ExecTest.py

ExecTest.py

# coding: utf-8
import struct

def with_metaclass(meta, *bases):
    """Create a base class with a metaclass. For 2/3 compatibility."""
    class metaclass(meta):
        __call__ = type.__call__
        __init__ = type.__init__
        def __new__(cls, name, this_bases, d):
            if this_bases is None:
                return type.__new__(cls, name, (), d)
            return meta(name, bases, d)
    return metaclass("NewBase", None, {})

class BinaryFieldBase():
    _format = 'i'

class BinaryObjectMeta(type):
    def __new__(metaclass, class_name, class_bases, class_attr):
        if class_name != 'BinaryObjectBase':
            class_attr['_structs'] = []
            func_string = 'def unpack_from(self, data, offset = 0):\n'
        
            partial_struct = class_attr['_byte_order']
            partial_list = ''
            partial_idx = 0
            for i,key in enumerate(class_attr['_field_order']):
                field = class_attr[key]
                
                if issubclass(field.__class__, BinaryFieldBase):
                    partial_struct += field._format
                    partial_list += 'self.{}, '.format(key)
                elif issubclass(field.__class__, BinaryObjectBase) and field._flat:
                    pass
                elif issubclass(field.__class__, BinaryObjectBase) and not field._flat:
                    if len(partial_struct) > 1:
                        sId = len(class_attr['_structs'])
                        class_attr['_structs'].append(struct.Struct(partial_struct))
                        func_string += '\n\tsz = self._structs[{0}].size\n'.format(sId)
                        func_string += '\t' + partial_list[:-2] + ' = self._structs[{0}].unpack_from(data, offset)\n'.format(sId)
                        func_string += '\toffset += sz\n'
                        
                        partial_struct = class_attr['_byte_order']
                        partial_list = ''
                        partial_idx = i
                    func_string += '\n\tself.{}.unpack_from(data, offset)\n'.format(key)
                    func_string += '\toffset += self.{}.size\n'.format(key)
                else:
                    print field
                    print field.__class__
                    print field.__dict__
                    
                    
            if len(partial_struct) > 1:
                sId = len(class_attr['_structs'])
                class_attr['_structs'].append(struct.Struct(partial_struct))
                func_string += '\n\tsz = self._structs[{0}].size\n'.format(sId)
                func_string += '\t' + partial_list[:-2] + ' = self._structs[{0}].unpack_from(data, offset)\n'.format(sId)
                func_string += '\toffset += sz\n'
            print func_string
        
        return type.__new__(metaclass, class_name, class_bases, class_attr)

class BinaryObjectBase(with_metaclass(BinaryObjectMeta, object)):
    _byte_order = '='
    _field_order = None
    _structs = None
    

class subItem(BinaryObjectBase):
    _flat = False
    _byte_order = '='
    _field_order = ['c','d','e']
    c = BinaryFieldBase()
    d = BinaryFieldBase()
    e = BinaryFieldBase()

class subItemFlat(BinaryObjectBase):
    _flat = True
    _byte_order = '='
    _field_order = ['c','d','e']
    c = BinaryFieldBase()
    d = BinaryFieldBase()
    e = BinaryFieldBase()

class test(BinaryObjectBase):
    _byte_order = '='
    _field_order = ['a','b','sub','f','g','h']
    a = BinaryFieldBase()
    b = BinaryFieldBase()
    sub = subItem()
    f = BinaryFieldBase()
    g = BinaryFieldBase()
    h = subItemFlat()