# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
# Spack Project Developers. See the top-level COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)
from __future__ import division
import os
import re
import functools
import collections
import inspect
from datetime import datetime, timedelta
from six import string_types
import sys
# Ignore emacs backups when listing modules
ignore_modules = [r'^\.#', '~$']
class classproperty(property):
"""classproperty decorator: like property but for classmethods."""
def __get__(self, cls, owner):
return self.fget.__get__(None, owner)()
def index_by(objects, *funcs):
"""Create a hierarchy of dictionaries by splitting the supplied
set of objects on unique values of the supplied functions.
Values are used as keys. For example, suppose you have four
objects with attributes that look like this::
a = Spec(name="boost", compiler="gcc", arch="bgqos_0")
b = Spec(name="mrnet", compiler="intel", arch="chaos_5_x86_64_ib")
c = Spec(name="libelf", compiler="xlc", arch="bgqos_0")
d = Spec(name="libdwarf", compiler="intel", arch="chaos_5_x86_64_ib")
list_of_specs = [a,b,c,d]
index1 = index_by(list_of_specs, lambda s: s.arch,
lambda s: s.compiler)
index2 = index_by(list_of_specs, lambda s: s.compiler)
``index1`` now has two levels of dicts, with lists at the
leaves, like this::
{ 'bgqos_0' : { 'gcc' : [a], 'xlc' : [c] },
'chaos_5_x86_64_ib' : { 'intel' : [b, d] }
}
And ``index2`` is a single level dictionary of lists that looks
like this::
{ 'gcc' : [a],
'intel' : [b,d],
'xlc' : [c]
}
If any elemnts in funcs is a string, it is treated as the name
of an attribute, and acts like getattr(object, name). So
shorthand for the above two indexes would be::
index1 = index_by(list_of_specs, 'arch', 'compiler')
index2 = index_by(list_of_specs, 'compiler')
You can also index by tuples by passing tuples::
index1 = index_by(list_of_specs, ('arch', 'compiler'))
Keys in the resulting dict will look like ('gcc', 'bgqos_0').
"""
if not funcs:
return objects
f = funcs[0]
if isinstance(f, str):
f = lambda x: getattr(x, funcs[0])
elif isinstance(f, tuple):
f = lambda x: tuple(getattr(x, p) for p in funcs[0])
result = {}
for o in objects:
key = f(o)
result.setdefault(key, []).append(o)
for key, objects in result.items():
result[key] = index_by(objects, *funcs[1:])
return result
def caller_locals():
"""This will return the locals of the *parent* of the caller.
This allows a function to insert variables into its caller's
scope. Yes, this is some black magic, and yes it's useful
for implementing things like depends_on and provides.
"""
# Passing zero here skips line context for speed.
stack = inspect.stack(0)
try:
return stack[2][0].f_locals
finally:
del stack
def get_calling_module_name():
"""Make sure that the caller is a class definition, and return the
enclosing module's name.
"""
# Passing zero here skips line context for speed.
stack = inspect.stack(0)
try:
# Make sure locals contain __module__
caller_locals = stack[2][0].f_locals
finally:
del stack
if '__module__' not in caller_locals:
raise RuntimeError("Must invoke get_calling_module_name() "
"from inside a class definition!")
module_name = caller_locals['__module__']
base_name = module_name.split('.')[-1]
return base_name
def attr_required(obj, attr_name):
"""Ensure that a class has a required attribute."""
if not hasattr(obj, attr_name):
raise RequiredAttributeError(
"No required attribute '%s' in class '%s'"
% (attr_name, obj.__class__.__name__))
def attr_setdefault(obj, name, value):
"""Like dict.setdefault, but for objects."""
if not hasattr(obj, name):
setattr(obj, name, value)
return getattr(obj, name)
def has_method(cls, name):
for base in inspect.getmro(cls):
if base is object:
continue
if name in base.__dict__:
return True
return False
def union_dicts(*dicts):
"""Use update() to combine all dicts into one.
This builds a new dictionary, into which we ``update()`` each element
of ``dicts`` in order. Items from later dictionaries will override
items from earlier dictionaries.
