Python-сообщество

#ifndef PATCHER_H
#define PATCHER_H

#include <stdio.h>

int patcher_start(FILE *fp);
int patcher_patch(size_t offset, const char *bytes, size_t length);
int patcher_can_patch(long offset, long length);
int patcher_end();

#endif

#include "patcher.h"

static FILE *_fp;

int patcher_start(FILE *fp)
{
    _fp = fp;
    return 1;
}

int patcher_end(void)
{
    _fp = NULL;
    return 1;
}

int patcher_patch(size_t offset, const char *bytes, size_t length)
{
    if (fseek(_fp, offset, SEEK_SET))
        return 0;
    if (fwrite(bytes, length, 1, _fp) != 1)
        return 0;
    return 1;
}

int patcher_can_patch(long offset, long length)
{
    long old_offset, end_offset;

    old_offset = ftell(_fp);
    if (old_offset < 0)
        return 0;
    if (fseek(_fp, 0, SEEK_END))
        return 0;
    end_offset = ftell(_fp);
    if (end_offset < 0)
        return 0;
    if (fseek(_fp, old_offset, SEEK_SET))
        return 0;
    return offset + length <= end_offset;
}

 debug = True
   
class Base:
    pass
   
def service(name):
    def decorator(cls):
        return _ServiceLocator(cls, name)
    return decorator
   
class _ServiceLocator:
  
    __instances = {}
  
    def __init__(self, cls, name):
        self.cls = cls
        self.name = name
  
        if debug:
            def _locator(this):              # FUCK!!!
                if isinstance(this, Base): #BABAM!!!!!!!!
                    return self                 #BUBUH!!!!!
                return None
        else:
            def _locator(this):
                raise NotImplemented()
   
        cls._locator = _locator
   
    def __call__(self, *args, **kwargs):
        if self.name in self.__instances:
            return self.__instances[self.name]
  
        instance = self.cls(*args, **kwargs)
        self.__instances[self.name] = instance
        return instance
  
    @classmethod
    def get_instance(cls, name):
        return cls.__instances[name]
   
@service("FooService")
class Foo(Base):
    pass
   
f = Foo()
print f._locator()