msgpack: add optional msgpack.v5 support

The msgpack.v5 code located in msgpack_v5.go and
msgpack_v5_helper_test.go for tests. It is the same logic for
submodules.

An user can use msgpack.v5 with a build tag:
go_tarantool_msgpack_v5

Part of #124

Author: oleg-jukovec

CHANGELOG.md

@@ -44,6 +44,7 @@ CI and documentation.
 - queue-utube handling (#85)
 - Master discovery (#113)
 - SQL support (#62)
+- Optional msgpack.v5 usage (#124)
 
 ### Changed
 

README.md

@@ -26,6 +26,7 @@ faster than other packages according to public benchmarks.
 * [Documentation](#documentation)
   * [API reference](#api-reference)
   * [Walking\-through example](#walking-through-example)
+  * [msgpack.v5 migration](#msgpackv5-migration)
 * [Contributing](#contributing)
 * [Alternative connectors](#alternative-connectors)
 
@@ -68,7 +69,15 @@ This allows us to introduce new features without losing backward compatibility.
    go_tarantool_call_17
    ```
    **Note:** In future releases, `Call17` may be used as default `Call` behavior.
-3. To run fuzz tests with decimals, you can use the build tag:
+3. To replace usage of `msgpack.v2` with `msgpack.v5`, you can use the build
+   tag:
+   ```
+   go_tarantool_msgpack_v5
+   ```
+   **Note:** In future releases, `msgpack.v5` may be used by default. We recommend
+   to read [msgpack.v5 migration notes](#msgpackv5-migration) and try to
+   use msgpack.v5 before the changes.
+4. To run fuzz tests with decimals, you can use the build tag:
    ```
    go_tarantool_decimal_fuzzing
    ```
@@ -144,6 +153,30 @@ There are two parameters:
 * a space number (it could just as easily have been a space name), and
 * a tuple.
 
+### msgpack.v5 migration
+
+Most function names and argument types in `msgpack.v5` and `msgpack.v2`
+have not changed (except at least `EncodeInt`, `EncodeUint` and `RegisterExt`).
+But there are a lot of changes in a logic of encoding and deconding. On the plus
+side the migration seems easy, but on the minus side you need to be very
+careful.
+
+First of all, `EncodeInt8`, `EncodeInt16`, `EncodeInt32`, `EncodeInt64`
+and `EncodeUint*` analogues at `msgpack.v5` encode numbers as is without loss of
+type. In `msgpack.v2` the type of a number is reduced to a value.
+
+Secondly, a base decoding function does not convert numbers to `int64` or
+`uint64`. The change makes manual type conversions much more difficult and can
+lead to runtime erros with an old code. We recommend not use type conversions
+and give preference to `*Typed` functions (besides, it's faster).
+
+There are also changes in the logic that can lead to errors in the old code,
+[as example](https://github.com/vmihailenco/msgpack/issues/327). Although in
+`msgpack.v5` has added some functions for the logic tuning see
+[UseLooseInterfaceDecoding](https://pkg.go.dev/github.com/vmihailenco/msgpack/v5#Decoder.UseLooseInterfaceDecoding), [UseCompactInts](https://pkg.go.dev/github.com/vmihailenco/msgpack/v5#Encoder.UseCompactInts) etc, but it is still impossible
+to achieve full compliance of behavior between `msgpack.v5` and `msgpack.v2`. So
+we don't go this way. We use standart settings if it possible.
+
 ## Contributing
 
