crud: improve Result* types

Now a user can specify his custom type as a type for rows. The patch
also removes unnecessary types to make it easier for a user to work
with the API.

Part of #271

Author: oleg-jukovec

crud/delete.go

@@ -6,9 +6,6 @@ import (
 	"github.com/tarantool/go-tarantool"
 )
 
-// DeleteResult describes result for `crud.delete` method.
-type DeleteResult = Result
-
 // DeleteOpts describes options for `crud.delete` method.
 type DeleteOpts = SimpleOperationOpts
 

crud/error.go

@@ -75,6 +75,30 @@ type ErrorMany struct {
 	Errors []Error
 }
 
+// DecodeMsgpack provides custom msgpack decoder.
+func (e *ErrorMany) DecodeMsgpack(d *decoder) error {
+	l, err := d.DecodeArrayLen()
+	if err != nil {
+		return err
+	}
+
+	var errs []Error
+	for i := 0; i < l; i++ {
+		var crudErr *Error = nil
+		if err := d.Decode(&crudErr); err != nil {
+			return err
+		} else if crudErr != nil {
+			errs = append(errs, *crudErr)
+		}
+	}
+
+	if len(errs) > 0 {
+		*e = ErrorMany{Errors: errs}
+	}
+
+	return nil
+}
+
 // Error converts an Error to a string.
 func (errs ErrorMany) Error() string {
 	var str []string

