skiplist 中抽象了一个通用的queue

plugin/mempool/price/cache.go

@@ -3,7 +3,6 @@ package price
 import (
 	"github.com/33cn/chain33/common/skiplist"
 	"github.com/33cn/chain33/system/mempool"
-	"github.com/33cn/chain33/types"
 	"github.com/golang/protobuf/proto"
 )
 
@@ -22,10 +21,26 @@ func (item *priceScore) GetScore() int64 {
 	return item.Value.Fee / int64(txSize)
 }
 
+func (item *priceScore) Hash() []byte {
+	return item.Value.Hash()
+}
+
+func (item *priceScore) Compare(cmp skiplist.Scorer) int {
+	it := cmp.(*priceScore)
+	//时间越小，权重越高
+	if item.EnterTime < it.EnterTime {
+		return skiplist.Big
+	}
+	if item.EnterTime == it.EnterTime {
+		return skiplist.Equal
+	}
+	return skiplist.Small
+}
+
 // NewQueue 创建队列
 func NewQueue(subcfg subConfig) *Queue {
 	return &Queue{
-		Queue:     skiplist.NewQueue(),
+		Queue:     skiplist.NewQueue(subcfg.PoolCacheSize),
 		subConfig: subcfg,
 	}
 }
@@ -39,6 +54,11 @@ func (cache *Queue) GetItem(hash string) (*mempool.Item, error) {
 	return item.(*priceScore).Item, nil
 }
 
+//Push 加入数据到队列
+func (cache *Queue) Push(item *mempool.Item) error {
+	return cache.Queue.Push(&priceScore{Item: item})
+}
+
 //Walk 获取数据通过 key
 func (cache *Queue) Walk(count int, cb func(tx *mempool.Item) bool) {
 	cache.Queue.Walk(count, func(item skiplist.Scorer) bool {
@@ -46,36 +66,6 @@ func (cache *Queue) Walk(count int, cb func(tx *mempool.Item) bool) {
 	})
 }
 
-// Push 把给定tx添加到Queue；如果tx已经存在Queue中或Mempool已满则返回对应error
-func (cache *Queue) Push(item *mempool.Item) error {
-	hash := item.Value.Hash()
-	if cache.Exist(string(hash)) {
-		return types.ErrTxExist
-	}
-	sv := cache.CreateSkipValue(&priceScore{Item: item})
-	if int64(cache.Size()) >= cache.subConfig.PoolCacheSize {
-		tail := cache.Last().(*priceScore)
-		lasthash := string(tail.Value.Hash())
-		//价格高存留
-		switch sv.Compare(cache.CreateSkipValue(tail)) {
-		case -1:
-			cache.Queue.Remove(lasthash)
-		case 0:
-			if item.EnterTime < tail.EnterTime {
-				cache.Queue.Remove(lasthash)
-				break
-			}
-			return types.ErrMemFull
-		case 1:
-			return types.ErrMemFull
-		default:
-			return types.ErrMemFull
-		}
-	}
-	cache.Queue.Push(string(hash), &priceScore{Item: item})
-	return nil
-}
-
 // GetProperFee 获取合适的手续费率,取前100的平均手续费率
 func (cache *Queue) GetProperFee() int64 {
 	var sumFeeRate int64

