misc

scouterx/common/structure/cacheset/cacheset.go

@@ -1,78 +1,77 @@
 package cacheset
 
 import (
-	"github.com/emirpasic/gods/lists/singlylinkedlist"
+	"github.com/emirpasic/gods/sets/linkedhashset"
 	"strconv"
 	"sync"
 )
 
 var lock sync.RWMutex
 
 type CacheSet struct {
-	table    map[interface{}]struct{}
-	ordering *singlylinkedlist.List
+	table    *linkedhashset.Set
 	maxSize  int
 }
 
 var itemExists = struct{}{}
 
 func New(maxSize int) *CacheSet {
-	set := &CacheSet{
-		table:    make(map[interface{}]struct{}),
-		ordering: singlylinkedlist.New(),
-		maxSize:  maxSize,
+	s := &CacheSet{
+		table:           linkedhashset.New(),
+		maxSize:         maxSize,
 	}
-	return set
+	return s
 }
 
 func (set *CacheSet) Add(item interface{}) {
 	lock.Lock()
 	defer lock.Unlock()
-	var contains bool
-	if _, contains = set.table[item]; !contains {
+	if !set.table.Contains(item) {
 		set.removeExceeded()
-		set.table[item] = itemExists
-		set.ordering.Append(item)
+		set.table.Add(item)
 	}
 }
 
 func (set *CacheSet) removeExceeded() {
-	for set.ordering.Size() >= set.maxSize {
-		item, exist := set.ordering.Get(0)
-		if exist {
-			set.ordering.Remove(0)
-			delete(set.table, item)
-		}
+	removalCount := set.table.Size() - set.maxSize
+	if removalCount < 0 {
+		return
+	}
+	var removals []interface{}
+	iterator := set.table.Iterator()
+
+	for i := removalCount; i >= 0; i-- {
+		iterator.Next()
+		removals = append(removals, iterator.Value())
+	}
+	for _, removal := range removals {
+		set.table.Remove(removal)
 	}
 }
 
 func (set *CacheSet) Contains(item interface{}) bool {
 	lock.RLock()
 	defer lock.RUnlock()
-	if _, contains := set.table[item]; !contains {
-		return false
-	}
-	return true
+	return set.table.Contains(item)
 }
 
 func (set *CacheSet) Empty() bool {
 	lock.Lock()
 	defer lock.Unlock()
-	return set.Size() == 0
+	return set.table. Size() == 0
 }
 
 func (set *CacheSet) Size() int {
-	return set.ordering.Size()
+	return set.table.Size()
 }
 
 func (set *CacheSet) Clear() {
 	lock.Lock()
 	defer lock.Unlock()
-	set.table = make(map[interface{}]struct{})
-	set.ordering.Clear()
+	set.table = linkedhashset.New()
 }
 
 func (set *CacheSet) String() string {
-	return "CacheSet[" + strconv.Itoa(set.ordering.Size()) + "]"
+	return "CacheSet[" + strconv.Itoa(set.Size()) + "]"
 }