Implement the LRU Cache

1 files changed, 64 insertions, 0 deletions

diff --git a/cache/lru_id_cache.go b/cache/lru_id_cache.go
new file mode 100644
index 00000000..e31f2843
--- /dev/null
+++ b/cache/lru_id_cache.go
@@ -0,0 +1,64 @@
+package cache
+
+import (
+	lru "github.com/hashicorp/golang-lru"
+
+	"github.com/MichaelMure/git-bug/entity"
+)
+
+type LRUIdCache struct {
+	parentCache *lru.Cache
+	maxSize     int
+	onEvict     func(id entity.Id)
+}
+
+func NewLRUIdCache(size int, onEvicted func(id entity.Id)) (*LRUIdCache, error) {
+	cache, err := lru.New(size)
+	if err != nil {
+		return nil, err
+	}
+
+	return &LRUIdCache{
+		cache,
+		size,
+		onEvicted,
+	}, nil
+}
+
+func (c *LRUIdCache) Add(id entity.Id) bool {
+	return c.parentCache.Add(id, nil)
+}
+
+func (c *LRUIdCache) Contains(id entity.Id) bool {
+	return c.parentCache.Contains(id)
+}
+
+func (c *LRUIdCache) Get(id entity.Id) bool {
+	_, present := c.parentCache.Get(id)
+	return present
+}
+
+func (c *LRUIdCache) GetOldest() (entity.Id, bool) {
+	id, _, present := c.parentCache.GetOldest()
+	return id.(entity.Id), present
+}
+
+func (c *LRUIdCache) GetAll() (ids []entity.Id) {
+	interfaceKeys := c.parentCache.Keys()
+	for _, id := range interfaceKeys {
+		ids = append(ids, id.(entity.Id))
+	}
+	return
+}
+
+func (c *LRUIdCache) Len() int {
+	return c.parentCache.Len()
+}
+
+func (c *LRUIdCache) Remove(id entity.Id) bool {
+	return c.parentCache.Remove(id)
+}
+
+func (c *LRUIdCache) Resize(size int) int {
+	return c.parentCache.Resize(size)
+}