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dbus-fast/src/dbus_fast/_private/unmarshaller.py
J. Nick Koston 888a3c3ea5
feat: improve performance of unmarshalling boolean Variants (#431) 
* feat: improve performance of boolean Variants

There are only two of these type and relatively common
so we can use pre-constructed objects

* chore: tweaks
2025-03-22 16:03:56 -10:00

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from __future__ import annotations
import array
import errno
import io
import socket
import sys
from collections.abc import Iterable
from struct import Struct
from typing import TYPE_CHECKING, Any, Callable
from ..constants import MESSAGE_FLAG_MAP, MESSAGE_TYPE_MAP, MessageFlag
from ..errors import InvalidMessageError
from ..message import Message
from ..signature import SignatureType, Variant, get_signature_tree
from .constants import BIG_ENDIAN, LITTLE_ENDIAN, PROTOCOL_VERSION
MESSAGE_FLAG_INTENUM = MessageFlag
MAX_UNIX_FDS = 16
MAX_UNIX_FDS_SIZE = array.array("i").itemsize
UNIX_FDS_CMSG_LENGTH = socket.CMSG_LEN(MAX_UNIX_FDS_SIZE)
UNPACK_SYMBOL = {LITTLE_ENDIAN: "<", BIG_ENDIAN: ">"}
UINT32_CAST = "I"
UINT32_SIZE = 4
UINT32_DBUS_TYPE = "u"
INT16_CAST = "h"
INT16_SIZE = 2
INT16_DBUS_TYPE = "n"
UINT16_CAST = "H"
UINT16_SIZE = 2
UINT16_DBUS_TYPE = "q"
SYS_IS_LITTLE_ENDIAN = sys.byteorder == "little"
SYS_IS_BIG_ENDIAN = sys.byteorder == "big"
DBUS_TO_CTYPE = {
"y": ("B", 1), # byte
INT16_DBUS_TYPE: (INT16_CAST, INT16_SIZE), # int16
UINT16_DBUS_TYPE: (UINT16_CAST, UINT16_SIZE), # uint16
"i": ("i", 4), # int32
UINT32_DBUS_TYPE: (UINT32_CAST, UINT32_SIZE), # uint32
"x": ("q", 8), # int64
"t": ("Q", 8), # uint64
"d": ("d", 8), # double
"h": (UINT32_CAST, UINT32_SIZE), # uint32
}
UNPACK_HEADER_LITTLE_ENDIAN = Struct("<III").unpack_from
UNPACK_HEADER_BIG_ENDIAN = Struct(">III").unpack_from
UINT32_UNPACK_LITTLE_ENDIAN = Struct(f"<{UINT32_CAST}").unpack_from
UINT32_UNPACK_BIG_ENDIAN = Struct(f">{UINT32_CAST}").unpack_from
INT16_UNPACK_LITTLE_ENDIAN = Struct(f"<{INT16_CAST}").unpack_from
INT16_UNPACK_BIG_ENDIAN = Struct(f">{INT16_CAST}").unpack_from
UINT16_UNPACK_LITTLE_ENDIAN = Struct(f"<{UINT16_CAST}").unpack_from
UINT16_UNPACK_BIG_ENDIAN = Struct(f">{UINT16_CAST}").unpack_from
HEADER_SIGNATURE_SIZE = 16
HEADER_ARRAY_OF_STRUCT_SIGNATURE_POSITION = 12
# Most common signatures
SIGNATURE_TREE_EMPTY = get_signature_tree("")
SIGNATURE_TREE_B = get_signature_tree("b")
SIGNATURE_TREE_N = get_signature_tree("n")
SIGNATURE_TREE_S = get_signature_tree("s")
SIGNATURE_TREE_O = get_signature_tree("o")
SIGNATURE_TREE_U = get_signature_tree("u")
SIGNATURE_TREE_Y = get_signature_tree("y")
SIGNATURE_TREE_AY = get_signature_tree("ay")
SIGNATURE_TREE_AS = get_signature_tree("as")
SIGNATURE_TREE_AS_TYPES_0 = SIGNATURE_TREE_AS.root_type
