test: add examples for lrucache function

algorithm/lru_cache.go

@@ -1,102 +0,0 @@
-package algorithm
-
-type lruNode[K comparable, V any] struct {
-	key   K
-	value V
-	pre   *lruNode[K, V]
-	next  *lruNode[K, V]
-}
-
-// newLruNode return a lruNode pointer
-func newLruNode[K comparable, V any](key K, value V) *lruNode[K, V] {
-	return &lruNode[K, V]{
-		key:   key,
-		value: value,
-		pre:   nil,
-		next:  nil,
-	}
-}
-
-// LRUCache lru cache (thread unsafe)
-type LRUCache[K comparable, V any] struct {
-	cache    map[K]*lruNode[K, V]
-	head     *lruNode[K, V]
-	tail     *lruNode[K, V]
-	capacity int
-	length   int
-}
-
-// NewLRUCache return a LRUCache pointer
-func NewLRUCache[K comparable, V any](capacity int) *LRUCache[K, V] {
-	return &LRUCache[K, V]{
-		cache:    make(map[K]*lruNode[K, V], capacity),
-		head:     nil,
-		tail:     nil,
-		capacity: capacity,
-		length:   0,
-	}
-}
-
-// Get value of key from lru cache
-func (l *LRUCache[K, V]) Get(key K) (V, bool) {
-	var value V
-
-	node, ok := l.cache[key]
-	if ok {
-		l.moveToHead(node)
-		return node.value, true
-	}
-
-	return value, false
-}
-
-// Put value of key into lru cache
-func (l *LRUCache[K, V]) Put(key K, value V) {
-	node, ok := l.cache[key]
-	if !ok {
-		newNode := newLruNode(key, value)
-		l.cache[key] = newNode
-		l.addNode(newNode)
-
-		if len(l.cache) > l.capacity {
-			oldKey := l.deleteNode(l.head)
-			delete(l.cache, oldKey)
-		}
-	} else {
-		node.value = value
-		l.moveToHead(node)
-	}
-	l.length = len(l.cache)
-}
-
-func (l *LRUCache[K, V]) addNode(node *lruNode[K, V]) {
-	if l.tail != nil {
-		l.tail.next = node
-		node.pre = l.tail
-		node.next = nil
-	}
-	l.tail = node
-	if l.head == nil {
-		l.head = node
-	}
-}
-
-func (l *LRUCache[K, V]) deleteNode(node *lruNode[K, V]) K {
-	if node == l.tail {
-		l.tail = l.tail.pre
-	} else if node == l.head {
-		l.head = l.head.next
-	} else {
-		node.pre.next = node.next
-		node.next.pre = node.pre
-	}
-	return node.key
-}
-
-func (l *LRUCache[K, V]) moveToHead(node *lruNode[K, V]) {
-	if l.tail == node {
-		return
-	}
-	l.deleteNode(node)
-	l.addNode(node)
-}

algorithm/lru_cache_test.go

@@ -1,36 +0,0 @@
-package algorithm
-
-import (
-	"testing"
-
-	"github.com/duke-git/lancet/v2/internal"
-)
-
-func TestLRUCache(t *testing.T) {
-	asssert := internal.NewAssert(t, "TestLRUCache")
-
-	cache := NewLRUCache[int, int](2)
-
-	cache.Put(1, 1)
-	cache.Put(2, 2)
-
-	_, ok := cache.Get(0)
-	asssert.Equal(false, ok)
-
-	v, ok := cache.Get(1)
-	asssert.Equal(true, ok)
-	asssert.Equal(1, v)
-
-	v, ok = cache.Get(2)
-	asssert.Equal(true, ok)
-	asssert.Equal(2, v)
-
-	cache.Put(3, 3)
-	v, ok = cache.Get(1)
-	asssert.Equal(false, ok)
-	asssert.NotEqual(1, v)
-
-	v, ok = cache.Get(3)
-	asssert.Equal(true, ok)
-	asssert.Equal(3, v)
-}