[#472] blobstor: implement write-cache

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

pkg/local_object_storage/writecache/options.go

@@ -0,0 +1,100 @@
+package writecache
+
+import (
+	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobstor"
+	meta "github.com/nspcc-dev/neofs-node/pkg/local_object_storage/metabase"
+	"go.uber.org/zap"
+)
+
+// Option represents write-cache configuration option.
+type Option func(*options)
+
+type options struct {
+	log *zap.Logger
+	// path is a path to a directory for write-cache.
+	path string
+	// blobstor is the main persistent storage.
+	blobstor *blobstor.BlobStor
+	// metabase is the metabase instance.
+	metabase *meta.DB
+	// maxMemSize is the maximum total size of all objects cached in memory.
+	// 1 GiB by default.
+	maxMemSize uint64
+	// maxDBSize is the maximum size of database in bytes.
+	// Unrestricted by default.
+	maxDBSize uint64
+	// maxObjectSize is the maximum size of the object stored in the write-cache.
+	maxObjectSize uint64
+	// smallObjectSize is the maximum size of the object stored in the database.
+	smallObjectSize uint64
+	// workersCount is the number of workers flushing objects in parallel.
+	workersCount int
+}
+
+// WithLogger sets logger.
+func WithLogger(log *zap.Logger) Option {
+	return func(o *options) {
+		o.log = log
+	}
+}
+
+// WithPath sets path to writecache db.
+func WithPath(path string) Option {
+	return func(o *options) {
+		o.path = path
+	}
+}
+
+// WithBlobstor sets main object storage.
+func WithBlobstor(bs *blobstor.BlobStor) Option {
+	return func(o *options) {
+		o.blobstor = bs
+	}
+}
+
+// WithMetabase sets metabase.
+func WithMetabase(db *meta.DB) Option {
+	return func(o *options) {
+		o.metabase = db
+	}
+}
+
+// WithMaxMemSize sets maximum size for in-memory DB.
+func WithMaxMemSize(sz uint64) Option {
+	return func(o *options) {
+		o.maxMemSize = sz
+	}
+}
+
+// WithMaxDBSize sets maximum size for on-disk DB.
+func WithMaxDBSize(sz uint64) Option {
+	return func(o *options) {
+		o.maxDBSize = sz
+	}
+}
+
+// WithMaxObjectSize sets maximum object size to be stored in write-cache.
+func WithMaxObjectSize(sz uint64) Option {
+	return func(o *options) {
+		if sz > 0 {
+			o.maxObjectSize = sz
+		}
+	}
+}
+
+// WithSmallObjectSize sets maximum object size to be stored in write-cache.
+func WithSmallObjectSize(sz uint64) Option {
+	return func(o *options) {
+		if sz > 0 {
+			o.smallObjectSize = sz
+		}
+	}
+}
+
+func WithFlushWorkersCount(c int) Option {
+	return func(o *options) {
+		if c > 0 {
+			o.workersCount = c
+		}
+	}
+}