event.py 文件源码

def register(name, handler, mask=None, filename=None, lineno=None):
    """Register an Event handler"""

    # already registered
    if name in _handlers:
        return AlreadyRegistered

    if handler is not None:
        # handle string containing python code
        if isinstance(handler, str):
            tmp = "def %s(e):\n%s" % (name, handler)
            try:
                code = bb.methodpool.compile_cache(tmp)
                if not code:
                    if filename is None:
                        filename = "%s(e)" % name
                    code = compile(tmp, filename, "exec", ast.PyCF_ONLY_AST)
                    if lineno is not None:
                        ast.increment_lineno(code, lineno-1)
                    code = compile(code, filename, "exec")
                    bb.methodpool.compile_cache_add(tmp, code)
            except SyntaxError:
                logger.error("Unable to register event handler '%s':\n%s", name,
                             ''.join(traceback.format_exc(limit=0)))
                _handlers[name] = noop
                return
            env = {}
            bb.utils.better_exec(code, env)
            func = bb.utils.better_eval(name, env)
            _handlers[name] = func
        else:
            _handlers[name] = handler

        if not mask or '*' in mask:
            _catchall_handlers[name] = True
        else:
            for m in mask:
                if _event_handler_map.get(m, None) is None:
                    _event_handler_map[m] = {}
                _event_handler_map[m][name] = True

        return Registered