from ctypes import Structure, c_ulong, POINTER, cast, addressof, py_object, c_long, c_void_p

from common import get_object_field_or_null, EMPTY, DUMMY

class PyDictKeyEntry(Structure):

_fields_ = [

('me_hash', c_long),

('me_key', py_object),

('me_value', py_object),

]

class PyDictKeysObject(Structure):

_fields_ = [

('dk_refcnt', c_long),

('dk_size', c_long),

('dict_lookup_func', POINTER(c_void_p)),

('dk_usable', c_long),

('dk_entries', PyDictKeyEntry),

]

class PyDictObject(Structure):

_fields_ = [

('ob_refcnt', c_ulong),

('ob_type', c_ulong),

('ma_used', c_long),

('ma_keys', POINTER(PyDictKeysObject)),

# Not actually a void*, split tables are not supported right now

('ma_values', POINTER(c_void_p))

]

def dictobject(d):

return cast(id(d), POINTER(PyDictObject)).contents

d = {0: 0}

del d[0]

dummy_internal = dictobject(d).ma_keys.contents.dk_entries.me_key

del d

def usable_fraction(size):

return (size * 2 + 1) // 3

def dump_py_dict(d):

do = dictobject(d)

keys = []

hashes = []

values = []

size = do.ma_keys.contents.dk_size

entries = cast(addressof(do.ma_keys.contents.dk_entries), POINTER(PyDictKeyEntry))

for i in range(size):

key = get_object_field_or_null(entries[i], 'me_key')

keys.append(key if key is not dummy_internal else DUMMY)

for i, key in enumerate(keys):

if key is EMPTY:

hashes.append(EMPTY)

values.append(EMPTY)

else:

hashes.append(entries[i].me_hash)

values.append(get_object_field_or_null(entries[i], 'me_value'))

return hashes, keys, values, usable_fraction(do.ma_keys.contents.dk_size) - do.ma_keys.contents.dk_usable, do.ma_used