From 9a4cd01eb83b47c64e6a96adfc0633d41f341863 Mon Sep 17 00:00:00 2001
From: Leonard Lyubich <leonard@nspcc.ru>
Date: Thu, 19 Nov 2020 11:15:49 +0300
Subject: [PATCH] [#186] localstorage: Implement utility functions over
 StorageEngine

Implement Put/Get/GetRange/Select/SelectAll functions over storage
engine. These functions are going to be used by Object service.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
---
 pkg/local_object_storage/engine/get.go    | 25 +++++++++++++++++++++++
 pkg/local_object_storage/engine/head.go   | 12 +++++++++++
 pkg/local_object_storage/engine/put.go    |  9 ++++++++
 pkg/local_object_storage/engine/select.go | 17 +++++++++++++++
 4 files changed, 63 insertions(+)

diff --git a/pkg/local_object_storage/engine/get.go b/pkg/local_object_storage/engine/get.go
index 56aa2cf9f..8caf43024 100644
--- a/pkg/local_object_storage/engine/get.go
+++ b/pkg/local_object_storage/engine/get.go
@@ -97,3 +97,28 @@ func (e *StorageEngine) Get(prm *GetPrm) (*GetRes, error) {
 		obj: obj,
 	}, nil
 }
+
+// Get reads object from local storage by provided address.
+func Get(storage *StorageEngine, addr *objectSDK.Address) (*object.Object, error) {
+	res, err := storage.Get(new(GetPrm).
+		WithAddress(addr),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return res.Object(), nil
+}
+
+// GetRange reads object payload range from local storage by provided address.
+func GetRange(storage *StorageEngine, addr *objectSDK.Address, rng *objectSDK.Range) ([]byte, error) {
+	res, err := storage.Get(new(GetPrm).
+		WithAddress(addr).
+		WithPayloadRange(rng.GetOffset(), rng.GetLength()),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return res.Object().Payload(), nil
+}
diff --git a/pkg/local_object_storage/engine/head.go b/pkg/local_object_storage/engine/head.go
index 153afe491..b4a3fbdf4 100644
--- a/pkg/local_object_storage/engine/head.go
+++ b/pkg/local_object_storage/engine/head.go
@@ -73,3 +73,15 @@ func (e *StorageEngine) Head(prm *HeadPrm) (*HeadRes, error) {
 		head: head,
 	}, nil
 }
+
+// Head reads object header from local storage by provided address.
+func Head(storage *StorageEngine, addr *objectSDK.Address) (*object.Object, error) {
+	res, err := storage.Head(new(HeadPrm).
+		WithAddress(addr),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return res.Header(), nil
+}
diff --git a/pkg/local_object_storage/engine/put.go b/pkg/local_object_storage/engine/put.go
index ff085a958..062b11a01 100644
--- a/pkg/local_object_storage/engine/put.go
+++ b/pkg/local_object_storage/engine/put.go
@@ -89,3 +89,12 @@ func (e *StorageEngine) objectExists(obj *object.Object, shards []*shard.Shard)
 
 	return exists
 }
+
+// Put writes provided object to local storage.
+func Put(storage *StorageEngine, obj *object.Object) error {
+	_, err := storage.Put(new(PutPrm).
+		WithObject(obj),
+	)
+
+	return err
+}
diff --git a/pkg/local_object_storage/engine/select.go b/pkg/local_object_storage/engine/select.go
index e09254517..5ed466314 100644
--- a/pkg/local_object_storage/engine/select.go
+++ b/pkg/local_object_storage/engine/select.go
@@ -58,3 +58,20 @@ func (e *StorageEngine) Select(prm *SelectPrm) (*SelectRes, error) {
 		addrList: addrList,
 	}, nil
 }
+
+// Select selects objects from local storage using provided filters.
+func Select(storage *StorageEngine, fs object.SearchFilters) ([]*object.Address, error) {
+	res, err := storage.Select(new(SelectPrm).
+		WithFilters(fs),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return res.AddressList(), nil
+}
+
+// SelectAll selects all objects from local storage.
+func SelectAll(storage *StorageEngine) ([]*object.Address, error) {
+	return Select(storage, object.SearchFilters{})
+}