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 []interface{}

	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([]interface{}, initcap, initcap)
	hm.growsize = initcap - initcap>>2
	return hm
}

func (hm *HashMap) grow() {
	if hm.size >= hm.growsize {
		newsize := hm.size << 1
		newtable := make([]interface{}, newsize, newsize)
		hm.growsize = newsize - newsize>>2
		hm.size = 0

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

				if n == nil {
					bkt = &Bucket{size: 1}
					newtable[index] = bkt
					bkt.head = &bNode{Value: cur.Value, Key: cur.Key}
					hm.size++
					cur = cur.Next
				} else {
					bkt = n.(*Bucket)
				}

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

			}

			hm.table = newtable
		}
	}
}

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

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

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

	// bucket := n.(*avlTree)
	// if bucket.Put(key, value) {
	// 	hm.size++

	// 	if hm.size >= hm.growsize {
	// 		newsize := hm.size << 1
	// 		newtable := make([]interface{}, newsize, newsize)
	// 		hm.growsize = newsize - newsize>>2

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

	// 			}
	// 		}

	// 		hm.table = newtable

	// 	}
	// }

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

		hm.grow()
		return
	}

	bkt := n.(*Bucket)
	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()
}