From 2398afe985bc304e08df824b476bc045aa6bd39a Mon Sep 17 00:00:00 2001
From: Michal Niewrzal <michal@storj.io>
Date: Tue, 3 Nov 2020 16:03:20 +0100
Subject: [PATCH] satellite/metainfo/metabase: add GetLatestObjectLastSegment
 request

Change-Id: I50c452e379f78864b38921f31e53a0554642ab02
---
 satellite/metainfo/metabase/get.go       | 50 ++++++++++++++
 satellite/metainfo/metabase/get_test.go  | 83 ++++++++++++++++++++++++
 satellite/metainfo/metabase/test_test.go | 15 +++++
 3 files changed, 148 insertions(+)

diff --git a/satellite/metainfo/metabase/get.go b/satellite/metainfo/metabase/get.go
index 77c26d5d7..3c4f3b01c 100644
--- a/satellite/metainfo/metabase/get.go
+++ b/satellite/metainfo/metabase/get.go
@@ -196,3 +196,53 @@ func (db *DB) GetSegmentByPosition(ctx context.Context, opts GetSegmentByPositio
 
 	return segment, nil
 }
+
+// GetLatestObjectLastSegment contains arguments necessary for fetching a last segment information.
+type GetLatestObjectLastSegment struct {
+	ObjectLocation
+}
+
+// GetLatestObjectLastSegment returns an object last segment information.
+func (db *DB) GetLatestObjectLastSegment(ctx context.Context, opts GetLatestObjectLastSegment) (segment Segment, err error) {
+	defer mon.Task()(&ctx)(&err)
+
+	if err := opts.Verify(); err != nil {
+		return Segment{}, err
+	}
+
+	err = db.db.QueryRow(ctx, `
+		SELECT
+			stream_id, position,
+			root_piece_id, encrypted_key_nonce, encrypted_key,
+			encrypted_size, plain_offset, plain_size,
+			redundancy,
+			inline_data, remote_pieces
+		FROM segments
+		WHERE
+			stream_id = (SELECT stream_id FROM objects WHERE
+				project_id   = $1 AND
+				bucket_name  = $2 AND
+				object_key   = $3 AND
+				status       = 1
+				ORDER BY version DESC
+				LIMIT 1
+			)
+		ORDER BY position DESC
+		LIMIT 1
+	`, opts.ProjectID, opts.BucketName, []byte(opts.ObjectKey)).
+		Scan(
+			&segment.StreamID, &segment.Position,
+			&segment.RootPieceID, &segment.EncryptedKeyNonce, &segment.EncryptedKey,
+			&segment.EncryptedSize, &segment.PlainOffset, &segment.PlainSize,
+			redundancyScheme{&segment.Redundancy},
+			&segment.InlineData, &segment.Pieces,
+		)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return Segment{}, storj.ErrObjectNotFound.Wrap(Error.New("object or segment missing"))
+		}
+		return Segment{}, Error.New("unable to query segment: %w", err)
+	}
+
+	return segment, nil
+}
diff --git a/satellite/metainfo/metabase/get_test.go b/satellite/metainfo/metabase/get_test.go
index 153c0e8aa..9a0e11d22 100644
--- a/satellite/metainfo/metabase/get_test.go
+++ b/satellite/metainfo/metabase/get_test.go
@@ -407,3 +407,86 @@ func TestGetSegmentByPosition(t *testing.T) {
 		})
 	})
 }
+
+func TestGetLatestObjectLastSegment(t *testing.T) {
+	All(t, func(ctx *testcontext.Context, t *testing.T, db *metabase.DB) {
+		obj := randObjectStream()
+		location := obj.Location()
+		now := time.Now()
+
+		for _, test := range invalidObjectLocations(location) {
+			test := test
+			t.Run(test.Name, func(t *testing.T) {
+				defer DeleteAll{}.Check(ctx, t, db)
+				GetLatestObjectLastSegment{
+					Opts: metabase.GetLatestObjectLastSegment{
+						ObjectLocation: test.ObjectLocation,
+					},
+					ErrClass: test.ErrClass,
+					ErrText:  test.ErrText,
+				}.Check(ctx, t, db)
+
+				Verify{}.Check(ctx, t, db)
+			})
+		}
+
+		t.Run("Object or segment missing", func(t *testing.T) {
+			defer DeleteAll{}.Check(ctx, t, db)
+
+			GetLatestObjectLastSegment{
+				Opts: metabase.GetLatestObjectLastSegment{
+					ObjectLocation: location,
+				},
+				ErrClass: &storj.ErrObjectNotFound,
+				ErrText:  "metabase: object or segment missing",
+			}.Check(ctx, t, db)
+
+			Verify{}.Check(ctx, t, db)
+		})
+
+		t.Run("Get last segment", func(t *testing.T) {
+			defer DeleteAll{}.Check(ctx, t, db)
+
+			createObject(ctx, t, db, obj, 2)
+
+			expectedSegmentSecond := metabase.Segment{
+				StreamID: obj.StreamID,
+				Position: metabase.SegmentPosition{
+					Index: 2,
+				},
+				RootPieceID:       storj.PieceID{1},
+				EncryptedKey:      []byte{3},
+				EncryptedKeyNonce: []byte{4},
+				EncryptedSize:     1024,
+				PlainSize:         512,
+				Pieces:            metabase.Pieces{{Number: 0, StorageNode: storj.NodeID{2}}},
+				Redundancy:        defaultTestRedundancy,
+			}
+
+			expectedSegmentFirst := expectedSegmentSecond
+			expectedSegmentFirst.Position.Index = 1
+
+			GetLatestObjectLastSegment{
+				Opts: metabase.GetLatestObjectLastSegment{
+					ObjectLocation: location,
+				},
+				Result: expectedSegmentSecond,
+			}.Check(ctx, t, db)
+
+			Verify{
+				Objects: []metabase.RawObject{
+					{
+						ObjectStream: obj,
+						CreatedAt:    now,
+						Status:       metabase.Committed,
+						Encryption:   defaultTestEncryption,
+					},
+				},
+				Segments: []metabase.RawSegment{
+					metabase.RawSegment(expectedSegmentFirst),
+					metabase.RawSegment(expectedSegmentSecond),
+				},
+			}.Check(ctx, t, db)
+		})
+	})
+}
diff --git a/satellite/metainfo/metabase/test_test.go b/satellite/metainfo/metabase/test_test.go
index 965d05d4b..b79a75c62 100644
--- a/satellite/metainfo/metabase/test_test.go
+++ b/satellite/metainfo/metabase/test_test.go
@@ -148,6 +148,21 @@ func (step GetSegmentByPosition) Check(ctx *testcontext.Context, t *testing.T, d
 	require.Zero(t, diff)
 }
 
+type GetLatestObjectLastSegment struct {
+	Opts     metabase.GetLatestObjectLastSegment
+	Result   metabase.Segment
+	ErrClass *errs.Class
+	ErrText  string
+}
+
+func (step GetLatestObjectLastSegment) Check(ctx *testcontext.Context, t *testing.T, db *metabase.DB) {
+	result, err := db.GetLatestObjectLastSegment(ctx, step.Opts)
+	checkError(t, err, step.ErrClass, step.ErrText)
+
+	diff := cmp.Diff(step.Result, result, cmpopts.EquateApproxTime(5*time.Second))
+	require.Zero(t, diff)
+}
+
 type DeleteObjectExactVersion struct {
 	Opts     metabase.DeleteObjectExactVersion
 	Result   metabase.DeleteObjectResult