119 lines
3.1 KiB
Python
119 lines
3.1 KiB
Python
|
|
||
|
|
import io
|
||
|
|
import struct
|
||
|
|
|
||
|
|
class Reader:
|
||
|
|
def __init__(self, file, chunk_id: str, parent=None, indent=0):
|
||
|
|
self.file = file
|
||
|
|
self.size: int = 0
|
||
|
|
self.size_pos = None
|
||
|
|
self.parent = parent
|
||
|
|
self.header = chunk_id
|
||
|
|
self.indent = " " * indent
|
||
|
|
|
||
|
|
|
||
|
|
def __enter__(self):
|
||
|
|
self.size_pos = self.file.tell()
|
||
|
|
self.file.seek(4,1) #skip header, will add check later
|
||
|
|
self.size = self.read_u32()
|
||
|
|
|
||
|
|
padding_length = 4 - (self.size % 4) if self.size % 4 > 0 else 0
|
||
|
|
self.end_pos = self.size_pos + padding_length + self.size + 8
|
||
|
|
|
||
|
|
print(self.indent + "Begin " + self.header + ", Size: " + str(self.size) + ", Pos: " + str(self.size_pos))
|
||
|
|
|
||
|
|
return self
|
||
|
|
|
||
|
|
|
||
|
|
def __exit__(self, exc_type, exc_value, traceback):
|
||
|
|
if self.size > self.MAX_SIZE:
|
||
|
|
raise OverflowError(f".msh file overflowed max size. size = {self.size} MAX_SIZE = {self.MAX_SIZE}")
|
||
|
|
|
||
|
|
print(self.indent + "End " + self.header)
|
||
|
|
self.file.seek(self.end_pos)
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
def read_bytes(self,num_bytes):
|
||
|
|
return self.file.read(num_bytes)
|
||
|
|
|
||
|
|
|
||
|
|
def read_string(self):
|
||
|
|
last_byte = self.read_bytes(1)
|
||
|
|
result = b''
|
||
|
|
while last_byte[0] != 0x0:
|
||
|
|
result += last_byte
|
||
|
|
last_byte = self.read_bytes(1)
|
||
|
|
|
||
|
|
return result.decode("utf-8")
|
||
|
|
|
||
|
|
def read_i8(self, num=1):
|
||
|
|
buf = self.read_bytes(num)
|
||
|
|
result = struct.unpack(f"<{num}b", buf)
|
||
|
|
return result[0] if num == 1 else result
|
||
|
|
|
||
|
|
def read_u8(self, num=1):
|
||
|
|
buf = self.read_bytes(num)
|
||
|
|
result = struct.unpack(f"<{num}B", buf)
|
||
|
|
return result[0] if num == 1 else result
|
||
|
|
|
||
|
|
def read_i16(self, num=1):
|
||
|
|
buf = self.read_bytes(num * 2)
|
||
|
|
result = struct.unpack(f"<{num}h", buf)
|
||
|
|
return result[0] if num == 1 else result
|
||
|
|
|
||
|
|
def read_u16(self, num=1):
|
||
|
|
buf = self.read_bytes(num * 2)
|
||
|
|
result = struct.unpack(f"<{num}H", buf)
|
||
|
|
return result[0] if num == 1 else result
|
||
|
|
|
||
|
|
def read_i32(self, num=1):
|
||
|
|
buf = self.read_bytes(num * 4)
|
||
|
|
result = struct.unpack(f"<{num}i", buf)
|
||
|
|
return result[0] if num == 1 else result
|
||
|
|
|
||
|
|
def read_u32(self, num=1):
|
||
|
|
buf = self.read_bytes(num * 4)
|
||
|
|
result = struct.unpack(f"<{num}I", buf)
|
||
|
|
return result[0] if num == 1 else result
|
||
|
|
|
||
|
|
def read_f32(self, num=1):
|
||
|
|
buf = self.read_bytes(num * 4)
|
||
|
|
result = struct.unpack(f"<{num}f", buf)
|
||
|
|
return result[0] if num == 1 else result
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
def read_child(self, child_id: str):
|
||
|
|
child = Reader(self.file, chunk_id=child_id, parent=self, indent=int(len(self.indent) / 2) + 1)
|
||
|
|
return child
|
||
|
|
|
||
|
|
|
||
|
|
def skip_bytes(self,num):
|
||
|
|
self.file.seek(num,1)
|
||
|
|
|
||
|
|
|
||
|
|
def peak_next_header(self):
|
||
|
|
buf = self.read_bytes(4);
|
||
|
|
self.file.seek(-4,1)
|
||
|
|
return buf.decode("utf-8")
|
||
|
|
|
||
|
|
|
||
|
|
def could_have_child(self):
|
||
|
|
return self.end_pos - self.file.tell() >= 8
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
MAX_SIZE: int = 2147483647 - 8
|
||
|
|
|
||
|
|
'''
|
||
|
|
with open("/Users/will/Desktop/spacedoortest/spa1_prop_impdoor.msh", "rb") as tst_stream:
|
||
|
|
with Reader(tst_stream, "HEDR") as hedr:
|
||
|
|
print(hedr.peak_next_header())
|
||
|
|
'''
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|