gem5/python/m5/smartdict.py
Nathan Binkert 40bab977bc Better handling of latency/frequency parameter types
python/m5/config.py:
    Addr is slightly different from memory size in that Addr
    will take non strings.
    Deal with the fact that the convert.toFoo functions only accept
    strings.
    Add RootFrequency as a special type for the Root.frequency
    parameter which is not scaled.
    Add ClockPeriod parameter type.
python/m5/convert.py:
    Be more strict about what's allowed.
    Only accept strings as inputs for these conversion functions.
    If the user wants to accept something else, they need to deal
    with the failure and convert other types on their own.
python/m5/objects/Bus.mpy:
    Use the new ClockPeriod parameter type
python/m5/objects/Root.mpy:
    Can't use integers for frequency anymore
python/m5/smartdict.py:
    rename SmartDict.Proxy to just Variable.  Create a new class
    UndefinedVariable that is returned when the user tries to get
    a variable that is not in the dict.  Undefined variable evaluates
    to false, and will cause an error elsewhere.

--HG--
extra : convert_revision : 1d55246fd1af65106f102396234827d6401ef9ce
2005-03-25 22:59:29 -05:00

126 lines
4.3 KiB
Python

# The SmartDict class fixes a couple of issues with using the content
# of os.environ or similar dicts of strings as Python variables:
#
# 1) Undefined variables should return False rather than raising KeyError.
#
# 2) String values of 'False', '0', etc., should evaluate to False
# (not just the empty string).
#
# #1 is solved by overriding __getitem__, and #2 is solved by using a
# proxy class for values and overriding __nonzero__ on the proxy.
# Everything else is just to (a) make proxies behave like normal
# values otherwise, (b) make sure any dict operation returns a proxy
# rather than a normal value, and (c) coerce values written to the
# dict to be strings.
from convert import *
class Variable(str):
"""Intelligent proxy class for SmartDict. Variable will use the
various convert functions to attempt to convert values to useable
types"""
def __int__(self):
return toInteger(str(self))
def __long__(self):
return toLong(str(self))
def __float__(self):
return toFloat(str(self))
def __nonzero__(self):
return toBool(str(self))
def convert(self, other):
t = type(other)
if t == bool:
return bool(self)
if t == int:
return int(self)
if t == long:
return long(self)
if t == float:
return float(self)
return str(self)
def __lt__(self, other):
return self.convert(other) < other
def __le__(self, other):
return self.convert(other) <= other
def __eq__(self, other):
return self.convert(other) == other
def __ne__(self, other):
return self.convert(other) != other
def __gt__(self, other):
return self.convert(other) > other
def __ge__(self, other):
return self.convert(other) >= other
def __add__(self, other):
return self.convert(other) + other
def __sub__(self, other):
return self.convert(other) - other
def __mul__(self, other):
return self.convert(other) * other
def __div__(self, other):
return self.convert(other) / other
def __truediv__(self, other):
return self.convert(other) / other
def __radd__(self, other):
return other + self.convert(other)
def __rsub__(self, other):
return other - self.convert(other)
def __rmul__(self, other):
return other * self.convert(other)
def __rdiv__(self, other):
return other / self.convert(other)
def __rtruediv__(self, other):
return other / self.convert(other)
class UndefinedVariable(object):
"""Placeholder class to represent undefined variables. Will
generally cause an exception whenever it is used, but evaluates to
zero for boolean truth testing such as in an if statement"""
def __nonzero__(self):
return False
class SmartDict(dict):
"""Dictionary class that holds strings, but intelligently converts
those strings to other types depending on their usage"""
def __getitem__(self, key):
"""returns a Variable proxy if the values exists in the database and
returns an UndefinedVariable otherwise"""
if key in self:
return Variable(dict.get(self, key))
else:
# Note that this does *not* change the contents of the dict,
# so that even after we call env['foo'] we still get a
# meaningful answer from "'foo' in env" (which
# calls dict.__contains__, which we do not override).
return UndefinedVariable()
def __setitem__(self, key, item):
"""intercept the setting of any variable so that we always
store strings in the dict"""
dict.__setitem__(self, key, str(item))
def values(self):
return [ Variable(v) for v in dict.values(self) ]
def itervalues(self):
for value in dict.itervalues(self):
yield Variable(value)
def items(self):
return [ (k, Variable(v)) for k,v in dict.items(self) ]
def iteritems(self):
for key,value in dict.iteritems(self):
yield key, Variable(value)
def get(self, key, default='False'):
return Variable(dict.get(self, key, str(default)))
def setdefault(self, key, default='False'):
return Variable(dict.setdefault(self, key, str(default)))
__all__ = [ 'SmartDict' ]