Created
April 3, 2024 12:41
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from construct import * | |
def sizeof_struct(subcon, value, parent=None): | |
ctx = Container(value) | |
ctx._ = parent or Container() | |
ctx._params = Container() | |
ctx._parsing = False | |
ctx._sizing = True | |
ctx._building = False | |
size = 0 | |
for sc in subcon.subcons: | |
if sc.name: | |
size += sizeof(sc.subcon, ctx[sc.name], parent=ctx) | |
else: | |
size += sc._sizeof(ctx, "(sizeof)") | |
return size | |
def sizeof(subcon, value, parent=None): | |
if not parent or not hasattr(parent, "_params"): | |
parent = Container(parent) if parent else Container() | |
parent._params = Container() | |
parent._parsing = False | |
parent._sizing = True | |
parent._building = False | |
try: | |
return subcon._sizeof(parent, "(sizeof)") | |
except SizeofError: | |
pass | |
if isinstance(subcon, (Hex, Dec, HexDump, Aligned, StringEncoded, OffsettedEnd)): | |
return sizeof(subcon.subcon, value, parent) | |
if isinstance(subcon, (GreedyRange, RepeatUntil)): | |
subcon = subcon.subcon | |
itemsize = subcon.sizeof() | |
if itemsize: | |
return len(value) * itemsize | |
elif value and hasattr(value[name][0], "sizeof"): | |
return sum([x.sizeof() for x in value]) | |
else: | |
return sum([sizeof(subcon, x, parent) for x in value]) | |
if subcon == GreedyBytes: | |
return len(value) | |
if isinstance(subcon, Prefixed): | |
return subcon.lengthfield.sizeof() + len(value) | |
if isinstance(subcon, NullTerminated): | |
return sizeof(subcon.subcon, value, parent) + 1 | |
if isinstance(subcon, Struct): | |
return sizeof_struct(subcon, value, parent) | |
raise Exception(f"Don't know how to calculate size for {subcon}, {value}") |
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