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Apply max height splay method #989

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8 changes: 4 additions & 4 deletions pkg/document/document_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -132,22 +132,22 @@ func TestDocument(t *testing.T) {
root.SetNewArray("k1").AddInteger(1).AddInteger(2).AddInteger(3)
assert.Equal(t, 3, root.GetArray("k1").Len())
assert.Equal(t, `{"k1":[1,2,3]}`, root.Marshal())
assert.Equal(t, "[0,0]0[1,1]1[2,1]2[3,1]3", root.GetArray("k1").ToTestString())
assert.Equal(t, "[0,0,1]0[1,1,2]1[2,1,3]2[3,1,4]3", root.GetArray("k1").ToTestString())

root.GetArray("k1").Delete(1)
assert.Equal(t, `{"k1":[1,3]}`, root.Marshal())
assert.Equal(t, 2, root.GetArray("k1").Len())
assert.Equal(t, "[0,0]0[1,1]1[2,0]2[1,1]3", root.GetArray("k1").ToTestString())
assert.Equal(t, "[0,0,1]0[1,1,2]1[2,0,3]2[1,1,1]3", root.GetArray("k1").ToTestString())

root.GetArray("k1").InsertIntegerAfter(0, 2)
assert.Equal(t, `{"k1":[1,2,3]}`, root.Marshal())
assert.Equal(t, 3, root.GetArray("k1").Len())
assert.Equal(t, "[0,0]0[1,1]1[3,1]2[1,0]2[1,1]3", root.GetArray("k1").ToTestString())
assert.Equal(t, "[0,0,1]0[1,1,2]1[3,1,3]2[1,0,2]2[1,1,1]3", root.GetArray("k1").ToTestString())

root.GetArray("k1").InsertIntegerAfter(2, 4)
assert.Equal(t, `{"k1":[1,2,3,4]}`, root.Marshal())
assert.Equal(t, 4, root.GetArray("k1").Len())
assert.Equal(t, "[0,0]0[1,1]1[2,1]2[2,0]2[3,1]3[4,1]4", root.GetArray("k1").ToTestString())
assert.Equal(t, "[0,0,1]0[1,1,2]1[2,1,3]2[2,0,4]2[3,1,5]3[4,1,6]4", root.GetArray("k1").ToTestString())

for i := 0; i < root.GetArray("k1").Len(); i++ {
assert.Equal(
Expand Down
98 changes: 86 additions & 12 deletions pkg/splay/splay.go
Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,7 @@ type Value interface {
type Node[V Value] struct {
value V
weight int
height int

left *Node[V]
right *Node[V]
Expand All @@ -45,7 +46,8 @@ type Node[V Value] struct {
// NewNode creates a new instance of Node.
func NewNode[V Value](value V) *Node[V] {
n := &Node[V]{
value: value,
value: value,
height: 1,
}
n.InitWeight()
return n
Expand All @@ -70,6 +72,20 @@ func (t *Node[V]) rightWeight() int {
return t.right.weight
}

func (t *Node[V]) leftHeight() int {
if t.left == nil {
return 0
}
return t.left.height
}

func (t *Node[V]) rightHeight() int {
if t.right == nil {
return 0
}
return t.right.height
}

// InitWeight sets initial weight of this node.
func (t *Node[V]) InitWeight() {
t.weight = t.value.Len()
Expand All @@ -92,13 +108,15 @@ func (t *Node[V]) hasLinks() bool {
// Tree is weighted binary search tree which is based on Splay tree.
// original paper on Splay Trees: https://www.cs.cmu.edu/~sleator/papers/self-adjusting.pdf
type Tree[V Value] struct {
root *Node[V]
root *Node[V]
nodeCount int
}

// NewTree creates a new instance of Tree.
func NewTree[V Value](root *Node[V]) *Tree[V] {
return &Tree[V]{
root: root,
root: root,
nodeCount: 0,
}
}

Expand All @@ -114,6 +132,7 @@ func (t *Tree[V]) Insert(node *Node[V]) *Node[V] {

