mirror of
https://gitee.com/johng/gf.git
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787 lines
19 KiB
Go
787 lines
19 KiB
Go
// Copyright 2019 gf Author(https://github.com/gogf/gf). All Rights Reserved.
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//
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// This Source Code Form is subject to the terms of the MIT License.
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// If a copy of the MIT was not distributed with this file,
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// You can obtain one at https://github.com/gogf/gf.
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package gtree
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import (
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"encoding/json"
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"fmt"
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"github.com/gogf/gf/util/gconv"
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"github.com/gogf/gf/container/gvar"
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"github.com/gogf/gf/internal/rwmutex"
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)
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// AVLTree holds elements of the AVL tree.
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type AVLTree struct {
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mu *rwmutex.RWMutex
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root *AVLTreeNode
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comparator func(v1, v2 interface{}) int
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size int
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}
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// AVLTreeNode is a single element within the tree.
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type AVLTreeNode struct {
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Key interface{}
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Value interface{}
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parent *AVLTreeNode
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children [2]*AVLTreeNode
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b int8
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}
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// NewAVLTree instantiates an AVL tree with the custom key comparator.
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// The parameter <safe> is used to specify whether using tree in concurrent-safety,
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// which is false in default.
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func NewAVLTree(comparator func(v1, v2 interface{}) int, safe ...bool) *AVLTree {
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return &AVLTree{
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mu: rwmutex.New(safe...),
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comparator: comparator,
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}
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}
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// NewAVLTreeFrom instantiates an AVL tree with the custom key comparator and data map.
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// The parameter <safe> is used to specify whether using tree in concurrent-safety,
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// which is false in default.
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func NewAVLTreeFrom(comparator func(v1, v2 interface{}) int, data map[interface{}]interface{}, safe ...bool) *AVLTree {
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tree := NewAVLTree(comparator, safe...)
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for k, v := range data {
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tree.put(k, v, nil, &tree.root)
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}
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return tree
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}
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// Clone returns a new tree with a copy of current tree.
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func (tree *AVLTree) Clone(safe ...bool) *AVLTree {
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newTree := NewAVLTree(tree.comparator, !tree.mu.IsSafe())
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newTree.Sets(tree.Map())
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return newTree
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}
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// Set inserts node into the tree.
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func (tree *AVLTree) Set(key interface{}, value interface{}) {
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tree.mu.Lock()
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defer tree.mu.Unlock()
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tree.put(key, value, nil, &tree.root)
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}
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// Sets batch sets key-values to the tree.
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func (tree *AVLTree) Sets(data map[interface{}]interface{}) {
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tree.mu.Lock()
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defer tree.mu.Unlock()
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for key, value := range data {
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tree.put(key, value, nil, &tree.root)
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}
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}
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// Search searches the tree with given <key>.
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// Second return parameter <found> is true if key was found, otherwise false.
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func (tree *AVLTree) Search(key interface{}) (value interface{}, found bool) {
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tree.mu.RLock()
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defer tree.mu.RUnlock()
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if node, found := tree.doSearch(key); found {
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return node.Value, true
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}
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return nil, false
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}
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// doSearch searches the tree with given <key>.
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// Second return parameter <found> is true if key was found, otherwise false.
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func (tree *AVLTree) doSearch(key interface{}) (node *AVLTreeNode, found bool) {
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node = tree.root
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for node != nil {
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cmp := tree.comparator(key, node.Key)
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switch {
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case cmp == 0:
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return node, true
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case cmp < 0:
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node = node.children[0]
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case cmp > 0:
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node = node.children[1]
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}
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}
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return nil, false
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}
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// Get searches the node in the tree by <key> and returns its value or nil if key is not found in tree.
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func (tree *AVLTree) Get(key interface{}) (value interface{}) {
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value, _ = tree.Search(key)
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return
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}
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// doSetWithLockCheck checks whether value of the key exists with mutex.Lock,
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// if not exists, set value to the map with given <key>,
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// or else just return the existing value.
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//
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// When setting value, if <value> is type of <func() interface {}>,
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// it will be executed with mutex.Lock of the hash map,
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// and its return value will be set to the map with <key>.
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//
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// It returns value with given <key>.