crud/example_test.go

@@ -0,0 +1,150 @@
+package crud_test
+
+import (
+	"fmt"
+	"reflect"
+	"time"
+
+	"github.com/tarantool/go-tarantool"
+	"github.com/tarantool/go-tarantool/crud"
+)
+
+const (
+	exampleServer = "127.0.0.1:3013"
+	exampleSpace  = "test"
+)
+
+var exampleOpts = tarantool.Opts{
+	Timeout: 500 * time.Millisecond,
+	User:    "test",
+	Pass:    "test",
+}
+
+func exampleConnect() *tarantool.Connection {
+	conn, err := tarantool.Connect(exampleServer, exampleOpts)
+	if err != nil {
+		panic("Connection is not established: " + err.Error())
+	}
+	return conn
+}
+
+// ExampleResult_rowsInterface demonstrates how to use a helper type Result
+// to decode a crud response. In this example, rows are decoded as an
+// interface{} type.
+func ExampleResult_rowsInterface() {
+	conn := exampleConnect()
+	req := crud.NewReplaceRequest(exampleSpace).
+		Tuple([]interface{}{uint(2010), nil, "bla"})
+
+	ret := crud.Result{}
+	if err := conn.Do(req).GetTyped(&ret); err != nil {
+		fmt.Printf("Failed to execute request: %s", err)
+		return
+	}
+
+	fmt.Println(ret.Metadata)
+	fmt.Println(ret.Rows)
+	// Output:
+	// [{id unsigned false} {bucket_id unsigned true} {name string false}]
+	// [[2010 45 bla]]
+}
+
+// ExampleResult_rowsCustomType demonstrates how to use a helper type Result
+// to decode a crud response. In this example, rows are decoded as a
+// custom type.
+func ExampleResult_rowsCustomType() {
+	conn := exampleConnect()
+	req := crud.NewReplaceRequest(exampleSpace).
+		Tuple([]interface{}{uint(2010), nil, "bla"})
+
+	type Tuple struct {
+		_msgpack struct{} `msgpack:",asArray"` //nolint: structcheck,unused
+		Id       uint64
+		BucketId uint64
+		Name     string
+	}
+	ret := crud.MakeResult(reflect.TypeOf(Tuple{}))
+
+	if err := conn.Do(req).GetTyped(&ret); err != nil {
+		fmt.Printf("Failed to execute request: %s", err)
+		return
+	}
+
+	fmt.Println(ret.Metadata)
+	rows := ret.Rows.([]Tuple)
+	fmt.Println(rows)
+	// Output:
+	// [{id unsigned false} {bucket_id unsigned true} {name string false}]
+	// [{{} 2010 45 bla}]
+}
+
+// ExampleResult_many demonstrates that there is no difference in a
+// response from *ManyRequest.
+func ExampleResult_many() {
+	conn := exampleConnect()
+	req := crud.NewReplaceManyRequest(exampleSpace).
+		Tuples([]crud.Tuple{
+			[]interface{}{uint(2010), nil, "bla"},
+			[]interface{}{uint(2011), nil, "bla"},
+		})
+
+	ret := crud.Result{}
+	if err := conn.Do(req).GetTyped(&ret); err != nil {
+		fmt.Printf("Failed to execute request: %s", err)
+		return
+	}
+
+	fmt.Println(ret.Metadata)
+	fmt.Println(ret.Rows)
+	// Output:
+	// [{id unsigned false} {bucket_id unsigned true} {name string false}]
+	// [[2010 45 bla] [2011 4 bla]]
+}
+
+// ExampleResult_error demonstrates how to use a helper type Result
+// to handle a crud error.
+func ExampleResult_error() {
+	conn := exampleConnect()
+	req := crud.NewReplaceRequest("not_exist").
+		Tuple([]interface{}{uint(2010), nil, "bla"})
+
+	ret := crud.Result{}
+	if err := conn.Do(req).GetTyped(&ret); err != nil {
+		crudErr := err.(crud.Error)
+		fmt.Printf("Failed to execute request: %s", crudErr)
+	} else {
+		fmt.Println(ret.Metadata)
+		fmt.Println(ret.Rows)
+	}
+	// Output:
+	// Failed to execute request: ReplaceError: Space "not_exist" doesn't exist
+}
+
+// ExampleResult_errorMany demonstrates how to use a helper type Result
+// to handle a crud error for a *ManyRequest.
+func ExampleResult_errorMany() {
+	conn := exampleConnect()
+	initReq := crud.NewReplaceRequest("not_exist").
+		Tuple([]interface{}{uint(2010), nil, "bla"})
+	if _, err := conn.Do(initReq).Get(); err != nil {
+		fmt.Printf("Failed to initialize the example: %s\n", err)
+	}
+
+	req := crud.NewInsertManyRequest(exampleSpace).
+		Tuples([]crud.Tuple{
+			[]interface{}{uint(2010), nil, "bla"},
+			[]interface{}{uint(2010), nil, "bla"},
+		})
+	ret := crud.Result{}
+	if err := conn.Do(req).GetTyped(&ret); err != nil {
+		crudErr := err.(crud.ErrorMany)
+		// We need to trim the error message to make the example repeatable.
+		errmsg := crudErr.Error()[:10]
+		fmt.Printf("Failed to execute request: %s", errmsg)
+	} else {
+		fmt.Println(ret.Metadata)
+		fmt.Println(ret.Rows)
+	}
+	// Output:
+	// Failed to execute request: CallError:
+}

crud/get.go

@@ -6,9 +6,6 @@ import (
 	"github.com/tarantool/go-tarantool"
 )
 
-// GetResult describes result for `crud.get` method.
-type GetResult = Result
-
 // GetOpts describes options for `crud.get` method.
 type GetOpts struct {
 	// Timeout is a `vshard.call` timeout and vshard

crud/insert.go

@@ -6,9 +6,6 @@ import (
 	"github.com/tarantool/go-tarantool"
 )
 
-// InsertResult describes result for `crud.insert` method.
-type InsertResult = Result
-
 // InsertOpts describes options for `crud.insert` method.
 type InsertOpts = SimpleOperationOpts
 
@@ -65,9 +62,6 @@ func (req *InsertRequest) Context(ctx context.Context) *InsertRequest {
 	return req
 }
 
-// InsertObjectResult describes result for `crud.insert_object` method.
-type InsertObjectResult = Result
-
 // InsertObjectOpts describes options for `crud.insert_object` method.
 type InsertObjectOpts = SimpleOperationObjectOpts
 

crud/insert_many.go

@@ -6,9 +6,6 @@ import (
 	"github.com/tarantool/go-tarantool"
 )
 
