X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/865e5c1e3730117870eb1e485d553383626b882f..HEAD:/lib/ctrlctx/db.go

diff --git a/lib/ctrlctx/db.go b/lib/ctrlctx/db.go
index 127be489df..d33fd8ab53 100644
--- a/lib/ctrlctx/db.go
+++ b/lib/ctrlctx/db.go
@@ -10,8 +10,11 @@ import (
 	"sync"
 
 	"git.arvados.org/arvados.git/lib/controller/api"
+	"git.arvados.org/arvados.git/sdk/go/arvados"
 	"git.arvados.org/arvados.git/sdk/go/ctxlog"
 	"github.com/jmoiron/sqlx"
+
+	// sqlx needs lib/pq to talk to PostgreSQL
 	_ "github.com/lib/pq"
 )
 
@@ -66,7 +69,7 @@ type finishFunc func(*error)
 // commit or rollback the transaction, if any.
 //
 //	func example(ctx context.Context) (err error) {
-//		ctx, finishtx := New(ctx, dber)
+//		ctx, finishtx := New(ctx, getdb)
 //		defer finishtx(&err)
 //		// ...
 //		tx, err := CurrentTx(ctx)
@@ -106,6 +109,26 @@ func New(ctx context.Context, getdb func(context.Context) (*sqlx.DB, error)) (co
 	}
 }
 
+// NewTx starts a new transaction. The caller is responsible for
+// calling Commit or Rollback. This is suitable for database queries
+// that are separate from the API transaction (see CurrentTx), e.g.,
+// ones that will be committed even if the API call fails, or held
+// open after the API call finishes.
+func NewTx(ctx context.Context) (*sqlx.Tx, error) {
+	txn, ok := ctx.Value(contextKeyTransaction).(*transaction)
+	if !ok {
+		return nil, ErrNoTransaction
+	}
+	db, err := txn.getdb(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return db.Beginx()
+}
+
+// CurrentTx returns a transaction that will be committed after the
+// current API call completes, or rolled back if the current API call
+// returns an error.
 func CurrentTx(ctx context.Context) (*sqlx.Tx, error) {
 	txn, ok := ctx.Value(contextKeyTransaction).(*transaction)
 	if !ok {
@@ -120,3 +143,45 @@ func CurrentTx(ctx context.Context) (*sqlx.Tx, error) {
 	})
 	return txn.tx, txn.err
 }
+
+var errDBConnection = errors.New("database connection error")
+
+type DBConnector struct {
+	PostgreSQL arvados.PostgreSQL
+	pgdb       *sqlx.DB
+	mtx        sync.Mutex
+}
+
+func (dbc *DBConnector) GetDB(ctx context.Context) (*sqlx.DB, error) {
+	dbc.mtx.Lock()
+	defer dbc.mtx.Unlock()
+	if dbc.pgdb != nil {
+		return dbc.pgdb, nil
+	}
+	db, err := sqlx.Open("postgres", dbc.PostgreSQL.Connection.String())
+	if err != nil {
+		ctxlog.FromContext(ctx).WithError(err).Error("postgresql connect failed")
+		return nil, errDBConnection
+	}
+	if p := dbc.PostgreSQL.ConnectionPool; p > 0 {
+		db.SetMaxOpenConns(p)
+	}
+	if err := db.Ping(); err != nil {
+		ctxlog.FromContext(ctx).WithError(err).Error("postgresql connect succeeded but ping failed")
+		db.Close()
+		return nil, errDBConnection
+	}
+	dbc.pgdb = db
+	return db, nil
+}
+
+func (dbc *DBConnector) Close() error {
+	dbc.mtx.Lock()
+	defer dbc.mtx.Unlock()
+	var err error
+	if dbc.pgdb != nil {
+		err = dbc.pgdb.Close()
+		dbc.pgdb = nil
+	}
+	return err
+}