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func (tree *AVLTree) doSetWithLockCheck(key interface{}, value interface{}) interface{} {
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tree.mu.Lock()
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defer tree.mu.Unlock()
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if node, found := tree.doSearch(key); found {
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return node.Value
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}
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if f, ok := value.(func() interface{}); ok {
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value = f()
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}
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if value != nil {
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tree.put(key, value, nil, &tree.root)
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}
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return value
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}
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// GetOrSet returns the value by key,
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// or sets value with given <value> if it does not exist and then returns this value.
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func (tree *AVLTree) GetOrSet(key interface{}, value interface{}) interface{} {
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if v, ok := tree.Search(key); !ok {
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return tree.doSetWithLockCheck(key, value)
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} else {
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return v
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}
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}
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// GetOrSetFunc returns the value by key,
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// or sets value with returned value of callback function <f> if it does not exist
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// and then returns this value.
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func (tree *AVLTree) GetOrSetFunc(key interface{}, f func() interface{}) interface{} {
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if v, ok := tree.Search(key); !ok {
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return tree.doSetWithLockCheck(key, f())
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} else {
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return v
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}
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}
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// GetOrSetFuncLock returns the value by key,
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// or sets value with returned value of callback function <f> if it does not exist
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// and then returns this value.
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//
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// GetOrSetFuncLock differs with GetOrSetFunc function is that it executes function <f>
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// with mutex.Lock of the hash map.
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func (tree *AVLTree) GetOrSetFuncLock(key interface{}, f func() interface{}) interface{} {
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if v, ok := tree.Search(key); !ok {
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return tree.doSetWithLockCheck(key, f)
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} else {
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return v
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}
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}
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// GetVar returns a gvar.Var with the value by given <key>.
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// The returned gvar.Var is un-concurrent safe.
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func (tree *AVLTree) GetVar(key interface{}) *gvar.Var {
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return gvar.New(tree.Get(key))
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}
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// GetVarOrSet returns a gvar.Var with result from GetVarOrSet.
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// The returned gvar.Var is un-concurrent safe.
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func (tree *AVLTree) GetVarOrSet(key interface{}, value interface{}) *gvar.Var {
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return gvar.New(tree.GetOrSet(key, value))
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}
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// GetVarOrSetFunc returns a gvar.Var with result from GetOrSetFunc.
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// The returned gvar.Var is un-concurrent safe.
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func (tree *AVLTree) GetVarOrSetFunc(key interface{}, f func() interface{}) *gvar.Var {
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return gvar.New(tree.GetOrSetFunc(key, f))
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}
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// GetVarOrSetFuncLock returns a gvar.Var with result from GetOrSetFuncLock.
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// The returned gvar.Var is un-concurrent safe.
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func (tree *AVLTree) GetVarOrSetFuncLock(key interface{}, f func() interface{}) *gvar.Var {
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return gvar.New(tree.GetOrSetFuncLock(key, f))
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}
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// SetIfNotExist sets <value> to the map if the <key> does not exist, and then returns true.
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// It returns false if <key> exists, and <value> would be ignored.
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func (tree *AVLTree) SetIfNotExist(key interface{}, value interface{}) bool {
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if !tree.Contains(key) {
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tree.doSetWithLockCheck(key, value)
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return true
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}
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return false
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}
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// SetIfNotExistFunc sets value with return value of callback function <f>, and then returns true.
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// It returns false if <key> exists, and <value> would be ignored.
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func (tree *AVLTree) SetIfNotExistFunc(key interface{}, f func() interface{}) bool {
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if !tree.Contains(key) {
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tree.doSetWithLockCheck(key, f())
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return true
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}
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return false
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}
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// SetIfNotExistFuncLock sets value with return value of callback function <f>, and then returns true.
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// It returns false if <key> exists, and <value> would be ignored.
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//
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// SetIfNotExistFuncLock differs with SetIfNotExistFunc function is that
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// it executes function <f> with mutex.Lock of the hash map.
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func (tree *AVLTree) SetIfNotExistFuncLock(key interface{}, f func() interface{}) bool {
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if !tree.Contains(key) {
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tree.doSetWithLockCheck(key, f)
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return true
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}
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return false
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}
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// Contains checks whether <key> exists in the tree.
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func (tree *AVLTree) Contains(key interface{}) bool {
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_, ok := tree.Search(key)
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return ok
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}
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// Remove removes the node from the tree by key.
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// Key should adhere to the comparator's type assertion, otherwise method panics.