SIGNATURE_TREE_A_SV = get_signature_tree("a{sv}")
SIGNATURE_TREE_A_SV_TYPES_0 = SIGNATURE_TREE_A_SV.root_type
SIGNATURE_TREE_AO = get_signature_tree("ao")
SIGNATURE_TREE_AO_TYPES_0 = SIGNATURE_TREE_AO.root_type
SIGNATURE_TREE_OAS = get_signature_tree("oas")
SIGNATURE_TREE_OAS_TYPES_1 = SIGNATURE_TREE_OAS.types[1]
SIGNATURE_TREE_AY_TYPES_0 = SIGNATURE_TREE_AY.root_type
SIGNATURE_TREE_A_QV = get_signature_tree("a{qv}")
SIGNATURE_TREE_A_QV_TYPES_0 = SIGNATURE_TREE_A_QV.root_type
SIGNATURE_TREE_SA_SV_AS = get_signature_tree("sa{sv}as")
SIGNATURE_TREE_SA_SV_AS_TYPES_1 = SIGNATURE_TREE_SA_SV_AS.types[1]
SIGNATURE_TREE_SA_SV_AS_TYPES_2 = SIGNATURE_TREE_SA_SV_AS.types[2]
SIGNATURE_TREE_OA_SA_SV = get_signature_tree("oa{sa{sv}}")
SIGNATURE_TREE_OA_SA_SV_TYPES_1 = SIGNATURE_TREE_OA_SA_SV.types[1]
SIGNATURE_TREE_A_OA_SA_SV = get_signature_tree("a{oa{sa{sv}}}")
SIGNATURE_TREE_A_OA_SA_SV_TYPES_0 = SIGNATURE_TREE_A_OA_SA_SV.root_type
TOKEN_B_AS_INT = ord("b")
TOKEN_U_AS_INT = ord("u")
TOKEN_Y_AS_INT = ord("y")
TOKEN_A_AS_INT = ord("a")
TOKEN_O_AS_INT = ord("o")
TOKEN_S_AS_INT = ord("s")
TOKEN_G_AS_INT = ord("g")
TOKEN_N_AS_INT = ord("n")
TOKEN_X_AS_INT = ord("x")
TOKEN_T_AS_INT = ord("t")
TOKEN_D_AS_INT = ord("d")
TOKEN_Q_AS_INT = ord("q")
TOKEN_V_AS_INT = ord("v")
TOKEN_LEFT_CURLY_AS_INT = ord("{")
TOKEN_LEFT_PAREN_AS_INT = ord("(")
VARIANT_BOOL_TRUE = Variant._factory(SIGNATURE_TREE_B, True)
VARIANT_BOOL_FALSE = Variant._factory(SIGNATURE_TREE_B, False)
ARRAY = array.array
SOL_SOCKET = socket.SOL_SOCKET
SCM_RIGHTS = socket.SCM_RIGHTS
EAGAIN = errno.EAGAIN
EWOULDBLOCK = errno.EWOULDBLOCK
HEADER_IDX_TO_ARG_NAME = [
"",
"path",
"interface",
"member",
"error_name",
"reply_serial",
"destination",
"sender",
"signature",
"unix_fds",
]
HEADER_PATH_IDX = HEADER_IDX_TO_ARG_NAME.index("path")
HEADER_INTERFACE_IDX = HEADER_IDX_TO_ARG_NAME.index("interface")
HEADER_MEMBER_IDX = HEADER_IDX_TO_ARG_NAME.index("member")
HEADER_ERROR_NAME_IDX = HEADER_IDX_TO_ARG_NAME.index("error_name")
HEADER_REPLY_SERIAL_IDX = HEADER_IDX_TO_ARG_NAME.index("reply_serial")
HEADER_DESTINATION_IDX = HEADER_IDX_TO_ARG_NAME.index("destination")
HEADER_SENDER_IDX = HEADER_IDX_TO_ARG_NAME.index("sender")
HEADER_SIGNATURE_IDX = HEADER_IDX_TO_ARG_NAME.index("signature")
HEADER_UNIX_FDS_IDX = HEADER_IDX_TO_ARG_NAME.index("unix_fds")
_EMPTY_HEADERS: list[Any | None] = [None] * len(HEADER_IDX_TO_ARG_NAME)
_SignatureType = SignatureType
_int = int
READER_TYPE = Callable[["Unmarshaller", SignatureType], Any]
MARSHALL_STREAM_END_ERROR = BlockingIOError
DEFAULT_BUFFER_SIZE = io.DEFAULT_BUFFER_SIZE
def unpack_parser_factory(unpack_from: Callable, size: int) -> READER_TYPE:
"""Build a parser that unpacks the bytes using the given unpack_from function."""
