From 01b05745d8ea16efaeb71b4bb68e7b65355e1598 Mon Sep 17 00:00:00 2001
From: crazycs <crazycs520@gmail.com>
Date: Thu, 1 Apr 2021 22:05:24 +0800
Subject: [PATCH] execdetails: refine cop task execution stats display in plan
 (#23461)

---
 distsql/select_result_test.go        |  2 +-
 executor/explainfor_test.go          |  2 +-
 util/execdetails/execdetails.go      | 11 +++++++----
 util/execdetails/execdetails_test.go |  8 ++++++--
 4 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/distsql/select_result_test.go b/distsql/select_result_test.go
index 38a57ebe94..2046f53c51 100644
--- a/distsql/select_result_test.go
+++ b/distsql/select_result_test.go
@@ -48,5 +48,5 @@ func (s *testSuite) TestUpdateCopRuntimeStats(c *C) {
 	c.Assert(ctx.GetSessionVars().StmtCtx.RuntimeStatsColl, NotNil)
 	c.Assert(len(sr.selectResp.GetExecutionSummaries()), Equals, len(sr.copPlanIDs))
 	sr.updateCopRuntimeStats(context.Background(), &copr.CopRuntimeStats{ExecDetails: execdetails.ExecDetails{CalleeAddress: "callee"}}, 0)
-	c.Assert(ctx.GetSessionVars().StmtCtx.RuntimeStatsColl.GetOrCreateCopStats(1234, "tikv").String(), Equals, "tikv_task:{time:1ns, loops:1}, scan_detail: {total_process_keys: 0, total_keys: 0, rocksdb: {delete_skipped_count: 0, key_skipped_count: 0, block: {cache_hit_count: 0, read_count: 0, read_byte: 0 Bytes}}}")
+	c.Assert(ctx.GetSessionVars().StmtCtx.RuntimeStatsColl.GetOrCreateCopStats(1234, "tikv").String(), Equals, "tikv_task:{time:1ns, loops:1}")
 }
diff --git a/executor/explainfor_test.go b/executor/explainfor_test.go
index 9aa42dda62..a113200a92 100644
--- a/executor/explainfor_test.go
+++ b/executor/explainfor_test.go
@@ -113,7 +113,7 @@ func (s *testSerialSuite) TestExplainFor(c *C) {
 		}
 		c.Assert(buf.String(), Matches, ""+
 			"TableReader_5 10000.00 0 root  time:.*, loops:1, cop_task: {num:.*, max:.*, proc_keys: 0, rpc_num: 1, rpc_time:.*} data:TableFullScan_4 N/A N/A\n"+
-			"└─TableFullScan_4 10000.00 0 cop.* table:t1 tikv_task:{time:.*, loops:0}, scan_detail:.* keep order:false, stats:pseudo N/A N/A")
+			"└─TableFullScan_4 10000.00 0 cop.* table:t1 tikv_task:{time:.*, loops:0} keep order:false, stats:pseudo N/A N/A")
 	}
 	tkRoot.MustQuery("select * from t1;")
 	check()
diff --git a/util/execdetails/execdetails.go b/util/execdetails/execdetails.go
index 322b639f3c..010b301963 100644
--- a/util/execdetails/execdetails.go
+++ b/util/execdetails/execdetails.go
@@ -243,9 +243,11 @@ func (sd *ScanDetail) Merge(scanDetail *ScanDetail) {
 	atomic.AddUint64(&sd.RocksdbBlockReadByte, scanDetail.RocksdbBlockReadByte)
 }
 
+var zeroScanDetail = ScanDetail{}
+
 // String implements the fmt.Stringer interface.
 func (sd *ScanDetail) String() string {
-	if sd == nil {
+	if sd == nil || *sd == zeroScanDetail {
 		return ""
 	}
 	buf := bytes.NewBuffer(make([]byte, 0, 16))
@@ -612,10 +614,11 @@ func (crs *CopRuntimeStats) String() string {
 			buf.WriteString("}")
 		}
 	}
-	if !isTiFlashCop {
-		if detail := crs.scanDetail; detail != nil {
+	if !isTiFlashCop && crs.scanDetail != nil {
+		detail := crs.scanDetail.String()
+		if detail != "" {
 			buf.WriteString(", ")
-			buf.WriteString(detail.String())
+			buf.WriteString(detail)
 		}
 	}
 	return buf.String()
diff --git a/util/execdetails/execdetails_test.go b/util/execdetails/execdetails_test.go
index 4702ba3439..702cdf4d07 100644
--- a/util/execdetails/execdetails_test.go
+++ b/util/execdetails/execdetails_test.go
@@ -130,8 +130,7 @@ func TestCopRuntimeStats(t *testing.T) {
 		t.Fatalf("cop stats string is not expect, got: %v", copStats[0].String())
 	}
 
-	if stats.GetOrCreateCopStats(aggID, "tikv").String() != "tikv_task:{proc max:4ns, min:3ns, p80:4ns, p95:4ns, iters:7, tasks:2}, "+
-		"scan_detail: {total_process_keys: 0, total_keys: 0, rocksdb: {delete_skipped_count: 0, key_skipped_count: 0, block: {cache_hit_count: 0, read_count: 0, read_byte: 0 Bytes}}}" {
+	if stats.GetOrCreateCopStats(aggID, "tikv").String() != "tikv_task:{proc max:4ns, min:3ns, p80:4ns, p95:4ns, iters:7, tasks:2}" {
 		t.Fatalf("agg cop stats string is not as expected, got: %v", stats.GetOrCreateCopStats(aggID, "tikv").String())
 	}
 	rootStats := stats.GetRootStats(tableReaderID)
@@ -150,6 +149,11 @@ func TestCopRuntimeStats(t *testing.T) {
 		"scan_detail: {total_process_keys: 0, total_keys: 15, rocksdb: {delete_skipped_count: 5, key_skipped_count: 0, block: {cache_hit_count: 10, read_count: 0, read_byte: 100 Bytes}}}" {
 		t.Fatalf(cop.String())
 	}
+
+	zeroScanDetail := ScanDetail{}
+	if zeroScanDetail.String() != "" {
+		t.Fatalf(zeroScanDetail.String())
+	}
 }
 
 func TestCopRuntimeStatsForTiFlash(t *testing.T) {