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func (tree *AVLTree) Remove(key interface{}) (value interface{}) {
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tree.mu.Lock()
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defer tree.mu.Unlock()
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value, _ = tree.remove(key, &tree.root)
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return
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}
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// Removes batch deletes values of the tree by <keys>.
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func (tree *AVLTree) Removes(keys []interface{}) {
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tree.mu.Lock()
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defer tree.mu.Unlock()
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for _, key := range keys {
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tree.remove(key, &tree.root)
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}
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}
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// IsEmpty returns true if tree does not contain any nodes.
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func (tree *AVLTree) IsEmpty() bool {
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return tree.Size() == 0
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}
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// Size returns number of nodes in the tree.
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func (tree *AVLTree) Size() int {
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tree.mu.RLock()
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defer tree.mu.RUnlock()
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return tree.size
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}
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// Keys returns all keys in asc order.
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func (tree *AVLTree) Keys() []interface{} {
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keys := make([]interface{}, tree.Size())
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index := 0
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tree.IteratorAsc(func(key, value interface{}) bool {
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keys[index] = key
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index++
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return true
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})
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return keys
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}
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// Values returns all values in asc order based on the key.
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func (tree *AVLTree) Values() []interface{} {
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values := make([]interface{}, tree.Size())
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index := 0
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tree.IteratorAsc(func(key, value interface{}) bool {
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values[index] = value
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index++
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return true
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})
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return values
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}
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// Left returns the minimum element of the AVL tree
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// or nil if the tree is empty.
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func (tree *AVLTree) Left() *AVLTreeNode {
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tree.mu.RLock()
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defer tree.mu.RUnlock()
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node := tree.bottom(0)
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if tree.mu.IsSafe() {
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return &AVLTreeNode{
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Key: node.Key,
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Value: node.Value,
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}
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}
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return node
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}
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// Right returns the maximum element of the AVL tree
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// or nil if the tree is empty.
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func (tree *AVLTree) Right() *AVLTreeNode {
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tree.mu.RLock()
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defer tree.mu.RUnlock()
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node := tree.bottom(1)
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if tree.mu.IsSafe() {
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return &AVLTreeNode{
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Key: node.Key,
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Value: node.Value,
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}
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}
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return node
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}
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// Floor Finds floor node of the input key, return the floor node or nil if no floor node is found.
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// Second return parameter is true if floor was found, otherwise false.
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//
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// Floor node is defined as the largest node that is smaller than or equal to the given node.
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// A floor node may not be found, either because the tree is empty, or because
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// all nodes in the tree is larger than the given node.
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//
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// Key should adhere to the comparator's type assertion, otherwise method panics.
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func (tree *AVLTree) Floor(key interface{}) (floor *AVLTreeNode, found bool) {
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tree.mu.RLock()
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defer tree.mu.RUnlock()
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n := tree.root
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for n != nil {
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c := tree.comparator(key, n.Key)
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switch {
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case c == 0:
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return n, true
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case c < 0:
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n = n.children[0]
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case c > 0:
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floor, found = n, true
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n = n.children[1]
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}
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}
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if found {
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return
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}
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return nil, false
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}
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// Ceiling finds ceiling node of the input key, return the ceiling node or nil if no ceiling node is found.
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// Second return parameter is true if ceiling was found, otherwise false.
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//
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// Ceiling node is defined as the smallest node that is larger than or equal to the given node.
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// A ceiling node may not be found, either because the tree is empty, or because
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// all nodes in the tree is smaller than the given node.
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//
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// Key should adhere to the comparator's type assertion, otherwise method panics.
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func (tree *AVLTree) Ceiling(key interface{}) (ceiling *AVLTreeNode, found bool) {
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tree.mu.RLock()
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defer tree.mu.RUnlock()
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n := tree.root
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for n != nil {
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c := tree.comparator(key, n.Key)
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switch {
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case c == 0:
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return n, true
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case c > 0:
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n = n.children[1]
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case c < 0:
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ceiling, found = n, true
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n = n.children[0]
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}
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}
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if found {
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return
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}
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return nil, false
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}
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// Clear removes all nodes from the tree.
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func (tree *AVLTree) Clear() {
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tree.mu.Lock()
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defer tree.mu.Unlock()
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tree.root = nil
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tree.size = 0
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}
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// Replace the data of the tree with given <data>.
