config: centralize default buffer sizes (task 388)

3 files changed, 15 insertions, 4 deletions

diff --git a/internal/config/buffers.go b/internal/config/buffers.go
new file mode 100644
index 0000000..61986d8
--- /dev/null
+++ b/internal/config/buffers.go
@@ -0,0 +1,10 @@
+package config
+
+const (
+	// DefaultChannelBufferSize is the shared default for high-volume trace and
+	// TUI event channels.
+	DefaultChannelBufferSize = 4096
+
+	// DefaultEventMapSize is the default BPF event ring-buffer map size.
+	DefaultEventMapSize = DefaultChannelBufferSize * 16
+)
diff --git a/internal/flags/flags.go b/internal/flags/flags.go
index 50a5926..df4187c 100644
--- a/internal/flags/flags.go
+++ b/internal/flags/flags.go
@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"ior/internal/collapse"
+	appconfig "ior/internal/config"
 	"ior/internal/globalfilter"
 )
 
@@ -56,7 +57,7 @@ func NewFlags() Config {
 	return Config{
 		PidFilter:       -1,
 		TidFilter:       -1,
-		EventMapSize:    4096 * 16,
+		EventMapSize:    appconfig.DefaultEventMapSize,
 		Duration:        900,
 		LiveInterval:    200 * time.Millisecond,
 		TUIExportEnable: true,
diff --git a/internal/ior.go b/internal/ior.go
index 8258f01..c14ab37 100644
--- a/internal/ior.go
+++ b/internal/ior.go
@@ -15,6 +15,7 @@ import (
 	"syscall"
 	"time"
 
+	appconfig "ior/internal/config"
 	"ior/internal/event"
 	"ior/internal/flags"
 	"ior/internal/flamegraph"
@@ -201,7 +202,7 @@ func tuiTraceStarterFromRunTrace(
 			bindings.SetEventStreamSource(streamSource)
 			bindings.SetLiveTrie(liveTrie)
 		}
-		streamEvents := make(chan eventstream.StreamEvent, 4096)
+		streamEvents := make(chan eventstream.StreamEvent, appconfig.DefaultChannelBufferSize)
 
 		go func() {
 			for ev := range streamEvents {
@@ -372,8 +373,7 @@ func setupBPFModule(parentCtx context.Context, cfg flags.Config) (*bpf.Module, *
 }
 
 func setupEventChannel(bpfModule *bpf.Module) (chan []byte, error) {
-	// 4096 channel size minimizes event drops.
-	ch := make(chan []byte, 4096)
+	ch := make(chan []byte, appconfig.DefaultChannelBufferSize)
 	rb, err := bpfModule.InitRingBuf("event_map", ch)
 	if err != nil {
 		return nil, err