Added Isolation concept

Author: asmyasnikov

internal/query/transaction.go

@@ -45,7 +45,7 @@ func begin(
 	response, err := client.BeginTransaction(ctx,
 		&Ydb_Query.BeginTransactionRequest{
 			SessionId:  sessionID,
-			TxSettings: txSettings.ToYdbQuerySettings(),
+			TxSettings: txSettings.ToQuerySettings(),
 		},
 	)
 	if err != nil {
@@ -185,7 +185,7 @@ func (tx *Transaction) txControl() *baseTx.Control {
 	}
 
 	return baseTx.NewControl(
-		baseTx.BeginTx(tx.txSettings...),
+		tx.txSettings,
 	)
 }
 

internal/tx/isolation.go

@@ -0,0 +1,74 @@
+package tx
+
+import (
+	"fmt"
+
+	"github.com/ydb-platform/ydb-go-genproto/protos/Ydb_Query"
+	"github.com/ydb-platform/ydb-go-genproto/protos/Ydb_Table"
+)
+
+type Isolation int
+
+func (iso Isolation) ToTableSettings() *Ydb_Table.TransactionSettings {
+	return iso.tableTxSelector().BeginTx
+}
+
+func (iso Isolation) ToQuerySettings() *Ydb_Query.TransactionSettings {
+	return iso.queryTxSelector().BeginTx
+}
+
+func (iso Isolation) applyQueryTxSelector(txControl *Ydb_Query.TransactionControl) {
+	txControl.TxSelector = iso.queryTxSelector()
+}
+
+func (iso Isolation) applyTableTxSelector(txControl *Ydb_Table.TransactionControl) {
+	txControl.TxSelector = iso.tableTxSelector()
+}
+
+func (iso Isolation) applyTxControlOption(txControl *Control) {
+	txControl.selector = iso
+}
+
+func (iso Isolation) tableTxSelector() *Ydb_Table.TransactionControl_BeginTx {
+	switch iso {
+	case SerializableRW:
+		return tableSerializableReadWriteTxSelector
+	case SnapshotRO:
+		return tableSnapshotReadOnlyTxSelector
+	case OnlineRO:
+		return tableOnlineReadOnlyForbidInconsistentReadsTxSelector
+	case OnlineROWithInconsistentReads:
+		return tableOnlineReadOnlyAllowInconsistentReadsTxSelector
+	case StaleRO:
+		return tableStaleReadOnlyTxSelector
+	default:
+		panic(fmt.Sprintf("unknown isolation: %d", iso))
+	}
+}
+
+func (iso Isolation) queryTxSelector() *Ydb_Query.TransactionControl_BeginTx {
+	switch iso {
+	case SerializableRW:
+		return querySerializableReadWriteTxSelector
+	case SnapshotRO:
+		return querySnapshotReadOnlyTxSelector
+	case OnlineRO:
+		return queryOnlineReadOnlyForbidInconsistentReadsTxSelector
+	case OnlineROWithInconsistentReads:
+		return queryOnlineReadOnlyAllowInconsistentReadsTxSelector
+	case StaleRO:
+		return queryStaleReadOnlyTxSelector
+	default:
+		panic(fmt.Sprintf("unknown isolation: %d", iso))
+	}
+}
+
+const (
+	SerializableRW = Isolation(iota)
+	SnapshotRO
+	OnlineRO
+	OnlineROWithInconsistentReads
+	StaleRO
+)
+
+var _ Settings = Isolation(0)