-// InsertManyResult describes result for `crud.insert_many` method.
-type InsertManyResult = ResultMany
-
 // InsertManyOpts describes options for `crud.insert_many` method.
 type InsertManyOpts = OperationManyOpts
 
@@ -65,9 +62,6 @@ func (req *InsertManyRequest) Context(ctx context.Context) *InsertManyRequest {
 	return req
 }
 
-// InsertObjectManyResult describes result for `crud.insert_object_many` method.
-type InsertObjectManyResult = ResultMany
-
 // InsertObjectManyOpts describes options for `crud.insert_object_many` method.
 type InsertObjectManyOpts = OperationObjectManyOpts
 

crud/max.go

@@ -6,9 +6,6 @@ import (
 	"github.com/tarantool/go-tarantool"
 )
 
-// MaxResult describes result for `crud.max` method.
-type MaxResult = Result
-
 // MaxOpts describes options for `crud.max` method.
 type MaxOpts = BorderOpts
 

crud/min.go

@@ -6,9 +6,6 @@ import (
 	"github.com/tarantool/go-tarantool"
 )
 
-// MinResult describes result for `crud.min` method.
-type MinResult = Result
-
 // MinOpts describes options for `crud.min` method.
 type MinOpts = BorderOpts
 

crud/msgpack.go

@@ -5,6 +5,7 @@ package crud
 
 import (
 	"gopkg.in/vmihailenco/msgpack.v2"
+	msgpcode "gopkg.in/vmihailenco/msgpack.v2/codes"
 )
 
 type encoder = msgpack.Encoder
@@ -21,3 +22,8 @@ type MapObject map[string]interface{}
 func (o MapObject) EncodeMsgpack(enc *encoder) {
 	enc.Encode(o)
 }
+
+func msgpackIsArray(code byte) bool {
+	return code == msgpcode.Array16 || code == msgpcode.Array32 ||
+		msgpcode.IsFixedArray(code)
+}

crud/msgpack_v5.go

@@ -5,6 +5,7 @@ package crud
 
 import (
 	"github.com/vmihailenco/msgpack/v5"
+	"github.com/vmihailenco/msgpack/v5/msgpcode"
 )
 
 type encoder = msgpack.Encoder
@@ -21,3 +22,8 @@ type MapObject map[string]interface{}
 func (o MapObject) EncodeMsgpack(enc *encoder) {
 	enc.Encode(o)
 }
+
+func msgpackIsArray(code byte) bool {
+	return code == msgpcode.Array16 || code == msgpcode.Array32 ||
+		msgpcode.IsFixedArray(code)
+}

crud/replace.go

@@ -6,9 +6,6 @@ import (
 	"github.com/tarantool/go-tarantool"
 )
 
-// ReplaceResult describes result for `crud.replace` method.
-type ReplaceResult = Result
-
 // ReplaceOpts describes options for `crud.replace` method.
 type ReplaceOpts = SimpleOperationOpts
 
@@ -65,9 +62,6 @@ func (req *ReplaceRequest) Context(ctx context.Context) *ReplaceRequest {
 	return req
 }
 
-// ReplaceObjectResult describes result for `crud.replace_object` method.
-type ReplaceObjectResult = Result
-
 // ReplaceObjectOpts describes options for `crud.replace_object` method.
 type ReplaceObjectOpts = SimpleOperationObjectOpts
 

crud/replace_many.go

@@ -6,9 +6,6 @@ import (
 	"github.com/tarantool/go-tarantool"
 )
 
-// ReplaceManyResult describes result for `crud.replace_many` method.
-type ReplaceManyResult = ResultMany
-
 // ReplaceManyOpts describes options for `crud.replace_many` method.
 type ReplaceManyOpts = OperationManyOpts
 
@@ -65,9 +62,6 @@ func (req *ReplaceManyRequest) Context(ctx context.Context) *ReplaceManyRequest
 	return req
 }
 
-// ReplaceObjectManyResult describes result for `crud.replace_object_many` method.
-type ReplaceObjectManyResult = ResultMany
-
 // ReplaceObjectManyOpts describes options for `crud.replace_object_many` method.
 type ReplaceObjectManyOpts = OperationObjectManyOpts