[#70] Support bucket/container caching

Mainly it was added because
we need to know if TZ hashing is disabled or not for container

Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>

internal/cache/buckets.go

@@ -0,0 +1,68 @@
+package cache
+
+import (
+	"fmt"
+	"time"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/internal/data"
+	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/internal/logs"
+	"github.com/bluele/gcache"
+	"go.uber.org/zap"
+)
+
+// BucketCache contains cache with objects and the lifetime of cache entries.
+type BucketCache struct {
+	cache  gcache.Cache
+	logger *zap.Logger
+}
+
+// Config stores expiration params for cache.
+type Config struct {
+	Size     int
+	Lifetime time.Duration
+	Logger   *zap.Logger
+}
+
+const (
+	// DefaultBucketCacheSize is a default maximum number of entries in cache.
+	DefaultBucketCacheSize = 1e3
+	// DefaultBucketCacheLifetime is a default lifetime of entries in cache.
+	DefaultBucketCacheLifetime = time.Minute
+)
+
+// DefaultBucketConfig returns new default cache expiration values.
+func DefaultBucketConfig(logger *zap.Logger) *Config {
+	return &Config{
+		Size:     DefaultBucketCacheSize,
+		Lifetime: DefaultBucketCacheLifetime,
+		Logger:   logger,
+	}
+}
+
+// NewBucketCache creates an object of BucketCache.
+func NewBucketCache(config *Config) *BucketCache {
+	gc := gcache.New(config.Size).LRU().Expiration(config.Lifetime).Build()
+	return &BucketCache{cache: gc, logger: config.Logger}
+}
+
+// Get returns a cached object.
+func (o *BucketCache) Get(key string) *data.BucketInfo {
+	entry, err := o.cache.Get(key)
+	if err != nil {
+		return nil
+	}
+
+	result, ok := entry.(*data.BucketInfo)
+	if !ok {
+		o.logger.Warn(logs.InvalidCacheEntryType, zap.String("actual", fmt.Sprintf("%T", entry)),
+			zap.String("expected", fmt.Sprintf("%T", result)))
+		return nil
+	}
+
+	return result
+}
+
+// Put puts an object to cache.
+func (o *BucketCache) Put(bkt *data.BucketInfo) error {
+	return o.cache.Set(bkt.Name, bkt)
+}