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import collections.abc
import reprlib
import sys
__all__ = ('Map',)
# Python version of _map.c. The topmost comment there explains
# all datastructures and algorithms.
# The code here follows C code closely on purpose to make
# debugging and testing easier.
def map_hash(o):
x = hash(o)
return (x & 0xffffffff) ^ ((x >> 32) & 0xffffffff)
def map_mask(hash, shift):
return (hash >> shift) & 0x01f
def map_bitpos(hash, shift):
return 1 << map_mask(hash, shift)
def map_bitcount(v):
v = v - ((v >> 1) & 0x55555555)
v = (v & 0x33333333) + ((v >> 2) & 0x33333333)
v = (v & 0x0F0F0F0F) + ((v >> 4) & 0x0F0F0F0F)
v = v + (v >> 8)
v = (v + (v >> 16)) & 0x3F
return v
def map_bitindex(bitmap, bit):
return map_bitcount(bitmap & (bit - 1))
W_EMPTY, W_NEWNODE, W_NOT_FOUND = range(3)
class BitmapNode:
def __init__(self, size, bitmap, array):
self.size = size
self.bitmap = bitmap
assert isinstance(array, list) and len(array) == size
self.array = array
def clone(self):
return BitmapNode(self.size, self.bitmap, self.array.copy())
def assoc(self, shift, hash, key, val):
bit = map_bitpos(hash, shift)
idx = map_bitindex(self.bitmap, bit)
if self.bitmap & bit:
key_idx = 2 * idx
val_idx = key_idx + 1
key_or_null = self.array[key_idx]
val_or_node = self.array[val_idx]
if key_or_null is None:
sub_node, added = val_or_node.assoc(
shift + 5, hash, key, val)
if val_or_node is sub_node:
return self, False
ret = self.clone()
ret.array[val_idx] = sub_node
return ret, added
if key == key_or_null:
if val is val_or_node:
return self, False
ret = self.clone()
ret.array[val_idx] = val
return ret, False
existing_key_hash = map_hash(key_or_null)
if existing_key_hash == hash:
sub_node = CollisionNode(
4, hash, [key_or_null, val_or_node, key, val])
else:
sub_node = BitmapNode(0, 0, [])
sub_node, _ = sub_node.assoc(
shift + 5, existing_key_hash,
key_or_null, val_or_node)
sub_node, _ = sub_node.assoc(
shift + 5, hash, key, val)
ret = self.clone()
ret.array[key_idx] = None
ret.array[val_idx] = sub_node
return ret, True
else:
key_idx = 2 * idx
val_idx = key_idx + 1
n = map_bitcount(self.bitmap)
new_array = self.array[:key_idx]
new_array.append(key)
new_array.append(val)
new_array.extend(self.array[key_idx:])
return BitmapNode(2 * (n + 1), self.bitmap | bit, new_array), True
def find(self, shift, hash, key):
bit = map_bitpos(hash, shift)
if not (self.bitmap & bit):
raise KeyError
idx = map_bitindex(self.bitmap, bit)
key_idx = idx * 2
val_idx = key_idx + 1
key_or_null = self.array[key_idx]
val_or_node = self.array[val_idx]
if key_or_null is None:
return val_or_node.find(shift + 5, hash, key)
if key == key_or_null:
return val_or_node
raise KeyError(key)
def without(self, shift, hash, key):
bit = map_bitpos(hash, shift)
if not (self.bitmap & bit):
return W_NOT_FOUND, None
idx = map_bitindex(self.bitmap, bit)
key_idx = 2 * idx
val_idx = key_idx + 1
key_or_null = self.array[key_idx]
val_or_node = self.array[val_idx]
if key_or_null is None:
res, sub_node = val_or_node.without(shift + 5, hash, key)
if res is W_EMPTY:
raise RuntimeError('unreachable code') # pragma: no cover
elif res is W_NEWNODE:
if (type(sub_node) is BitmapNode and
sub_node.size == 2 and
sub_node.array[0] is not None):
clone = self.clone()
clone.array[key_idx] = sub_node.array[0]
clone.array[val_idx] = sub_node.array[1]
return W_NEWNODE, clone
clone = self.clone()
clone.array[val_idx] = sub_node
return W_NEWNODE, clone
else:
assert sub_node is None
return res, None
else:
if key == key_or_null:
if self.size == 2:
return W_EMPTY, None
new_array = self.array[:key_idx]
new_array.extend(self.array[val_idx + 1:])
new_node = BitmapNode(
self.size - 2, self.bitmap & ~bit, new_array)
return W_NEWNODE, new_node
else:
return W_NOT_FOUND, None
def keys(self):
for i in range(0, self.size, 2):
key_or_null = self.array[i]
if key_or_null is None:
val_or_node = self.array[i + 1]
yield from val_or_node.keys()
else:
yield key_or_null
def values(self):
for i in range(0, self.size, 2):
key_or_null = self.array[i]
val_or_node = self.array[i + 1]
if key_or_null is None:
yield from val_or_node.values()
else:
yield val_or_node
def items(self):
for i in range(0, self.size, 2):
key_or_null = self.array[i]
val_or_node = self.array[i + 1]
if key_or_null is None:
yield from val_or_node.items()
else:
yield key_or_null, val_or_node
def dump(self, buf, level): # pragma: no cover
buf.append(
' ' * (level + 1) +
'BitmapNode(size={} count={} bitmap={} id={:0x}):'.format(
self.size, self.size / 2, bin(self.bitmap), id(self)))
for i in range(0, self.size, 2):
key_or_null = self.array[i]
val_or_node = self.array[i + 1]
pad = ' ' * (level + 2)
if key_or_null is None:
buf.append(pad + 'None:')
val_or_node.dump(buf, level + 2)
else:
