[#122] Refactor

Signed-off-by: Denis Kirillov <denis@nspcc.ru>

api/cache/buckets.go

@@ -0,0 +1,77 @@
+package cache
+
+import (
+	"time"
+
+	"github.com/bluele/gcache"
+	cid "github.com/nspcc-dev/neofs-api-go/pkg/container/id"
+	"github.com/nspcc-dev/neofs-api-go/pkg/owner"
+)
+
+type (
+	// BucketCache provides interface for lru cache for objects.
+	BucketCache interface {
+		Get(key string) *BucketInfo
+		Put(bkt *BucketInfo) error
+		Delete(key string) bool
+	}
+
+	// BucketInfo stores basic bucket data.
+	BucketInfo struct {
+		Name     string
+		CID      *cid.ID
+		Owner    *owner.ID
+		Created  time.Time
+		BasicACL uint32
+	}
+
+	// GetBucketCache contains cache with objects and lifetime of cache entries.
+	GetBucketCache struct {
+		cache    gcache.Cache
+		lifetime time.Duration
+	}
+)
+
+// NewBucketCache creates an object of BucketCache.
+func NewBucketCache(cacheSize int, lifetime time.Duration) *GetBucketCache {
+	gc := gcache.New(cacheSize).LRU().Build()
+
+	return &GetBucketCache{cache: gc, lifetime: lifetime}
+}
+
+// Get returns cached object.
+func (o *GetBucketCache) Get(key string) *BucketInfo {
+	entry, err := o.cache.Get(key)
+	if err != nil {
+		return nil
+	}
+
+	result, ok := entry.(*BucketInfo)
+	if !ok {
+		return nil
+	}
+
+	return result
+}
+
+// Put puts an object to cache.
+func (o *GetBucketCache) Put(bkt *BucketInfo) error {
+	return o.cache.SetWithExpire(bkt.Name, bkt, o.lifetime)
+}
+
+// Delete deletes an object from cache.
+func (o *GetBucketCache) Delete(key string) bool {
+	return o.cache.Remove(key)
+}
+
+const bktVersionSettingsObject = ".s3-versioning-settings"
+
+// SettingsObjectName is system name for bucket settings file.
+func (b *BucketInfo) SettingsObjectName() string {
+	return bktVersionSettingsObject
+}
+
+// SettingsObjectKey is key to use in SystemCache.
+func (b *BucketInfo) SettingsObjectKey() string {
+	return b.Name + bktVersionSettingsObject
+}