// InsertAfter inserts the node after the given previous node.
func (t *Tree[V]) InsertAfter(prev *Node[V], node *Node[V]) *Node[V] {
t.BalancingTreeHeight()
t.Splay(prev)
t.root = node
node.right = prev.right
Expand All @@ -124,10 +143,29 @@ func (t *Tree[V]) InsertAfter(prev *Node[V], node *Node[V]) *Node[V] {
prev.parent = node
prev.right = nil

t.UpdateWeight(prev)
t.UpdateNode(prev)
t.UpdateNode(node)
t.nodeCount++
return node
}

// UpdateNode recalculates the height and weight of this node with the value and children.
func (t *Tree[V]) UpdateNode(node *Node[V]) {
t.UpdateWeight(node)
t.UpdateHeight(node)
}

return node
// MaxHeightSplay finds and splays a deapest node.
func (t *Tree[V]) MaxHeightSplay() {
node := t.root
for node.height > 1 {
if node.left != nil && node.left.height+1 == node.height {
node = node.left
} else {
node = node.right
}
}
t.Splay(node)
}

// Splay moves the given node to the root.
Expand Down Expand Up @@ -166,8 +204,26 @@ func (t *Tree[V]) Splay(node *Node[V]) {
}
}

// BalancingTreeHeight call MaxHeightSplay if n(node count) is greater than 1000 and 50*log n
func (t *Tree[V]) BalancingTreeHeight() {
if t.root != nil && t.nodeCount > 1000 {
var threshold uint64
threshold = 1
log := 1
for threshold < uint64(t.nodeCount) {
threshold *= 2
log++
}

if uint64(t.root.height) > uint64(50*log) {
t.MaxHeightSplay()
}
}
}

// IndexOf Find the index of the given node.
func (t *Tree[V]) IndexOf(node *Node[V]) int {
t.BalancingTreeHeight()
if node == nil || node != t.root && !node.hasLinks() {
return -1
}
Expand All @@ -187,6 +243,7 @@ func (t *Tree[V]) IndexOf(node *Node[V]) int {

// Find returns the Node and offset of the given index.
func (t *Tree[V]) Find(index int) (*Node[V], int, error) {
t.BalancingTreeHeight()
if t.root == nil {
return nil, 0, nil
}
Expand Down Expand Up @@ -228,9 +285,10 @@ func (t *Tree[V]) ToTestString() string {

traverseInOrder(t.root, func(node *Node[V]) {
builder.WriteString(fmt.Sprintf(
"[%d,%d]%s",
"[%d,%d,%d]%s",
node.weight,
node.value.Len(),
node.height,
node.value.String(),
))
})
Expand Down Expand Up @@ -265,15 +323,29 @@ func (t *Tree[V]) UpdateWeight(node *Node[V]) {
}
}

// UpdateHeight recalculates the height of this node with the value and children.
func (t *Tree[V]) UpdateHeight(node *Node[V]) {
node.height = 1

if node.left != nil && node.height < node.leftHeight()+1 {
node.height = node.leftHeight() + 1
}

if node.right != nil && node.height < node.rightHeight()+1 {
node.height = node.rightHeight() + 1
}
}

func (t *Tree[V]) updateTreeWeight(node *Node[V]) {
for node != nil {
t.UpdateWeight(node)
t.UpdateNode(node)
node = node.parent
}
}

// Delete deletes the given node from this Tree.
func (t *Tree[V]) Delete(node *Node[V]) {
t.BalancingTreeHeight()
t.Splay(node)

leftTree := NewTree(node.left)
Expand All @@ -300,8 +372,9 @@ func (t *Tree[V]) Delete(node *Node[V]) {

node.unlink()
if t.root != nil {
t.UpdateWeight(t.root)
t.UpdateNode(t.root)
}
t.nodeCount--
}