buf.append(pad + '{!r}: {!r}'.format(key_or_null, val_or_node))
class CollisionNode:
def __init__(self, size, hash, array):
self.size = size
self.hash = hash
self.array = array
def find_index(self, key):
for i in range(0, self.size, 2):
if self.array[i] == key:
return i
return -1
def find(self, shift, hash, key):
for i in range(0, self.size, 2):
if self.array[i] == key:
return self.array[i + 1]
raise KeyError(key)
def assoc(self, shift, hash, key, val):
if hash == self.hash:
key_idx = self.find_index(key)
if key_idx == -1:
new_array = self.array.copy()
new_array.append(key)
new_array.append(val)
new_node = CollisionNode(self.size + 2, hash, new_array)
return new_node, True
val_idx = key_idx + 1
if self.array[val_idx] is val:
return self, False
new_array = self.array.copy()
new_array[val_idx] = val
return CollisionNode(self.size, hash, new_array), False
else:
new_node = BitmapNode(
2, map_bitpos(self.hash, shift), [None, self])
return new_node.assoc(shift, hash, key, val)
def without(self, shift, hash, key):
if hash != self.hash:
return W_NOT_FOUND, None
key_idx = self.find_index(key)
if key_idx == -1:
return W_NOT_FOUND, None
new_size = self.size - 2
if new_size == 0:
# Shouldn't be ever reachable
return W_EMPTY, None # pragma: no cover
if new_size == 2:
if key_idx == 0:
new_array = [self.array[2], self.array[3]]
else:
assert key_idx == 2
new_array = [self.array[0], self.array[1]]
new_node = BitmapNode(2, map_bitpos(hash, shift), new_array)
return W_NEWNODE, new_node
new_array = self.array[:key_idx]
new_array.extend(self.array[key_idx + 2:])
new_node = CollisionNode(self.size - 2, self.hash, new_array)
return W_NEWNODE, new_node
def keys(self):
for i in range(0, self.size, 2):
yield self.array[i]
def values(self):
for i in range(1, self.size, 2):
yield self.array[i]
def items(self):
for i in range(0, self.size, 2):
yield self.array[i], self.array[i + 1]
def dump(self, buf, level): # pragma: no cover
pad = ' ' * (level + 1)
buf.append(
pad + 'CollisionNode(size={} id={:0x}):'.format(
self.size, id(self)))
pad = ' ' * (level + 2)
for i in range(0, self.size, 2):
key = self.array[i]
val = self.array[i + 1]
buf.append('{}{!r}: {!r}'.format(pad, key, val))
class GenWrapper:
def __init__(self, count, gen):
self.__count = count
self.__gen = gen
def __len__(self):
return self.__count
def __iter__(self):
return self
def __next__(self):
return next(self.__gen)
class Map:
def __init__(self):
self.__count = 0
self.__root = BitmapNode(0, 0, [])
self.__hash = -1
def __len__(self):
return self.__count
def __eq__(self, other):
if not isinstance(other, Map):
return NotImplemented
if len(self) != len(other):
return False
for key, val in self.__root.items():
try:
oval = other.__root.find(0, map_hash(key), key)
except KeyError:
return False
else:
if oval != val:
return False
return True
def set(self, key, val):
new_count = self.__count
new_root, added = self.__root.assoc(0, map_hash(key), key, val)
if new_root is self.__root:
assert not added
return self
if added:
new_count += 1
m = Map.__new__(Map)
m.__count = new_count
m.__root = new_root
m.__hash = -1
return m
def delete(self, key):
res, node = self.__root.without(0, map_hash(key), key)
if res is W_EMPTY:
return Map()
elif res is W_NOT_FOUND:
raise KeyError(key)
else:
m = Map.__new__(Map)
m.__count = self.__count - 1
m.__root = node
m.__hash = -1
return m
def get(self, key, default=None):
try:
return self.__root.find(0, map_hash(key), key)
except KeyError:
return default
def __getitem__(self, key):
return self.__root.find(0, map_hash(key), key)
def __contains__(self, key):
try:
self.__root.find(0, map_hash(key), key)
except KeyError:
return False
else:
return True
def __iter__(self):
yield from self.__root.keys()
def keys(self):
return GenWrapper(self.__count, self.__root.keys())
def values(self):
return GenWrapper(self.__count, self.__root.values())
def items(self):
return GenWrapper(self.__count, self.__root.items())
def __hash__(self):
if self.__hash != -1:
return self.__hash
MAX = sys.maxsize
MASK = 2 * MAX + 1
h = 1927868237 * (self.__count * 2 + 1)
h &= MASK
for key, value in self.__root.items():
hx = hash(key)
h ^= (hx ^ (hx << 16) ^ 89869747) * 3644798167
h &= MASK
hx = hash(value)
h ^= (hx ^ (hx << 16) ^ 89869747) * 3644798167
h &= MASK
h = h * 69069 + 907133923
h &= MASK
if h > MAX:
h -= MASK + 1 # pragma: no cover
if h == -1:
h = 590923713 # pragma: no cover
self.__hash = h
return h
@reprlib.recursive_repr("{...}")
def __repr__(self):
items = []
for key, val in self.items():
items.append("{!r}: {!r}".format(key, val))
return '<immutables.Map({{{}}}) at 0x{:0x}>'.format(
', '.join(items), id(self))
def __dump__(self): # pragma: no cover
buf = []
self.__root.dump(buf, 0)
return '\n'.join(buf)
collections.abc.Mapping.register(Map)
|