vendor/github.com/33cn/chain33/common/skiplist/queue.go

+package skiplist
+
+import (
+	"container/list"
+
+	"github.com/33cn/chain33/types"
+)
+
+//Scorer 接口实现 Value的 Score 功能
+type Scorer interface {
+	GetScore() int64
+	Hash() []byte
+	Compare(Scorer) int
+}
+
+// Queue 价格队列模式(价格=手续费/交易字节数,价格高者优先,同价则时间早优先)
+type Queue struct {
+	txMap   map[string]*list.Element
+	txList  *SkipList
+	maxsize int64
+}
+
+// NewQueue 创建队列
+func NewQueue(maxsize int64) *Queue {
+	return &Queue{
+		txMap:   make(map[string]*list.Element),
+		txList:  NewSkipList(&SkipValue{Score: -1, Value: nil}),
+		maxsize: maxsize,
+	}
+}
+
+/*
+为了处理相同 Score 的问题，需要一个队列保存相同 Score 下面的交易
+*/
+func (cache *Queue) insertSkipValue(item Scorer) *list.Element {
+	skvalue := cache.CreateSkipValue(item)
+	value := cache.txList.Find(skvalue)
+	var txlist *list.List
+	if value == nil {
+		txlist = list.New()
+		skvalue.Value = txlist
+		cache.txList.Insert(skvalue)
+	} else {
+		txlist = value.Value.(*list.List)
+	}
+	return txlist.PushBack(item)
+}
+
+func (cache *Queue) deleteSkipValue(item *list.Element) error {
+	if item == nil {
+		return nil
+	}
+	skvalue := cache.CreateSkipValue(item.Value.(Scorer))
+	value := cache.txList.Find(skvalue)
+	var txlist *list.List
+	if value == nil {
+		return types.ErrNotFound
+	}
+	txlist = value.Value.(*list.List)
+	txlist.Remove(item)
+	if txlist.Len() == 0 {
+		cache.txList.Delete(value)
+	}
+	return nil
+}
+
+//CreateSkipValue 创建一个 仅仅有 score 的Value
+func (cache *Queue) CreateSkipValue(item Scorer) *SkipValue {
+	skvalue := &SkipValue{Score: item.GetScore()}
+	return skvalue
+}
+
+//Exist 是否存在
+func (cache *Queue) Exist(hash string) bool {
+	_, exists := cache.txMap[hash]
+	return exists
+}
+
+//GetItem 获取数据通过 key
+func (cache *Queue) GetItem(hash string) (Scorer, error) {
+	if k, exist := cache.txMap[hash]; exist {
+		return k.Value.(Scorer), nil
+	}
+	return nil, types.ErrNotFound
+}
+
+//Insert Scorer item to queue
+func (cache *Queue) Insert(hash string, item Scorer) error {
+	cache.txMap[string(hash)] = cache.insertSkipValue(item)
+	return nil
+}
+
+// Push 把给定tx添加到Queue；如果tx已经存在Queue中或Mempool已满则返回对应error
+func (cache *Queue) Push(item Scorer) error {
+	hash := item.Hash()
+	if cache.Exist(string(hash)) {
+		return types.ErrTxExist
+	}
+	sv := cache.CreateSkipValue(item)
+	if int64(cache.Size()) >= cache.maxsize {
+		tail := cache.Last()
+		lasthash := string(tail.Hash())
+		//价格高存留
+		switch sv.Compare(cache.CreateSkipValue(tail)) {
+		case Big:
+			cache.Remove(lasthash)
+		case Equal:
+			//再score 相同的情况下，item 之间的比较方法
+			//权重大的留下来
+			if item.Compare(tail) == Big {
+				cache.Remove(lasthash)
+				break
+			}
+			return types.ErrMemFull
+		case Small:
+			return types.ErrMemFull
+		default:
+			return types.ErrMemFull
+		}
+	}
+	cache.Insert(string(hash), item)
+	return nil
+}
+
+// Remove 删除数据
+func (cache *Queue) Remove(hash string) error {
+	elm, ok := cache.txMap[hash]
+	if !ok {
+		return types.ErrNotFound
+	}
+	err := cache.deleteSkipValue(elm)
+	if err != nil {
+		return err
+	}
+	delete(cache.txMap, hash)
+	return nil
+}
+
+// Size 数据总数
+func (cache *Queue) Size() int {
+	return len(cache.txMap)
+}
+
+//Last 取出最后一个交易
+func (cache *Queue) Last() Scorer {
+	if cache.Size() == 0 {
+		return nil
+	}
+	tailqueue := cache.txList.GetIterator().Last()
+	tail := tailqueue.Value.(*list.List).Back().Value.(Scorer)
+	return tail
+}
+
+//First 取出第一个交易
+func (cache *Queue) First() Scorer {
+	if cache.Size() == 0 {
+		return nil
+	}
+	tailqueue := cache.txList.GetIterator().First()
+	tail := tailqueue.Value.(*list.List).Front().Value.(Scorer)
+	return tail
+}
+
+// Walk 遍历整个队列
+func (cache *Queue) Walk(count int, cb func(value Scorer) bool) {
+	i := 0
+	cache.txList.Walk(func(item interface{}) bool {
+		l := item.(*list.List)
+		for e := l.Front(); e != nil; e = e.Next() {
+			if !cb(e.Value.(Scorer)) {
+				return false
+			}
+			i++
+			if i == count {
+				return false
+			}
+		}
+		return true
+	})
+}

vendor/github.com/33cn/chain33/common/skiplist/skiplist.go

@@ -14,14 +14,21 @@ type SkipValue struct {
 	Value interface{}
 }
 
+//Compare Const
+const (
+	Big   = -1
+	Small = 1
+	Equal = 0
+)
+
 // Compare 比较函数,这样的比较排序是从大到小
 func (v *SkipValue) Compare(value *SkipValue) int {
 	if v.Score > value.Score {
-		return -1
+		return Big
 	} else if v.Score == value.Score {
-		return 0
+		return Equal
 	}
-	return 1
+	return Small
 }
 
 // skipListNode 跳跃表节点