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func (tree *AVLTree) Replace(data map[interface{}]interface{}) {
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tree.mu.Lock()
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defer tree.mu.Unlock()
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tree.root = nil
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tree.size = 0
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for key, value := range data {
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tree.put(key, value, nil, &tree.root)
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}
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}
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// String returns a string representation of container
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func (tree *AVLTree) String() string {
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tree.mu.RLock()
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defer tree.mu.RUnlock()
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str := ""
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if tree.size != 0 {
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output(tree.root, "", true, &str)
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}
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return str
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}
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// Print prints the tree to stdout.
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func (tree *AVLTree) Print() {
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fmt.Println(tree.String())
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}
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// Map returns all key-value items as map.
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func (tree *AVLTree) Map() map[interface{}]interface{} {
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m := make(map[interface{}]interface{}, tree.Size())
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tree.IteratorAsc(func(key, value interface{}) bool {
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m[key] = value
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return true
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})
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return m
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}
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// MapStrAny returns all key-value items as map[string]interface{}.
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func (tree *AVLTree) MapStrAny() map[string]interface{} {
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m := make(map[string]interface{}, tree.Size())
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tree.IteratorAsc(func(key, value interface{}) bool {
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m[gconv.String(key)] = value
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return true
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})
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return m
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}
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// Flip exchanges key-value of the tree to value-key.
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// Note that you should guarantee the value is the same type as key,
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// or else the comparator would panic.
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//
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// If the type of value is different with key, you pass the new <comparator>.
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func (tree *AVLTree) Flip(comparator ...func(v1, v2 interface{}) int) {
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t := (*AVLTree)(nil)
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if len(comparator) > 0 {
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t = NewAVLTree(comparator[0], !tree.mu.IsSafe())
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} else {
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t = NewAVLTree(tree.comparator, !tree.mu.IsSafe())
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}
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tree.IteratorAsc(func(key, value interface{}) bool {
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t.put(value, key, nil, &t.root)
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return true
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})
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tree.mu.Lock()
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tree.root = t.root
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tree.size = t.size
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tree.mu.Unlock()
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}
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// Iterator is alias of IteratorAsc.
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func (tree *AVLTree) Iterator(f func(key, value interface{}) bool) {
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tree.IteratorAsc(f)
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}
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// IteratorFrom is alias of IteratorAscFrom.
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func (tree *AVLTree) IteratorFrom(key interface{}, match bool, f func(key, value interface{}) bool) {
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tree.IteratorAscFrom(key, match, f)
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}
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// IteratorAsc iterates the tree in ascending order with given callback function <f>.
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// If <f> returns true, then it continues iterating; or false to stop.
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func (tree *AVLTree) IteratorAsc(f func(key, value interface{}) bool) {
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tree.mu.RLock()
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defer tree.mu.RUnlock()
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tree.doIteratorAsc(tree.bottom(0), f)
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}
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// IteratorAscFrom iterates the tree in ascending order with given callback function <f>.
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// The parameter <key> specifies the start entry for iterating. The <match> specifies whether
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// starting iterating if the <key> is fully matched, or else using index searching iterating.
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// If <f> returns true, then it continues iterating; or false to stop.
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func (tree *AVLTree) IteratorAscFrom(key interface{}, match bool, f func(key, value interface{}) bool) {
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tree.mu.RLock()
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defer tree.mu.RUnlock()
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node, found := tree.doSearch(key)
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if match {
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if found {
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tree.doIteratorAsc(node, f)
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}
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} else {
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tree.doIteratorAsc(node, f)
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}
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}
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func (tree *AVLTree) doIteratorAsc(node *AVLTreeNode, f func(key, value interface{}) bool) {
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for node != nil {
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if !f(node.Key, node.Value) {
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return
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}
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node = node.Next()
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}
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}
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// IteratorDesc iterates the tree in descending order with given callback function <f>.
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// If <f> returns true, then it continues iterating; or false to stop.
