// Tx returns a copy of the store that runs in the context of the given
// transaction.
func (s *store) Tx(tx db.Tx) Store {
return &store{
Collection: tx.C(s.Collection.Name()),
session: &session{
Database: tx,
stores: make(map[string]*store),
},
}
}
// Benchmarking Append() with transactions.
func BenchmarkAppendTxUpper(b *testing.B) {
var sess db.Database
var err error
if sess, err = db.Open(Adapter, settings); err != nil {
b.Fatal(err)
}
defer sess.Close()
var tx db.Tx
if tx, err = sess.Transaction(); err != nil {
b.Fatal(err)
}
var artist db.Collection
if artist, err = tx.Collection("artist"); err != nil {
b.Fatal(err)
}
if err = artist.Truncate(); err != nil {
b.Fatal(err)
}
item := struct {
Name string `db:"name"`
}{"Hayao Miyazaki"}
b.ResetTimer()
for i := 0; i < b.N; i++ {
if _, err = artist.Append(item); err != nil {
b.Fatal(err)
}
}
if err = tx.Commit(); err != nil {
b.Fatal(err)
}
}
// Attempts to test database transactions.
func TestTransactionsAndRollback(t *testing.T) {
var sess db.Database
var err error
type artistType struct {
ID int64 `db:"id,omitempty"`
Name string `db:"name"`
}
if sess, err = db.Open(Adapter, settings); err != nil {
t.Fatal(err)
}
defer sess.Close()
// Simple transaction that should not fail.
var tx db.Tx
if tx, err = sess.Transaction(); err != nil {
t.Fatal(err)
}
var artist db.Collection
if artist, err = tx.Collection("artist"); err != nil {
t.Fatal(err)
}
if err = artist.Truncate(); err != nil {
t.Fatal(err)
}
// Simple transaction
if _, err = artist.Append(artistType{1, "First"}); err != nil {
t.Fatal(err)
}
if err = tx.Commit(); err != nil {
t.Fatal(err)
}
// Attempt to use the same transaction should fail.
if _, err = tx.Collection("artist"); err == nil {
t.Fatalf("Illegal, transaction has already been commited.")
}
// Use another transaction.
if tx, err = sess.Transaction(); err != nil {
t.Fatal(err)
}
if artist, err = tx.Collection("artist"); err != nil {
t.Fatal(err)
}
// Won't fail.
if _, err = artist.Append(artistType{2, "Second"}); err != nil {
t.Fatal(err)
}
// Won't fail.
if _, err = artist.Append(artistType{3, "Third"}); err != nil {
t.Fatal(err)
}
// Will fail.
if _, err = artist.Append(artistType{1, "Duplicated"}); err == nil {
t.Fatal("Should have failed, as we have already inserted ID 1.")
}
if err = tx.Rollback(); err != nil {
t.Fatal(err)
}
if err = tx.Commit(); err == nil {
t.Fatalf("Should have failed, as we've already rolled back.")
}
// Let's verify we still have one element.
if artist, err = sess.Collection("artist"); err != nil {
t.Fatal(err)
}
var count uint64
if count, err = artist.Find().Count(); err != nil {
t.Fatal(err)
}
if count != 1 {
t.Fatalf("Expecting only one element.")
}
// Attempt to add some rows.
if tx, err = sess.Transaction(); err != nil {
t.Fatal(err)
}
if artist, err = tx.Collection("artist"); err != nil {
t.Fatal(err)
}
// Won't fail.
if _, err = artist.Append(artistType{2, "Second"}); err != nil {
t.Fatal(err)
}
// Won't fail.
if _, err = artist.Append(artistType{3, "Third"}); err != nil {
t.Fatal(err)
}
// Then rollback for no reason.
if err = tx.Rollback(); err != nil {
t.Fatal(err)
}
if err = tx.Commit(); err == nil {
t.Fatalf("Should have failed, as we've already rolled back.")
}
// Let's verify we still have one element.
if artist, err = sess.Collection("artist"); err != nil {
t.Fatal(err)
}
if count, err = artist.Find().Count(); err != nil {
t.Fatal(err)
}
if count != 1 {
t.Fatalf("Expecting only one element.")
}
// Attempt to add some rows.
if tx, err = sess.Transaction(); err != nil {
t.Fatal(err)
}
if artist, err = tx.Collection("artist"); err != nil {
t.Fatal(err)
}
// Won't fail.
if _, err = artist.Append(artistType{2, "Second"}); err != nil {
t.Fatal(err)
}
// Won't fail.
if _, err = artist.Append(artistType{3, "Third"}); err != nil {
t.Fatal(err)
}
if err = tx.Commit(); err != nil {
t.Fatal(err)
}
if err = tx.Rollback(); err == nil {
t.Fatalf("Should have failed, as we've already commited.")
}
// Let's verify we have 3 rows.
if artist, err = sess.Collection("artist"); err != nil {
t.Fatal(err)
}
if count, err = artist.Find().Count(); err != nil {
t.Fatal(err)
}
if count != 3 {
t.Fatalf("Expecting 3 elements.")
}
}