def _unpack_from_parser(self: Unmarshaller, signature: SignatureType) -> Any:
self._pos += size + (-self._pos & (size - 1)) # align
return unpack_from(self._buf, self._pos - size)[0]
return _unpack_from_parser
def build_simple_parsers(
endian: int,
) -> dict[str, Callable[[Unmarshaller, SignatureType], Any]]:
"""Build a dict of parsers for simple types."""
parsers: dict[str, READER_TYPE] = {}
for dbus_type, ctype_size in DBUS_TO_CTYPE.items():
ctype, size = ctype_size
size = ctype_size[1]
parsers[dbus_type] = unpack_parser_factory(
Struct(f"{UNPACK_SYMBOL[endian]}{ctype}").unpack_from, size
)
return parsers
try:
import cython
except ImportError:
from ._cython_compat import FAKE_CYTHON as cython
int_ = int
bytearray_ = bytearray
def is_compiled() -> bool:
return cython.compiled
def _ustr_uint32(buf: bytearray_, pos: int_, endian: int_) -> int_:
if endian == LITTLE_ENDIAN:
return (
buf[pos] | (buf[pos + 1] << 8) | (buf[pos + 2] << 16) | (buf[pos + 3] << 24)
)
return buf[pos + 3] | (buf[pos + 2] << 8) | (buf[pos + 1] << 16) | (buf[pos] << 24)
def buffer_to_uint32(buf: bytearray, pos: int, endian: int) -> int:
return _ustr_uint32(buf, pos, endian)
def _ustr_int16(buf: bytearray_, pos: int_, endian: int_) -> int_:
# Caution: this function will only work with Cython
# because it relies on casting the result to a signed int
# and will return an unsigned int if not compiled.
if endian == LITTLE_ENDIAN:
return buf[pos] | (buf[pos + 1] << 8) # pragma: no cover
return buf[pos + 1] | (buf[pos] << 8) # pragma: no cover
def buffer_to_int16(buf: bytearray | bytes, pos: int, endian: int) -> int:
# Caution: this function will only work with Cython
# because it relies on casting the result to a signed int
# and will return an unsigned int if not compiled.
return _ustr_int16(buf, pos, endian)
def _ustr_uint16(buf: bytearray_, pos: int_, endian: int_) -> int_:
if endian == LITTLE_ENDIAN:
return buf[pos] | (buf[pos + 1] << 8)
return buf[pos + 1] | (buf[pos] << 8)
def buffer_to_uint16(buf: bytearray, pos: int, endian: int) -> int:
return _ustr_uint16(buf, pos, endian)
# Alignment padding is handled with the following formula below
#
# For any align value, the correct padding formula is:
#
# (align - (pos % align)) % align
#
# However, if align is a power of 2 (always the case here), the slow MOD
# operator can be replaced by a bitwise AND:
#
# (align - (pos & (align - 1))) & (align - 1)
#
# Which can be simplified to:
#
# (-pos) & (align - 1)
#
#
class Unmarshaller:
"""Unmarshall messages from a stream.
When calling with sock and _negotiate_unix_fd False, the unmashaller must
be called continuously for each new message as it will buffer the data
until a complete message is available.
"""
__slots__ = (
"_body_len",
"_buf",
"_buf_len",
"_buf_ustr",
"_endian",
"_flag",
"_header_len",
"_int16_unpack",
"_message",
"_message_type",
"_msg_len",
"_negotiate_unix_fd",
"_pos",
"_read_complete",
"_readers",
"_serial",
"_sock",
"_sock_with_fds_reader",
"_sock_without_fds_reader",
"_stream",
"_stream_reader",
"_uint16_unpack",
"_uint32_unpack",
"_unix_fds",
)
_stream_reader: Callable[[int], bytes]
def __init__(
self,
stream: io.BufferedRWPair | None = None,
sock: socket.socket | None = None,
negotiate_unix_fd: bool = True,
) -> None:
self._unix_fds: list[int] = []
self._buf: bytearray = bytearray.__new__(bytearray) # Actual buffer
self._buf_ustr = self._buf # Used to avoid type checks
self._buf_len = 0
self._stream = stream
self._sock = sock
self._message: Message | None = None
self._readers: dict[str, READER_TYPE] = {}
self._pos = 0
self._body_len = 0
self._serial = 0
self._header_len = 0
self._message_type = 0
self._flag = 0
self._msg_len = 0
self._uint32_unpack: Callable[[bytearray, int], tuple[int]] | None = None
self._int16_unpack: Callable[[bytearray, int], tuple[int]] | None = None
self._uint16_unpack: Callable[[bytearray, int], tuple[int]] | None = None
self._negotiate_unix_fd = negotiate_unix_fd
self._read_complete = False
if stream:
if isinstance(stream, io.BufferedRWPair) and hasattr(stream, "reader"):
self._stream_reader = stream.reader.read
else:
self._stream_reader = stream.read
elif self._negotiate_unix_fd:
if TYPE_CHECKING:
assert self._sock is not None
self._sock_with_fds_reader = self._sock.recvmsg
else:
if TYPE_CHECKING:
assert self._sock is not None
self._sock_without_fds_reader = self._sock.recv
self._endian = 0
def _next_message(self) -> None:
"""Reset the unmarshaller to its initial state.