internal/tx/settings.go

@@ -9,33 +9,83 @@ var (
 	querySerializableReadWrite = &Ydb_Query.TransactionSettings_SerializableReadWrite{
 		SerializableReadWrite: &Ydb_Query.SerializableModeSettings{},
 	}
+	querySerializableReadWriteTxSelector = &Ydb_Query.TransactionControl_BeginTx{
+		BeginTx: &Ydb_Query.TransactionSettings{
+			TxMode: querySerializableReadWrite,
+		},
+	}
 	queryStaleReadOnly = &Ydb_Query.TransactionSettings_StaleReadOnly{
 		StaleReadOnly: &Ydb_Query.StaleModeSettings{},
 	}
+	queryStaleReadOnlyTxSelector = &Ydb_Query.TransactionControl_BeginTx{
+		BeginTx: &Ydb_Query.TransactionSettings{
+			TxMode: queryStaleReadOnly,
+		},
+	}
 	querySnapshotReadOnly = &Ydb_Query.TransactionSettings_SnapshotReadOnly{
 		SnapshotReadOnly: &Ydb_Query.SnapshotModeSettings{},
 	}
+	querySnapshotReadOnlyTxSelector = &Ydb_Query.TransactionControl_BeginTx{
+		BeginTx: &Ydb_Query.TransactionSettings{
+			TxMode: querySnapshotReadOnly,
+		},
+	}
 	queryOnlineReadOnlyAllowInconsistentReads = &Ydb_Query.TransactionSettings_OnlineReadOnly{
 		OnlineReadOnly: &Ydb_Query.OnlineModeSettings{AllowInconsistentReads: true},
 	}
+	queryOnlineReadOnlyAllowInconsistentReadsTxSelector = &Ydb_Query.TransactionControl_BeginTx{
+		BeginTx: &Ydb_Query.TransactionSettings{
+			TxMode: queryOnlineReadOnlyAllowInconsistentReads,
+		},
+	}
 	queryOnlineReadOnlyForbidInconsistentReads = &Ydb_Query.TransactionSettings_OnlineReadOnly{
 		OnlineReadOnly: &Ydb_Query.OnlineModeSettings{AllowInconsistentReads: false},
 	}
+	queryOnlineReadOnlyForbidInconsistentReadsTxSelector = &Ydb_Query.TransactionControl_BeginTx{
+		BeginTx: &Ydb_Query.TransactionSettings{
+			TxMode: queryOnlineReadOnlyForbidInconsistentReads,
+		},
+	}
 	tableSerializableReadWrite = &Ydb_Table.TransactionSettings_SerializableReadWrite{
 		SerializableReadWrite: &Ydb_Table.SerializableModeSettings{},
 	}
+	tableSerializableReadWriteTxSelector = &Ydb_Table.TransactionControl_BeginTx{
+		BeginTx: &Ydb_Table.TransactionSettings{
+			TxMode: tableSerializableReadWrite,
+		},
+	}
 	tableStaleReadOnly = &Ydb_Table.TransactionSettings_StaleReadOnly{
 		StaleReadOnly: &Ydb_Table.StaleModeSettings{},
 	}
+	tableStaleReadOnlyTxSelector = &Ydb_Table.TransactionControl_BeginTx{
+		BeginTx: &Ydb_Table.TransactionSettings{
+			TxMode: tableStaleReadOnly,
+		},
+	}
 	tableSnapshotReadOnly = &Ydb_Table.TransactionSettings_SnapshotReadOnly{
 		SnapshotReadOnly: &Ydb_Table.SnapshotModeSettings{},
 	}
+	tableSnapshotReadOnlyTxSelector = &Ydb_Table.TransactionControl_BeginTx{
+		BeginTx: &Ydb_Table.TransactionSettings{
+			TxMode: tableSnapshotReadOnly,
+		},
+	}
 	tableOnlineReadOnlyAllowInconsistentReads = &Ydb_Table.TransactionSettings_OnlineReadOnly{
 		OnlineReadOnly: &Ydb_Table.OnlineModeSettings{AllowInconsistentReads: true},
 	}
+	tableOnlineReadOnlyAllowInconsistentReadsTxSelector = &Ydb_Table.TransactionControl_BeginTx{
+		BeginTx: &Ydb_Table.TransactionSettings{
+			TxMode: tableOnlineReadOnlyAllowInconsistentReads,
+		},
+	}
 	tableOnlineReadOnlyForbidInconsistentReads = &Ydb_Table.TransactionSettings_OnlineReadOnly{
 		OnlineReadOnly: &Ydb_Table.OnlineModeSettings{AllowInconsistentReads: false},
 	}
+	tableOnlineReadOnlyForbidInconsistentReadsTxSelector = &Ydb_Table.TransactionControl_BeginTx{
+		BeginTx: &Ydb_Table.TransactionSettings{
+			TxMode: tableOnlineReadOnlyForbidInconsistentReads,
+		},
+	}
 )
 
 // Transaction settings options
@@ -44,10 +94,45 @@ type (
 		ApplyQueryTxSettingsOption(txSettings *Ydb_Query.TransactionSettings)
 		ApplyTableTxSettingsOption(txSettings *Ydb_Table.TransactionSettings)
 	}
-	Settings []SettingsOption
+	Settings interface {
+		ControlOption
+		Selector
+
+		ToTableSettings() *Ydb_Table.TransactionSettings
+		ToQuerySettings() *Ydb_Query.TransactionSettings
+	}
+	Options []SettingsOption
 )
 
