Golang List.Front方法代碼示例

func filter(idx int, vals, bits *list.List) []interface{} {
	if vals == nil || bits == nil {
		return nil
	}

	var shifted uint = 0

	valsPerCase := make([]interface{}, vals.Len())

	for i, v, b := 0, vals.Front(), bits.Front(); v != nil && b != nil; v, b = v.Next(), b.Next() {
		valIdx := idx >> shifted
		mask := int(math.Pow(2, float64(b.Value.(uint))) - 1)
		valIdx &= mask

		if valIdx >= len(v.Value.([]interface{})) {
			return nil
		}

		valsPerCase[i] = v.Value.([]interface{})[valIdx]
		i++

		shifted += b.Value.(uint)
	}

	return valsPerCase
}

func StrList2StrArray(l *list.List) []string {
	output := make([]string, 0)
	for i := l.Front(); i != nil; i = i.Next() {
		output = append(output, i.Value.(string))
	}
	return output
}

// bootstrapStores bootstraps uninitialized stores once the cluster
// and node IDs have been established for this node. Store IDs are
// allocated via a sequence id generator stored at a system key per
// node.
func (n *Node) bootstrapStores(bootstraps *list.List, stopper *stop.Stopper) {
	log.Infof("bootstrapping %d store(s)", bootstraps.Len())
	if n.ClusterID == "" {
		panic("ClusterID missing during store bootstrap of auxiliary store")
	}

	// Bootstrap all waiting stores by allocating a new store id for
	// each and invoking store.Bootstrap() to persist.
	inc := int64(bootstraps.Len())
	firstID, err := allocateStoreIDs(n.Descriptor.NodeID, inc, n.ctx.DB)
	if err != nil {
		log.Fatal(err)
	}
	sIdent := roachpb.StoreIdent{
		ClusterID: n.ClusterID,
		NodeID:    n.Descriptor.NodeID,
		StoreID:   firstID,
	}
	for e := bootstraps.Front(); e != nil; e = e.Next() {
		s := e.Value.(*storage.Store)
		if err := s.Bootstrap(sIdent, stopper); err != nil {
			log.Fatal(err)
		}
		if err := s.Start(stopper); err != nil {
			log.Fatal(err)
		}
		n.stores.AddStore(s)
		sIdent.StoreID++
		log.Infof("bootstrapped store %s", s)
		// Done regularly in Node.startGossip, but this cuts down the time
		// until this store is used for range allocations.
		s.GossipStore()
	}
}

func convertArgumentsToSlice(arguments *list.List) []string {
	argumentSlice := make([]string, 0, arguments.Len())
	for e := arguments.Front(); e != nil; e = e.Next() {
		argumentSlice = append(argumentSlice, e.Value.(string))
	}
	return argumentSlice
}

func outOfOrder(l *list.List) {
	iTotal := 25
	if iTotal > l.Len() {
		iTotal = l.Len()
	}
	ll := make([]*list.List, iTotal)

	for i := 0; i < iTotal; i++ {
		ll[i] = list.New()
	}
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	for e := l.Front(); e != nil; e = e.Next() {
		fpath, ok := e.Value.(string)
		if !ok {
			panic("The path is invalid string")
		}
		if rand.Int()%2 == 0 {
			ll[r.Intn(iTotal)].PushFront(fpath)
		} else {
			ll[r.Intn(iTotal)].PushBack(fpath)
		}
	}

	r0 := rand.New(rand.NewSource(time.Now().UnixNano()))
	l.Init()
	for i := 0; i < iTotal; i++ {
		if r0.Intn(2) == 0 {
			l.PushBackList(ll[i])
		} else {
			l.PushFrontList(ll[i])
		}
		ll[i].Init()
	}
}

func copyList(l *list.List) *list.List {
	n := list.New()
	for e := l.Front(); e != nil; e = e.Next() {
		n.PushBack(e.Value.(string))
	}
	return n
}