Call this before processing a new message.
"""
if self._unix_fds:
self._unix_fds = []
to_clear = HEADER_SIGNATURE_SIZE + self._msg_len
if self._buf_len == to_clear:
self._buf = bytearray.__new__(bytearray)
self._buf_len = 0
else:
del self._buf[:to_clear]
self._buf_len -= to_clear
self._buf_ustr = self._buf
self._msg_len = 0 # used to check if we have ready the header
self._read_complete = False # used to check if we have ready the message
# No need to reset the unpack functions, they are set in _read_header
# every time a new message is processed.
@property
def message(self) -> Message | None:
"""Return the message that has been unmarshalled."""
if self._read_complete:
return self._message
return None
def _has_another_message_in_buffer(self) -> bool:
"""Check if there is another message in the buffer."""
return self._buf_len > HEADER_SIGNATURE_SIZE + self._msg_len
def _read_sock_with_fds(self, pos: _int, missing_bytes: _int) -> None:
"""reads from the socket, storing any fds sent and handling errors
from the read itself.
This function is greedy and will read as much data as possible
from the underlying socket.
"""
# This will raise BlockingIOError if there is no data to read
# which we store in the MARSHALL_STREAM_END_ERROR object
try:
recv = self._sock_with_fds_reader(missing_bytes, UNIX_FDS_CMSG_LENGTH)
except OSError as e:
errno = e.errno
if errno == EAGAIN or errno == EWOULDBLOCK:
raise MARSHALL_STREAM_END_ERROR
raise
msg = recv[0]
ancdata = recv[1]
if ancdata:
for level, type_, data in ancdata:
if not (level == SOL_SOCKET and type_ == SCM_RIGHTS):
continue
self._unix_fds.extend(
ARRAY("i", data[: len(data) - (len(data) % MAX_UNIX_FDS_SIZE)])
)
if not msg:
raise EOFError
self._buf += msg
self._buf_len = len(self._buf)
if self._buf_len < pos:
raise MARSHALL_STREAM_END_ERROR
def _read_sock_without_fds(self, pos: _int) -> None:
"""reads from the socket and handling errors from the read itself.
This function is greedy and will read as much data as possible
from the underlying socket.
"""
# This will raise BlockingIOError if there is no data to read
# which we store in the MARSHALL_STREAM_END_ERROR object
while True:
try:
data = self._sock_without_fds_reader(DEFAULT_BUFFER_SIZE)
except OSError as e:
errno = e.errno
if errno == EAGAIN or errno == EWOULDBLOCK:
raise MARSHALL_STREAM_END_ERROR
raise
if not data:
raise EOFError
self._buf += data
self._buf_len = len(self._buf)
if self._buf_len >= pos:
return
def _read_stream(self, pos: _int, missing_bytes: _int) -> None:
"""Read from the stream."""
data = self._stream_reader(missing_bytes)
if data is None:
raise MARSHALL_STREAM_END_ERROR
if not data:
raise EOFError
self._buf += data
self._buf_len = len(self._buf)
if self._buf_len < pos:
raise MARSHALL_STREAM_END_ERROR
def _read_to_pos(self, pos: _int) -> None:
"""
Read from underlying socket into buffer.
Raises BlockingIOError if there is not enough data to be read.
:arg pos:
The pos to read to. If not enough bytes are available in the
buffer, read more from it.
