added select auto fail/retry

daos/base_retry_test.go

@@ -0,0 +1,60 @@
+package daos
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestGetDefaultRetryInterval(t *testing.T) {
+	if i := getDefaultRetryInterval(-1); i.Milliseconds() != 1500 {
+		t.Fatalf("Expected 1500ms, got %v", i)
+	}
+
+	if i := getDefaultRetryInterval(999); i.Milliseconds() != 1500 {
+		t.Fatalf("Expected 1500ms, got %v", i)
+	}
+
+	if i := getDefaultRetryInterval(3); i.Milliseconds() != 500 {
+		t.Fatalf("Expected 500ms, got %v", i)
+	}
+}
+
+func TestBaseLockRetry(t *testing.T) {
+	scenarios := []struct {
+		err              error
+		failUntilAttempt int
+		expectedAttempts int
+	}{
+		{nil, 3, 1},
+		{errors.New("test"), 3, 1},
+		{errors.New("database is locked"), 3, 3},
+	}
+
+	for i, s := range scenarios {
+		lastAttempt := 0
+
+		err := baseLockRetry(func(attempt int) error {
+			lastAttempt = attempt
+
+			if attempt < s.failUntilAttempt {
+				return s.err
+			}
+
+			return nil
+		}, s.failUntilAttempt+2)
+
+		if lastAttempt != s.expectedAttempts {
+			t.Errorf("[%d] Expected lastAttempt to be %d, got %d", i, s.expectedAttempts, lastAttempt)
+		}
+
+		if s.failUntilAttempt == s.expectedAttempts && err != nil {
+			t.Errorf("[%d] Expected nil, got err %v", i, err)
+			continue
+		}
+
+		if s.failUntilAttempt != s.expectedAttempts && s.err != nil && err == nil {
+			t.Errorf("[%d] Expected error %q, got nil", i, s.err)
+			continue
+		}
+	}
+}