pool: implemented Role Stringer interface

implemented Role Stringer interface for human-readable printing

Author: Maksim Konovalov

CHANGELOG.md

@@ -9,6 +9,7 @@ Versioning](http://semver.org/spec/v2.0.0.html) except to the first release.
 ## [Unreleased]
 
 ### Added
+- Implemented Stringer interface for pool.Role type (#405).
 - Add err log to `ConnectionPool.Add()` in case, when unable to establish 
   connection and ctx is not canceled; 
   also added logs for error case of `ConnectionPool.tryConnect()` calls in 

go.sum

@@ -1,4 +1,3 @@
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=

pool/connection_pool.go

@@ -141,7 +141,7 @@ func newEndpoint(name string, dialer tarantool.Dialer, opts tarantool.Opts) *end
 		opts:     opts,
 		notify:   make(chan tarantool.ConnEvent, 100),
 		conn:     nil,
-		role:     UnknownRole,
+		role:     RoleUnknown,
 		shutdown: make(chan struct{}),
 		close:    make(chan struct{}),
 		closed:   make(chan struct{}),
@@ -391,7 +391,7 @@ func (p *ConnectionPool) GetInfo() map[string]ConnectionInfo {
 		if conn != nil {
 			info[name] = ConnectionInfo{ConnectedNow: conn.ConnectedNow(), ConnRole: role}
 		} else {
-			info[name] = ConnectionInfo{ConnectedNow: false, ConnRole: UnknownRole}
+			info[name] = ConnectionInfo{ConnectedNow: false, ConnRole: RoleUnknown}
 		}
 	}
 
@@ -1034,45 +1034,45 @@ func (p *ConnectionPool) getConnectionRole(conn *tarantool.Connection) (Role, er
 	}
 
 	if err != nil {
-		return UnknownRole, err
+		return RoleUnknown, err
 	}
 	if len(data) < 1 {
-		return UnknownRole, ErrIncorrectResponse
+		return RoleUnknown, ErrIncorrectResponse
 	}
 
 	instanceStatus, ok := data[0].(map[interface{}]interface{})["status"]
 	if !ok {
-		return UnknownRole, ErrIncorrectResponse
+		return RoleUnknown, ErrIncorrectResponse
 	}
 	if instanceStatus != "running" {
-		return UnknownRole, ErrIncorrectStatus
+		return RoleUnknown, ErrIncorrectStatus
 	}
 
 	replicaRole, ok := data[0].(map[interface{}]interface{})[roFieldName]
 	if !ok {
-		return UnknownRole, ErrIncorrectResponse
+		return RoleUnknown, ErrIncorrectResponse
 	}
 
 	switch replicaRole {
 	case false:
-		return MasterRole, nil
+		return RoleMaster, nil
 	case true:
-		return ReplicaRole, nil
+		return RoleReplica, nil
 	}
 
-	return UnknownRole, nil
+	return RoleUnknown, nil
 }
 
 func (p *ConnectionPool) getConnectionFromPool(name string) (*tarantool.Connection, Role) {
 	if conn := p.rwPool.GetConnection(name); conn != nil {
-		return conn, MasterRole
+		return conn, RoleMaster
 	}
 
 	if conn := p.roPool.GetConnection(name); conn != nil {
-		return conn, ReplicaRole
+		return conn, RoleReplica
 	}
 
-	return p.anyPool.GetConnection(name), UnknownRole
+	return p.anyPool.GetConnection(name), RoleUnknown
 }
 
 func (p *ConnectionPool) deleteConnection(name string) {
@@ -1103,9 +1103,9 @@ func (p *ConnectionPool) addConnection(name string,
 			watch := false
 			switch watcher.mode {
 			case RW:
-				watch = role == MasterRole
+				watch = role == RoleMaster
 			case RO:
-				watch = role == ReplicaRole
+				watch = role == RoleReplica
 			default:
 				watch = true
 			}
@@ -1129,9 +1129,9 @@ func (p *ConnectionPool) addConnection(name string,
 	p.anyPool.AddConnection(name, conn)
 
