neutron中的QOS实现源码-objects中的实现

policy.py

实现了对qos policy的增删改查操作，里面涉及到数据库中的操作。

QosPolicy类

QosPolicy类继承父类neutron.objects.NeutronDbObject，先实例化数据库对象，后面会对resource_type进行CURD操作，包括port_binding_model、network_binding_model等。

    db_model = qos_db_model.QosPolicy
    port_binding_model = qos_db_model.QosPortPolicyBinding
    network_binding_model = qos_db_model.QosNetworkPolicyBinding

to_dict返回便于遍历的dict列表

    def to_dict(self):
        dict_ = super(QosPolicy, self).to_dict()
        if 'rules' in dict_:
            dict_['rules'] = [rule.to_dict() for rule in dict_['rules']]
        return dict_

父类neutron.objects.NeutronDbObject的实现方法

    def to_dict(self):
        return dict(self.items())

方法get_by_id可以直接进行引用，根据ID从数据库中查到policy_obj，调用reload_rules()后返回。

    def get_by_id(cls, context, id):
        admin_context = context.elevated()
        with db_api.autonested_transaction(admin_context.session):
            policy_obj = super(QosPolicy, cls).get_by_id(admin_context, id)
            if (not policy_obj or
                not cls._is_policy_accessible(context, policy_obj)):
                return

            policy_obj.reload_rules()
            return policy_obj

方法get_objects()

    def get_objects(cls, context, **kwargs):
        admin_context = context.elevated()
        with db_api.autonested_transaction(admin_context.session):
            objs = super(QosPolicy, cls).get_objects(admin_context,
                                                     **kwargs)
            result = []
            for obj in objs:
                if not cls._is_policy_accessible(context, obj):
                    continue
                obj.reload_rules()
                result.append(obj)
            return result

方法get_network_policy()

    def get_network_policy(cls, context, network_id):
        return cls._get_object_policy(context, cls.network_binding_model,
                                      network_id=network_id)

方法get_port_policy()

    def get_port_policy(cls, context, port_id):
        return cls._get_object_policy(context, cls.port_binding_model,
                                      port_id=port_id)

方法create()

    def create(self):
        with db_api.autonested_transaction(self._context.session):
            super(QosPolicy, self).create()
            self.reload_rules()

方法delete

    def delete(self):
        models = (
            ('network', self.network_binding_model),
            ('port', self.port_binding_model)
        )
        with db_api.autonested_transaction(self._context.session):
            for object_type, model in models:
                binding_db_obj = db_api.get_object(self._context, model,
                                                   policy_id=self.id)
                if binding_db_obj:
                    raise exceptions.QosPolicyInUse(
                        policy_id=self.id,
                        object_type=object_type,
                        object_id=binding_db_obj['%s_id' % object_type])

            super(QosPolicy, self).delete()

方法attach_network、attach_port、detach_network、detach_port调用数据库进行增删改查操作。

    def attach_network(self, network_id):
        qos_db_api.create_policy_network_binding(self._context,
                                                 policy_id=self.id,
                                                 network_id=network_id)

    def attach_port(self, port_id):
        qos_db_api.create_policy_port_binding(self._context,
                                              policy_id=self.id,
                                              port_id=port_id)

    def detach_network(self, network_id):
        qos_db_api.delete_policy_network_binding(self._context,
                                                 policy_id=self.id,
                                                 network_id=network_id)

    def detach_port(self, port_id):
        qos_db_api.delete_policy_port_binding(self._context,
                                              policy_id=self.id,
                                              port_id=port_id)

rule.py

QosRule类

主要继承自neutron.objects.NeutronDbObject父类

def should_apply_to_port(self, port):
        """Check whether a rule can be applied to a specific port.

        This function has the logic to decide whether a rule should
        be applied to a port or not, depending on the source of the
        policy (network, or port). Eventually rules could override
        this method, or we could make it abstract to allow different
        rule behaviour.
        """
        is_network_rule = self.qos_policy_id != port[qos_consts.QOS_POLICY_ID]
        is_network_device_port = any(port['device_owner'].startswith(prefix)
                                     for prefix
                                     in constants.DEVICE_OWNER_PREFIXES)

        return not (is_network_rule and is_network_device_port)

should_apply_to_port返回应用于network的port的rule结果

QosBandwidthLimitRule类

继承父类QosRule

得到了一个数据库rule对象 定义好枚举结构，生成rule_type

    db_model = qos_db_model.QosBandwidthLimitRule

    fields = {
        'max_kbps': obj_fields.IntegerField(nullable=True),
        'max_burst_kbps': obj_fields.IntegerField(nullable=True)
    }

    rule_type = qos_consts.RULE_TYPE_BANDWIDTH_LIMIT

rule_type.py

主要实现了QosRuleType类和RuleTypeField类。

RuleTypeField类

继承了父类oslo_versionedobjects.fields.BaseEnumField，定义fields的key-filed的键值对

QosRuleType类

继承父类neutron.objects.NeutronObject，循环遍历得到rule_types

    def get_objects(cls, **kwargs):
        cls.validate_filters(**kwargs)
        core_plugin = manager.NeutronManager.get_plugin()
        return [cls(type=type_)
                for type_ in core_plugin.supported_qos_rule_types]

get_rules方法

接收neutron.db.api的数据库API请求，使用session将对象和数据库表形成映射

def get_rules(context, qos_policy_id):
    all_rules = []
    with db_api.autonested_transaction(context.session):
        for rule_type in qos_consts.VALID_RULE_TYPES:
            rule_cls_name = 'Qos%sRule' % utils.camelize(rule_type)
            rule_cls = getattr(sys.modules[__name__], rule_cls_name)

            rules = rule_cls.get_objects(context, qos_policy_id=qos_policy_id)
            all_rules.extend(rules)
    return all_rules