// DeleteRange separates the range between given 2 boundaries from this Tree.
Expand All @@ -311,6 +384,7 @@ func (t *Tree[V]) Delete(node *Node[V]) {
// but rightBoundary can be nil means range to delete includes the end of tree.
// Refer to the design document: ./design/range-deletion-in-slay-tree.md
func (t *Tree[V]) DeleteRange(leftBoundary, rightBoundary *Node[V]) {
t.BalancingTreeHeight()
if rightBoundary == nil {
t.Splay(leftBoundary)
t.cutOffRight(leftBoundary)
Expand Down Expand Up @@ -351,8 +425,8 @@ func (t *Tree[V]) rotateLeft(pivot *Node[V]) {
pivot.left = root
pivot.left.parent = pivot

t.UpdateWeight(root)
t.UpdateWeight(pivot)
t.UpdateNode(root)
t.UpdateNode(pivot)
}

func (t *Tree[V]) rotateRight(pivot *Node[V]) {
Expand All @@ -376,8 +450,8 @@ func (t *Tree[V]) rotateRight(pivot *Node[V]) {
pivot.right = root
pivot.right.parent = pivot

t.UpdateWeight(root)
t.UpdateWeight(pivot)
t.UpdateNode(root)
t.UpdateNode(pivot)
}

func (t *Tree[V]) rightmost() *Node[V] {
Expand Down
26 changes: 13 additions & 13 deletions pkg/splay/splay_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -56,16 +56,16 @@ func TestSplayTree(t *testing.T) {
assert.Equal(t, 0, idx)

nodeA := tree.Insert(newSplayNode("A2"))
assert.Equal(t, "[2,2]A2", tree.ToTestString())
assert.Equal(t, "[2,2,1]A2", tree.ToTestString())
nodeB := tree.Insert(newSplayNode("B23"))
assert.Equal(t, "[2,2]A2[5,3]B23", tree.ToTestString())
assert.Equal(t, "[2,2,1]A2[5,3,2]B23", tree.ToTestString())
nodeC := tree.Insert(newSplayNode("C234"))
assert.Equal(t, "[2,2]A2[5,3]B23[9,4]C234", tree.ToTestString())
assert.Equal(t, "[2,2,1]A2[5,3,2]B23[9,4,3]C234", tree.ToTestString())
nodeD := tree.Insert(newSplayNode("D2345"))
assert.Equal(t, "[2,2]A2[5,3]B23[9,4]C234[14,5]D2345", tree.ToTestString())
assert.Equal(t, "[2,2,1]A2[5,3,2]B23[9,4,3]C234[14,5,4]D2345", tree.ToTestString())

tree.Splay(nodeB)
assert.Equal(t, "[2,2]A2[14,3]B23[9,4]C234[5,5]D2345", tree.ToTestString())
assert.Equal(t, "[2,2,1]A2[14,3,3]B23[9,4,2]C234[5,5,1]D2345", tree.ToTestString())

assert.Equal(t, 0, tree.IndexOf(nodeA))
assert.Equal(t, 2, tree.IndexOf(nodeB))
Expand All @@ -92,20 +92,20 @@ func TestSplayTree(t *testing.T) {
tree := splay.NewTree[*stringValue](nil)

nodeH := tree.Insert(newSplayNode("H"))
assert.Equal(t, "[1,1]H", tree.ToTestString())
assert.Equal(t, "[1,1,1]H", tree.ToTestString())
assert.Equal(t, 1, tree.Len())
nodeE := tree.Insert(newSplayNode("E"))
assert.Equal(t, "[1,1]H[2,1]E", tree.ToTestString())
assert.Equal(t, "[1,1,1]H[2,1,2]E", tree.ToTestString())
assert.Equal(t, 2, tree.Len())
nodeL := tree.Insert(newSplayNode("LL"))
assert.Equal(t, "[1,1]H[2,1]E[4,2]LL", tree.ToTestString())
assert.Equal(t, "[1,1,1]H[2,1,2]E[4,2,3]LL", tree.ToTestString())
assert.Equal(t, 4, tree.Len())
nodeO := tree.Insert(newSplayNode("O"))
assert.Equal(t, "[1,1]H[2,1]E[4,2]LL[5,1]O", tree.ToTestString())
assert.Equal(t, "[1,1,1]H[2,1,2]E[4,2,3]LL[5,1,4]O", tree.ToTestString())
assert.Equal(t, 5, tree.Len())

tree.Delete(nodeE)
assert.Equal(t, "[4,1]H[3,2]LL[1,1]O", tree.ToTestString())
assert.Equal(t, "[4,1,3]H[3,2,2]LL[1,1,1]O", tree.ToTestString())
assert.Equal(t, 4, tree.Len())

assert.Equal(t, tree.IndexOf(nodeH), 0)
Expand All @@ -121,7 +121,7 @@ func TestSplayTree(t *testing.T) {
tree.DeleteRange(nodes[6], nil)
assert.Equal(
t,
"[1,1]A[3,2]BB[6,3]CCC[10,4]DDDD[15,5]EEEEE[19,4]FFFF[22,3]GGG[0,0]HH[0,0]I",
"[1,1,1]A[3,2,2]BB[6,3,3]CCC[10,4,4]DDDD[15,5,5]EEEEE[19,4,6]FFFF[22,3,7]GGG[0,0,2]HH[0,0,1]I",
tree.ToTestString(),
)

