# util.py
# Copyright (C) 2006, 2007, 2008, 2009, 2010 Michael Bayer mike_mp@zzzcomputing.com
#
# This module is part of Mako and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
import sys
py3k = getattr(sys, 'py3kwarning', False) or sys.version_info >= (3, 0)
jython = sys.platform.startswith('java')
win32 = sys.platform.startswith('win')
if py3k:
from io import StringIO
else:
try:
from cStringIO import StringIO
except:
from StringIO import StringIO
import codecs, re, weakref, os, time, operator
try:
import threading
import thread
except ImportError:
import dummy_threading as threading
import dummy_thread as thread
if win32 or jython:
time_func = time.clock
else:
time_func = time.time
def function_named(fn, name):
"""Return a function with a given __name__.
Will assign to __name__ and return the original function if possible on
the Python implementation, otherwise a new function will be constructed.
"""
fn.__name__ = name
return fn
def verify_directory(dir):
"""create and/or verify a filesystem directory."""
tries = 0
while not os.path.exists(dir):
try:
tries += 1
os.makedirs(dir, 0775)
except:
if tries > 5:
raise
def to_list(x, default=None):
if x is None:
return default
if not isinstance(x, (list, tuple)):
return [x]
else:
return x
class SetLikeDict(dict):
"""a dictionary that has some setlike methods on it"""
def union(self, other):
"""produce a 'union' of this dict and another (at the key level).
values in the second dict take precedence over that of the first"""
x = SetLikeDict(**self)
x.update(other)
return x
class FastEncodingBuffer(object):
"""a very rudimentary buffer that is faster than StringIO,
but doesnt crash on unicode data like cStringIO."""
def __init__(self, encoding=None, errors='strict', unicode=False):
self.data = []
self.encoding = encoding
if unicode:
self.delim = u''
else:
self.delim = ''
self.unicode = unicode
self.errors = errors
self.write = self.data.append
def truncate(self):
self.data =[]
def getvalue(self):
if self.encoding:
return self.delim.join(self.data).encode(self.encoding, self.errors)
else:
return self.delim.join(self.data)
class LRUCache(dict):
"""A dictionary-like object that stores a limited number of items, discarding
lesser used items periodically.
this is a rewrite of LRUCache from Myghty to use a periodic timestamp-based
paradigm so that synchronization is not really needed. the size management
is inexact.
"""
class _Item(object):
def __init__(self, key, value):
self.key = key
self.value = value
self.timestamp = time_func()
def __repr__(self):
return repr(self.value)
def __init__(self, capacity, threshold=.5):
self.capacity = capacity
self.threshold = threshold
def __getitem__(self, key):
item = dict.__getitem__(self, key)
item.timestamp = time_func()
return item.value
def values(self):
return [i.value for i in dict.values(self)]
def setdefault(self, key, value):
if key in self:
return self[key]
else:
self[key] = value
return value
def __setitem__(self, key, value):
item = dict.get(self, key)
if item is None:
item = self._Item(key, value)
dict.__setitem__(self, key, item)
else:
item.value = value
self._manage_size()
def _manage_size(self):
while len(self) > self.capacity + self.capacity * self.threshold:
bytime = sorted(dict.values(self),
key=operator.attrgetter('timestamp'), reverse=True)
for item in bytime[self.capacity:]:
try:
del self[item.key]
except KeyError:
# if we couldnt find a key, most likely some other thread broke in
# on us. loop around and try again
break
# Regexp to match python magic encoding line
_PYTHON_MAGIC_COMMENT_re = re.compile(
r'[ \t\f]* \# .* coding[=:][ \t]*([-\w.]+)',
re.VERBOSE)
def parse_encoding(fp):
"""Deduce the encoding of a Python source file (binary mode) from magic comment.
It does this in the same way as the `Python interpreter`__
.. __: http://docs.python.org/ref/encodings.html
The ``fp`` argument should be a seekable file object in binary mode.
