[#2] rpc/client: Remove additional wrapper

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

rpc/client/client.go

@@ -1,29 +1,19 @@
 package client
 
-import (
-	"sync"
-
-	"github.com/TrueCloudLab/frostfs-api-go/v2/rpc/grpc"
-)
-
 // Client represents client for exchanging messages
 // with a remote server using Protobuf RPC.
 type Client struct {
-	*cfg
+	cfg
-
-	gRPCClientOnce sync.Once
-	gRPCClient     *grpc.Client
 }
 
 // New creates, configures via options and returns new Client instance.
 func New(opts ...Option) *Client {
-	c := defaultCfg()
+	var c Client
+	c.initDefault()
 
 	for _, opt := range opts {
-		opt(c)
+		opt(&c.cfg)
 	}
 
-	return &Client{
+	return &c
-		cfg: c,
-	}
 }

rpc/client/conn.go

@@ -9,14 +9,8 @@ import (
 // Returns non-nil result after the first Init() call
 // completed without a connection error.
 //
-// Conn is NPE-safe: returns nil if Client is nil.
-//
 // Client should not be used after Close() call
 // on the connection: behavior is undefined.
 func (c *Client) Conn() io.Closer {
-	if c != nil {
+	return c.conn
-		return c.gRPCClient.Conn()
-	}
-
-	return nil
 }

rpc/client/connect.go

@@ -7,28 +7,11 @@ import (
 	"net"
 	"net/url"
 
-	"github.com/TrueCloudLab/frostfs-api-go/v2/rpc/grpc"
 	grpcstd "google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/credentials/insecure"
 )
 
-func (c *Client) createGRPCClient(ctx context.Context) (err error) {
-	c.gRPCClientOnce.Do(func() {
-		if err = c.openGRPCConn(ctx); err != nil {
-			err = fmt.Errorf("open gRPC connection: %w", err)
-			return
-		}
-
-		c.gRPCClient = grpc.New(
-			grpc.WithClientConnection(c.conn),
-			grpc.WithRWTimeout(c.rwTimeout),
-		)
-	})
-
-	return
-}
-
 var errInvalidEndpoint = errors.New("invalid endpoint options")
 
 func (c *Client) openGRPCConn(ctx context.Context) error {

rpc/client/init.go

@@ -1,11 +1,12 @@
 package client
 
 import (
+	"context"
 	"io"
 
 	"github.com/TrueCloudLab/frostfs-api-go/v2/rpc/common"
-	"github.com/TrueCloudLab/frostfs-api-go/v2/rpc/grpc"
 	"github.com/TrueCloudLab/frostfs-api-go/v2/rpc/message"
+	"google.golang.org/grpc"
 )
 
 // MessageReader is an interface of the Message reader.
@@ -45,39 +46,24 @@ func (c *Client) Init(info common.CallMethodInfo, opts ...CallOption) (MessageRe
 		opt(prm)
 	}
 
-	return c.initGRPC(info, prm)
+	if err := c.openGRPCConn(prm.ctx); err != nil {
-}
-
-type rwGRPC struct {
-	grpc.MessageReadWriter
-}
-
-func (g rwGRPC) ReadMessage(m message.Message) error {
-	// Can be optimized: we can create blank message here.
-	gm := m.ToGRPCMessage()
-
-	if err := g.MessageReadWriter.ReadMessage(gm); err != nil {
-		return err
-	}
-
-	return m.FromGRPCMessage(gm)
-}
-
-func (g rwGRPC) WriteMessage(m message.Message) error {
-	return g.MessageReadWriter.WriteMessage(m.ToGRPCMessage())
-}
-
-func (c *Client) initGRPC(info common.CallMethodInfo, prm *callParameters) (MessageReadWriter, error) {
-	if err := c.createGRPCClient(prm.ctx); err != nil {
 		return nil, err
 	}
 
