From 0c0f013a60c812f46df1b8fa2863d1038e0e0208 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@victoriametrics.com>
Date: Mon, 30 Sep 2024 14:06:20 +0200
Subject: [PATCH] lib/logstorage: skip values with zero hits for 'uniq', 'top'
 and 'field_values' pipes

See https://github.com/VictoriaMetrics/victorialogs-datasource/issues/72#issuecomment-2352078483
---
 docs/VictoriaLogs/CHANGELOG.md |  2 ++
 lib/logstorage/pipe_top.go     |  4 ++++
 lib/logstorage/pipe_uniq.go    | 32 +++++++++++++++-----------------
 3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/docs/VictoriaLogs/CHANGELOG.md b/docs/VictoriaLogs/CHANGELOG.md
index b6516630c..f01ed1c59 100644
--- a/docs/VictoriaLogs/CHANGELOG.md
+++ b/docs/VictoriaLogs/CHANGELOG.md
@@ -15,6 +15,8 @@ according to [these docs](https://docs.victoriametrics.com/victorialogs/quicksta
 
 ## tip
 
+* BUGFIX: do not return field values with zero matching logs from [`field_values`](https://docs.victoriametrics.com/victorialogs/logsql/#field_values-pipe), [`top`](https://docs.victoriametrics.com/victorialogs/logsql/#top-pipe) and [`uniq`](https://docs.victoriametrics.com/victorialogs/logsql/#uniq-pipe) pipes. See [this issue](https://github.com/VictoriaMetrics/victorialogs-datasource/issues/72#issuecomment-2352078483).
+
 ## [v0.32.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.32.0-victorialogs)
 
 Released at 2024-09-29
diff --git a/lib/logstorage/pipe_top.go b/lib/logstorage/pipe_top.go
index 034038b0a..fb196cacb 100644
--- a/lib/logstorage/pipe_top.go
+++ b/lib/logstorage/pipe_top.go
@@ -207,6 +207,10 @@ func (shard *pipeTopProcessorShard) writeBlock(br *blockResult) {
 }
 
 func (shard *pipeTopProcessorShard) updateState(v string, hits uint64) {
+	if hits == 0 {
+		return
+	}
+
 	m := shard.getM()
 	pHits, ok := m[v]
 	if !ok {
diff --git a/lib/logstorage/pipe_uniq.go b/lib/logstorage/pipe_uniq.go
index c33cfc7f0..4803ac45a 100644
--- a/lib/logstorage/pipe_uniq.go
+++ b/lib/logstorage/pipe_uniq.go
@@ -166,24 +166,18 @@ func (shard *pipeUniqProcessorShard) writeBlock(br *blockResult) bool {
 			return true
 		}
 		if c.valueType == valueTypeDict {
-			if needHits {
-				a := encoding.GetUint64s(len(c.dictValues))
-				hits := a.A
-				clear(hits)
-				valuesEncoded := c.getValuesEncoded(br)
-				for _, v := range valuesEncoded {
-					idx := unmarshalUint8(v)
-					hits[idx]++
-				}
-				for i, v := range c.dictValues {
-					shard.updateState(v, hits[i])
-				}
-				encoding.PutUint64s(a)
-			} else {
-				for _, v := range c.dictValues {
-					shard.updateState(v, 0)
-				}
+			a := encoding.GetUint64s(len(c.dictValues))
+			hits := a.A
+			clear(hits)
+			valuesEncoded := c.getValuesEncoded(br)
+			for _, v := range valuesEncoded {
+				idx := unmarshalUint8(v)
+				hits[idx]++
 			}
+			for i, v := range c.dictValues {
+				shard.updateState(v, hits[i])
+			}
+			encoding.PutUint64s(a)
 			return true
 		}
 
@@ -230,6 +224,10 @@ func (shard *pipeUniqProcessorShard) writeBlock(br *blockResult) bool {
 }
 
 func (shard *pipeUniqProcessorShard) updateState(v string, hits uint64) {
+	if hits == 0 {
+		return
+	}
+
 	m := shard.getM()
 	pHits, ok := m[v]
 	if !ok {