Add index name and persist sort columns (siglens#2018)

* Add index name and persist sort columns

* Addressed Comments

pkg/segment/sortindex/sortindex.go

@@ -29,6 +29,7 @@ import (
 	"sort"
 	"sync"
 
+	"github.com/siglens/siglens/pkg/config"
 	"github.com/siglens/siglens/pkg/segment/reader/segread/segreader"
 	segutils "github.com/siglens/siglens/pkg/segment/utils"
 	"github.com/siglens/siglens/pkg/utils"
@@ -41,13 +42,10 @@ type Block struct {
 	RecNums  []uint16 `json:"recNums"`
 }
 
-type SortColumnConfig struct {
-	columns []string
-	mu      sync.RWMutex
-}
+var sortConfigMutex sync.RWMutex
 
-var sortConfig = &SortColumnConfig{
-	columns: make([]string, 0),
+type SortColumnsConfig struct {
+	Indexes map[string][]string `json:"indexes"`
 }
 
 var VERSION_SORT_INDEX = []byte{1}
@@ -67,6 +65,10 @@ const (
 
 var AllSortModes = []SortMode{SortAsAuto, SortAsNumeric, SortAsString}
 
+func getSortColumnsConfigPath() string {
+	return filepath.Join(config.GetDataPath(), "common", "sort_columns.json")
+}
+
 func (sm SortMode) String() string {
 	switch sm {
 	case SortAsAuto:
@@ -658,37 +660,93 @@ func readMetadata(file *os.File) (*metadata, error) {
 	return meta, nil
 }
 
-func SetSortColumns(columnNames []string) error {
-	sortConfig.mu.Lock()
-	defer sortConfig.mu.Unlock()
+func SetSortColumns(indexName string, columnNames []string) error {
+	configPath := getSortColumnsConfigPath()
+
+	sortConfigMutex.Lock()
+	defer sortConfigMutex.Unlock()
+
+	dir := filepath.Dir(configPath)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return fmt.Errorf("SetSortColumns: failed to create config directory: %v", err)
+	}
 
-	// TODO: Persist sort column names to disk
 	for _, col := range columnNames {
 		if col == "" {
 			return fmt.Errorf("SetSortColumns: column names must be non-empty strings")
 		}
 	}
 
-	sortConfig.columns = columnNames
+	config := SortColumnsConfig{
+		Indexes: make(map[string][]string),
+	}
+
+	data, err := os.ReadFile(configPath)
+	if err == nil {
+		if err := json.Unmarshal(data, &config); err != nil {
+			return fmt.Errorf("SetSortColumns: failed to parse sort columns config: %v", err)
+		}
+	}
+
+	config.Indexes[indexName] = columnNames
+
+	data, err = json.MarshalIndent(config, "", "    ")
+	if err != nil {
+		return fmt.Errorf("SetSortColumns: failed to marshal sort columns config: %v", err)
+	}
+
+	err = os.WriteFile(configPath, data, 0644)
+	if err != nil {
+		return fmt.Errorf("SetSortColumns: failed to write sort columns config: %v", err)
+	}
 
 	return nil
 }
 
-func GetSortColumns() []string {
-	sortConfig.mu.RLock()
-	defer sortConfig.mu.RUnlock()
-	return sortConfig.columns
+func GetSortColumnNamesForIndex(indexName string) []string {
+	configPath := getSortColumnsConfigPath()
+
+	sortConfigMutex.RLock()
+	defer sortConfigMutex.RUnlock()
+
+	data, err := os.ReadFile(configPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			log.Debugf("GetSortColumnNamesForIndex: no sort columns config file found: %v", err)
+		} else {
+			log.Errorf("GetSortColumnNamesForIndex: error reading config file: %v", err)
+		}
+		return make([]string, 0)
+	}
+
+	var config SortColumnsConfig
+	if err := json.Unmarshal(data, &config); err != nil {
+		log.Errorf("GetSortColumnNamesForIndex: failed to parse sort columns config: %v", err)
+		return make([]string, 0)
+	}
+
+	return config.Indexes[indexName]
 }
 
 func SetSortColumnsAPI(ctx *fasthttp.RequestCtx) {
-	var columns []string
-	if err := json.Unmarshal(ctx.PostBody(), &columns); err != nil {
+	var request struct {
+		IndexName string   `json:"indexName"`
+		Columns   []string `json:"columns"`
+	}
+
+	if err := json.Unmarshal(ctx.PostBody(), &request); err != nil {
 		ctx.SetStatusCode(fasthttp.StatusBadRequest)
 		ctx.SetBodyString("Invalid request body: " + err.Error())
 		return
 	}
 
-	if err := SetSortColumns(columns); err != nil {
+	if request.IndexName == "" {
+		ctx.SetStatusCode(fasthttp.StatusBadRequest)
+		ctx.SetBodyString("Missing index name")
+		return
+	}
+
+	if err := SetSortColumns(request.IndexName, request.Columns); err != nil {
 		ctx.SetStatusCode(fasthttp.StatusInternalServerError)
 		ctx.SetBodyString("Failed to set sort columns: " + err.Error())
 		return

pkg/segment/writer/segstore.go

@@ -828,7 +828,7 @@ func (segstore *SegStore) checkAndRotateColFiles(streamid string, forceRotate bo
 		updateRecentlyRotatedSegmentFiles(segstore.SegmentKey)
 		metadata.AddSegMetaToMetadata(&segmeta)
 
-		go writeSortIndexes(segstore.SegmentKey)
+		go writeSortIndexes(segstore.SegmentKey, segstore.VirtualTableName)
 
 		if blobErr == nil {
 			// upload ingest node dir to s3
@@ -847,13 +847,13 @@ func (segstore *SegStore) checkAndRotateColFiles(streamid string, forceRotate bo
 	return nil
 }
 
-func writeSortIndexes(segkey string) {
+func writeSortIndexes(segkey string, indexName string) {
 
 	if config.IsSortIndexEnabled() {
 		sortedIndexWG.Add(1)
 		defer sortedIndexWG.Done()
 
-		for _, cname := range sortindex.GetSortColumns() {
+		for _, cname := range sortindex.GetSortColumnNamesForIndex(indexName) {
 			err := sortindex.WriteSortIndex(segkey, cname, sortindex.AllSortModes)
 			if err != nil {
 				log.Errorf("writeSortIndexes: failed to write sort index for segkey=%v, cname=%v; err=%v",