GODRIVER-1632 fixing function for retryable writes (#433)

Author: KritiRav

mongo/change_stream_deployment.go

@@ -27,10 +27,6 @@ func (c *changeStreamDeployment) SelectServer(context.Context, description.Serve
 	return c, nil
 }
 
-func (c *changeStreamDeployment) SupportsRetryWrites() bool {
-	return false
-}
-
 func (c *changeStreamDeployment) Kind() description.TopologyKind {
 	return c.topologyKind
 }

mongo/client_test.go

@@ -43,10 +43,6 @@ func (md mockDeployment) SelectServer(context.Context, description.ServerSelecto
 	return nil, nil
 }
 
-func (md mockDeployment) SupportsRetryWrites() bool {
-	return false
-}
-
 func (md mockDeployment) Kind() description.TopologyKind {
 	return description.Single
 }

mongo/integration/mtest/opmsg_deployment.go

@@ -111,12 +111,6 @@ func (md *mockDeployment) SelectServer(context.Context, description.ServerSelect
 	return md, nil
 }
 
-// SupportsRetry implements the Deployment interface. It always returns true to allow for testing
-// retryability.
-func (md *mockDeployment) SupportsRetryWrites() bool {
-	return true
-}
-
 // Kind implements the Deployment interface. It always returns description.Single.
 func (md *mockDeployment) Kind() description.TopologyKind {
 	return description.Single

x/mongo/driver/description/server.go

@@ -391,3 +391,8 @@ func decodeStringMap(element bsoncore.Element, name string) (map[string]string,
 	}
 	return m, nil
 }
+
+// SupportsRetryWrites returns true if this description represents a server that supports retryable writes.
+func (s Server) SupportsRetryWrites() bool {
+	return s.SessionTimeoutMinutes != 0 && s.Kind != Standalone
+}

x/mongo/driver/driver.go

@@ -10,7 +10,6 @@ import (
 // Deployment is implemented by types that can select a server from a deployment.
 type Deployment interface {
 	SelectServer(context.Context, description.ServerSelector) (Server, error)
-	SupportsRetryWrites() bool
 	Kind() description.TopologyKind
 }
 
@@ -114,10 +113,6 @@ func (ssd SingleServerDeployment) SelectServer(context.Context, description.Serv
 	return ssd.Server, nil
 }
 
-// SupportsRetryWrites implements the Deployment interface. It always returns Type(0), because a single
-// server does not support retryability.
-func (SingleServerDeployment) SupportsRetryWrites() bool { return false }
-
 // Kind implements the Deployment interface. It always returns description.Single.
 func (SingleServerDeployment) Kind() description.TopologyKind { return description.Single }
 
@@ -137,10 +132,6 @@ func (ssd SingleConnectionDeployment) SelectServer(context.Context, description.
 	return ssd, nil
 }
 
-// SupportsRetryWrites implements the Deployment interface. It always returns Type(0), because a single
-// connection does not support retryability.
-func (ssd SingleConnectionDeployment) SupportsRetryWrites() bool { return false }
-
 // Kind implements the Deployment interface. It always returns description.Single.
 func (ssd SingleConnectionDeployment) Kind() description.TopologyKind { return description.Single }
 

x/mongo/driver/operation.go

@@ -539,7 +539,7 @@ func (op Operation) retryable(desc description.Server) bool {
 		if op.Client != nil && (op.Client.Committing || op.Client.Aborting) {
 			return true
 		}
-		if op.Deployment.SupportsRetryWrites() &&
+		if desc.SupportsRetryWrites() &&
 			desc.WireVersion != nil && desc.WireVersion.Max >= 6 &&
 			op.Client != nil && !(op.Client.TransactionInProgress() || op.Client.TransactionStarting()) &&
 			writeconcern.AckWrite(op.WriteConcern) {

x/mongo/driver/operation_test.go

@@ -113,11 +113,6 @@ func TestOperation(t *testing.T) {
 		}
 	})
 	t.Run("retryableWrite", func(t *testing.T) {
-		deploymentRetry := new(mockDeployment)
-		deploymentRetry.returns.retry = true
-
-		deploymentNoRetry := new(mockDeployment)
-
 		sessPool := session.NewPool(nil)
 		id, err := uuid.New()
 		noerr(t, err)
@@ -139,31 +134,33 @@ func TestOperation(t *testing.T) {
 		wcAck := writeconcern.New(writeconcern.WMajority())
 		wcUnack := writeconcern.New(writeconcern.W(0))
 
