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# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
class Atom:
def __init__(self, ident, string, ty="nsStaticAtom"):
self.ident = ident
self.string = string
self.ty = ty
self.atom_type = self.__class__.__name__
self.hash = hash_string(string)
self.is_ascii_lowercase = is_ascii_lowercase(string)
class PseudoElementAtom(Atom):
def __init__(self, ident, string):
Atom.__init__(self, ident, string, ty="nsCSSPseudoElementStaticAtom")
class AnonBoxAtom(Atom):
def __init__(self, ident, string):
Atom.__init__(self, ident, string, ty="nsCSSAnonBoxPseudoStaticAtom")
class NonInheritingAnonBoxAtom(AnonBoxAtom):
def __init__(self, ident, string):
AnonBoxAtom.__init__(self, ident, string)
class InheritingAnonBoxAtom(AnonBoxAtom):
def __init__(self, ident, string):
AnonBoxAtom.__init__(self, ident, string)
GOLDEN_RATIO_U32 = 0x9E3779B9
def rotate_left_5(value):
return ((value << 5) | (value >> 27)) & 0xFFFFFFFF
def wrapping_multiply(x, y):
return (x * y) & 0xFFFFFFFF
# Calculate the precomputed hash of the static atom. This is a port of
# mozilla::HashString(const char16_t*), which is what we use for atomizing
# strings. An assertion in nsAtomTable::RegisterStaticAtoms ensures that
# the value we compute here matches what HashString() would produce.
def hash_string(s):
h = 0
for c in s:
h = wrapping_multiply(GOLDEN_RATIO_U32, rotate_left_5(h) ^ ord(c))
return h
# Returns true if lowercasing this string in an ascii-case-insensitive way
# would leave the string unchanged.
def is_ascii_lowercase(s):
for c in s:
if c >= "A" and c <= "Z":
return False
return True
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