:returns:
None
"""
missing_bytes = pos - self._buf_len
if missing_bytes <= 0:
return
if self._sock is None:
self._read_stream(pos, missing_bytes)
elif self._negotiate_unix_fd:
self._read_sock_with_fds(pos, missing_bytes)
else:
self._read_sock_without_fds(pos)
self._buf_ustr = self._buf
def read_uint32_unpack(self, type_: _SignatureType) -> int:
return self._read_uint32_unpack()
def _read_uint32_unpack(self) -> int:
self._pos += UINT32_SIZE + (-self._pos & (UINT32_SIZE - 1)) # align
if cython.compiled:
if self._buf_len < self._pos:
raise IndexError("Not enough data to read uint32")
return _ustr_uint32(self._buf_ustr, self._pos - UINT32_SIZE, self._endian)
return self._uint32_unpack(self._buf, self._pos - UINT32_SIZE)[0]
def read_uint16_unpack(self, type_: _SignatureType) -> int:
return self._read_uint16_unpack()
def _read_uint16_unpack(self) -> int:
self._pos += UINT16_SIZE + (-self._pos & (UINT16_SIZE - 1)) # align
if cython.compiled:
if self._buf_len < self._pos:
raise IndexError("Not enough data to read uint16")
return _ustr_uint16(self._buf_ustr, self._pos - UINT16_SIZE, self._endian)
return self._uint16_unpack(self._buf, self._pos - UINT16_SIZE)[0]
def read_int16_unpack(self, type_: _SignatureType) -> int:
return self._read_int16_unpack()
def _read_int16_unpack(self) -> int:
self._pos += INT16_SIZE + (-self._pos & (INT16_SIZE - 1)) # align
if cython.compiled:
if self._buf_len < self._pos:
raise IndexError("Not enough data to read int16")
return _ustr_int16(self._buf_ustr, self._pos - INT16_SIZE, self._endian)
return self._int16_unpack(self._buf, self._pos - INT16_SIZE)[0]
def read_boolean(self, type_: _SignatureType) -> bool:
return self._read_boolean()
def _read_boolean(self) -> bool:
return bool(self._read_uint32_unpack())
def read_string_unpack(self, type_: _SignatureType) -> str:
return self._read_string_unpack()
def _read_string_unpack(self) -> str:
"""Read a string using unpack."""
self._pos += UINT32_SIZE + (-self._pos & (UINT32_SIZE - 1)) # align
str_start = self._pos
# read terminating '\0' byte as well (str_length + 1)
if cython.compiled:
if self._buf_len < self._pos:
raise IndexError("Not enough data to read uint32")
self._pos += (
_ustr_uint32(self._buf_ustr, str_start - UINT32_SIZE, self._endian) + 1
)
if self._buf_len < self._pos:
raise IndexError("Not enough data to read string")
else:
self._pos += self._uint32_unpack(self._buf, str_start - UINT32_SIZE)[0] + 1
return self._buf_ustr[str_start : self._pos - 1].decode()
def read_signature(self, type_: _SignatureType) -> str:
return self._read_signature()
def _read_signature(self) -> str:
if cython.compiled:
if self._buf_len < self._pos:
raise IndexError("Not enough data to read signature")
signature_len = self._buf_ustr[self._pos] # byte
o = self._pos + 1
# read terminating '\0' byte as well (str_length + 1)
self._pos = o + signature_len + 1
if cython.compiled:
if self._buf_len < self._pos:
raise IndexError("Not enough data to read signature")
return self._buf_ustr[o : o + signature_len].decode()
def read_variant(self, type_: _SignatureType) -> Variant:
return self._read_variant()
def _read_variant(self) -> Variant:
signature = self._read_signature()
token_as_int = ord(signature[0])
# verify in Variant is only useful on construction not unmarshalling
if len(signature) == 1:
if token_as_int == TOKEN_N_AS_INT:
return Variant._factory(SIGNATURE_TREE_N, self._read_int16_unpack())
if token_as_int == TOKEN_S_AS_INT:
return Variant._factory(SIGNATURE_TREE_S, self._read_string_unpack())
if token_as_int == TOKEN_B_AS_INT:
return VARIANT_BOOL_TRUE if self._read_boolean() else VARIANT_BOOL_FALSE
if token_as_int == TOKEN_O_AS_INT:
return Variant._factory(SIGNATURE_TREE_O, self._read_string_unpack())
if token_as_int == TOKEN_U_AS_INT:
return Variant._factory(SIGNATURE_TREE_U, self._read_uint32_unpack())
if token_as_int == TOKEN_Y_AS_INT:
if cython.compiled:
if self._buf_len < self._pos:
raise IndexError("Not enough data to read byte")
self._pos += 1
return Variant._factory(SIGNATURE_TREE_Y, self._buf_ustr[self._pos - 1])
elif token_as_int == TOKEN_A_AS_INT:
if signature == "ay":
return Variant._factory(
SIGNATURE_TREE_AY, self.read_array(SIGNATURE_TREE_AY_TYPES_0)