-	rw, err := c.gRPCClient.Init(info, grpc.WithContext(prm.ctx))
+	ctx, cancel := context.WithCancel(prm.ctx)
+	stream, err := c.conn.NewStream(ctx, &grpc.StreamDesc{
+		StreamName:    info.Name,
+		ServerStreams: info.ServerStream(),
+		ClientStreams: info.ClientStream(),
+	}, toMethodName(info))
 	if err != nil {
+		cancel()
 		return nil, err
 	}
 
-	return &rwGRPC{
+	return &streamWrapper{
-		MessageReadWriter: rw,
+		ClientStream: stream,
+		cancel:       cancel,
+		timeout:      c.rwTimeout,
 	}, nil
 }

rpc/client/options.go

@@ -31,11 +31,9 @@ const (
 	defaultRWTimeout   = 1 * time.Minute
 )
 
-func defaultCfg() *cfg {
+func (c *cfg) initDefault() {
-	return &cfg{
+	c.dialTimeout = defaultDialTimeout
-		dialTimeout: defaultDialTimeout,
+	c.rwTimeout = defaultRWTimeout
-		rwTimeout:   defaultRWTimeout,
-	}
 }
 
 // WithNetworkAddress returns option to specify

rpc/client/stream_wrapper.go

@@ -0,0 +1,58 @@
+package client
+
+import (
+	"context"
+	"time"
+
+	"github.com/TrueCloudLab/frostfs-api-go/v2/rpc/message"
+	"google.golang.org/grpc"
+)
+
+type streamWrapper struct {
+	grpc.ClientStream
+	timeout time.Duration
+	cancel  context.CancelFunc
+}
+
+func (w streamWrapper) ReadMessage(m message.Message) error {
+	// Can be optimized: we can create blank message here.
+	gm := m.ToGRPCMessage()
+
+	err := w.withTimeout(func() error {
+		return w.ClientStream.RecvMsg(gm)
+	})
+	if err != nil {
+		return err
+	}
+
+	return m.FromGRPCMessage(gm)
+}
+
+func (w streamWrapper) WriteMessage(m message.Message) error {
+	return w.withTimeout(func() error {
+		return w.ClientStream.SendMsg(m.ToGRPCMessage())
+	})
+}
+
+func (w *streamWrapper) Close() error {
+	return w.withTimeout(w.ClientStream.CloseSend)
+}
+
+func (w *streamWrapper) withTimeout(closure func() error) error {
+	ch := make(chan error, 1)
+	go func() {
+		ch <- closure()
+		close(ch)
+	}()
+
+	tt := time.NewTimer(w.timeout)
+
+	select {
+	case err := <-ch:
+		tt.Stop()
+		return err
+	case <-tt.C:
+		w.cancel()
+		return context.DeadlineExceeded
+	}
+}

rpc/client/util.go

@@ -1,4 +1,4 @@
-package grpc
+package client
 
 import (
 	"fmt"

rpc/grpc/call_options.go

@@ -1,25 +0,0 @@
-package grpc
-
-import (
-	"context"
-)
-
-// CallOption is a messaging session option within RPC.
-type CallOption func(*callParameters)
-
-type callParameters struct {
-	ctx context.Context
-}
-
-func defaultCallParameters() *callParameters {
-	return &callParameters{
-		ctx: context.Background(),
-	}
-}
-
-// WithContext returns option to set RPC context.
-func WithContext(ctx context.Context) CallOption {
-	return func(prm *callParameters) {
-		prm.ctx = ctx
-	}
-}

rpc/grpc/client.go

@@ -1,23 +0,0 @@
-package grpc
-
-// Client represents client for exchanging messages
-// with a remote server using gRPC protocol.
-type Client struct {
-	*cfg
-}
-
-// Option is a Client's constructor option.
-type Option func(*cfg)
-
-// New creates, configures via options and returns new Client instance.
-func New(opts ...Option) *Client {
-	c := defaultCfg()
-
-	for _, opt := range opts {
-		opt(c)
-	}
-
-	return &Client{
-		cfg: c,
-	}
-}

