[#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>

cmd/http-gw/settings.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"time"
 
+	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/internal/cache"
 	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/internal/logs"
 	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/resolver"
 	grpctracing "git.frostfs.info/TrueCloudLab/frostfs-observability/tracing/grpc"
@@ -103,6 +104,10 @@ const (
 	// Sets max buffer size for read payload in put operations.
 	cfgBufferMaxSizeForPut = "frostfs.buffer_max_size_for_put"
 
+	// Caching.
+	cfgBucketsCacheLifetime = "cache.buckets.lifetime"
+	cfgBucketsCacheSize     = "cache.buckets.size"
+
 	// Command line args.
 	cmdHelp          = "help"
 	cmdVersion       = "version"
@@ -541,3 +546,44 @@ func fetchSoftMemoryLimit(cfg *viper.Viper) int64 {
 
 	return int64(softMemoryLimit)
 }
+
+func getCacheOptions(v *viper.Viper, l *zap.Logger) *cache.Config {
+	cacheCfg := cache.DefaultBucketConfig(l)
+
+	cacheCfg.Lifetime = fetchCacheLifetime(v, l, cfgBucketsCacheLifetime, cacheCfg.Lifetime)
+	cacheCfg.Size = fetchCacheSize(v, l, cfgBucketsCacheSize, cacheCfg.Size)
+
+	return cacheCfg
+}
+
+func fetchCacheLifetime(v *viper.Viper, l *zap.Logger, cfgEntry string, defaultValue time.Duration) time.Duration {
+	if v.IsSet(cfgEntry) {
+		lifetime := v.GetDuration(cfgEntry)
+		if lifetime <= 0 {
+			l.Error("invalid lifetime, using default value (in seconds)",
+				zap.String("parameter", cfgEntry),
+				zap.Duration("value in config", lifetime),
+				zap.Duration("default", defaultValue))
+		} else {
+			return lifetime
+		}
+	}
+
+	return defaultValue
+}
+
+func fetchCacheSize(v *viper.Viper, l *zap.Logger, cfgEntry string, defaultValue int) int {
+	if v.IsSet(cfgEntry) {
+		size := v.GetInt(cfgEntry)
+		if size <= 0 {
+			l.Error("invalid cache size, using default value",
+				zap.String("parameter", cfgEntry),
+				zap.Int("value in config", size),
+				zap.Int("default", defaultValue))
+		} else {
+			return size
+		}
+	}
+
+	return defaultValue
+}