"""
The module provides help methods to calculate size of nontrivial types.
"""
import typing
from zserio.bitbuffer import BitBuffer
from zserio.exception import PythonRuntimeException
from zserio.limits import INT64_MIN
[docs]def bitsizeof_varint16(value: int) -> int:
"""
Gets bit size of variable 16-bit signed integer value.
:param value: Value to use for bit size calculation.
:returns: Bit size of the value.
:raises PythonRuntimeException: Throws if given value is out of range for varint16 type.
"""
return _bitsizeof_varnum(abs(value), VARINT16_MAX_VALUES, "varint16")
[docs]def bitsizeof_varint32(value: int) -> int:
"""
Gets bit size of variable 32-bit signed integer value.
:param value: Value to use for bit size calculation.
:returns: Bit size of the value.
:raises PythonRuntimeException: Throws if given value is out of range for varint32 type.
"""
return _bitsizeof_varnum(abs(value), VARINT32_MAX_VALUES, "varint32")
[docs]def bitsizeof_varint64(value: int) -> int:
"""
Gets bit size of variable 64-bit signed integer value.
:param value: Value to use for bit size calculation.
:returns: Bit size of the value.
:raises PythonRuntimeException: Throws if given value is out of range for varint64 type.
"""
return _bitsizeof_varnum(abs(value), VARINT64_MAX_VALUES, "varint64")
[docs]def bitsizeof_varint(value: int) -> int:
"""
Gets bit size of variable signed integer value (up to 9 bytes).
:param value: Value to use for bit size calculation.
:returns: Bit size of the value.
:raises PythonRuntimeException: Throws if given value is out of range for varint type.
"""
if value == INT64_MIN:
return 8 # INT64_MIN is stored as -0
return _bitsizeof_varnum(abs(value), VARINT_MAX_VALUES, "varint")
[docs]def bitsizeof_varuint16(value: int) -> int:
"""
Gets bit size of variable 16-bit unsigned integer value.
:param value: Value to use for bit size calculation.
:returns: Bit size of the value.
:raises PythonRuntimeException: Throws if given value is out of range for varuint16 type.
"""
return _bitsizeof_varnum(value, VARUINT16_MAX_VALUES, "varuint16")
[docs]def bitsizeof_varuint32(value: int) -> int:
"""
Gets bit size of variable 32-bit unsigned integer value.
:param value: Value to use for bit size calculation.
:returns: Bit size of the value.
:raises PythonRuntimeException: Throws if given value is out of range for varuint32 type.
"""
return _bitsizeof_varnum(value, VARUINT32_MAX_VALUES, "varuint32")
[docs]def bitsizeof_varuint64(value: int) -> int:
"""
Gets bit size of variable 64-bit unsigned integer value.
:param value: Value to use for bit size calculation.
:returns: Bit size of the value.
:raises PythonRuntimeException: Throws if given value is out of range for varuint64 type.
"""
return _bitsizeof_varnum(value, VARUINT64_MAX_VALUES, "varuint64")
[docs]def bitsizeof_varuint(value: int) -> int:
"""
Gets bit size of variable unsigned integer value (up to 9 bytes).
:param value: Value to use for bit size calculation.
:returns: Bit size of the value.
:raises PythonRuntimeException: Throws if given value is out of range for varuint type.
"""
return _bitsizeof_varnum(value, VARUINT_MAX_VALUES, "varuint")
[docs]def bitsizeof_varsize(value: int) -> int:
"""
Gets bit size of variable size integer value.
:param value: Value to use for bit size calculation.
:returns: Bit size of the value.
:raises PythonRuntimeException: Throws if given value is out of range for varsize type.
"""
return _bitsizeof_varnum(value, VARSIZE_MAX_VALUES, "varsize")
[docs]def bitsizeof_bytes(value: bytearray) -> int:
"""
Gets bit size of bytes.
:param value: Bytes value to use for bit size calculation.
:raises PythonRuntimeException: Throws if given string is too long.
"""
return bitsizeof_varsize(len(value)) + len(value) * 8
[docs]def bitsizeof_string(string: str) -> int:
"""
Gets bit size of string.
:param string: String value to use for bit size calculation.
:raises PythonRuntimeException: Throws if given string is too long.
"""
string_bytes = string.encode("utf-8")
return bitsizeof_varsize(len(string_bytes)) + len(string_bytes) * 8
[docs]def bitsizeof_bitbuffer(bitbuffer: BitBuffer) -> int:
"""
Gets the bit size of bit buffer which is stored in bit stream.
:param bitbuffer: Bit buffer for calculation.
:returns: Length of bit buffer in bits.
:raises PythonRuntimeException: Throws if given bit buffer is too long.
"""
bitbuffer_size = bitbuffer.bitsize
# bit buffer consists of varsize for bit size followed by the bits
return bitsizeof_varsize(bitbuffer_size) + bitbuffer_size
def _bitsizeof_varnum(value: int, max_values: typing.Sequence[int], varint_name: str) -> int:
if value >= 0:
abs_value = abs(value)
for i, max_value in enumerate(max_values):
if abs_value <= max_value:
return (i + 1) * 8
raise PythonRuntimeException(f"bitsizeof: Value '{value}' is out of range for '{varint_name}'!")
VARINT16_MAX_VALUES = [(1 << (6)) - 1, (1 << (6 + 8)) - 1]
VARINT32_MAX_VALUES = [
(1 << (6)) - 1,
(1 << (6 + 7)) - 1,
(1 << (6 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 8)) - 1,
]
VARINT64_MAX_VALUES = [
(1 << (6)) - 1,
(1 << (6 + 7)) - 1,
(1 << (6 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 7 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 7 + 7 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 7 + 7 + 7 + 7 + 8)) - 1,
]
VARINT_MAX_VALUES = [
(1 << (6)) - 1,
(1 << (6 + 7)) - 1,
(1 << (6 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 7 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 7 + 7 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 7 + 7 + 7 + 7 + 7)) - 1,
(1 << (6 + 7 + 7 + 7 + 7 + 7 + 7 + 7 + 8)) - 1,
]
VARUINT16_MAX_VALUES = [(1 << (7)) - 1, (1 << (7 + 8)) - 1]
VARUINT32_MAX_VALUES = [
(1 << (7)) - 1,
(1 << (7 + 7)) - 1,
(1 << (7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 8)) - 1,
]
VARUINT64_MAX_VALUES = [
(1 << (7)) - 1,
(1 << (7 + 7)) - 1,
(1 << (7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7 + 7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7 + 7 + 7 + 7 + 8)) - 1,
]
VARUINT_MAX_VALUES = [
(1 << (7)) - 1,
(1 << (7 + 7)) - 1,
(1 << (7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7 + 7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7 + 7 + 7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7 + 7 + 7 + 7 + 7 + 8)) - 1,
]
VARSIZE_MAX_VALUES = [
(1 << (7)) - 1,
(1 << (7 + 7)) - 1,
(1 << (7 + 7 + 7)) - 1,
(1 << (7 + 7 + 7 + 7)) - 1,
(1 << (2 + 7 + 7 + 7 + 8)) - 1,
]