func (this *UKB) initSynsetVector(ls *list.List, pv []float64) {
	nw := 0
	uniq := make(map[string]*Word)
	for s := ls.Front(); s != nil; s = s.Next() {
		for w := s.Value.(*Sentence).Front(); w != nil; w = w.Next() {
			if this.RE_wnpos.MatchString(w.Value.(*Word).getTag(0)) {
				key := w.Value.(*Word).getLCForm() + "#" + strings.ToLower(w.Value.(*Word).getTag(0))[0:1]
				if uniq[key] == nil {
					nw++
					uniq[key] = w.Value.(*Word)
				}
			}
		}
	}

	for _, u := range uniq {
		lsen := u.getSenses(0)
		nsyn := lsen.Len()
		for s := lsen.Front(); s != nil; s = s.Next() {
			syn := this.wn.getVertex(s.Value.(FloatPair).first)
			if syn == VERTEX_NOT_FOUND {
				LOG.Warn("Unknown synset " + s.Value.(FloatPair).first + " ignored. Please check consistency between sense dictionary and KB")
			} else {
				pv[syn] += (1.0 / float64(nw)) * (1.0 / float64(nsyn))
			}
		}
	}
}

func houseKeeping(get, give chan interface{},
	factory func() interface{}) {
	q := new(list.List)
	for {
		if q.Len() == 0 {
			atomic.AddInt64(&makes, 1)
			q.PushFront(queued{when: time.Now(), data: factory()})
		}

		element := q.Front()
		timeout := time.NewTimer(time.Minute)
		select {
		case b := <-give:
			timeout.Stop()
			q.PushFront(queued{when: time.Now(), data: b})

		case get <- element.Value.(queued).data:
			timeout.Stop()
			q.Remove(element)

		case <-timeout.C:
			e := q.Front()
			for e != nil {
				n := e.Next()
				if time.Since(e.Value.(queued).when) > time.Minute {
					q.Remove(e)
					e.Value = nil
				}
				e = n
			}
		}
	}
}

func computeAverages(execution_results *list.List) (float64, float64, int) {
	average_concurrent_users, average_response_time := 0.0, 0.0
	var result *httpActionResult
	var avg_rt_counter time.Duration
	max_concurrent_users := 0
	avg_cu_counter := 0.0
	counter := 0.0
	if execution_results.Len() > 0 {
		for elem := execution_results.Front(); elem != nil; elem = elem.Next() {
			result = elem.Value.(*httpActionResult)
			avg_cu_counter += float64(result.concurrent_users)
			if result.concurrent_users > max_concurrent_users {
				max_concurrent_users = result.concurrent_users
			}
			if result.is_client_error == false &&
				result.is_server_error == false &&
				result.has_timed_out == false {
				avg_rt_counter += result.response_time
				counter++
			}
		}
		average_concurrent_users = avg_cu_counter / float64(execution_results.Len())
		numerator := avg_rt_counter.Seconds() * 1000.0
		average_response_time = float64(numerator) / counter
	}
	return average_concurrent_users, average_response_time,
		max_concurrent_users
}

func loadInputTemplate(name string, loader TemplateLoader) (Template, error) {
	t, err := loader.LoadTemplate(name)
	if err != nil {
		return Template{}, nil
	}

	load_tracker := map[string]bool{name: true}
	var load_queue list.List
	for _, new_name := range t.InputDependencies {
		if !load_tracker[new_name] {
			load_tracker[new_name] = true
			load_queue.PushBack(new_name)
		}
	}

	for e := load_queue.Front(); e != nil; e = e.Next() {
		template_name := e.Value.(string)
		new_template, err := loader.LoadTemplate(template_name)

		if err != nil {
			return Template{}, err
		}

		t.Inputs = append(t.Inputs, new_template.Inputs...)
		for _, new_name := range new_template.InputDependencies {
			if !load_tracker[new_name] {
				load_tracker[new_name] = true
				load_queue.PushBack(new_name)
			}
		}
	}

	return t, nil
}

func main() {

	give := make(chan []byte)
	get := make(chan []byte)

	go func() {
		q := new(list.List)

		for {
			if q.Len() == 0 {
				q.PushFront(make([]byte, 100))
			}

			e := q.Front()

			select {
			case s := <-give:
				q.PushFront(s)

			case get <- e.Value.([]byte):
				q.Remove(e)
			}
		}
	}()

