From bb86d7e2231a9c64b2792f58d45d6a2cdf39190b Mon Sep 17 00:00:00 2001
From: jiashuo <js982986555@live.com>
Date: Sat, 8 May 2021 11:07:56 +0800
Subject: [PATCH] add dassert

---
 pegasus/scanner.go | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pegasus/scanner.go b/pegasus/scanner.go
index a453b35..e707f74 100644
--- a/pegasus/scanner.go
+++ b/pegasus/scanner.go
@@ -29,9 +29,9 @@ type ScannerOptions struct {
 const (
 	batchScanning     = 0
 	batchScanFinished = -1 // Scanner's batch is finished, clean up it and switch to the status batchEmpty
-	batchEmpty        = -2
-	batchRpcError     = -3
-	batchUnknownError = -4
+	batchEmpty        = -2 // scan context has been removed
+	batchRpcError     = -3 // rpc error, include ERR_SESSION_RESET,ERR_OBJECT_NOT_FOUND,ERR_INVALID_STATE, ERR_TIMEOUT
+	batchUnknownError = -4 // rpc succeed, but operation encounter some unknown error in server side
 )
 
 // Scanner defines the interface of client-side scanning.