)
if signature == "a{qv}":
return Variant._factory(
SIGNATURE_TREE_A_QV, self.read_array(SIGNATURE_TREE_A_QV_TYPES_0)
)
if signature == "as":
return Variant._factory(
SIGNATURE_TREE_AS, self.read_array(SIGNATURE_TREE_AS_TYPES_0)
)
if signature == "a{sv}":
return Variant._factory(
SIGNATURE_TREE_A_SV, self.read_array(SIGNATURE_TREE_A_SV_TYPES_0)
)
if signature == "ao":
return Variant._factory(
SIGNATURE_TREE_AO, self.read_array(SIGNATURE_TREE_AO_TYPES_0)
)
tree = get_signature_tree(signature)
signature_type = tree.root_type
return Variant._factory(
tree, self._readers[signature_type.token](self, signature_type)
)
def read_struct(self, type_: _SignatureType) -> list[Any]:
self._pos += -self._pos & 7 # align 8
readers = self._readers
return [
readers[child_type.token](self, child_type) for child_type in type_.children
]
def read_dict_entry(self, type_: _SignatureType) -> tuple[Any, Any]:
self._pos += -self._pos & 7 # align 8
return self._readers[type_.children[0].token](
self, type_.children[0]
), self._readers[type_.children[1].token](self, type_.children[1])
def read_array(self, type_: _SignatureType) -> Iterable[Any]:
self._pos += -self._pos & 3 # align 4 for the array
self._pos += (
-self._pos & (UINT32_SIZE - 1)
) + UINT32_SIZE # align for the uint32
if cython.compiled:
if self._buf_len < self._pos:
raise IndexError("Not enough data to read uint32")
array_length = _ustr_uint32(
self._buf_ustr, self._pos - UINT32_SIZE, self._endian
)
else:
array_length = self._uint32_unpack(self._buf, self._pos - UINT32_SIZE)[0]
child_type: SignatureType = type_.children[0]
token_as_int = child_type.token_as_int
if (
token_as_int == TOKEN_X_AS_INT
or token_as_int == TOKEN_T_AS_INT
or token_as_int == TOKEN_D_AS_INT
or token_as_int == TOKEN_LEFT_CURLY_AS_INT
or token_as_int == TOKEN_LEFT_PAREN_AS_INT
):
# the first alignment is not included in the array size
self._pos += -self._pos & 7 # align 8
if token_as_int == TOKEN_Y_AS_INT:
self._pos += array_length
if cython.compiled:
if self._buf_len < self._pos:
raise IndexError("Not enough data to read byte")
return self._buf_ustr[self._pos - array_length : self._pos]
if token_as_int == TOKEN_LEFT_CURLY_AS_INT:
result_dict: dict[Any, Any] = {}
key: str | int
beginning_pos = self._pos
children = child_type.children
child_0 = children[0]
child_1 = children[1]
child_0_token_as_int = child_0.token_as_int
child_1_token_as_int = child_1.token_as_int
# Strings with variant values are the most common case
# so we optimize for that by inlining the string reading
# and the variant reading here
if (
child_0_token_as_int == TOKEN_O_AS_INT
or child_0_token_as_int == TOKEN_S_AS_INT
) and child_1_token_as_int == TOKEN_V_AS_INT:
while self._pos - beginning_pos < array_length:
self._pos += -self._pos & 7 # align 8
key = self._read_string_unpack()
result_dict[key] = self._read_variant()
elif (
child_0_token_as_int == TOKEN_Q_AS_INT
and child_1_token_as_int == TOKEN_V_AS_INT
):
while self._pos - beginning_pos < array_length:
self._pos += -self._pos & 7 # align 8
key = self._read_uint16_unpack()
result_dict[key] = self._read_variant()
elif (
child_0_token_as_int == TOKEN_O_AS_INT
or child_0_token_as_int == TOKEN_S_AS_INT
) and child_1_token_as_int == TOKEN_A_AS_INT:
while self._pos - beginning_pos < array_length:
self._pos += -self._pos & 7 # align 8
key = self._read_string_unpack()
result_dict[key] = self.read_array(child_1)
else:
reader_1 = self._readers[child_1.token]
reader_0 = self._readers[child_0.token]
while self._pos - beginning_pos < array_length:
self._pos += -self._pos & 7 # align 8
key = reader_0(self, child_0)
result_dict[key] = reader_1(self, child_1)
return result_dict
if array_length == 0:
return []
result_list = []
beginning_pos = self._pos
if token_as_int == TOKEN_O_AS_INT or token_as_int == TOKEN_S_AS_INT:
while self._pos - beginning_pos < array_length:
result_list.append(self._read_string_unpack())
return result_list
reader = self._readers[child_type.token]
while self._pos - beginning_pos < array_length:
result_list.append(reader(self, child_type))
return result_list
def _header_fields(self, header_length: _int) -> list[Any]:
"""Header fields are always a(yv)."""