rpc/grpc/conn.go

@@ -1,19 +0,0 @@
-package grpc
-
-import (
-	"io"
-)
-
-// Conn returns underlying connection.
-//
-// Conn is NPE-safe: returns nil if Client is nil.
-//
-// Client should not be used after Close() call
-// on the connection: behavior is undefined.
-func (c *Client) Conn() io.Closer {
-	if c != nil {
-		return c.con
-	}
-
-	return nil
-}

rpc/grpc/init.go

@@ -1,96 +1,4 @@
 package grpc
 
-import (
-	"context"
-	"io"
-	"time"
-
-	"github.com/TrueCloudLab/frostfs-api-go/v2/rpc/common"
-	"google.golang.org/grpc"
-)
-
 // Message represents raw gRPC message.
 type Message interface{}
-
-// MessageReadWriter is a component interface
-// for transmitting raw messages over gRPC protocol.
-type MessageReadWriter interface {
-	// ReadMessage reads the next message from the remote server,
-	// and writes it to the argument.
-	ReadMessage(Message) error
-
-	// WriteMessage sends message from argument to remote server.
-	WriteMessage(Message) error
-
-	// Closes the communication session with the remote server.
-	//
-	// All calls to send/receive messages must be done before closing.
-	io.Closer
-}
-
-type streamWrapper struct {
-	grpc.ClientStream
-	timeout time.Duration
-	cancel  context.CancelFunc
-}
-
-func (w streamWrapper) ReadMessage(m Message) error {
-	return w.withTimeout(func() error {
-		return w.ClientStream.RecvMsg(m)
-	})
-}
-
-func (w streamWrapper) WriteMessage(m Message) error {
-	return w.withTimeout(func() error {
-		return w.ClientStream.SendMsg(m)
-	})
-}
-
-func (w *streamWrapper) Close() error {
-	return w.withTimeout(w.ClientStream.CloseSend)
-}
-
-func (w *streamWrapper) withTimeout(closure func() error) error {
-	ch := make(chan error, 1)
-	go func() {
-		ch <- closure()
-		close(ch)
-	}()
-
-	tt := time.NewTimer(w.timeout)
-
-	select {
-	case err := <-ch:
-		tt.Stop()
-		return err
-	case <-tt.C:
-		w.cancel()
-		return context.DeadlineExceeded
-	}
-}
-
-// Init initiates a messaging session within the RPC configured by options.
-func (c *Client) Init(info common.CallMethodInfo, opts ...CallOption) (MessageReadWriter, error) {
-	prm := defaultCallParameters()
-
-	for _, opt := range opts {
-		opt(prm)
-	}
-
-	ctx, cancel := context.WithCancel(prm.ctx)
-	stream, err := c.con.NewStream(ctx, &grpc.StreamDesc{
-		StreamName:    info.Name,
-		ServerStreams: info.ServerStream(),
-		ClientStreams: info.ClientStream(),
-	}, toMethodName(info))
-	if err != nil {
-		cancel()
-		return nil, err
-	}
-
-	return &streamWrapper{
-		ClientStream: stream,
-		cancel:       cancel,
-		timeout:      c.rwTimeout,
-	}, nil
-}

rpc/grpc/options.go

@@ -1,36 +0,0 @@
-package grpc
-
-import (
-	"time"
-
-	"google.golang.org/grpc"
-)
-
-const defaultRWTimeout = 1 * time.Minute
-
-type cfg struct {
-	con       *grpc.ClientConn
-	rwTimeout time.Duration
-}
-
-func defaultCfg() *cfg {
-	return &cfg{
-		rwTimeout: defaultRWTimeout,
-	}
-}
-
-// WithClientConnection returns option to set gRPC connection
-// to the remote server.
-func WithClientConnection(con *grpc.ClientConn) Option {
-	return func(c *cfg) {
-		c.con = con
-	}
-}
-
-// WithRWTimeout returns option to specify rwTimeout
-// for reading and writing single gRPC message.
-func WithRWTimeout(t time.Duration) Option {
-	return func(c *cfg) {
-		c.rwTimeout = t
-	}
-}