Args:
dicts (list): list of dictionaries
Return: (dict): a merged dictionary containing combined keys and
values from ``dicts``.
"""
result = {}
for d in dicts:
result.update(d)
return result
def memoized(func):
"""Decorator that caches the results of a function, storing them in
an attribute of that function.
"""
func.cache = {}
@functools.wraps(func)
def _memoized_function(*args):
if not isinstance(args, collections.Hashable):
# Not hashable, so just call the function.
return func(*args)
if args not in func.cache:
func.cache[args] = func(*args)
return func.cache[args]
return _memoized_function
def list_modules(directory, **kwargs):
"""Lists all of the modules, excluding ``__init__.py``, in a
particular directory. Listed packages have no particular
order."""
list_directories = kwargs.setdefault('directories', True)
for name in os.listdir(directory):
if name == '__init__.py':
continue
path = os.path.join(directory, name)
if list_directories and os.path.isdir(path):
init_py = os.path.join(path, '__init__.py')
if os.path.isfile(init_py):
yield name
elif name.endswith('.py'):
if not any(re.search(pattern, name) for pattern in ignore_modules):
yield re.sub('.py$', '', name)
def key_ordering(cls):
"""Decorates a class with extra methods that implement rich comparison
operations and ``__hash__``. The decorator assumes that the class
implements a function called ``_cmp_key()``. The rich comparison
operations will compare objects using this key, and the ``__hash__``
function will return the hash of this key.
If a class already has ``__eq__``, ``__ne__``, ``__lt__``, ``__le__``,
``__gt__``, or ``__ge__`` defined, this decorator will overwrite them.
Raises:
TypeError: If the class does not have a ``_cmp_key`` method
"""
def setter(name, value):
value.__name__ = name
setattr(cls, name, value)
if not has_method(cls, '_cmp_key'):
raise TypeError("'%s' doesn't define _cmp_key()." % cls.__name__)
setter('__eq__',
lambda s, o:
(s is o) or (o is not None and s._cmp_key() == o._cmp_key()))
setter('__lt__',
lambda s, o: o is not None and s._cmp_key() < o._cmp_key())
setter('__le__',
lambda s, o: o is not None and s._cmp_key() <= o._cmp_key())
setter('__ne__',
lambda s, o:
(s is not o) and (o is None or s._cmp_key() != o._cmp_key()))
setter('__gt__',
lambda s, o: o is None or s._cmp_key() > o._cmp_key())
setter('__ge__',
lambda s, o: o is None or s._cmp_key() >= o._cmp_key())
setter('__hash__', lambda self: hash(self._cmp_key()))
return cls
@key_ordering
class HashableMap(collections.MutableMapping):
"""This is a hashable, comparable dictionary. Hash is performed on
a tuple of the values in the dictionary."""
def __init__(self):
self.dict = {}
def __getitem__(self, key):
return self.dict[key]
def __setitem__(self, key, value):
self.dict[key] = value
def __iter__(self):
return iter(self.dict)
def __len__(self):
return len(self.dict)
def __delitem__(self, key):
del self.dict[key]
def _cmp_key(self):
return tuple(sorted(self.values()))
def copy(self):
"""Type-agnostic clone method. Preserves subclass type."""
# Construct a new dict of my type
self_type = type(self)
clone = self_type()
# Copy everything from this dict into it.
for key in self:
clone[key] = self[key].copy()
return clone
def in_function(function_name):
"""True if the caller was called from some function with
the supplied Name, False otherwise."""
stack = inspect.stack()
try:
for elt in stack[2:]:
if elt[3] == function_name:
return True
return False
finally:
del stack
def check_kwargs(kwargs, fun):
"""Helper for making functions with kwargs. Checks whether the kwargs
are empty after all of them have been popped off. If they're
not, raises an error describing which kwargs are invalid.
Example::
def foo(self, **kwargs):
x = kwargs.pop('x', None)
y = kwargs.pop('y', None)
z = kwargs.pop('z', None)
check_kwargs(kwargs, self.foo)
# This raises a TypeError:
foo(w='bad kwarg')
"""
if kwargs:
raise TypeError(
"'%s' is an invalid keyword argument for function %s()."
