working skiplist

weed/util/skiplist/skiplist_test.go

@@ -0,0 +1,212 @@
+package skiplist
+
+import (
+	"bytes"
+	"math/rand"
+	"strconv"
+	"testing"
+)
+
+const (
+	maxN = 10000
+)
+
+func TestInsertAndFind(t *testing.T) {
+
+	k0 := []byte("0")
+	var list *SkipList
+
+	var listPointer *SkipList
+	listPointer.Insert(k0)
+	if _, ok := listPointer.Find(k0); ok {
+		t.Fail()
+	}
+
+	list = New()
+	if _, ok := list.Find(k0); ok {
+		t.Fail()
+	}
+	if !list.IsEmpty() {
+		t.Fail()
+	}
+
+	// Test at the beginning of the list.
+	for i := 0; i < maxN; i++ {
+		key := []byte(strconv.Itoa(maxN-i))
+		list.Insert(key)
+	}
+	for i := 0; i < maxN; i++ {
+		key := []byte(strconv.Itoa(maxN-i))
+		if _, ok := list.Find(key); !ok {
+			t.Fail()
+		}
+	}
+
+
+	list = New()
+	// Test at the end of the list.
+	for i := 0; i < maxN; i++ {
+		key := []byte(strconv.Itoa(i))
+		list.Insert(key)
+	}
+	for i := 0; i < maxN; i++ {
+		key := []byte(strconv.Itoa(i))
+		if _, ok := list.Find(key); !ok {
+			t.Fail()
+		}
+	}
+
+	list = New()
+	// Test at random positions in the list.
+	rList := rand.Perm(maxN)
+	for _, e := range rList {
+		key := []byte(strconv.Itoa(e))
+		println("insert", e)
+		list.Insert(key)
+	}
+	for _, e := range rList {
+		key := []byte(strconv.Itoa(e))
+		println("find", e)
+		if _, ok := list.Find(key); !ok {
+			t.Fail()
+		}
+	}
+	println("print list")
+	list.println()
+
+}
+
+func Element(x int) []byte {
+	return []byte(strconv.Itoa(x))
+}
+
+func TestDelete(t *testing.T) {
+
+	k0 := []byte("0")
+
+	var list *SkipList
+
+	// Delete on empty list
+	list.Delete(k0)
+
+	list = New()
+
+	list.Delete(k0)
+	if !list.IsEmpty() {
+		t.Fail()
+	}
+
+	list.Insert(k0)
+	list.Delete(k0)
+	if !list.IsEmpty() {
+		t.Fail()
+	}
+
+	// Delete elements at the beginning of the list.
+	for i := 0; i < maxN; i++ {
+		list.Insert(Element(i))
+	}
+	for i := 0; i < maxN; i++ {
+		list.Delete(Element(i))
+	}
+	if !list.IsEmpty() {
+		t.Fail()
+	}
+
+	list = New()
+	// Delete elements at the end of the list.
+	for i := 0; i < maxN; i++ {
+		list.Insert(Element(i))
+	}
+	for i := 0; i < maxN; i++ {
+		list.Delete(Element(maxN - i - 1))
+	}
+	if !list.IsEmpty() {
+		t.Fail()
+	}
+
+	list = New()
+	// Delete elements at random positions in the list.
+	rList := rand.Perm(maxN)
+	for _, e := range rList {
+		list.Insert(Element(e))
+	}
+	for _, e := range rList {
+		list.Delete(Element(e))
+	}
+	if !list.IsEmpty() {
+		t.Fail()
+	}
+}
+
+func TestNext(t *testing.T) {
+	list := New()
+
+	for i := 0; i < maxN; i++ {
+		list.Insert(Element(i))
+	}
+
+	smallest := list.GetSmallestNode()
+	largest := list.GetLargestNode()
+
+	lastNode := smallest
+	node := lastNode
+	for node != largest {
+		node = list.Next(node)
+		// Must always be incrementing here!
+		if bytes.Compare(node.Values[0], lastNode.Values[0]) <= 0 {
+			t.Fail()
+		}
+		// Next.Prev must always point to itself!
+		if list.Next(list.Prev(node)) != node {
+			t.Fail()
+		}
+		lastNode = node
+	}
+
+	if list.Next(largest) != smallest {
+		t.Fail()
+	}
+}
+
+func TestPrev(t *testing.T) {
+	list := New()
+
+	for i := 0; i < maxN; i++ {
+		list.Insert(Element(i))
+	}
+
+	smallest := list.GetSmallestNode()
+	largest := list.GetLargestNode()
+
+	lastNode := largest
+	node := lastNode
+	for node != smallest {
+		node = list.Prev(node)
+		// Must always be incrementing here!
+		if bytes.Compare(node.Values[0], lastNode.Values[0]) >= 0 {
+			t.Fail()
+		}
+		// Next.Prev must always point to itself!
+		if list.Prev(list.Next(node)) != node {
+			t.Fail()
+		}
+		lastNode = node
+	}
+
+	if list.Prev(smallest) != largest {
+		t.Fail()
+	}
+}
+
+func TestGetNodeCount(t *testing.T) {
+	list := New()
+
+	for i := 0; i < maxN; i++ {
+		list.Insert(Element(i))
+	}
+
+	if list.GetNodeCount() != maxN {
+		t.Fail()
+	}
+}