From f43f18ecda9008209338e54ffd5deb19f207f849 Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <e.stratonikov@yadro.com>
Date: Sat, 18 Feb 2023 10:13:14 +0300
Subject: [PATCH] [#19] transformer: Cover with unit-tests

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
---
 object/transformer/transformer_test.go | 164 +++++++++++++++++++++++++
 1 file changed, 164 insertions(+)
 create mode 100644 object/transformer/transformer_test.go

diff --git a/object/transformer/transformer_test.go b/object/transformer/transformer_test.go
new file mode 100644
index 00000000..fe35fe3c
--- /dev/null
+++ b/object/transformer/transformer_test.go
@@ -0,0 +1,164 @@
+package transformer
+
+import (
+	"crypto/rand"
+	"testing"
+
+	cidtest "github.com/TrueCloudLab/frostfs-sdk-go/container/id/test"
+	objectSDK "github.com/TrueCloudLab/frostfs-sdk-go/object"
+	"github.com/TrueCloudLab/frostfs-sdk-go/version"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/stretchr/testify/require"
+)
+
+func TestTransformer(t *testing.T) {
+	const maxSize = 100
+
+	tt := new(testTarget)
+
+	target, _ := newPayloadSizeLimiter(maxSize, tt)
+
+	ver := version.Current()
+	cnr := cidtest.ID()
+	hdr := objectSDK.New()
+	hdr.SetContainerID(cnr)
+	hdr.SetType(objectSDK.TypeRegular)
+	hdr.SetVersion(&ver)
+	require.NoError(t, target.WriteHeader(hdr))
+
+	expectedPayload := make([]byte, maxSize*2+maxSize/2)
+	_, _ = rand.Read(expectedPayload)
+
+	_, err := target.Write(expectedPayload)
+	require.NoError(t, err)
+
+	ids, err := target.Close()
+	require.NoError(t, err)
+
+	require.Equal(t, 4, len(tt.objects)) // 3 parts + linking object
+
+	var actualPayload []byte
+	for i := range tt.objects {
+		childCnr, ok := tt.objects[i].ContainerID()
+		require.True(t, ok)
+		require.Equal(t, cnr, childCnr)
+		require.Equal(t, objectSDK.TypeRegular, tt.objects[i].Type())
+
+		payload := tt.objects[i].Payload()
+		require.EqualValues(t, tt.objects[i].PayloadSize(), len(payload))
+		actualPayload = append(actualPayload, payload...)
+
+		switch i {
+		case 0, 1:
+			require.EqualValues(t, maxSize, len(payload))
+		case 2:
+			require.EqualValues(t, maxSize/2, len(payload))
+		case 3:
+			parID, ok := tt.objects[i].ParentID()
+			require.True(t, ok)
+			require.Equal(t, ids.ParentID(), &parID)
+		}
+	}
+	require.Equal(t, expectedPayload, actualPayload)
+}
+
+func BenchmarkTransformer(b *testing.B) {
+	ver := version.Current()
+	cnr := cidtest.ID()
+	hdr := objectSDK.New()
+	hdr.SetContainerID(cnr)
+	hdr.SetType(objectSDK.TypeRegular)
+	hdr.SetVersion(&ver)
+
+	b.Run("small", func(b *testing.B) {
+		benchmarkTransformer(b, hdr, 8*1024)
+	})
+	b.Run("big", func(b *testing.B) {
+		benchmarkTransformer(b, hdr, 64*1024*1024*9/2)
+	})
+}
+
+func benchmarkTransformer(b *testing.B, header *objectSDK.Object, payloadSize int) {
+	const maxSize = 64 * 1024 * 1024
+
+	payload := make([]byte, payloadSize)
+
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		f, _ := newPayloadSizeLimiter(maxSize, benchTarget{})
+		if err := f.WriteHeader(header); err != nil {
+			b.Fatalf("write header: %v", err)
+		}
+		if _, err := f.Write(payload); err != nil {
+			b.Fatalf("write: %v", err)
+		}
+		if _, err := f.Close(); err != nil {
+			b.Fatalf("close: %v", err)
+		}
+	}
+}
+
+func newPayloadSizeLimiter(maxSize uint64, nextTarget ObjectTarget) (ObjectTarget, *keys.PrivateKey) {
+	p, err := keys.NewPrivateKey()
+	if err != nil {
+		panic(err)
+	}
+
+	return NewPayloadSizeLimiter(maxSize, true, func() ObjectTarget {
+		return NewFormatTarget(&FormatterParams{
+			Key:          &p.PrivateKey,
+			NextTarget:   nextTarget,
+			NetworkState: dummyEpochSource(123),
+		})
+	}), p
+}
+
+type dummyEpochSource uint64
+
+func (s dummyEpochSource) CurrentEpoch() uint64 {
+	return uint64(s)
+}
+
+type benchTarget struct{}
+
+func (benchTarget) WriteHeader(object *objectSDK.Object) error {
+	return nil
+}
+
+func (benchTarget) Write(p []byte) (n int, err error) {
+	return len(p), nil
+}
+
+func (benchTarget) Close() (*AccessIdentifiers, error) {
+	return nil, nil
+}
+
+type testTarget struct {
+	current *objectSDK.Object
+	payload []byte
+	objects []*objectSDK.Object
+}
+
+func (tt *testTarget) WriteHeader(object *objectSDK.Object) error {
+	tt.current = object
+	return nil
+}
+
+func (tt *testTarget) Write(p []byte) (n int, err error) {
+	tt.payload = append(tt.payload, p...)
+	return len(p), nil
+}
+
+func (tt *testTarget) Close() (*AccessIdentifiers, error) {
+	tt.current.SetPayload(tt.payload)
+	// We need to marshal, because current implementation reuses written object.
+	data, _ := tt.current.Marshal()
+	obj := objectSDK.New()
+	_ = obj.Unmarshal(data)
+
+	tt.objects = append(tt.objects, obj)
+	tt.current = nil
+	tt.payload = nil
+	return nil, nil // AccessIdentifiers should not be used.
+}