 	switch role {
-	case MasterRole:
+	case RoleMaster:
 		p.rwPool.AddConnection(name, conn)
-	case ReplicaRole:
+	case RoleReplica:
 		p.roPool.AddConnection(name, conn)
 	}
 	return nil
@@ -1223,7 +1223,7 @@ func (p *ConnectionPool) updateConnection(e *endpoint) {
 			if !opened {
 				e.conn.Close()
 				e.conn = nil
-				e.role = UnknownRole
+				e.role = RoleUnknown
 				return
 			}
 
@@ -1234,7 +1234,7 @@ func (p *ConnectionPool) updateConnection(e *endpoint) {
 				e.conn.Close()
 				p.handlerDeactivated(e.name, e.conn, role)
 				e.conn = nil
-				e.role = UnknownRole
+				e.role = RoleUnknown
 				return
 			}
 
@@ -1244,7 +1244,7 @@ func (p *ConnectionPool) updateConnection(e *endpoint) {
 				e.conn.Close()
 				p.handlerDeactivated(e.name, e.conn, role)
 				e.conn = nil
-				e.role = UnknownRole
+				e.role = RoleUnknown
 				return
 			}
 			e.role = role
@@ -1258,7 +1258,7 @@ func (p *ConnectionPool) updateConnection(e *endpoint) {
 		e.conn.Close()
 		p.handlerDeactivated(e.name, e.conn, e.role)
 		e.conn = nil
-		e.role = UnknownRole
+		e.role = RoleUnknown
 		return
 	}
 }
@@ -1272,7 +1272,7 @@ func (p *ConnectionPool) tryConnect(ctx context.Context, e *endpoint) error {
 	}
 
 	e.conn = nil
-	e.role = UnknownRole
+	e.role = RoleUnknown
 
 	connOpts := e.opts
 	connOpts.Notify = e.notify
@@ -1329,7 +1329,7 @@ func (p *ConnectionPool) reconnect(ctx context.Context, e *endpoint) {
 
 	p.handlerDeactivated(e.name, e.conn, e.role)
 	e.conn = nil
-	e.role = UnknownRole
+	e.role = RoleUnknown
 
 	if err := p.tryConnect(ctx, e); err != nil {
 		log.Printf("tarantool: reconnect to %s failed: %s\n", e.name, err)
@@ -1411,7 +1411,7 @@ func (p *ConnectionPool) controller(ctx context.Context, e *endpoint) {
 							p.poolsMutex.Unlock()
 							p.handlerDeactivated(e.name, e.conn, e.role)
 							e.conn = nil
-							e.role = UnknownRole
+							e.role = RoleUnknown
 						} else {
 							p.poolsMutex.Unlock()
 						}

pool/connection_pool_test.go

@@ -252,8 +252,8 @@ func TestConnect_unavailable(t *testing.T) {
 	require.NoError(t, err, "failed to create a pool")
 	require.NotNilf(t, connPool, "pool is nil after Connect")
 	require.Equal(t, map[string]pool.ConnectionInfo{
-		servers[0]: pool.ConnectionInfo{ConnectedNow: false, ConnRole: pool.UnknownRole},
-		servers[1]: pool.ConnectionInfo{ConnectedNow: false, ConnRole: pool.UnknownRole},
+		servers[0]: pool.ConnectionInfo{ConnectedNow: false, ConnRole: pool.RoleUnknown},
+		servers[1]: pool.ConnectionInfo{ConnectedNow: false, ConnRole: pool.RoleUnknown},
 	}, connPool.GetInfo())
 }
 