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func (tree *AVLTree) IteratorDesc(f func(key, value interface{}) bool) {
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tree.mu.RLock()
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defer tree.mu.RUnlock()
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tree.doIteratorDesc(tree.bottom(1), f)
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}
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// IteratorDescFrom iterates the tree in descending order with given callback function <f>.
|
|
// The parameter <key> specifies the start entry for iterating. The <match> specifies whether
|
|
// starting iterating if the <key> is fully matched, or else using index searching iterating.
|
|
// If <f> returns true, then it continues iterating; or false to stop.
|
|
func (tree *AVLTree) IteratorDescFrom(key interface{}, match bool, f func(key, value interface{}) bool) {
|
|
tree.mu.RLock()
|
|
defer tree.mu.RUnlock()
|
|
node, found := tree.doSearch(key)
|
|
if match {
|
|
if found {
|
|
tree.doIteratorDesc(node, f)
|
|
}
|
|
} else {
|
|
tree.doIteratorDesc(node, f)
|
|
}
|
|
}
|
|
|
|
func (tree *AVLTree) doIteratorDesc(node *AVLTreeNode, f func(key, value interface{}) bool) {
|
|
for node != nil {
|
|
if !f(node.Key, node.Value) {
|
|
return
|
|
}
|
|
node = node.Prev()
|
|
}
|
|
}
|
|
|
|
func (tree *AVLTree) put(key interface{}, value interface{}, p *AVLTreeNode, qp **AVLTreeNode) bool {
|
|
q := *qp
|
|
if q == nil {
|
|
tree.size++
|
|
*qp = &AVLTreeNode{Key: key, Value: value, parent: p}
|
|
return true
|
|
}
|
|
|
|
c := tree.comparator(key, q.Key)
|
|
if c == 0 {
|
|
q.Key = key
|
|
q.Value = value
|
|
return false
|
|
}
|
|
|
|
if c < 0 {
|
|
c = -1
|
|
} else {
|
|
c = 1
|
|
}
|
|
a := (c + 1) / 2
|
|
if tree.put(key, value, q, &q.children[a]) {
|
|
return putFix(int8(c), qp)
|
|
}
|
|
return false
|
|
}
|
|
|
|
func (tree *AVLTree) remove(key interface{}, qp **AVLTreeNode) (value interface{}, fix bool) {
|
|
q := *qp
|
|
if q == nil {
|
|
return nil, false
|
|
}
|
|
|
|
c := tree.comparator(key, q.Key)
|
|
if c == 0 {
|
|
tree.size--
|
|
value = q.Value
|
|
fix = true
|
|
if q.children[1] == nil {
|
|
if q.children[0] != nil {
|
|
q.children[0].parent = q.parent
|
|
}
|
|
*qp = q.children[0]
|
|
return
|
|
}
|
|
if removeMin(&q.children[1], &q.Key, &q.Value) {
|
|
return value, removeFix(-1, qp)
|
|
}
|
|
return
|
|
}
|
|
|
|
if c < 0 {
|
|
c = -1
|
|
} else {
|
|
c = 1
|
|
}
|
|
a := (c + 1) / 2
|
|
value, fix = tree.remove(key, &q.children[a])
|
|
if fix {
|
|
return value, removeFix(int8(-c), qp)
|
|
}
|
|
return value, false
|
|
}
|
|
|
|
func removeMin(qp **AVLTreeNode, minKey *interface{}, minVal *interface{}) bool {
|
|
q := *qp
|
|
if q.children[0] == nil {
|
|
*minKey = q.Key
|
|
*minVal = q.Value
|
|
if q.children[1] != nil {
|
|
q.children[1].parent = q.parent
|
|
}
|
|
*qp = q.children[1]
|
|
return true
|
|
}
|
|
fix := removeMin(&q.children[0], minKey, minVal)
|
|
if fix {
|
|
return removeFix(1, qp)
|
|
}
|
|
return false
|
|
}
|
|
|
|
func putFix(c int8, t **AVLTreeNode) bool {
|
|
s := *t
|
|
if s.b == 0 {