beginning_pos = self._pos
headers = _EMPTY_HEADERS.copy()
if cython.compiled:
if self._buf_len < self._pos + header_length:
raise IndexError("Not enough data to read header")
while self._pos - beginning_pos < header_length:
# Now read the y (byte) of struct (yv)
self._pos += (-self._pos & 7) + 1 # align 8 + 1 for 'y' byte
field_0 = self._buf_ustr[self._pos - 1]
# Now read the v (variant) of struct (yv)
# first we read the signature
signature_len = self._buf_ustr[self._pos] # byte
o = self._pos + 1
if cython.compiled:
if self._buf_len < o + signature_len:
raise IndexError("Not enough data to read signature")
self._pos += signature_len + 2 # one for the byte, one for the '\0'
if field_0 == HEADER_UNIX_FDS_IDX: # defined by self._unix_fds
continue
token_as_int = self._buf_ustr[o]
# Now that we have the token we can read the variant value
# Strings and signatures are the most common types
# so we inline them for performance
if token_as_int == TOKEN_O_AS_INT or token_as_int == TOKEN_S_AS_INT:
headers[field_0] = self._read_string_unpack()
elif token_as_int == TOKEN_G_AS_INT:
headers[field_0] = self._read_signature()
else:
token = self._buf_ustr[o : o + signature_len].decode()
# There shouldn't be any other types in the header
# but just in case, we'll read it using the slow path
headers[field_0] = self._readers[token](
self, get_signature_tree(token).root_type
)
return headers
def _read_header(self) -> None:
"""Read the header of the message."""
# Signature is of the header is
# BYTE, BYTE, BYTE, BYTE, UINT32, UINT32, ARRAY of STRUCT of (BYTE,VARIANT)
self._read_to_pos(HEADER_SIGNATURE_SIZE)
endian = self._buf_ustr[0]
self._message_type = self._buf_ustr[1]
self._flag = self._buf_ustr[2]
protocol_version = self._buf_ustr[3]
if protocol_version != PROTOCOL_VERSION:
raise InvalidMessageError(
f"got unknown protocol version: {protocol_version}"
)
if endian != LITTLE_ENDIAN and endian != BIG_ENDIAN:
raise InvalidMessageError(
f"Expecting endianness as the first byte, got {endian} from {self._buf}"
)
if cython.compiled:
self._body_len = _ustr_uint32(self._buf_ustr, 4, endian)
self._serial = _ustr_uint32(self._buf_ustr, 8, endian)
self._header_len = _ustr_uint32(self._buf_ustr, 12, endian)
elif endian == LITTLE_ENDIAN:
(
self._body_len,
self._serial,
self._header_len,
) = UNPACK_HEADER_LITTLE_ENDIAN(self._buf, 4)
self._uint32_unpack = UINT32_UNPACK_LITTLE_ENDIAN
self._int16_unpack = INT16_UNPACK_LITTLE_ENDIAN
self._uint16_unpack = UINT16_UNPACK_LITTLE_ENDIAN
else: # BIG_ENDIAN
self._body_len, self._serial, self._header_len = UNPACK_HEADER_BIG_ENDIAN(
self._buf, 4
)
self._uint32_unpack = UINT32_UNPACK_BIG_ENDIAN
self._int16_unpack = INT16_UNPACK_BIG_ENDIAN
self._uint16_unpack = UINT16_UNPACK_BIG_ENDIAN
# align 8
self._msg_len = self._header_len + (-self._header_len & 7) + self._body_len
if self._endian != endian:
self._readers = self._readers_by_type[endian]
self._endian = endian
def _read_body(self) -> None:
"""Read the body of the message."""
