all: querylog size memory

CHANGELOG.md

@@ -58,6 +58,7 @@ NOTE: Add new changes BELOW THIS COMMENT.
 
 ### Fixed
 
+- Zero value in `querylog.size_memory` disables logging ([#6570]).
 - Load balancing algorithm stuck on a single server ([#6480]).
 - Statistics for 7 days displayed as 168 hours on the dashboard.
 - Pre-filling the Edit static lease window with data ([#6534]).
@@ -71,6 +72,7 @@ NOTE: Add new changes BELOW THIS COMMENT.
 [#6534]: https://github.com/AdguardTeam/AdGuardHome/issues/6534
 [#6541]: https://github.com/AdguardTeam/AdGuardHome/issues/6541
 [#6545]: https://github.com/AdguardTeam/AdGuardHome/issues/6545
+[#6570]: https://github.com/AdguardTeam/AdGuardHome/issues/6570
 
 <!--
 NOTE: Add new changes ABOVE THIS COMMENT.

internal/home/config.go

@@ -267,7 +267,7 @@ type queryLogConfig struct {
 
 	// MemSize is the number of entries kept in memory before they are flushed
 	// to disk.
-	MemSize int `yaml:"size_memory"`
+	MemSize uint `yaml:"size_memory"`
 
 	// Enabled defines if the query log is enabled.
 	Enabled bool `yaml:"enabled"`

internal/querylog/qlog.go

@@ -202,10 +202,10 @@ func (l *queryLog) Add(params *AddParams) {
 		defer l.confMu.RUnlock()
 
 		isEnabled, fileIsEnabled = l.conf.Enabled, l.conf.FileEnabled
-		memSize = l.conf.MemSize
+		memSize = int(l.conf.MemSize)
 	}()
 
-	if !isEnabled || memSize == 0 {
+	if !isEnabled {
 		return
 	}
 

internal/querylog/querylog.go

@@ -63,7 +63,7 @@ type Config struct {
 
 	// MemSize is the number of entries kept in a memory buffer before they are
 	// flushed to disk.
-	MemSize int
+	MemSize uint
 
 	// Enabled tells if the query log is enabled.
 	Enabled bool
@@ -143,14 +143,17 @@ func newQueryLog(conf Config) (l *queryLog, err error) {
 		}
 	}
 
-	if conf.MemSize < 0 {
-		return nil, errors.Error("memory size must be greater or equal to zero")
+	memSize := int(conf.MemSize)
+	if memSize == 0 {
+		// If query log is not diabled, we still need to write entries to a
+		// file.  And all writing goes through a buffer.
+		memSize = 1
 	}
 
 	l = &queryLog{
 		findClient: findClient,
 
-		buffer: aghalg.NewRingBuffer[*logEntry](conf.MemSize),
+		buffer: aghalg.NewRingBuffer[*logEntry](memSize),
 
 		conf:    &Config{},
 		confMu:  &sync.RWMutex{},