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feat: speed up unmarshall (#34)

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J. Nick Koston 2022-09-24 11:18:50 -10:00 committed by GitHub
parent a4bc2392c4
commit 5a1e26f430
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 36 additions and 16 deletions
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52
src/dbus_fast/_private/unmarshaller.py
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@ -96,7 +96,6 @@ class Unmarshaller:
__slots__ = (
"unix_fds",
"can_cast",
"buf",
"view",
"offset",
@ -114,7 +113,6 @@ class Unmarshaller:
def __init__(self, stream: io.BufferedRWPair, sock=None):
self.unix_fds: List[int] = []
self.can_cast = False
self.buf = bytearray() # Actual buffer
self.view = None # Memory view of the buffer
self.offset = 0
@ -243,9 +241,9 @@ class Unmarshaller:
if reader: # complex type
return reader(self, type_)
self.offset += size + (-self.offset & (size - 1)) # align
if self.can_cast:
return self.view[self.offset - size : self.offset].cast(ctype)[0]
return struct.unpack_from(self.view, self.offset - size)[0]
if struct: # struct only set if we cannot cast
return struct.unpack_from(self.view, self.offset - size)[0]
return self.view[self.offset - size : self.offset].cast(ctype)[0]
def header_fields(self, header_length):
"""Header fields are always a(yv)."""
@ -290,11 +288,10 @@ class Unmarshaller:
self.msg_len = (
self.header_len + (-self.header_len & 7) + self.body_len
) # align 8
if (sys.byteorder == "little" and endian == LITTLE_ENDIAN) or (
can_cast = bool(sys.byteorder == "little" and endian == LITTLE_ENDIAN) or (
sys.byteorder == "big" and endian == BIG_ENDIAN
):
self.can_cast = True
self.readers = self._readers_by_type[endian]
)
self.readers = self._readers_by_type[(endian, can_cast)]
def _read_body(self):
"""Read the body of the message."""
@ -351,19 +348,42 @@ class Unmarshaller:
"v": (read_variant, None, None, None),
}
_ctype_by_endian: Dict[int, Dict[str, Tuple[None, str, int, Struct]]] = {
endian: {
_ctype_by_endian: Dict[
Tuple[int, bool], Dict[str, Tuple[None, str, int, Struct]]
] = {
endian_can_cast: {
dbus_type: (
None,
*ctype_size,
Struct(f"{UNPACK_SYMBOL[endian]}{ctype_size[0]}"),
None
if endian_can_cast[1]
else Struct(f"{UNPACK_SYMBOL[endian_can_cast[0]]}{ctype_size[0]}"),
)
for dbus_type, ctype_size in DBUS_TO_CTYPE.items()
}
for endian in (BIG_ENDIAN, LITTLE_ENDIAN)
for endian_can_cast in [
(LITTLE_ENDIAN, True),
(LITTLE_ENDIAN, False),
(BIG_ENDIAN, True),
(BIG_ENDIAN, False),
]
}
_readers_by_type: Dict[int, READER_TYPE] = {
BIG_ENDIAN: {**_ctype_by_endian[BIG_ENDIAN], **_complex_parsers},
LITTLE_ENDIAN: {**_ctype_by_endian[LITTLE_ENDIAN], **_complex_parsers},
_readers_by_type: Dict[Tuple[int, bool], READER_TYPE] = {
(LITTLE_ENDIAN, True): {
**_ctype_by_endian[(LITTLE_ENDIAN, True)],
**_complex_parsers,
},
(LITTLE_ENDIAN, False): {
**_ctype_by_endian[(LITTLE_ENDIAN, False)],
**_complex_parsers,
},
(BIG_ENDIAN, True): {
**_ctype_by_endian[(BIG_ENDIAN, True)],
**_complex_parsers,
},
(BIG_ENDIAN, False): {
**_ctype_by_endian[(BIG_ENDIAN, False)],
**_complex_parsers,
},
}