grab.go

package periodic

import (
	"bytes"
	"container/list"
	"fmt"
	"sync"
)

type grabItem struct {
	w     *worker
	msgID []byte
}

func (item grabItem) has(Func string) bool {
	for _, F := range item.w.funcs {
		if F == Func {
			return true
		}
	}
	return false
}

func (item grabItem) equal(item1 grabItem) bool {
	if item1.w == item.w && bytes.Equal(item.msgID, item1.msgID) {
		return true
	}
	return false
}

type grabQueue struct {
	list   *list.List
	locker *sync.Mutex
}

func (g *grabQueue) push(item grabItem) {
	defer g.locker.Unlock()
	g.locker.Lock()
	g.list.PushBack(item)
}

func (g *grabQueue) get(Func string) (item grabItem, err error) {
	defer g.locker.Unlock()
	g.locker.Lock()
	for e := g.list.Front(); e != nil; e = e.Next() {
		item = e.Value.(grabItem)
		if item.has(Func) {
			return
		}
	}
	err = fmt.Errorf("func name: %s not found", Func)
	return
}

func (g *grabQueue) remove(item grabItem) {
	defer g.locker.Unlock()
	g.locker.Lock()
	for e := g.list.Front(); e != nil; e = e.Next() {
		item1 := e.Value.(grabItem)
		if item.equal(item1) {
			g.list.Remove(e)
		}
	}
}

func (g *grabQueue) removeWorker(w *worker) {
	defer g.locker.Unlock()
	g.locker.Lock()
	for e := g.list.Front(); e != nil; e = e.Next() {
		item := e.Value.(grabItem)
		if item.w == w {
			g.list.Remove(e)
		}
	}
}

func (g grabQueue) len() int {
	defer g.locker.Unlock()
	g.locker.Lock()
	return g.list.Len()
}

func newGrabQueue() *grabQueue {
	g := new(grabQueue)
	g.list = list.New()
	g.locker = new(sync.Mutex)
	return g
}