1 files changed, 19 insertions, 29 deletions

diff --git a/src/database/sql/sql.go b/src/database/sql/sql.go
index 9f056c51e2..960245065e 100644
--- a/src/database/sql/sql.go
+++ b/src/database/sql/sql.go
@@ -18,7 +18,6 @@ package sql
 import (
 	"context"
 	"database/sql/driver"
-	"database/sql/internal"
 	"errors"
 	"fmt"
 	"io"
@@ -115,12 +114,10 @@ func Named(name string, value interface{}) NamedArg {
 	return NamedArg{Name: name, Value: value}
 }
 
-// IsolationLevel is the transaction isolation level stored in Context.
-// The IsolationLevel is set with IsolationContext and the context
-// should be passed to BeginContext.
+// IsolationLevel is the transaction isolation level used in TxOptions.
 type IsolationLevel int
 
-// Various isolation levels that drivers may support in BeginContext.
+// Various isolation levels that drivers may support in BeginTx.
 // If a driver does not support a given isolation level an error may be returned.
 //
 // See https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels.
@@ -135,18 +132,12 @@ const (
 	LevelLinearizable
 )
 
-// IsolationContext returns a new Context that carries the provided isolation level.
-// The context must contain the isolation level before beginning the transaction
-// with BeginContext.
-func IsolationContext(ctx context.Context, level IsolationLevel) context.Context {
-	return context.WithValue(ctx, internal.IsolationLevelKey{}, driver.IsolationLevel(level))
-}
-
-// ReadOnlyWithContext returns a new Context that carries the provided
-// read-only transaction property. The context must contain the read-only property
-// before beginning the transaction with BeginContext.
-func ReadOnlyContext(ctx context.Context) context.Context {
-	return context.WithValue(ctx, internal.ReadOnlyKey{}, true)
+// TxOptions holds the transaction options to be used in DB.BeginTx.
+type TxOptions struct {
+	// Isolation is the transaction isolation level.
+	// If zero, the driver or database's default level is used.
+	Isolation IsolationLevel
+	ReadOnly  bool
 }
 
 // RawBytes is a byte slice that holds a reference to memory owned by
@@ -1311,28 +1302,27 @@ func (db *DB) QueryRow(query string, args ...interface{}) *Row {
 	return db.QueryRowContext(context.Background(), query, args...)
 }
 
-// BeginContext starts a transaction.
+// BeginTx starts a transaction.
 //
 // The provided context is used until the transaction is committed or rolled back.
 // If the context is canceled, the sql package will roll back
 // the transaction. Tx.Commit will return an error if the context provided to
-// BeginContext is canceled.
+// BeginTx is canceled.
 //
-// An isolation level may be set by setting the value in the context
-// before calling this. If a non-default isolation level is used
-// that the driver doesn't support an error will be returned. Different drivers
-// may have slightly different meanings for the same isolation level.
-func (db *DB) BeginContext(ctx context.Context) (*Tx, error) {
+// The provided TxOptions is optional and may be nil if defaults should be used.
+// If a non-default isolation level is used that the driver doesn't support,
+// an error will be returned.
+func (db *DB) BeginTx(ctx context.Context, opts *TxOptions) (*Tx, error) {
 	var tx *Tx
 	var err error
 	for i := 0; i < maxBadConnRetries; i++ {
-		tx, err = db.begin(ctx, cachedOrNewConn)
+		tx, err = db.begin(ctx, opts, cachedOrNewConn)
 		if err != driver.ErrBadConn {
 			break
 		}
 	}
 	if err == driver.ErrBadConn {
-		return db.begin(ctx, alwaysNewConn)
+		return db.begin(ctx, opts, alwaysNewConn)
 	}
 	return tx, err
 }
@@ -1340,17 +1330,17 @@ func (db *DB) BeginContext(ctx context.Context) (*Tx, error) {
 // Begin starts a transaction. The default isolation level is dependent on
 // the driver.
 func (db *DB) Begin() (*Tx, error) {
-	return db.BeginContext(context.Background())
+	return db.BeginTx(context.Background(), nil)
 }
 
-func (db *DB) begin(ctx context.Context, strategy connReuseStrategy) (tx *Tx, err error) {
+func (db *DB) begin(ctx context.Context, opts *TxOptions, strategy connReuseStrategy) (tx *Tx, err error) {
 	dc, err := db.conn(ctx, strategy)
 	if err != nil {
 		return nil, err
 	}
 	var txi driver.Tx
 	withLock(dc, func() {
-		txi, err = ctxDriverBegin(ctx, dc.ci)
+		txi, err = ctxDriverBegin(ctx, opts, dc.ci)
 	})
 	if err != nil {
 		db.putConn(dc, err)