lib/logstorage: properly cache replace() and replace_regexp() results for identical adjacent field values

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7162

(cherry picked from commit 2e635a42d8)

docs/VictoriaLogs/CHANGELOG.md

@@ -17,6 +17,8 @@ according to [these docs](https://docs.victoriametrics.com/victorialogs/quicksta
 
 * FEATURE: add support for extra filters across all the [HTTP querying APIs](https://docs.victoriametrics.com/victorialogs/querying/#http-api). See [these docs](https://docs.victoriametrics.com/victorialogs/querying/#extra-filters) for details. This is needed for implementing quick filtering on field values at [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7365).
 
+* BUGFIX: properly apply [`replace`](https://docs.victoriametrics.com/victorialogs/logsql/#replace-pipe) and [`replace_regexp`](https://docs.victoriametrics.com/victorialogs/logsql/#replace_regexp-pipe) pipes to identical values in adjacent log entries. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7162).
+
 ## [v0.39.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.39.0-victorialogs)
 
 Released at 2024-10-30

lib/logstorage/pipe_replace_regexp_test.go

@@ -70,6 +70,12 @@ func TestPipeReplaceRegexp(t *testing.T) {
 			{"_msg", `a_bc_d/ef`},
 			{"bar", `cde`},
 		},
+		{
+			{"_msg", `a_bc_d/ef`},
+		},
+		{
+			{"_msg", `1234`},
+		},
 		{
 			{"_msg", `1234`},
 		},
@@ -78,6 +84,12 @@ func TestPipeReplaceRegexp(t *testing.T) {
 			{"_msg", `a-bc-d-ef`},
 			{"bar", `cde`},
 		},
+		{
+			{"_msg", `a-bc-d-ef`},
+		},
+		{
+			{"_msg", `1234`},
+		},
 		{
 			{"_msg", `1234`},
 		},

lib/logstorage/pipe_replace_test.go

@@ -48,6 +48,12 @@ func TestPipeReplace(t *testing.T) {
 			{"_msg", `a_bc_def`},
 			{"bar", `cde`},
 		},
+		{
+			{"_msg", `a_bc_def`},
+		},
+		{
+			{"_msg", `1234`},
+		},
 		{
 			{"_msg", `1234`},
 		},
@@ -56,6 +62,12 @@ func TestPipeReplace(t *testing.T) {
 			{"_msg", `a-bc-def`},
 			{"bar", `cde`},
 		},
+		{
+			{"_msg", `a-bc-def`},
+		},
+		{
+			{"_msg", `1234`},
+		},
 		{
 			{"_msg", `1234`},
 		},

lib/logstorage/pipe_update.go

@@ -86,16 +86,19 @@ func (pup *pipeUpdateProcessor) writeBlock(workerID uint, br *blockResult) {
 
 	hadUpdates := false
 	vPrev := ""
+	vNew := ""
 	for rowIdx, v := range values {
 		if bm.isSetBit(rowIdx) {
 			if !hadUpdates || vPrev != v {
 				vPrev = v
 				hadUpdates = true
 
-				v = pup.updateFunc(&shard.a, v)
+				vNew = pup.updateFunc(&shard.a, v)
 			}
+			shard.rc.addValue(vNew)
+		} else {
+			shard.rc.addValue(v)
 		}
-		shard.rc.addValue(v)
 	}
 
 	br.addResultColumn(&shard.rc)