core/hotspot/slot.go

// Copyright 1999-2020 Alibaba Group Holding Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package hotspot

import (
	"github.com/alibaba/sentinel-golang/core/base"
	"github.com/alibaba/sentinel-golang/util"
)

const (
	RuleCheckSlotOrder = 4000
)

var (
	DefaultSlot = &Slot{}
)

type Slot struct {
}

func (s *Slot) Order() uint32 {
	return RuleCheckSlotOrder
}

func (s *Slot) Check(ctx *base.EntryContext) *base.TokenResult {
	res := ctx.Resource.Name()
	batch := int64(ctx.Input.BatchCount)

	result := ctx.RuleCheckResult
	tcs := getTrafficControllersFor(res)
	for _, tc := range tcs {
		arg := tc.ExtractArgs(ctx)
		if arg == nil {
			continue
		}
		r := canPassCheck(tc, arg, batch)
		if r == nil {
			continue
		}
		if r.Status() == base.ResultStatusBlocked {
			return r
		}
		if r.Status() == base.ResultStatusShouldWait {
			if nanosToWait := r.NanosToWait(); nanosToWait > 0 {
				// Handle waiting action.
				util.Sleep(nanosToWait)
			}
			continue
		}
	}
	return result
}

func canPassCheck(tc TrafficShapingController, arg interface{}, batch int64) *base.TokenResult {
	return canPassLocalCheck(tc, arg, batch)
}

func canPassLocalCheck(tc TrafficShapingController, arg interface{}, batch int64) *base.TokenResult {
	return tc.PerformChecking(arg, batch)
}