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import re
from typing import Tuple, Any, Callable, List, Optional
from fakeredis import _msgs as msgs
from fakeredis._commands import (
command,
Key,
Int,
BitOffset,
BitValue,
fix_range_string,
fix_range,
CommandItem,
)
from fakeredis._helpers import SimpleError, casematch
class BitfieldEncoding:
signed: bool
size: int
def __init__(self, encoding: bytes) -> None:
match = re.match(rb"^([ui])(\d+)$", encoding)
if match is None:
raise SimpleError(msgs.INVALID_BITFIELD_TYPE)
self.signed = match[1] == b"i"
self.size = int(match[2])
if self.size < 1 or self.size > (64 if self.signed else 63):
raise SimpleError(msgs.INVALID_BITFIELD_TYPE)
class BitmapCommandsMixin:
def __init(self, *args: Any, **kwargs: Any) -> None:
super().__init__(*args, **kwargs)
self.version: Tuple[int]
@staticmethod
def _bytes_as_bin_string(value: bytes) -> str:
return "".join([bin(i).lstrip("0b").rjust(8, "0") for i in value])
@command((Key(bytes), Int), (bytes,), flags=msgs.FLAG_DO_NOT_CREATE)
def bitpos(self, key: CommandItem, bit: int, *args: bytes) -> int:
if bit != 0 and bit != 1:
raise SimpleError(msgs.BIT_ARG_MUST_BE_ZERO_OR_ONE)
if len(args) > 3:
raise SimpleError(msgs.SYNTAX_ERROR_MSG)
if len(args) == 3 and self.version < (7,):
raise SimpleError(msgs.SYNTAX_ERROR_MSG)
bit_mode = False
if len(args) == 3 and self.version >= (7,):
bit_mode = casematch(args[2], b"bit")
if not bit_mode and not casematch(args[2], b"byte"):
raise SimpleError(msgs.SYNTAX_ERROR_MSG)
if key.value is None:
# The first clear bit is at 0, the first set bit is not found (-1).
return -1 if bit == 1 else 0
start = 0 if len(args) == 0 else Int.decode(args[0])
source_value = self._bytes_as_bin_string(key.value) if bit_mode else key.value
end = len(source_value) if len(args) <= 1 else Int.decode(args[1])
length = len(source_value)
start, end = fix_range(start, end, length)
if start == end == -1:
return -1
source_value = source_value[start:end] if bit_mode else self._bytes_as_bin_string(source_value[start:end])
result = source_value.find(str(bit))
if result != -1:
result += start if bit_mode else (start * 8)
elif bit == 0 and len(args) <= 1:
# Redis treats the value as padded with zero bytes to an infinity
# if the user is looking for the first clear bit and no end is set.
result = len(key.value) * 8
return result
@command(name="BITCOUNT", fixed=(Key(bytes),), repeat=(bytes,), flags=msgs.FLAG_DO_NOT_CREATE)
def bitcount(self, key: CommandItem, *args: bytes) -> int:
# Redis checks the argument count before decoding integers. That's why
# we can't declare them as Int.
if len(args) == 0:
if key.value is None:
return 0
return bin(int.from_bytes(key.value, "little")).count("1")
if not 2 <= len(args) <= 3:
raise SimpleError(msgs.SYNTAX_ERROR_MSG)
try:
start = Int.decode(args[0])
end = Int.decode(args[1])
except SimpleError as e:
if self.version >= (7, 4):
raise e
return 0
bit_mode = False
if len(args) == 3 and self.version < (7,):
raise SimpleError(msgs.SYNTAX_ERROR_MSG)
if len(args) == 3 and self.version >= (7,):
bit_mode = casematch(args[2], b"bit")
if not bit_mode and not casematch(args[2], b"byte"):
raise SimpleError(msgs.SYNTAX_ERROR_MSG)
if key.value is None:
return 0
if bit_mode:
value = self._bytes_as_bin_string(key.value if key.value else b"")
start, end = fix_range_string(start, end, len(value))
res: int = value.count("1", start, end)
return res
start, end = fix_range_string(start, end, len(key.value))
value = key.value[start:end]
return bin(int.from_bytes(value, "little")).count("1")
@command(fixed=(Key(bytes), BitOffset))
def getbit(self, key: CommandItem, offset: int) -> int:
value = key.get(b"")
byte = offset // 8
remaining = offset % 8
actual_bitoffset = 7 - remaining
try:
actual_val = value[byte]
except IndexError:
return 0
return 1 if (1 << actual_bitoffset) & actual_val else 0
@command((Key(bytes), BitOffset, BitValue))
def setbit(self, key: CommandItem, offset: int, value: int) -> int:
val = key.value if key.value is not None else b"\x00"
byte = offset // 8
remaining = offset % 8
actual_bitoffset = 7 - remaining
if len(val) - 1 < byte:
# We need to expand val so that we can set the appropriate
# bit.
needed = byte - (len(val) - 1)
val += b"\x00" * needed
old_byte = val[byte]
if value == 1:
new_byte = old_byte | (1 << actual_bitoffset)
else:
new_byte = old_byte & ~(1 << actual_bitoffset)
old_value = value if old_byte == new_byte else 1 - value
reconstructed = bytearray(val)
reconstructed[byte] = new_byte
if bytes(reconstructed) != key.value or (self.version == (6,) and old_byte != new_byte):
key.update(bytes(reconstructed))
return old_value
@staticmethod
def _bitop(op: Callable[[Any, Any], Any], *keys: CommandItem) -> Any:
value = keys[0].value
ans = keys[0].value
i = 1
while i < len(keys):
value = keys[i].value if keys[i].value is not None else b""
ans = bytes(op(a, b) for a, b in zip(ans, value))
i += 1
return ans
@command((bytes, Key()), (Key(bytes),))
def bitop(self, op_name: bytes, dst: CommandItem, *keys: CommandItem) -> int:
if len(keys) == 0:
raise SimpleError(msgs.WRONG_ARGS_MSG6.format("bitop"))
if casematch(op_name, b"and"):
res = self._bitop(lambda a, b: a & b, *keys)
elif casematch(op_name, b"or"):
res = self._bitop(lambda a, b: a | b, *keys)
elif casematch(op_name, b"xor"):
res = self._bitop(lambda a, b: a ^ b, *keys)
elif casematch(op_name, b"not"):
if len(keys) != 1:
raise SimpleError(msgs.BITOP_NOT_ONE_KEY_ONLY)
val = keys[0].value
res = bytes([((1 << 8) - 1 - val[i]) for i in range(len(val))])
else:
raise SimpleError(msgs.WRONG_ARGS_MSG6.format("bitop"))
dst.value = res
return len(dst.value)
def _bitfield_get(self, key: CommandItem, encoding: BitfieldEncoding, offset: int) -> int:
ans = 0
for i in range(0, encoding.size):
ans <<= 1
if self.getbit(key, offset + i):
ans += -1 if encoding.signed and i == 0 else 1
return ans
def _bitfield_set(
self,
key: CommandItem,
encoding: BitfieldEncoding,
offset: int,
overflow: bytes,
value: Optional[int] = None,
incr: int = 0,
) -> Optional[int]:
if encoding.signed:
min_value = -(1 << (encoding.size - 1))
max_value = (1 << (encoding.size - 1)) - 1
else:
min_value = 0
max_value = (1 << encoding.size) - 1
ans = self._bitfield_get(key, encoding, offset)
new_value = ans if value is None else value
if not encoding.signed:
new_value &= (1 << 64) - 1 # force cast to uint64_t
if overflow == b"FAIL" and not (min_value <= new_value + incr <= max_value):
return None # yes, failing in this context is not writing the value
elif overflow == b"SAT":
if new_value + incr > max_value:
new_value, incr = max_value, 0
# REDIS only checks for unsigned underflow on negative incr:
if (encoding.signed or incr < 0) and new_value + incr < min_value:
new_value, incr = min_value, 0
new_value += incr
new_value &= (1 << encoding.size) - 1
# normalize signed number by changing the sign associated to higher bit:
if encoding.signed and new_value > max_value:
new_value -= 1 << encoding.size
for i in range(0, encoding.size):
bit = (new_value >> (encoding.size - i - 1)) & 1
self.setbit(key, offset + i, bit)
return new_value if value is None else ans
@command(fixed=(Key(bytes),), repeat=(bytes,))
def bitfield(self, key: CommandItem, *args: bytes) -> List[Optional[int]]:
overflow = b"WRAP"
results: List[Optional[int]] = []
i = 0
while i < len(args):
if casematch(args[i], b"overflow") and i + 1 < len(args):
overflow = args[i + 1].upper()
if overflow not in (b"WRAP", b"SAT", b"FAIL"):
raise SimpleError(msgs.INVALID_OVERFLOW_TYPE)
i += 2
elif casematch(args[i], b"get") and i + 2 < len(args):
encoding = BitfieldEncoding(args[i + 1])
offset = BitOffset.decode(args[i + 2])
results.append(self._bitfield_get(key, encoding, offset))
i += 3
elif casematch(args[i], b"set") and i + 3 < len(args):
old_value = self._bitfield_set(
key=key,
encoding=BitfieldEncoding(args[i + 1]),
offset=BitOffset.decode(args[i + 2]),
value=Int.decode(args[i + 3]),
overflow=overflow,
)
results.append(old_value)
i += 4
elif casematch(args[i], b"incrby") and i + 3 < len(args):
old_value = self._bitfield_set(
key=key,
encoding=BitfieldEncoding(args[i + 1]),
offset=BitOffset.decode(args[i + 2]),
incr=Int.decode(args[i + 3]),
overflow=overflow,
)
results.append(old_value)
i += 4
else:
raise SimpleError(msgs.SYNTAX_ERROR_MSG)
return results
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