Moved SafeTx and SafeConn to their own files

db/safetx.go

@@ -0,0 +1,61 @@
+package db
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/pkg/errors"
+)
+
+// Extends sql.Tx for use with SafeConn
+type SafeTX struct {
+	tx *sql.Tx
+	sc *SafeConn
+}
+
+// Query the database inside the transaction
+func (stx *SafeTX) Query(
+	ctx context.Context,
+	query string,
+	args ...interface{},
+) (*sql.Rows, error) {
+	if stx.tx == nil {
+		return nil, errors.New("Cannot query without a transaction")
+	}
+	return stx.tx.QueryContext(ctx, query, args...)
+}
+
+// Exec a statement on the database inside the transaction
+func (stx *SafeTX) Exec(
+	ctx context.Context,
+	query string,
+	args ...interface{},
+) (sql.Result, error) {
+	if stx.tx == nil {
+		return nil, errors.New("Cannot exec without a transaction")
+	}
+	return stx.tx.ExecContext(ctx, query, args...)
+}
+
+// Commit the current transaction and release the read lock
+func (stx *SafeTX) Commit() error {
+	if stx.tx == nil {
+		return errors.New("Cannot commit without a transaction")
+	}
+	err := stx.tx.Commit()
+	stx.tx = nil
+
+	stx.sc.releaseReadLock()
+	return err
+}
+
+// Abort the current transaction, releasing the read lock
+func (stx *SafeTX) Rollback() error {
+	if stx.tx == nil {
+		return errors.New("Cannot rollback without a transaction")
+	}
+	err := stx.tx.Rollback()
+	stx.tx = nil
+	stx.sc.releaseReadLock()
+	return err
+}