seaweedfs/weed/util/skiplist/skiplist_test.go
2021-10-03 01:07:35 -07:00

245 lines
4.5 KiB
Go

package skiplist
import (
"bytes"
"fmt"
"math/rand"
"strconv"
"testing"
)
const (
maxN = 10000
)
func TestInsertAndFind(t *testing.T) {
k0 := []byte("0")
var list *SkipList
var listPointer *SkipList
listPointer.Insert(k0, 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, 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, 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, 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, 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), 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), 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), 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), 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.Key, lastNode.Key) <= 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), 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.Key, lastNode.Key) >= 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 TestFindGreaterOrEqual(t *testing.T) {
maxNumber := maxN * 100
var list *SkipList
var listPointer *SkipList
// Test on empty list.
if _, ok := listPointer.FindGreaterOrEqual(Element(0)); ok {
t.Fail()
}
list = New()
for i := 0; i < maxN; i++ {
list.Insert(Element(rand.Intn(maxNumber)), Element(i))
}
for i := 0; i < maxN; i++ {
key := Element(rand.Intn(maxNumber))
if v, ok := list.FindGreaterOrEqual(key); ok {
// if f is v should be bigger than the element before
if v.Prev != nil && bytes.Compare(v.Prev.Key, key) >= 0 {
fmt.Printf("PrevV: %s\n key: %s\n\n", string(v.Prev.Key), string(key))
t.Fail()
}
// v should be bigger or equal to f
// If we compare directly, we get an equal key with a difference on the 10th decimal point, which fails.
if bytes.Compare(v.Key, key) < 0 {
fmt.Printf("v: %s\n key: %s\n\n", string(v.Key), string(key))
t.Fail()
}
} else {
lastV := list.GetLargestNode().GetValue()
// It is OK, to fail, as long as f is bigger than the last element.
if bytes.Compare(key, lastV) <= 0 {
fmt.Printf("lastV: %s\n key: %s\n\n", string(lastV), string(key))
t.Fail()
}
}
}
}