Only retry an INSERT operation on unique constraint violation

The retry logic is used to generate an unique ID, but if there is
another error the DB code can fall into an infinite loop.

Signed-off-by: IWAMOTO Toshihiro <iwamoto@valinux.co.jp>

pkg/db/interface.go

@@ -109,6 +109,14 @@ func generateRandid() string {
 	return string(rs1Letters[rand.Intn(len(rs1Letters))]) + fmt.Sprintf("%016x", id)[1:]
 }
 
+func isDBDuplicateError(err error) bool {
+	errmsg := strings.ToLower(err.Error())
+	if strings.Contains(errmsg, "unique") || strings.Contains(errmsg, "duplicate") {
+		return true
+	}
+	return false
+}
+
 func (d *dbConn) GetStudyConfig(id string) (*api.StudyConfig, error) {
 	row := d.db.QueryRow("SELECT * FROM studies WHERE id = ?", id)
 
@@ -240,13 +248,10 @@ func (d *dbConn) CreateStudy(in *api.StudyConfig) (string, error) {
 		)
 		if err == nil {
 			break
-		} else {
-			errmsg := strings.ToLower(err.Error())
-			if strings.Contains(errmsg, "unique") || strings.Contains(errmsg, "duplicate") {
-				i--
-				if i > 0 {
-					continue
-				}
+		} else if isDBDuplicateError(err) {
+			i--
+			if i > 0 {
+				continue
 			}
 		}
 		return "", err
@@ -387,13 +392,10 @@ func (d *dbConn) CreateTrial(trial *api.Trial) error {
 		if err == nil {
 			trial.TrialId = trialID
 			break
-		} else {
-			errmsg := strings.ToLower(err.Error())
-			if strings.Contains(errmsg, "unique") || strings.Contains(errmsg, "duplicate") {
-				i--
-				if i > 0 {
-					continue
-				}
+		} else if isDBDuplicateError(err) {
+			i--
+			if i > 0 {
+				continue
 			}
 		}
 		return err
@@ -728,13 +730,10 @@ func (d *dbConn) CreateWorker(worker *api.Worker) (string, error) {
 		if err == nil {
 			worker.WorkerId = workerID
 			break
-		} else {
-			errmsg := strings.ToLower(err.Error())
-			if strings.Contains(errmsg, "unique") || strings.Contains(errmsg, "duplicate") {
-				i--
-				if i > 0 {
-					continue
-				}
+		} else if isDBDuplicateError(err) {
+			i--
+			if i > 0 {
+				continue
 			}
 		}
 		return "", err
@@ -915,7 +914,7 @@ func (d *dbConn) SetSuggestionParam(algorithm string, studyID string, params []*
 		paramID = generateRandid()
 		_, err = d.db.Exec("INSERT INTO suggestion_param VALUES (?, ?, ?, ?)",
 			paramID, algorithm, studyID, strings.Join(ps, ",\n"))
-		if err == nil {
+		if err == nil || !isDBDuplicateError(err) {
 			break
 		}
 	}
@@ -1023,7 +1022,7 @@ func (d *dbConn) SetEarlyStopParam(algorithm string, studyID string, params []*a
 		paramID := generateRandid()
 		_, err = d.db.Exec("INSERT INTO earlystopping_param VALUES (?,?, ?, ?)",
 			paramID, algorithm, studyID, strings.Join(ps, ",\n"))
-		if err == nil {
+		if err == nil || !isDBDuplicateError(err) {
 			break
 		}
 	}