-		descRetryable := description.Server{WireVersion: &description.VersionRange{Min: 0, Max: 7}}
-		descNotRetryable := description.Server{WireVersion: &description.VersionRange{Min: 0, Max: 5}}
+		descRetryable := description.Server{WireVersion: &description.VersionRange{Min: 0, Max: 7}, SessionTimeoutMinutes: 1}
+		descNotRetryableWireVersion := description.Server{WireVersion: &description.VersionRange{Min: 0, Max: 5}, SessionTimeoutMinutes: 1}
+		descNotRetryableStandalone := description.Server{WireVersion: &description.VersionRange{Min: 0, Max: 7}, SessionTimeoutMinutes: 1, Kind: description.Standalone}
 
 		testCases := []struct {
 			name string
 			op   Operation
 			desc description.Server
 			want Type
 		}{
-			{"deployment doesn't support", Operation{Deployment: deploymentNoRetry}, description.Server{}, Type(0)},
-			{"wire version too low", Operation{Deployment: deploymentRetry, Client: sess, WriteConcern: wcAck}, descNotRetryable, Type(0)},
+			{"deployment doesn't support", Operation{}, description.Server{}, Type(0)},
+			{"wire version too low", Operation{Client: sess, WriteConcern: wcAck}, descNotRetryableWireVersion, Type(0)},
+			{"standalone not supported", Operation{Client: sess, WriteConcern: wcAck}, descNotRetryableStandalone, Type(0)},
 			{
 				"transaction in progress",
-				Operation{Deployment: deploymentRetry, Client: sessInProgressTransaction, WriteConcern: wcAck},
+				Operation{Client: sessInProgressTransaction, WriteConcern: wcAck},
 				descRetryable, Type(0),
 			},
 			{
 				"transaction starting",
-				Operation{Deployment: deploymentRetry, Client: sessStartingTransaction, WriteConcern: wcAck},
+				Operation{Client: sessStartingTransaction, WriteConcern: wcAck},
 				descRetryable, Type(0),
 			},
-			{"unacknowledged write concern", Operation{Deployment: deploymentRetry, Client: sess, WriteConcern: wcUnack}, descRetryable, Type(0)},
+			{"unacknowledged write concern", Operation{Client: sess, WriteConcern: wcUnack}, descRetryable, Type(0)},
 			{
 				"acknowledged write concern",
-				Operation{Deployment: deploymentRetry, Client: sess, WriteConcern: wcAck, Type: Write},
+				Operation{Client: sess, WriteConcern: wcAck, Type: Write},
 				descRetryable, Write,
 			},
 		}
@@ -625,9 +622,6 @@ func (m *mockDeployment) SelectServer(ctx context.Context, desc description.Serv
 	return m.returns.server, m.returns.err
 }
 
-func (m *mockDeployment) SupportsRetryWrites() bool {
-	return m.returns.retry
-}
 func (m *mockDeployment) Kind() description.TopologyKind { return m.returns.kind }
 
 type mockServerSelector struct{}

x/mongo/driver/topology/topology.go

@@ -290,16 +290,6 @@ func (t *Topology) RequestImmediateCheck() {
 	t.serversLock.Unlock()
 }
 
-// SupportsSessions returns true if the topology supports sessions.
-func (t *Topology) SupportsSessions() bool {
-	return t.Description().SessionTimeoutMinutes != 0 && t.Description().Kind != description.Single
-}
-
-// SupportsRetryWrites returns true if the topology supports retryable writes, which it does if it supports sessions.
-func (t *Topology) SupportsRetryWrites() bool {
-	return t.SupportsSessions()
-}
-
 // SelectServer selects a server with given a selector. SelectServer complies with the
 // server selection spec, and will time out after severSelectionTimeout or when the
 // parent context is done.