-func (opts Settings) applyTableTxSelector(txControl *Ydb_Table.TransactionControl) {
+func (opts Options) applyTxControlOption(txControl *Control) {
+	txControl.selector = BeginTx(opts...)
+}
+
+func (opts Options) ToTableSettings() *Ydb_Table.TransactionSettings {
+	txSettings := &Ydb_Table.TransactionSettings{}
+	for _, opt := range opts {
+		if opt != nil {
+			opt.ApplyTableTxSettingsOption(txSettings)
+		}
+	}
+
+	return txSettings
+}
+
+func (opts Options) ToQuerySettings() *Ydb_Query.TransactionSettings {
+	txSettings := &Ydb_Query.TransactionSettings{}
+	for _, opt := range opts {
+		if opt != nil {
+			opt.ApplyQueryTxSettingsOption(txSettings)
+		}
+	}
+
+	return txSettings
+}
+
+var _ Settings = Options(nil)
+
+func (opts Options) applyTableTxSelector(txControl *Ydb_Table.TransactionControl) {
 	beginTx := &Ydb_Table.TransactionControl_BeginTx{
 		BeginTx: &Ydb_Table.TransactionSettings{},
 	}
@@ -59,7 +144,7 @@ func (opts Settings) applyTableTxSelector(txControl *Ydb_Table.TransactionContro
 	txControl.TxSelector = beginTx
 }
 
-func (opts Settings) applyQueryTxSelector(txControl *Ydb_Query.TransactionControl) {
+func (opts Options) applyQueryTxSelector(txControl *Ydb_Query.TransactionControl) {
 	beginTx := &Ydb_Query.TransactionControl_BeginTx{
 		BeginTx: &Ydb_Query.TransactionSettings{},
 	}
@@ -71,7 +156,7 @@ func (opts Settings) applyQueryTxSelector(txControl *Ydb_Query.TransactionContro
 	txControl.TxSelector = beginTx
 }
 
-func (opts Settings) ToYdbQuerySettings() *Ydb_Query.TransactionSettings {
+func (opts Options) ToYdbQuerySettings() *Ydb_Query.TransactionSettings {
 	txSettings := &Ydb_Query.TransactionSettings{}
 	for _, opt := range opts {
 		if opt != nil {
@@ -82,7 +167,7 @@ func (opts Settings) ToYdbQuerySettings() *Ydb_Query.TransactionSettings {
 	return txSettings
 }
 
-func (opts Settings) ToYdbTableSettings() *Ydb_Table.TransactionSettings {
+func (opts Options) ToYdbTableSettings() *Ydb_Table.TransactionSettings {
 	txSettings := &Ydb_Table.TransactionSettings{}
 	for _, opt := range opts {
 		if opt != nil {
@@ -94,7 +179,7 @@ func (opts Settings) ToYdbTableSettings() *Ydb_Table.TransactionSettings {
 }
 
 // NewSettings returns transaction settings
-func NewSettings(opts ...SettingsOption) Settings {
+func NewSettings(opts ...SettingsOption) Options {
 	return opts
 }
 

query/transaction.go

@@ -18,9 +18,27 @@ type (
 		CommitTx(ctx context.Context) (err error)
 		Rollback(ctx context.Context) (err error)
 	}
-	TransactionControl  = tx.Control
+
+	// TransactionControl is a special YDB object for define how to start (TransactionSettings) and end (CommitTx flag)
+	// of transaction per each query
+	// Deprecated: doesn't exists any use cases, when CommitTx=false
+	TransactionControl = tx.Control
+
 	TransactionSettings = tx.Settings
 	TransactionOption   = tx.SettingsOption
+
+	// Isolation is well-known definition about isolation concurrent transactions
+	// The closest concept of isolation in ydb is transaction settings.
+	// Almost TransactionSettings matches to standard isolation levels (excluding OnlineReadOnly)
+	Isolation = tx.Settings
+)
+
+const (
+	SerializableRW                = tx.SerializableRW
+	SnapshotRO                    = tx.SnapshotRO
+	OnlineRO                      = tx.OnlineRO
+	OnlineROWithInconsistentReads = tx.OnlineROWithInconsistentReads
+	StaleRO                       = tx.StaleRO
 )
 
 // BeginTx returns selector transaction control option
@@ -96,7 +114,7 @@ func SnapshotReadOnlyTxControl() *TransactionControl {
 
 // TxSettings returns transaction settings
 func TxSettings(opts ...tx.SettingsOption) TransactionSettings {
-	return opts
+	return tx.NewSettings(opts...)
 }
 
 func WithDefaultTxMode() TransactionOption {

table/table.go

@@ -177,7 +177,7 @@ type Session interface {
 }
 
 type (
-	TransactionSettings = tx.Settings
+	TransactionSettings = tx.Options
 	// Transaction control options
 	TxOption = tx.SettingsOption
 )