create

tree/btree.go

@@ -0,0 +1,112 @@
+package tree
+
+import "sync"
+
+const (
+	DefaultFreeListSize = 32
+)
+
+type FreeList[T Item[T]] struct {
+	mu       sync.Mutex
+	freelist []*bNode[T]
+}
+
+// 初始化B树
+type BTree[T Item[T]] struct {
+	degree int
+	length int
+	root   *bNode[T]
+}
+
+func NewBTree[T Item[T]](degree int) *BTree[T] {
+	return &BTree[T]{}
+}
+
+// nil cannot be added to the tree (will panic).
+func (t *BTree[T]) ReplaceOrInsert(item Item[T]) Item[T] {
+	return item
+}
+
+func (t *BTree[T]) Delete(item T) (T, bool) {
+	return *new(T), false
+}
+
+func (t *BTree[T]) Get(key T) (T, bool) {
+	return *new(T), false
+}
+
+// Has returns true if the given key is in the tree.
+func (t *BTree[T]) Has(key T) bool {
+	return false
+}
+
+// 升序
+func (t *BTree[T]) Ascend(iterator ItemIterator[T]) {
+}
+
+// 大于等于
+func (t *BTree[T]) AscendGreaterOrEqual(pivot Item[T], iterator ItemIterator[T]) {
+
+}
+
+// 小于
+func (t *BTree[T]) AscendLessThan(pivot Item[T], iterator ItemIterator[T]) {
+
+}
+
+// 范围迭代
+func (t *BTree[T]) AscendRange(greaterOrEqual, lessThan Item[T], iterator ItemIterator[T]) {
+
+}
+
+// 降序升序迭代
+func (t *BTree[T]) Descend(iterator ItemIterator[T]) {
+}
+
+// 大于，降序迭代
+func (t *BTree[T]) DescendGreaterThan(pivot Item[T], iterator ItemIterator[T]) {
+
+}
+
+// 小于等于，降序迭代
+func (t *BTree[T]) DescendLessOrEquql(pivot Item[T], iterator ItemIterator[T]) {
+
+}
+
+// 范围降序迭代
+func (t *BTree[T]) DescendRange(greaterOrEqual, lessThan Item[T], iterator ItemIterator[T]) {
+
+}
+
+func (t *BTree[T]) Min() (T, bool) {
+	return *new(T), false
+}
+
+func (t *BTree[T]) Max() (T, bool) {
+	return *new(T), false
+}
+
+func (t *BTree[T]) Len() int {
+	return t.length
+}
+
+func (t *BTree[T]) Clear() {
+
+}
+
+// items stores items in a node.
+type items[T Item[T]] []T
+
+// children stores child nodes in a node.
+type children[T Item[T]] []*bNode[T]
+
+type copyOnWriteContext[T Item[T]] struct {
+	freelist *FreeList[T]
+}
+
+// B树的内部节点
+type bNode[T Item[T]] struct {
+	items    items[T]
+	children children[T]
+	cow      *copyOnWriteContext[T]
+}