self._read_to_pos(HEADER_SIGNATURE_SIZE + self._msg_len)
self._pos = HEADER_ARRAY_OF_STRUCT_SIGNATURE_POSITION
header_fields = self._header_fields(self._header_len)
self._pos += -self._pos & 7 # align 8
signature: str = header_fields[HEADER_SIGNATURE_IDX]
if not self._body_len:
tree = SIGNATURE_TREE_EMPTY
body: list[Any] = []
else:
token_as_int = ord(signature[0])
if len(signature) == 1:
if token_as_int == TOKEN_O_AS_INT:
tree = SIGNATURE_TREE_O
body = [self._read_string_unpack()]
elif token_as_int == TOKEN_S_AS_INT:
tree = SIGNATURE_TREE_S
body = [self._read_string_unpack()]
else:
tree = get_signature_tree(signature)
body = [self._readers[t.token](self, t) for t in tree.types]
elif token_as_int == TOKEN_S_AS_INT and signature == "sa{sv}as":
tree = SIGNATURE_TREE_SA_SV_AS
body = [
self._read_string_unpack(),
self.read_array(SIGNATURE_TREE_SA_SV_AS_TYPES_1),
self.read_array(SIGNATURE_TREE_SA_SV_AS_TYPES_2),
]
elif token_as_int == TOKEN_O_AS_INT and signature == "oa{sa{sv}}":
tree = SIGNATURE_TREE_OA_SA_SV
body = [
self._read_string_unpack(),
self.read_array(SIGNATURE_TREE_OA_SA_SV_TYPES_1),
]
elif token_as_int == TOKEN_O_AS_INT and signature == "oas":
tree = SIGNATURE_TREE_OAS
body = [
self._read_string_unpack(),
self.read_array(SIGNATURE_TREE_OAS_TYPES_1),
]
elif token_as_int == TOKEN_A_AS_INT and signature == "a{oa{sa{sv}}}":
tree = SIGNATURE_TREE_A_OA_SA_SV
body = [self.read_array(SIGNATURE_TREE_A_OA_SA_SV_TYPES_0)]
else:
tree = get_signature_tree(signature)
body = [self._readers[t.token](self, t) for t in tree.types]
flags = MESSAGE_FLAG_MAP.get(self._flag)
if flags is None:
flags = MESSAGE_FLAG_INTENUM(self._flag)
message = Message.__new__(Message)
message._fast_init(
header_fields[HEADER_DESTINATION_IDX],
header_fields[HEADER_PATH_IDX],
header_fields[HEADER_INTERFACE_IDX],
header_fields[HEADER_MEMBER_IDX],
MESSAGE_TYPE_MAP[self._message_type],
flags,
header_fields[HEADER_ERROR_NAME_IDX],
header_fields[HEADER_REPLY_SERIAL_IDX] or 0,
header_fields[HEADER_SENDER_IDX],
self._unix_fds,
tree,
body,
self._serial,
# The D-Bus implementation already validates the message,
# so we don't need to do it again.
False,
)
self._message = message
self._read_complete = True
def unmarshall(self) -> Message | None:
"""Unmarshall the message.
The underlying read function will raise BlockingIOError if the
if there are not enough bytes in the buffer. This allows unmarshall
to be resumed when more data comes in over the wire.
"""
return self._unmarshall()
def _unmarshall(self) -> Message | None:
"""Unmarshall the message.
The underlying read function will raise BlockingIOError if the
if there are not enough bytes in the buffer. This allows unmarshall
to be resumed when more data comes in over the wire.
"""
if self._read_complete:
self._next_message()
try:
if not self._msg_len:
self._read_header()
self._read_body()
except MARSHALL_STREAM_END_ERROR:
return None
return self._message
_complex_parsers_unpack: dict[str, Callable[[Unmarshaller, SignatureType], Any]] = {
"b": read_boolean,
"o": read_string_unpack,
"s": read_string_unpack,
"g": read_signature,
"a": read_array,
"(": read_struct,
"{": read_dict_entry,
"v": read_variant,
"h": read_uint32_unpack,
UINT32_DBUS_TYPE: read_uint32_unpack,
INT16_DBUS_TYPE: read_int16_unpack,
UINT16_DBUS_TYPE: read_uint16_unpack,
}
_ctype_by_endian: dict[int, dict[str, READER_TYPE]] = {
endian: build_simple_parsers(endian) for endian in (LITTLE_ENDIAN, BIG_ENDIAN)
}
_readers_by_type: dict[int, dict[str, READER_TYPE]] = {
LITTLE_ENDIAN: {
**_ctype_by_endian[LITTLE_ENDIAN],
**_complex_parsers_unpack,
},
BIG_ENDIAN: {
**_ctype_by_endian[BIG_ENDIAN],
**_complex_parsers_unpack,
},
}
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