Expand All @@ -131,7 +131,7 @@ func TestSplayTree(t *testing.T) {
tree.DeleteRange(nodes[2], nodes[7])
assert.Equal(
t,
"[1,1]A[3,2]BB[6,3]CCC[0,0]DDDD[0,0]EEEEE[0,0]FFFF[0,0]GGG[9,2]HH[1,1]I",
"[1,1,1]A[3,2,2]BB[6,3,4]CCC[0,0,2]DDDD[0,0,1]EEEEE[0,0,3]FFFF[0,0,1]GGG[9,2,5]HH[1,1,1]I",
tree.ToTestString(),
)

Expand All @@ -143,7 +143,7 @@ func TestSplayTree(t *testing.T) {
tree.DeleteRange(nodes[2], nodes[8])
assert.Equal(
t,
"[1,1]A[3,2]BB[6,3]CCC[0,0]DDDD[0,0]EEEEE[0,0]FFFF[0,0]GGG[0,0]HH[7,1]I",
"[1,1,1]A[3,2,2]BB[6,3,4]CCC[0,0,2]DDDD[0,0,1]EEEEE[0,0,3]FFFF[0,0,1]GGG[0,0,2]HH[7,1,5]I",
tree.ToTestString(),
)
})
Expand Down
8 changes: 4 additions & 4 deletions test/bench/document_bench_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -142,22 +142,22 @@ func BenchmarkDocument(b *testing.B) {
root.SetNewArray("k1").AddInteger(1).AddInteger(2).AddInteger(3)
assert.Equal(b, 3, root.GetArray("k1").Len())
assert.Equal(b, `{"k1":[1,2,3]}`, root.Marshal())
assert.Equal(b, "[0,0]0[1,1]1[2,1]2[3,1]3", root.GetArray("k1").ToTestString())
assert.Equal(b, "[0,0,1]0[1,1,2]1[2,1,3]2[3,1,4]3", root.GetArray("k1").ToTestString())

root.GetArray("k1").Delete(1)
assert.Equal(b, `{"k1":[1,3]}`, root.Marshal())
assert.Equal(b, 2, root.GetArray("k1").Len())
assert.Equal(b, "[0,0]0[1,1]1[2,0]2[1,1]3", root.GetArray("k1").ToTestString())
assert.Equal(b, "[0,0,1]0[1,1,2]1[2,0,3]2[1,1,1]3", root.GetArray("k1").ToTestString())

root.GetArray("k1").InsertIntegerAfter(0, 2)
assert.Equal(b, `{"k1":[1,2,3]}`, root.Marshal())
assert.Equal(b, 3, root.GetArray("k1").Len())
assert.Equal(b, "[0,0]0[1,1]1[3,1]2[1,0]2[1,1]3", root.GetArray("k1").ToTestString())
assert.Equal(b, "[0,0,1]0[1,1,2]1[3,1,3]2[1,0,2]2[1,1,1]3", root.GetArray("k1").ToTestString())

root.GetArray("k1").InsertIntegerAfter(2, 4)
assert.Equal(b, `{"k1":[1,2,3,4]}`, root.Marshal())
assert.Equal(b, 4, root.GetArray("k1").Len())
assert.Equal(b, "[0,0]0[1,1]1[2,1]2[2,0]2[3,1]3[4,1]4", root.GetArray("k1").ToTestString())
assert.Equal(b, "[0,0,1]0[1,1,2]1[2,1,3]2[2,0,4]2[3,1,5]3[4,1,6]4", root.GetArray("k1").ToTestString())

for i := 0; i < root.GetArray("k1").Len(); i++ {
assert.Equal(
Expand Down
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