"""
pos = fp.tell()
fp.seek(0)
try:
line1 = fp.readline()
has_bom = line1.startswith(codecs.BOM_UTF8)
if has_bom:
line1 = line1[len(codecs.BOM_UTF8):]
m = _PYTHON_MAGIC_COMMENT_re.match(line1.decode('ascii', 'ignore'))
if not m:
try:
import parser
parser.suite(line1.decode('ascii', 'ignore'))
except (ImportError, SyntaxError):
# Either it's a real syntax error, in which case the source
# is not valid python source, or line2 is a continuation of
# line1, in which case we don't want to scan line2 for a magic
# comment.
pass
else:
line2 = fp.readline()
m = _PYTHON_MAGIC_COMMENT_re.match(line2.decode('ascii', 'ignore'))
if has_bom:
if m:
raise SyntaxError, \
"python refuses to compile code with both a UTF8" \
" byte-order-mark and a magic encoding comment"
return 'utf_8'
elif m:
return m.group(1)
else:
return None
finally:
fp.seek(pos)
def sorted_dict_repr(d):
"""repr() a dictionary with the keys in order.
Used by the lexer unit test to compare parse trees based on strings.
"""
keys = d.keys()
keys.sort()
return "{" + ", ".join(["%r: %r" % (k, d[k]) for k in keys]) + "}"
def restore__ast(_ast):
"""Attempt to restore the required classes to the _ast module if it
appears to be missing them
"""
if hasattr(_ast, 'AST'):
return
_ast.PyCF_ONLY_AST = 2 << 9
m = compile("""\
def foo(): pass
class Bar(object): pass
if False: pass
baz = 'mako'
1 + 2 - 3 * 4 / 5
6 // 7 % 8 << 9 >> 10
11 & 12 ^ 13 | 14
15 and 16 or 17
-baz + (not +18) - ~17
baz and 'foo' or 'bar'
(mako is baz == baz) is not baz != mako
mako > baz < mako >= baz <= mako
mako in baz not in mako""", '<unknown>', 'exec', _ast.PyCF_ONLY_AST)
_ast.Module = type(m)
for cls in _ast.Module.__mro__:
if cls.__name__ == 'mod':
_ast.mod = cls
elif cls.__name__ == 'AST':
_ast.AST = cls
_ast.FunctionDef = type(m.body[0])
_ast.ClassDef = type(m.body[1])
_ast.If = type(m.body[2])
_ast.Name = type(m.body[3].targets[0])
_ast.Store = type(m.body[3].targets[0].ctx)
_ast.Str = type(m.body[3].value)
_ast.Sub = type(m.body[4].value.op)
_ast.Add = type(m.body[4].value.left.op)
_ast.Div = type(m.body[4].value.right.op)
_ast.Mult = type(m.body[4].value.right.left.op)
_ast.RShift = type(m.body[5].value.op)
_ast.LShift = type(m.body[5].value.left.op)
_ast.Mod = type(m.body[5].value.left.left.op)
_ast.FloorDiv = type(m.body[5].value.left.left.left.op)
_ast.BitOr = type(m.body[6].value.op)
_ast.BitXor = type(m.body[6].value.left.op)
_ast.BitAnd = type(m.body[6].value.left.left.op)
_ast.Or = type(m.body[7].value.op)
_ast.And = type(m.body[7].value.values[0].op)
_ast.Invert = type(m.body[8].value.right.op)
_ast.Not = type(m.body[8].value.left.right.op)
_ast.UAdd = type(m.body[8].value.left.right.operand.op)
_ast.USub = type(m.body[8].value.left.left.op)
_ast.Or = type(m.body[9].value.op)
_ast.And = type(m.body[9].value.values[0].op)
_ast.IsNot = type(m.body[10].value.ops[0])
_ast.NotEq = type(m.body[10].value.ops[1])
_ast.Is = type(m.body[10].value.left.ops[0])
_ast.Eq = type(m.body[10].value.left.ops[1])
_ast.Gt = type(m.body[11].value.ops[0])
_ast.Lt = type(m.body[11].value.ops[1])
_ast.GtE = type(m.body[11].value.ops[2])
_ast.LtE = type(m.body[11].value.ops[3])
_ast.In = type(m.body[12].value.ops[0])
_ast.NotIn = type(m.body[12].value.ops[1])
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