|
|
s.b = c
|
|
return true
|
|
}
|
|
|
|
if s.b == -c {
|
|
s.b = 0
|
|
return false
|
|
}
|
|
|
|
if s.children[(c+1)/2].b == c {
|
|
s = singleRotate(c, s)
|
|
} else {
|
|
s = doubleRotate(c, s)
|
|
}
|
|
*t = s
|
|
return false
|
|
}
|
|
|
|
func removeFix(c int8, t **AVLTreeNode) bool {
|
|
s := *t
|
|
if s.b == 0 {
|
|
s.b = c
|
|
return false
|
|
}
|
|
|
|
if s.b == -c {
|
|
s.b = 0
|
|
return true
|
|
}
|
|
|
|
a := (c + 1) / 2
|
|
if s.children[a].b == 0 {
|
|
s = rotate(c, s)
|
|
s.b = -c
|
|
*t = s
|
|
return false
|
|
}
|
|
|
|
if s.children[a].b == c {
|
|
s = singleRotate(c, s)
|
|
} else {
|
|
s = doubleRotate(c, s)
|
|
}
|
|
*t = s
|
|
return true
|
|
}
|
|
|
|
func singleRotate(c int8, s *AVLTreeNode) *AVLTreeNode {
|
|
s.b = 0
|
|
s = rotate(c, s)
|
|
s.b = 0
|
|
return s
|
|
}
|
|
|
|
func doubleRotate(c int8, s *AVLTreeNode) *AVLTreeNode {
|
|
a := (c + 1) / 2
|
|
r := s.children[a]
|
|
s.children[a] = rotate(-c, s.children[a])
|
|
p := rotate(c, s)
|
|
|
|
switch {
|
|
default:
|
|
s.b = 0
|
|
r.b = 0
|
|
case p.b == c:
|
|
s.b = -c
|
|
r.b = 0
|
|
case p.b == -c:
|
|
s.b = 0
|
|
r.b = c
|
|
}
|
|
|
|
p.b = 0
|
|
return p
|
|
}
|
|
|
|
func rotate(c int8, s *AVLTreeNode) *AVLTreeNode {
|
|
a := (c + 1) / 2
|
|
r := s.children[a]
|
|
s.children[a] = r.children[a^1]
|
|
if s.children[a] != nil {
|
|
s.children[a].parent = s
|
|
}
|
|
r.children[a^1] = s
|
|
r.parent = s.parent
|
|
s.parent = r
|
|
return r
|
|
}
|
|
|
|
func (tree *AVLTree) bottom(d int) *AVLTreeNode {
|
|
n := tree.root
|
|
if n == nil {
|
|
return nil
|
|
}
|
|
|
|
for c := n.children[d]; c != nil; c = n.children[d] {
|
|
n = c
|
|
}
|
|
return n
|
|
}
|
|
|
|
// Prev returns the previous element in an inorder
|
|
// walk of the AVL tree.
|
|
func (node *AVLTreeNode) Prev() *AVLTreeNode {
|
|
return node.walk1(0)
|
|
}
|
|
|
|
// Next returns the next element in an inorder
|
|
// walk of the AVL tree.
|
|
func (node *AVLTreeNode) Next() *AVLTreeNode {
|
|
return node.walk1(1)
|
|
}
|
|
|
|
func (node *AVLTreeNode) walk1(a int) *AVLTreeNode {
|
|
if node == nil {
|
|
return nil
|
|
}
|
|
n := node
|
|
if n.children[a] != nil {
|
|
n = n.children[a]
|
|
for n.children[a^1] != nil {
|
|
n = n.children[a^1]
|
|
}
|
|
return n
|
|
}
|
|
|
|
p := n.parent
|
|
for p != nil && p.children[a] == n {
|
|
n = p
|
|
p = p.parent
|
|
}
|
|
return p
|
|
}
|
|
|
|
func output(node *AVLTreeNode, prefix string, isTail bool, str *string) {
|
|
if node.children[1] != nil {
|
|
newPrefix := prefix
|
|
if isTail {
|
|
newPrefix += "│ "
|
|
} else {
|
|
newPrefix += " "
|
|
}
|
|
output(node.children[1], newPrefix, false, str)
|
|
}
|
|
*str += prefix
|
|
if isTail {
|
|
*str += "└── "
|
|
} else {
|
|
*str += "┌── "
|
|
}
|
|
*str += fmt.Sprintf("%v\n", node.Key)
|
|
if node.children[0] != nil {
|
|
newPrefix := prefix
|
|
if isTail {
|
|
newPrefix += " "
|
|
} else {
|
|
newPrefix += "│ "
|
|
}
|
|
output(node.children[0], newPrefix, true, str)
|
|
}
|
|
}
|
|
|
|
// MarshalJSON implements the interface MarshalJSON for json.Marshal.
|
|
func (tree *AVLTree) MarshalJSON() ([]byte, error) {
|
|
return json.Marshal(tree.Map())
|
|
}
|