structure/hashmap/hashmap.go

package hashmap

import (
	"474420502.top/eson/structure/compare"
)

type HashCode func(key interface{}) uint

type HashMap struct {
	growfactor     uint
	slimmingfactor uint

	table []*avlTree

	GetHash HashCode
	Compare compare.Compare

	growsize uint
	size     uint
}

type bNode struct {
	Next       *bNode
	Key, Value interface{}
}

type Bucket struct {
	size uint
	head *bNode
}

func HashInt(key interface{}) uint {
	thekey := uint(key.(int))
	hbit := thekey & 0xffffffff
	lbit := (thekey & 0xffffffff00000000) >> 32
	return lbit ^ hbit
}

func New(hcode HashCode, comp compare.Compare) *HashMap {
	hm := &HashMap{}
	hm.growfactor = 2
	hm.GetHash = hcode
	hm.Compare = comp
	initcap := uint(8)
	hm.table = make([]*avlTree, initcap, initcap)
	hm.countNextGrow()
	return hm
}

// func (hm *HashMap) grow() {
// 	if hm.size >= hm.growsize {
// 		newsize := hm.size << 1
// 		newtable := make([]*Bucket, newsize, newsize)
// 		hm.growsize = newsize - newsize>>2

// 		for _, bucket := range hm.table {
// 			if bucket != nil {
// 				cur := bucket.head
// 				hash := hm.GetHash(cur.Key)
// 				index := hash % newsize
// 				// var bkt *Bucket
// 				bkt := newtable[index]

// 				if bkt == nil {
// 					bkt = &Bucket{size: 1}
// 					newtable[index] = bkt
// 					bkt.head = &bNode{Value: cur.Value, Key: cur.Key}

// 					cur = cur.Next
// 				}

// 				for ; cur != nil; cur = cur.Next {
// 					bn := &bNode{Value: cur.Value, Key: cur.Key}
// 					bkt.size++
// 					bn.Next = bkt.head
// 					bkt.head = bn
// 				}

// 			}

// 			hm.table = newtable
// 		}
// 	}
// }

func (hm *HashMap) countNextGrow() {
	hm.growsize = uint(len(hm.table)) << 2
}

func (hm *HashMap) grow() {
	if hm.size >= hm.growsize {
		newsize := hm.size << 1
		newtable := make([]*avlTree, newsize, newsize)

		for _, cur := range hm.table {
			if cur != nil {
				cur.Traversal(func(k, v interface{}) bool {
					hash := hm.GetHash(k)
					index := hash % newsize
					bkt := newtable[index]
					if bkt == nil {
						bkt = avlNew(hm.Compare)
						newtable[index] = bkt
					}
					bkt.Put(k, v)
					return true
				})
			}
		}

		hm.table = newtable
		hm.countNextGrow()
	}
}

func (hm *HashMap) Put(key, value interface{}) {
	hash := hm.GetHash(key)

	tlen := uint(len(hm.table))
	index := hash % tlen
	bkt := hm.table[index]

	if bkt == nil {
		bkt = avlNew(hm.Compare)
		hm.table[index] = bkt
	}

	if bkt.Put(key, value) {
		hm.size++
		hm.grow()
	}

	// if bkt == nil {
	// 	nbucket := &Bucket{size: 1}
	// 	hm.table[index] = nbucket
	// 	nbucket.head = &bNode{Value: value, Key: key}
	// 	hm.size++

	// 	hm.grow()
	// 	return
	// }

	// cur := bkt.head

	// for cur.Next != nil {
	// 	if hm.Compare(key, cur.Key) == 0 {
	// 		cur.Key = key
	// 		cur.Value = value
	// 		return
	// 	}
	// 	cur = cur.Next
	// }

	// bn := &bNode{Value: value, Key: key}
	// hm.size++
	// bkt.size++

	// bn.Next = bkt.head
	// bkt.head = bn

	// hm.grow()
}

func (hm *HashMap) Get(key interface{}) (interface{}, bool) {
	hash := hm.GetHash(key)

	tlen := uint(len(hm.table))
	index := hash % tlen
	bkt := hm.table[index]
	if bkt != nil {
		return bkt.Get(key)
	}

	return nil, false
}