Merge branch 'main' into 18842-arv-mount-disk-config

[arvados.git] / lib / ctrlctx / db.go

diff --git a/lib/ctrlctx/db.go b/lib/ctrlctx/db.go
index 127be489df3a27e553f6aa421a6f1c40cdbdcc55..2a05096ce18b7430e7e1e487dd5d710024ac9193 100644 (file)
--- 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"
 )
 
@@ -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 +143,33 @@ 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")
+               return nil, errDBConnection
+       }
+       dbc.pgdb = db
+       return db, nil
+}