support DB.BeginTx of golang 1.8

Signed-off-by: Penghui Liao <liaoishere@gmail.com>

orm/orm_go18.go

@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// +build go1.8
+
 // Package orm provide ORM for MySQL/PostgreSQL/sqlite
 // Simple Usage
 //
@@ -52,6 +54,7 @@
 package orm
 
 import (
+	"context"
 	"database/sql"
 	"errors"
 	"fmt"
@@ -458,11 +461,15 @@ func (o *orm) Using(name string) error {
 
 // begin transaction
 func (o *orm) Begin() error {
+	return o.BeginTx(context.Background(), nil)
+}
+
+func (o *orm) BeginTx(ctx context.Context, opts *sql.TxOptions) error {
 	if o.isTx {
 		return ErrTxHasBegan
 	}
 	var tx *sql.Tx
-	tx, err := o.db.(txer).Begin()
+	tx, err := o.db.(txer).BeginTx(ctx, opts)
 	if err != nil {
 		return err
 	}

orm/orm_log.go

@@ -15,6 +15,7 @@
 package orm
 
 import (
+	"context"
 	"database/sql"
 	"fmt"
 	"io"
@@ -150,6 +151,13 @@ func (d *dbQueryLog) Begin() (*sql.Tx, error) {
 	return tx, err
 }
 
+func (d *dbQueryLog) BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error) {
+	a := time.Now()
+	tx, err := d.db.(txer).BeginTx(ctx, opts)
+	debugLogQueies(d.alias, "db.BeginTx", "START TRANSACTION", a, err)
+	return tx, err
+}
+
 func (d *dbQueryLog) Commit() error {
 	a := time.Now()
 	err := d.db.(txEnder).Commit()

orm/orm_test.go

@@ -12,10 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// +build go1.8
+
 package orm
 
 import (
 	"bytes"
+	"context"
 	"database/sql"
 	"fmt"
 	"io/ioutil"
@@ -452,9 +455,9 @@ func TestNullDataTypes(t *testing.T) {
 	throwFail(t, AssertIs(*d.Float32Ptr, float32Ptr))
 	throwFail(t, AssertIs(*d.Float64Ptr, float64Ptr))
 	throwFail(t, AssertIs(*d.DecimalPtr, decimalPtr))
-	throwFail(t, AssertIs((*d.TimePtr).Format(testTime), timePtr.Format(testTime)))
-	throwFail(t, AssertIs((*d.DatePtr).Format(testDate), datePtr.Format(testDate)))
-	throwFail(t, AssertIs((*d.DateTimePtr).Format(testDateTime), dateTimePtr.Format(testDateTime)))
+	throwFail(t, AssertIs((*d.TimePtr).UTC().Format(testTime), timePtr.UTC().Format(testTime)))
+	throwFail(t, AssertIs((*d.DatePtr).UTC().Format(testDate), datePtr.UTC().Format(testDate)))
+	throwFail(t, AssertIs((*d.DateTimePtr).UTC().Format(testDateTime), dateTimePtr.UTC().Format(testDateTime)))
 }
 
 func TestDataCustomTypes(t *testing.T) {
@@ -1990,6 +1993,66 @@ func TestTransaction(t *testing.T) {
 
 }
 
+func TestTransactionIsolationLevel(t *testing.T) {
+	// this test worked when database support transaction isolation level
+	if IsSqlite {
+		return
+	}
+
+	o1 := NewOrm()
+	o2 := NewOrm()
+
+	// start two transaction with isolation level repeatable read
+	err := o1.BeginTx(context.Background(), &sql.TxOptions{Isolation: sql.LevelRepeatableRead})
+	throwFail(t, err)
+	err = o2.BeginTx(context.Background(), &sql.TxOptions{Isolation: sql.LevelRepeatableRead})
+	throwFail(t, err)
+
+	// o1 insert tag
+	var tag Tag
+	tag.Name = "test-transaction"
+	id, err := o1.Insert(&tag)
+	throwFail(t, err)
+	throwFail(t, AssertIs(id > 0, true))
+
+	// o2 query tag table, no result
+	num, err := o2.QueryTable("tag").Filter("name", "test-transaction").Count()
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 0))
+
+	// o1 commit
+	o1.Commit()
+
+	// o2 query tag table, still no result
+	num, err = o2.QueryTable("tag").Filter("name", "test-transaction").Count()
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 0))
+
+	// o2 commit and query tag table, get the result
+	o2.Commit()
+	num, err = o2.QueryTable("tag").Filter("name", "test-transaction").Count()
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+
+	num, err = o1.QueryTable("tag").Filter("name", "test-transaction").Delete()
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+}
+
+func TestBeginTxWithContextCanceled(t *testing.T) {
+	o := NewOrm()
+	ctx, cancel := context.WithCancel(context.Background())
+	o.BeginTx(ctx, nil)
+	id, err := o.Insert(&Tag{Name: "test-context"})
+	throwFail(t, err)
+	throwFail(t, AssertIs(id > 0, true))
+
+	// cancel the context before commit to make it error
+	cancel()
+	err = o.Commit()
+	throwFail(t, AssertIs(err, context.Canceled))
+}
+
 func TestReadOrCreate(t *testing.T) {
 	u := &User{
 		UserName: "Kyle",
@@ -2260,6 +2323,7 @@ func TestIgnoreCaseTag(t *testing.T) {
 	throwFail(t, AssertIs(info.fields.GetByName("Name02").column, "Name"))
 	throwFail(t, AssertIs(info.fields.GetByName("Name03").column, "name"))
 }
+
 func TestInsertOrUpdate(t *testing.T) {
 	RegisterModel(new(User))
 	user := User{UserName: "unique_username133", Status: 1, Password: "o"}

orm/types.go

@@ -15,6 +15,7 @@
 package orm
 
 import (
+	"context"
 	"database/sql"
 	"reflect"
 	"time"
@@ -106,6 +107,17 @@ type Ormer interface {
 	// 	...
 	// 	err = o.Rollback()
 	Begin() error
+	// begin transaction with provided context and option
+	// the provided context is used until the transaction is committed or rolled back.
+	// if the context is canceled, the transaction will be rolled back.
+	// 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.
+	// for example:
+	//  o := NewOrm()
+	// 	err := o.BeginTx(context.Background(), &sql.TxOptions{Isolation: sql.LevelRepeatableRead})
+	//  ...
+	//  err = o.Rollback()
+	BeginTx(ctx context.Context, opts *sql.TxOptions) error
 	// commit transaction
 	Commit() error
 	// rollback transaction
@@ -401,6 +413,7 @@ type dbQuerier interface {
 // transaction beginner
 type txer interface {
 	Begin() (*sql.Tx, error)
+	BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error)
 }
 
 // transaction ending