 See [the contributing guide](CONTRIBUTING.md) for detailed instructions on how

datetime/datetime_test.go

@@ -64,17 +64,17 @@ func assertDatetimeIsEqual(t *testing.T, tuples []interface{}, tm time.Time) {
 		if len(tpl) != 2 {
 			t.Fatalf("Unexpected return value body (tuple len = %d)", len(tpl))
 		}
-		if val, ok := tpl[dtIndex].(Datetime); !ok || !val.ToTime().Equal(tm) {
+		if val, ok := toDatetime(tpl[dtIndex]); !ok || !val.ToTime().Equal(tm) {
 			t.Fatalf("Unexpected tuple %d field %v, expected %v",
 				dtIndex,
-				val.ToTime(),
+				val,
 				tm)
 		}
 	}
 }
 
 func tupleInsertSelectDelete(t *testing.T, conn *Connection, tm time.Time) {
-	t.Helper()
+	//t.Helper()
 
 	dt, err := NewDatetime(tm)
 	if err != nil {
@@ -324,7 +324,11 @@ func (ev *Event) decodeMsgpackImpl(d *Decoder) error {
 	if err != nil {
 		return err
 	}
-	ev.Datetime = res.(Datetime)
+	dt, ok := toDatetime(res)
+	if !ok {
+		return fmt.Errorf("datetime doesn't match")
+	}
+	ev.Datetime = dt
 	return nil
 }
 
@@ -428,8 +432,8 @@ func TestCustomEncodeDecodeTuple1(t *testing.T) {
 	}
 
 	for i, tv := range []time.Time{tm1, tm2} {
-		dt := events[i].([]interface{})[1].(Datetime)
-		if !dt.ToTime().Equal(tv) {
+		dt, ok := toDatetime(events[i].([]interface{})[1])
+		if !ok || !dt.ToTime().Equal(tv) {
 			t.Fatalf("%v != %v", dt.ToTime(), tv)
 		}
 	}
@@ -501,7 +505,7 @@ func TestCustomEncodeDecodeTuple5(t *testing.T) {
 	if tpl, ok := resp.Data[0].([]interface{}); !ok {
 		t.Errorf("Unexpected body of Select")
 	} else {
-		if val, ok := tpl[0].(Datetime); !ok || !val.ToTime().Equal(tm) {
+		if val, ok := toDatetime(tpl[0]); !ok || !val.ToTime().Equal(tm) {
 			t.Fatalf("Unexpected body of Select")
 		}
 	}

datetime/msgpack.go

@@ -1,3 +1,6 @@
+//go:build !go_tarantool_msgpack_v5
+// +build !go_tarantool_msgpack_v5
+
 package datetime
 
 import (

datetime/msgpack_helper_test.go

@@ -1,7 +1,11 @@
+//go:build !go_tarantool_msgpack_v5
+// +build !go_tarantool_msgpack_v5
+
 package datetime_test
 
 import (
 	. "github.com/tarantool/go-tarantool"
+	. "github.com/tarantool/go-tarantool/datetime"
 	"gopkg.in/vmihailenco/msgpack.v2"
 )
 
@@ -29,6 +33,11 @@ func (c *Tuple2) DecodeMsgpack(d *msgpack.Decoder) error {
 	return c.decodeMsgpackImpl(&Decoder{Decoder: d})
 }
 
+func toDatetime(i interface{}) (dt Datetime, ok bool) {
+	dt, ok = i.(Datetime)
+	return
+}
+
 func marshal(v interface{}) ([]byte, error) {
 	return msgpack.Marshal(v)
 }

datetime/msgpack_v5.go

@@ -0,0 +1,12 @@
+//go:build go_tarantool_msgpack_v5
+// +build go_tarantool_msgpack_v5
+
+package datetime
+
+import (
+	"github.com/vmihailenco/msgpack/v5"
+)
+
+func init() {
+	msgpack.RegisterExt(datetime_extId, (*Datetime)(nil))
+}

