refactor: split ior.go mega-file into focused files (task 427)

ior.go had 763 lines covering 9+ concerns. Follow the eventloop_*.go
pattern and extract into three focused files:

- ior_bpfsetup.go: libbpfTracepoint{Program,Module} adapter types,
  setupBPFModule, setupBPFModuleError, setupEventChannel

- ior_profiling.go: profilingControl type, setupProfiling,
  profilingFilesForMode, stop()

- ior_parquet_sink.go: headlessParquetSink type, runHeadlessParquet,
  isHeadlessParquetMode, hasHeadlessParquetContentFilters,
  headlessParquetTraceConfig; inline parquetMetadata one-liner

ior.go shrinks from 763 → 453 lines, retaining entry, dispatch,
TUI wiring, and core trace execution.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/internal/ior_bpfsetup.go b/internal/ior_bpfsetup.go
new file mode 100644
index 0000000..cf0b112
--- /dev/null
+++ b/internal/ior_bpfsetup.go
@@ -0,0 +1,89 @@
+package internal
+
+import (
+	"context"
+	"fmt"
+
+	appconfig "ior/internal/config"
+	"ior/internal/flags"
+	"ior/internal/probemanager"
+	"ior/internal/tracepoints"
+	"ior/internal/tui"
+
+	bpf "github.com/aquasecurity/libbpfgo"
+)
+
+// libbpfTracepointProgram wraps a libbpf BPF program as a probemanager.Program.
+type libbpfTracepointProgram struct {
+	prog *bpf.BPFProg
+}
+
+func (p libbpfTracepointProgram) AttachTracepoint(category, name string) (probemanager.Link, error) {
+	return p.prog.AttachTracepoint(category, name)
+}
+
+// libbpfTracepointModule wraps a libbpf BPF module as a probemanager.Module.
+type libbpfTracepointModule struct {
+	module *bpf.Module
+}
+
+func (m libbpfTracepointModule) GetProgram(progName string) (probemanager.Program, error) {
+	prog, err := m.module.GetProgram(progName)
+	if err != nil {
+		return nil, err
+	}
+	return libbpfTracepointProgram{prog: prog}, nil
+}
+
+func setupBPFModuleError(stage string, err error) error {
+	if err == nil {
+		return nil
+	}
+	return fmt.Errorf("setup BPF module: %s: %w", stage, err)
+}
+
+// setupBPFModule loads and attaches the BPF module, attaching tracepoints
+// and registering the probe manager with any TUI runtime bindings.
+func setupBPFModule(parentCtx context.Context, cfg flags.Config) (*bpf.Module, *probemanager.Manager, func(), error) {
+	releaseBindings := func() {}
+
+	bpfModule, stage, err := loadBPFModule()
+	if err != nil {
+		return nil, nil, releaseBindings, setupBPFModuleError(stage, err)
+	}
+	if err := resizeBPFMaps(cfg, bpfModule); err != nil {
+		bpfModule.Close()
+		return nil, nil, releaseBindings, setupBPFModuleError("resize maps", err)
+	}
+	if err := setBPFGlobals(cfg, bpfModule); err != nil {
+		bpfModule.Close()
+		return nil, nil, releaseBindings, setupBPFModuleError("set globals", err)
+	}
+	if err := bpfModule.BPFLoadObject(); err != nil {
+		bpfModule.Close()
+		return nil, nil, releaseBindings, setupBPFModuleError("load object", err)
+	}
+
+	mgr := probemanager.NewManager(libbpfTracepointModule{module: bpfModule})
+	if err := mgr.AttachAll(cfg.ShouldIAttachTracepoint, tracepoints.List); err != nil {
+		mgr.Close()
+		bpfModule.Close()
+		return nil, nil, releaseBindings, setupBPFModuleError("attach probes", err)
+	}
+	if bindings, ok := tui.RuntimeBindingsFromContext(parentCtx); ok {
+		bindings.SetProbeManager(mgr)
+		releaseBindings = func() { bindings.SetProbeManager(nil) }
+	}
+	return bpfModule, mgr, releaseBindings, nil
+}
+
+// setupEventChannel initialises the BPF ring-buffer and returns the event channel.
+func setupEventChannel(bpfModule *bpf.Module) (chan []byte, error) {
+	ch := make(chan []byte, appconfig.DefaultChannelBufferSize)
+	rb, err := bpfModule.InitRingBuf("event_map", ch)
+	if err != nil {
+		return nil, err
+	}
+	rb.Poll(300)
+	return ch, nil
+}