class MyDynamicLengthDispatchMessage(Structure):
type = DispatchField(UBInt8())
body = DispatchTarget(None, type, {
0x1F: MySimpleFixedPayload,
0xCC: MyPayloadMessage,
})
eof = Magic(b'EOF')
class MyBasicDispatchMessage(Structure):
type = DispatchField(UBInt8())
length = LengthField(UBInt16())
body = DispatchTarget(
length, type, {
0x00: MyTargetMessage,
0x01: MyOtherTargetMessage,
None: MyDefaultTargetMessage
})
class ConditionalDispatch(Structure):
f1 = DispatchField(UBInt8())
f2 = UBInt8() # separate from f1
length = LengthField(UBInt8())
f3 = ConditionalField(DispatchTarget(length, f1, {
0: EmptyStructure,
1: BasicMessage
}),
condition=lambda m: m.f2 == 255)
class EthernetFrame(Structure):
preamble_sof = Magic('\xAA' * 8) # 8 bytes of 10101010
mac_dest = UBInt8Sequence(6)
mac_source = UBInt8Sequence(6)
ethertype = DispatchField(UBInt16())
payload = DispatchTarget(None, ethertype, {
0x0800: IPV4Frame,
# 0x85DD: IPV6Message,
# 0x0806: ARPMessage,
})
checksum = UBInt32()
class FieldAccessorMultiple(Structure):
# FieldAccessors can be referenced multiple times,
# and more than one attribute of a given field may be referenced.
# TODO: Figure out how to support LengthField(bits.upper)?
bits = BitField(8, upper=BitNum(4), lower=BitNum(4))
upper = bits.upper
lower = bits.lower
body = DispatchTarget(
None,
bits.lower,
{
0b1010: Structure16, # 0x0A
0b0101: One, # 0x05
})
class SuperMessage(Structure):
magic = Magic(b'\xAA\xAA')
# bitfield
options = BitField(8, b1=BitBool(), b2=BitBool(), rest=BitNum(6))
# unsigned big endian
ubint8 = UBInt8()
ubint16 = UBInt16()
ubint24 = UBInt24()
ubint32 = UBInt32()
ubint64 = UBInt64()
# signed big endian
sbint8 = SBInt8()
sbint16 = SBInt16()
sbint32 = SBInt32()
sbint64 = SBInt64()
# unsigned little endian
ulint8 = ULInt8()
ulint16 = ULInt16()
ulint32 = ULInt32()
ulint64 = ULInt64()
# signed little endian
slint8 = SLInt8()
slint16 = SLInt16()
slint32 = SLInt32()
slint64 = SLInt64()
# optional
optional_one = ConditionalField(UBInt8(), lambda m: m.options.b1)
optional_two = ConditionalField(UBInt8(), lambda m: m.options.b2)
# sequences with variable lengths
ubseql = LengthField(UBInt8())
ubseq = UBInt8Sequence(ubseql)
sbseql = LengthField(UBInt8())
sbseq = SBInt8Sequence(sbseql)
# sequences with fixed lengths
ubseqf = UBInt8Sequence(5)
sbseqf = SBInt8Sequence(5)
# don't change anything... for test coverage
ulint16_value = FieldProperty(ulint16)
ulint16_byte_string = FieldProperty(
ulint16,
onget=lambda v: str(v),
onset=lambda v: struct.unpack(">H", v)[0])
message_type = DispatchField(UBInt8())
submessage_length = LengthField(UBInt16())
submessage = DispatchTarget(submessage_length, message_type,
{0xEF: SuperChild})
# checksum starts after beginning magic, ends before
# the checksum
crc = CRCField(UBInt16(), crc16_ccitt, 2, -3)
eof = Magic(b'~')
class TypedArrayElement(Structure):
type = TypeField(UBInt8(), size_mapping)
value = DispatchTarget(type, type, dispatch_mapping)
class ErrorCaseSchema(Structure):
type = DispatchField(UBInt8())
length = LengthField(UBInt8())
body = DispatchTarget(length, type, {
0x00: MagicSchema
})
class FieldAccessorDispatch(Structure):
bits = BitField(8, upper=BitNum(5), lower=BitNum(3))
body = DispatchTarget(None, bits.upper, {
0: Zero,
1: One,
})
class Message(Structure):
tag = DispatchField(UBInt16())
length = LengthField(UBInt16())
message = DispatchTarget(length, tag, MESSAGE_DISPATCH_MAPPING)