221 lines
7.1 KiB
Python

import os
import struct
class DNAName:
"""
DNAName is a C-type name stored in the DNA
"""
__slots__ = (
"name_full",
"name_only",
"is_pointer",
"is_method_pointer",
"array_size",
)
def __init__(self, name_full):
self.name_full = name_full
self.name_only = self.calc_name_only()
self.is_pointer = self.calc_is_pointer()
self.is_method_pointer = self.calc_is_method_pointer()
self.array_size = self.calc_array_size()
def __repr__(self):
return '%s(%r)' % (type(self).__qualname__, self.name_full)
def as_reference(self, parent):
if parent is None:
result = b''
else:
result = parent + b'.'
result = result + self.name_only
return result
def calc_name_only(self):
result = self.name_full.strip(b'*()')
index = result.find(b'[')
if index != -1:
result = result[:index]
return result
def calc_is_pointer(self):
return (b'*' in self.name_full)
def calc_is_method_pointer(self):
return (b'(*' in self.name_full)
def calc_array_size(self):
result = 1
temp = self.name_full
index = temp.find(b'[')
while index != -1:
index_2 = temp.find(b']')
result *= int(temp[index + 1:index_2])
temp = temp[index_2 + 1:]
index = temp.find(b'[')
return result
class DNAField:
"""
DNAField is a coupled DNAStruct and DNAName
and cache offset for reuse
"""
__slots__ = (
# DNAName
"dna_name",
# tuple of 3 items
# [bytes (struct name), int (struct size), DNAStruct]
"dna_type",
# size on-disk
"dna_size",
# cached info (avoid looping over fields each time)
"dna_offset",
)
def __init__(self, dna_type, dna_name, dna_size, dna_offset):
self.dna_type = dna_type
self.dna_name = dna_name
self.dna_size = dna_size
self.dna_offset = dna_offset
class DNAStruct:
"""
DNAStruct is a C-type structure stored in the DNA
"""
__slots__ = (
"dna_type_id",
"size",
"fields",
"field_from_name",
"user_data",
)
def __init__(self, dna_type_id):
self.dna_type_id = dna_type_id
self.fields = []
self.field_from_name = {}
self.user_data = None
def __repr__(self):
return '%s(%r)' % (type(self).__qualname__, self.dna_type_id)
def field_from_path(self, header, handle, path):
"""
Support lookups as bytes or a tuple of bytes and optional index.
C style 'id.name' --> (b'id', b'name')
C style 'array[4]' --> ('array', 4)
"""
if type(path) is tuple:
name = path[0]
if len(path) >= 2 and type(path[1]) is not bytes:
name_tail = path[2:]
index = path[1]
assert (type(index) is int)
else:
name_tail = path[1:]
index = 0
else:
name = path
name_tail = None
index = 0
assert (type(name) is bytes)
field = self.field_from_name.get(name)
if field is not None:
handle.seek(field.dna_offset, os.SEEK_CUR)
if index != 0:
if field.dna_name.is_pointer:
index_offset = header.pointer_size * index
else:
index_offset = field.dna_type.size * index
assert (index_offset < field.dna_size)
handle.seek(index_offset, os.SEEK_CUR)
if not name_tail: # None or ()
return field
else:
return field.dna_type.field_from_path(header, handle, name_tail)
def field_get(self, header, handle, path,
default=...,
use_nil=True, use_str=True,
):
field = self.field_from_path(header, handle, path)
if field is None:
if default is not ...:
return default
else:
raise KeyError("%r not found in %r (%r)" %
(
path, [f.dna_name.name_only for f in self.fields],
self.dna_type_id))
dna_type = field.dna_type
dna_name = field.dna_name
dna_size = field.dna_size
if dna_name.is_pointer:
return DNA_IO.read_pointer(handle, header)
elif dna_type.dna_type_id == b'int':
if dna_name.array_size > 1:
return [DNA_IO.read_int(handle, header) for i in range(dna_name.array_size)]
return DNA_IO.read_int(handle, header)
elif dna_type.dna_type_id == b'short':
if dna_name.array_size > 1:
return [DNA_IO.read_short(handle, header) for i in range(dna_name.array_size)]
return DNA_IO.read_short(handle, header)
elif dna_type.dna_type_id == b'uint64_t':
if dna_name.array_size > 1:
return [DNA_IO.read_ulong(handle, header) for i in range(dna_name.array_size)]
return DNA_IO.read_ulong(handle, header)
elif dna_type.dna_type_id == b'float':
if dna_name.array_size > 1:
return [DNA_IO.read_float(handle, header) for i in range(dna_name.array_size)]
return DNA_IO.read_float(handle, header)
elif dna_type.dna_type_id == b'char':
if dna_size == 1:
# Single char, assume it's bitflag or int value, and not a string/bytes data...
return DNA_IO.read_char(handle, header)
if use_str:
if use_nil:
return DNA_IO.read_string0(handle, dna_name.array_size)
else:
return DNA_IO.read_string(handle, dna_name.array_size)
else:
if use_nil:
return DNA_IO.read_bytes0(handle, dna_name.array_size)
else:
return DNA_IO.read_bytes(handle, dna_name.array_size)
else:
raise NotImplementedError("%r exists but isn't pointer, can't resolve field %r" %
(path, dna_name.name_only), dna_name, dna_type)
def field_set(self, header, handle, path, value):
assert (type(path) == bytes)
field = self.field_from_path(header, handle, path)
if field is None:
raise KeyError("%r not found in %r" %
(path, [f.dna_name.name_only for f in self.fields]))
dna_type = field.dna_type
dna_name = field.dna_name
if dna_type.dna_type_id == b'char':
if type(value) is str:
return DNA_IO.write_string(handle, value, dna_name.array_size)
else:
return DNA_IO.write_bytes(handle, value, dna_name.array_size)
else:
raise NotImplementedError("Setting %r is not yet supported for %r" %
(dna_type, dna_name), dna_name, dna_type)