
else:
self[name] = value
def __delattr__(self, name):
if name in self.__slots__:
object.__delattr__(self, name)
else:
del self[name]
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