datetime/msgpack_v5_helper_test.go

@@ -0,0 +1,50 @@
+//go:build go_tarantool_msgpack_v5
+// +build go_tarantool_msgpack_v5
+
+package datetime_test
+
+import (
+	. "github.com/tarantool/go-tarantool"
+	. "github.com/tarantool/go-tarantool/datetime"
+	"github.com/vmihailenco/msgpack/v5"
+)
+
+func (t *Tuple1) EncodeMsgpack(e *msgpack.Encoder) error {
+	return t.encodeMsgpackImpl(&Encoder{Encoder: e})
+}
+
+func (t *Tuple1) DecodeMsgpack(d *msgpack.Decoder) error {
+	return t.decodeMsgpackImpl(&Decoder{Decoder: d})
+}
+
+func (ev *Event) EncodeMsgpack(e *msgpack.Encoder) error {
+	return ev.encodeMsgpackImpl(&Encoder{Encoder: e})
+}
+
+func (ev *Event) DecodeMsgpack(d *msgpack.Decoder) error {
+	return ev.decodeMsgpackImpl(&Decoder{Decoder: d})
+}
+
+func (c *Tuple2) EncodeMsgpack(e *msgpack.Encoder) error {
+	return c.encodeMsgpackImpl(&Encoder{Encoder: e})
+}
+
+func (c *Tuple2) DecodeMsgpack(d *msgpack.Decoder) error {
+	return c.decodeMsgpackImpl(&Decoder{Decoder: d})
+}
+
+func marshal(v interface{}) ([]byte, error) {
+	return msgpack.Marshal(v)
+}
+
+func unmarshal(data []byte, v interface{}) error {
+	return msgpack.Unmarshal(data, v)
+}
+
+func toDatetime(i interface{}) (dt Datetime, ok bool) {
+	var ptr *Datetime
+	if ptr, ok = i.(*Datetime); ok {
+		dt = *ptr
+	}
+	return
+}

decimal/decimal_test.go

@@ -60,8 +60,11 @@ func (t *TupleDecimal) decodeMsgpackImpl(d *Decoder) error {
 	if err != nil {
 		return err
 	}
-	t.number = res.(Decimal)
-
+	dec, ok := toDecimal(res)
+	if !ok {
+		return fmt.Errorf("decimal doesn't match")
+	}
+	t.number = dec
 	return nil
 }
 
@@ -347,7 +350,7 @@ func tupleValueIsDecimal(t *testing.T, tuples []interface{}, number decimal.Deci
 		if len(tpl) != 1 {
 			t.Fatalf("Unexpected return value body (tuple len)")
 		}
-		if val, ok := tpl[0].(Decimal); !ok || !val.Equal(number) {
+		if val, ok := toDecimal(tpl[0]); !ok || !val.Equal(number) {
 			t.Fatalf("Unexpected return value body (tuple 0 field)")
 		}
 	}
@@ -445,7 +448,10 @@ func TestMPDecode(t *testing.T) {
 			if err != nil {
 				t.Fatalf("Unmarshalling failed: %s", err.Error())
 			}
-			decActual := v.(Decimal)
+			decActual, ok := toDecimal(v)
+			if !ok {
+				t.Fatalf("Unable to convert to Decimal")
+			}
 
 			decExpected, err := decimal.NewFromString(testcase.numString)
 			if err != nil {

decimal/msgpack.go

@@ -1,3 +1,6 @@
+//go:build !go_tarantool_msgpack_v5
+// +build !go_tarantool_msgpack_v5
+
 package decimal
 
 import (

decimal/msgpack_helper_test.go

@@ -1,3 +1,6 @@
+//go:build !go_tarantool_msgpack_v5
+// +build !go_tarantool_msgpack_v5
+
 package decimal_test
 
 import (
@@ -14,6 +17,11 @@ func (t *TupleDecimal) DecodeMsgpack(d *msgpack.Decoder) error {
 	return t.decodeMsgpackImpl(&Decoder{Decoder: d})
 }
 
+func toDecimal(i interface{}) (dec Decimal, ok bool) {
+	dec, ok = i.(Decimal)
+	return
+}
+
 func marshal(v interface{}) ([]byte, error) {
 	return msgpack.Marshal(v)
 }