	// Gets a new buffer from the recycler.
	buffer := <-get

	// Give it back to the recycler.
	give <- buffer

	// Get the recycled buffer again.
	buffer = <-get
}

func LoadTemplates(name string, loader TemplateLoader) (*template.Template, error) {
	load_tracker := map[string]bool{name: true}
	var load_queue list.List
	load_queue.Init()
	load_queue.PushBack(name)

	t := template.New(name).Funcs(builtins)
	for e := load_queue.Front(); e != nil; e = e.Next() {
		template_name := e.Value.(string)
		new_template, err := loader.LoadTemplate(template_name)
		if err != nil {
			return nil, err
		}

		if _, err := t.Parse(new_template.Data); err != nil {
			return nil, err
		}

		if t.Lookup(template_name) == nil {
			return nil, fmt.Errorf(`template "%s"load failed.`, template_name)
		}

		for _, new_name := range new_template.Dependencies {
			if !load_tracker[new_name] {
				load_tracker[new_name] = true
				load_queue.PushBack(new_name)
			}
		}
	}

	return t, nil
}

func listen(mr *MapReduce, stage JobType, completed *int, jobs *list.List) {

	NumOther := 0
	switch stage {
	case Map:
		NumOther = mr.nReduce
	case Reduce:
		NumOther = mr.nMap
	}

	if jobs.Len() != 0 {
		select {
		//wait for worker responses
		case r := <-mr.responses:
			HandleResponse(r, completed, jobs)

		//wait for available if none are available
		case id := <-mr.available:
			w := mr.Workers[id]
			//pop off a job id
			j := jobs.Remove(jobs.Front()).(int)
			args := &DoJobArgs{mr.file, stage, j, NumOther}
			go SendRPC(mr, w, args, j)
		}
	} else {
		r := <-mr.responses
		HandleResponse(r, completed, jobs)
	}
}

func (k *Kademlia) closestContacts(searchID ID, excludedID ID, amount int) (contacts []Contact) {
	contacts = make([]Contact, 0)

	k.doInSearchOrder(searchID, func(index int) bool {
		// add as many contacts from bucket i as possible,

		currentBucket := k.Buckets[index].contacts
		sortedList := new(list.List)

		//sort that list |suspect|
		for e := currentBucket.Front(); e != nil; e = e.Next() {
			insertSorted(sortedList, e.Value.(Contact), func(first Contact, second Contact) int {
				firstDistance := first.NodeID.Xor(searchID)
				secondDistance := second.NodeID.Xor(searchID)
				return firstDistance.Compare(secondDistance)
			})
		}

		// (^._.^)~ kirby says add as much as you can to output slice
		for e := sortedList.Front(); e != nil; e = e.Next() {
			c := e.Value.(Contact)
			if !c.NodeID.Equals(excludedID) {
				contacts = append(contacts, c)
				// if the slice is full, break
				if len(contacts) == amount {
					return false
				}
			}
		}
		// slice isn't full, do on the next index
		return true
	})
	return
}

// pushMetric adds the metric to the end of the list and returns a comma separated string of the
// previous 61 entries.  We return 61 instead of 60 (an hour) because the chart on the client
// tracks deltas between these values - there is nothing to compare the first value against.
func pushMetric(history *list.List, ev expvar.Var) string {
	history.PushBack(ev.String())
	if history.Len() > 61 {
		history.Remove(history.Front())
	}
	return JoinStringList(history)
}