@@ -1016,17 +1016,17 @@ func (h *testHandler) Discovered(name string, conn *tarantool.Connection,
 	// discovered < 3 - initial open of connections
 	// discovered >= 3 - update a connection after a role update
 	if name == servers[0] {
-		if discovered < 3 && role != pool.MasterRole {
+		if discovered < 3 && role != pool.RoleMaster {
 			h.addErr(fmt.Errorf("unexpected init role %d for name %s", role, name))
 		}
-		if discovered >= 3 && role != pool.ReplicaRole {
+		if discovered >= 3 && role != pool.RoleReplica {
 			h.addErr(fmt.Errorf("unexpected updated role %d for name %s", role, name))
 		}
 	} else if name == servers[1] {
 		if discovered >= 3 {
 			h.addErr(fmt.Errorf("unexpected discovery for name %s", name))
 		}
-		if role != pool.ReplicaRole {
+		if role != pool.RoleReplica {
 			h.addErr(fmt.Errorf("unexpected role %d for name %s", role, name))
 		}
 	} else {
@@ -1047,15 +1047,15 @@ func (h *testHandler) Deactivated(name string, conn *tarantool.Connection,
 
 	if deactivated == 1 && name == servers[0] {
 		// A first close is a role update.
-		if role != pool.MasterRole {
+		if role != pool.RoleMaster {
 			h.addErr(fmt.Errorf("unexpected removed role %d for name %s", role, name))
 		}
 		return nil
 	}
 
 	if name == servers[0] || name == servers[1] {
 		// Close.
-		if role != pool.ReplicaRole {
+		if role != pool.RoleReplica {
 			h.addErr(fmt.Errorf("unexpected removed role %d for name %s", role, name))
 		}
 	} else {
@@ -1163,8 +1163,8 @@ func TestConnectionHandlerOpenError(t *testing.T) {
 	require.NoError(t, err, "failed to connect")
 	require.NotNil(t, connPool, "pool expected")
 	require.Equal(t, map[string]pool.ConnectionInfo{
-		servers[0]: pool.ConnectionInfo{ConnectedNow: false, ConnRole: pool.UnknownRole},
-		servers[1]: pool.ConnectionInfo{ConnectedNow: false, ConnRole: pool.UnknownRole},
+		servers[0]: pool.ConnectionInfo{ConnectedNow: false, ConnRole: pool.RoleUnknown},
+		servers[1]: pool.ConnectionInfo{ConnectedNow: false, ConnRole: pool.RoleUnknown},
 	}, connPool.GetInfo())
 	connPool.Close()
 

pool/const.go

@@ -1,3 +1,5 @@
+//go:generate stringer -type=Role -trimprefix=Role
+
 package pool
 
 /*
@@ -31,7 +33,7 @@ const (
 type Role uint32
 
 const (
-	UnknownRole Role = iota // A connection pool failed to discover mode of the instance.
-	MasterRole              // The instance is read-write mode.
-	ReplicaRole             // The instance is in read-only mode.
+	RoleUnknown Role = iota // A connection pool failed to discover mode of the instance.
+	RoleMaster              // The instance is read-write mode.
+	RoleReplica             // The instance is in read-only mode.
 )

pool/const_test.go

@@ -0,0 +1,14 @@
+package pool
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestRole_String checking that print is non-number(len = 1 ) Role
+func TestRole_String(t *testing.T) {
+	require.Equal(t, "Replica", RoleReplica.String())
+	require.Equal(t, "Unknown", RoleUnknown.String())
+	require.Equal(t, "Master", RoleMaster.String())
+}

pool/role_string.go

@@ -53,7 +53,7 @@ func (h *QueueConnectionHandler) Discovered(name string, conn *tarantool.Connect
 		return h.err
 	}
 
-	master := role == pool.MasterRole
+	master := role == pool.RoleMaster
 
 	q := queue.New(conn, h.name)
 
@@ -115,7 +115,7 @@ func (h *QueueConnectionHandler) Discovered(name string, conn *tarantool.Connect
 // Deactivated doesn't do anything useful for the example.
 func (h *QueueConnectionHandler) Deactivated(name string, conn *tarantool.Connection,
 	role pool.Role) error {
-	if role == pool.MasterRole {
+	if role == pool.RoleMaster {
 		atomic.AddInt32(&h.masterCnt, -1)
 	}
 	return nil