% (next(iter(kwargs)), fun.__name__))
def match_predicate(*args):
"""Utility function for making string matching predicates.
Each arg can be a:
* regex
* list or tuple of regexes
* predicate that takes a string.
This returns a predicate that is true if:
* any arg regex matches
* any regex in a list or tuple of regexes matches.
* any predicate in args matches.
"""
def match(string):
for arg in args:
if isinstance(arg, string_types):
if re.search(arg, string):
return True
elif isinstance(arg, list) or isinstance(arg, tuple):
if any(re.search(i, string) for i in arg):
return True
elif callable(arg):
if arg(string):
return True
else:
raise ValueError("args to match_predicate must be regex, "
"list of regexes, or callable.")
return False
return match
def dedupe(sequence):
"""Yields a stable de-duplication of an hashable sequence
Args:
sequence: hashable sequence to be de-duplicated
Returns:
stable de-duplication of the sequence
"""
seen = set()
for x in sequence:
if x not in seen:
yield x
seen.add(x)
def pretty_date(time, now=None):
"""Convert a datetime or timestamp to a pretty, relative date.
Args:
time (datetime or int): date to print prettily
now (datetime): dateimte for 'now', i.e. the date the pretty date
is relative to (default is datetime.now())
Returns:
(str): pretty string like 'an hour ago', 'Yesterday',
'3 months ago', 'just now', etc.
Adapted from https://stackoverflow.com/questions/1551382.
"""
if now is None:
now = datetime.now()
if type(time) is int:
diff = now - datetime.fromtimestamp(time)
elif isinstance(time, datetime):
diff = now - time
else:
raise ValueError("pretty_date requires a timestamp or datetime")
second_diff = diff.seconds
day_diff = diff.days
if day_diff < 0:
return ''
if day_diff == 0:
if second_diff < 10:
return "just now"
if second_diff < 60:
return str(second_diff) + " seconds ago"
if second_diff < 120:
return "a minute ago"
if second_diff < 3600:
return str(second_diff // 60) + " minutes ago"
if second_diff < 7200:
return "an hour ago"
if second_diff < 86400:
return str(second_diff // 3600) + " hours ago"
if day_diff == 1:
return "yesterday"
if day_diff < 7:
return str(day_diff) + " days ago"
if day_diff < 28:
weeks = day_diff // 7
if weeks == 1:
return "a week ago"
else:
return str(day_diff // 7) + " weeks ago"
if day_diff < 365:
months = day_diff // 30
if months == 1:
return "a month ago"
elif months == 12:
months -= 1
return str(months) + " months ago"
diff = day_diff // 365
if diff == 1:
return "a year ago"
else:
return str(diff) + " years ago"
def pretty_string_to_date(date_str, now=None):
"""Parses a string representing a date and returns a datetime object.
Args:
date_str (str): string representing a date. This string might be
in different format (like ``YYYY``, ``YYYY-MM``, ``YYYY-MM-DD``,
``YYYY-MM-DD HH:MM``, ``YYYY-MM-DD HH:MM:SS``)
or be a *pretty date* (like ``yesterday`` or ``two months ago``)
Returns:
(datetime): datetime object corresponding to ``date_str``
"""
pattern = {}
now = now or datetime.now()
# datetime formats
pattern[re.compile(r'^\d{4}$')] = lambda x: datetime.strptime(x, '%Y')
pattern[re.compile(r'^\d{4}-\d{2}$')] = lambda x: datetime.strptime(
x, '%Y-%m'
)
pattern[re.compile(r'^\d{4}-\d{2}-\d{2}$')] = lambda x: datetime.strptime(
x, '%Y-%m-%d'
)
pattern[re.compile(r'^\d{4}-\d{2}-\d{2} \d{2}:\d{2}$')] = \
lambda x: datetime.strptime(x, '%Y-%m-%d %H:%M')
pattern[re.compile(r'^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}$')] = \
lambda x: datetime.strptime(x, '%Y-%m-%d %H:%M:%S')
pretty_regex = re.compile(
r'(a|\d+)\s*(year|month|week|day|hour|minute|second)s?\s*ago')
def _n_xxx_ago(x):
how_many, time_period = pretty_regex.search(x).groups()
how_many = 1 if how_many == 'a' else int(how_many)
