Minor changes from self review

Signed-off-by: Matt Lord <[email protected]>

go/textutil/strings.go

@@ -142,14 +142,17 @@ func Title(s string) string {
 		s)
 }
 
+// TruncateText truncates the provided text to the specified length using the
+// provided indicator in place of the truncated text in the specified location
+// of the original.
 func TruncateText(text string, maxLen int, location TruncationLocation, truncationIndicator string) (string, error) {
-	if len(truncationIndicator)+2 >= maxLen {
-		return "", fmt.Errorf("the truncation indicator is too long for the provided text")
-	}
 	ol := len(text)
 	if ol <= maxLen {
 		return text, nil
 	}
+	if len(truncationIndicator)+2 >= maxLen {
+		return "", fmt.Errorf("the truncation indicator is too long for the provided text")
+	}
 	switch location {
 	case TruncationLocationMiddle:
 		prefix := int((float64(maxLen) * 0.5) - float64(len(truncationIndicator)))

go/textutil/strings_test.go

@@ -280,6 +280,7 @@ func TestTruncateText(t *testing.T) {
 			} else {
 				require.NoError(t, err)
 				require.Equal(t, tt.want, val)
+				require.LessOrEqual(t, len(val), tt.maxLen)
 			}
 		})
 	}

go/vt/vttablet/tabletmanager/vreplication/utils.go

@@ -34,14 +34,17 @@ import (
 
 const (
 	vreplicationLogTableName = "vreplication_log"
+	// Truncate values in the middle to preserve the end of the message which typically contains the
+	// error text.
+	truncationLocation = textutil.TruncationLocationMiddle
 	// This comes from the fact that the message column in the vreplication_log table is of type TEXT.
 	maxVReplicationLogMessageLen = 65535
 	// This comes from the fact that the message column in the vreplication table is varbinary(1000).
 	maxVReplicationMessageLen = 1000
 )
 
 // vrepliationLogTruncationStr is the string that is used to indicate that a message has been
-// truncated, in the middle, before being inserted into the vreplication_log table.
+// truncated before being inserted into one of the vreplication sidecar tables.
 var vreplicationLogTruncationStr = fmt.Sprintf(" ... %s ... ", sqlparser.TruncationText)
 
 const (
@@ -111,7 +114,7 @@ func insertLog(dbClient *vdbClient, typ string, vreplID int32, state, message st
 		// We perform the truncation, if needed, in the middle of the message as the end of the message is likely to
 		// be the most important part as it often explains WHY we e.g. failed to execute an INSERT in the workflow.
 		if len(message) > maxVReplicationLogMessageLen {
-			message, err = textutil.TruncateText(message, maxVReplicationLogMessageLen, textutil.TruncationLocationMiddle, vreplicationLogTruncationStr)
+			message, err = textutil.TruncateText(message, maxVReplicationLogMessageLen, truncationLocation, vreplicationLogTruncationStr)
 			if err != nil {
 				log.Errorf("Could not insert vreplication_log record because we failed to truncate the message: %v", err)
 				return

go/vt/vttablet/tabletmanager/vreplication/utils_test.go

@@ -81,7 +81,7 @@ func TestInsertLogTruncation(t *testing.T) {
 				err        error
 			)
 			if tc.expectTruncation {
-				messageOut, err = textutil.TruncateText(tc.message, maxVReplicationLogMessageLen, textutil.TruncationLocationMiddle, vreplicationLogTruncationStr)
+				messageOut, err = textutil.TruncateText(tc.message, maxVReplicationLogMessageLen, truncationLocation, vreplicationLogTruncationStr)
 				require.NoError(t, err)
 				require.True(t, strings.HasPrefix(messageOut, tc.message[:1024]))                 // Confirm we still have the same beginning
 				require.True(t, strings.HasSuffix(messageOut, tc.message[len(tc.message)-1024:])) // Confirm we still have the same end

go/vt/vttablet/tabletmanager/vreplication/vreplicator.go

@@ -452,7 +452,7 @@ func (vr *vreplicator) readSettings(ctx context.Context, dbClient *vdbClient) (s
 }
 
 func (vr *vreplicator) setMessage(message string) (err error) {
-	message, err = textutil.TruncateText(message, maxVReplicationMessageLen, textutil.TruncationLocationMiddle, vreplicationLogTruncationStr)
+	message, err = textutil.TruncateText(message, maxVReplicationMessageLen, truncationLocation, vreplicationLogTruncationStr)
 	if err != nil {
 		return err
 	}