Add watch mode for dynamic flamegraph updates

2 files changed, 16 insertions, 3 deletions

diff --git a/internal/flags/flags.go b/internal/flags/flags.go
index bc1654b..b2d9dce 100644
--- a/internal/flags/flags.go
+++ b/internal/flags/flags.go
@@ -71,9 +71,10 @@ type Flags struct {
 	TUIExportEnable  bool
 
 	// To convert ior data into native SVG format
-	IorDataFile     string
-	CollapsedFields []string
-	CountField      string
+	IorDataFile      string
+	IorWatchInterval time.Duration
+	CollapsedFields  []string
+	CountField       string
 }
 
 func Get() Flags {
@@ -130,6 +131,8 @@ func parse() error {
 	flag.BoolVar(&singleton.TUIExportEnable, "tuiExport", true, "Enable writing TUI snapshot export files")
 
 	flag.StringVar(&singleton.IorDataFile, "ior", "", "IOR data file to convert into native SVG flamegraph")
+	flag.DurationVar(&singleton.IorWatchInterval, "iorWatchInterval", 0,
+		"In -ior mode, poll input file for changes and regenerate outputs; also enables auto-reloading viewer")
 	fields := flag.String("fields", "",
 		fmt.Sprintf("Comma separated list of fields to collapse, valid are: %v", validCollapsedFields))
 	flag.StringVar(&singleton.CountField, "count", "count",
diff --git a/internal/flags/flags_test.go b/internal/flags/flags_test.go
index 11414d8..81d01ad 100644
--- a/internal/flags/flags_test.go
+++ b/internal/flags/flags_test.go
@@ -114,6 +114,16 @@ func TestParseFlamegraphJSONFlag(t *testing.T) {
 	}
 }
 
+func TestParseIorWatchIntervalFlag(t *testing.T) {
+	cfg, err := parseForTest(t, "-iorWatchInterval", "2s")
+	if err != nil {
+		t.Fatalf("parse returned error: %v", err)
+	}
+	if cfg.IorWatchInterval != 2*time.Second {
+		t.Fatalf("ior watch interval = %v, want %v", cfg.IorWatchInterval, 2*time.Second)
+	}
+}
+
 func TestParseDefaultCollapsedFieldsOrder(t *testing.T) {
 	cfg, err := parseForTest(t)
 	if err != nil {