# timedelta natively supports time periods up to 'weeks'.
# To apply month or year we convert to 30 and 365 days
if time_period == 'month':
how_many *= 30
time_period = 'day'
elif time_period == 'year':
how_many *= 365
time_period = 'day'
kwargs = {(time_period + 's'): how_many}
return now - timedelta(**kwargs)
pattern[pretty_regex] = _n_xxx_ago
# yesterday
callback = lambda x: now - timedelta(days=1)
pattern[re.compile('^yesterday$')] = callback
for regexp, parser in pattern.items():
if bool(regexp.match(date_str)):
return parser(date_str)
msg = 'date "{0}" does not match any valid format'.format(date_str)
raise ValueError(msg)
class RequiredAttributeError(ValueError):
def __init__(self, message):
super(RequiredAttributeError, self).__init__(message)
class ObjectWrapper(object):
"""Base class that wraps an object. Derived classes can add new behavior
while staying undercover.
This class is modeled after the stackoverflow answer:
* http://stackoverflow.com/a/1445289/771663
"""
def __init__(self, wrapped_object):
wrapped_cls = type(wrapped_object)
wrapped_name = wrapped_cls.__name__
# If the wrapped object is already an ObjectWrapper, or a derived class
# of it, adding type(self) in front of type(wrapped_object)
# results in an inconsistent MRO.
#
# TODO: the implementation below doesn't account for the case where we
# TODO: have different base classes of ObjectWrapper, say A and B, and
# TODO: we want to wrap an instance of A with B.
if type(self) not in wrapped_cls.__mro__:
self.__class__ = type(wrapped_name, (type(self), wrapped_cls), {})
else:
self.__class__ = type(wrapped_name, (wrapped_cls,), {})
self.__dict__ = wrapped_object.__dict__
class Singleton(object):
"""Simple wrapper for lazily initialized singleton objects."""
def __init__(self, factory):
"""Create a new singleton to be inited with the factory function.
Args:
factory (function): function taking no arguments that
creates the singleton instance.
"""
self.factory = factory
self._instance = None
@property
def instance(self):
if self._instance is None:
self._instance = self.factory()
return self._instance
def __getattr__(self, name):
return getattr(self.instance, name)
def __getitem__(self, name):
return self.instance[name]
def __contains__(self, element):
return element in self.instance
def __call__(self, *args, **kwargs):
return self.instance(*args, **kwargs)
def __iter__(self):
return iter(self.instance)
def __str__(self):
return str(self.instance)
def __repr__(self):
return repr(self.instance)
class LazyReference(object):
"""Lazily evaluated reference to part of a singleton."""
def __init__(self, ref_function):
self.ref_function = ref_function
def __getattr__(self, name):
return getattr(self.ref_function(), name)
def __getitem__(self, name):
return self.ref_function()[name]
def __str__(self):
return str(self.ref_function())
def __repr__(self):
return repr(self.ref_function())
def load_module_from_file(module_name, module_path):
"""Loads a python module from the path of the corresponding file.
Args:
module_name (str): namespace where the python module will be loaded,
e.g. ``foo.bar``
module_path (str): path of the python file containing the module
Returns:
A valid module object
Raises:
ImportError: when the module can't be loaded
FileNotFoundError: when module_path doesn't exist
"""
if sys.version_info[0] == 3 and sys.version_info[1] >= 5:
import importlib.util
spec = importlib.util.spec_from_file_location(module_name, module_path)
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)
elif sys.version_info[0] == 3 and sys.version_info[1] < 5:
import importlib.machinery
loader = importlib.machinery.SourceFileLoader(module_name, module_path)
module = loader.load_module()
elif sys.version_info[0] == 2:
import imp
module = imp.load_source(module_name, module_path)
return module