refactor: extract shared syscall stream row model

2 files changed, 185 insertions, 0 deletions

diff --git a/internal/streamrow/row.go b/internal/streamrow/row.go
new file mode 100644
index 0000000..457fcc0
--- /dev/null
+++ b/internal/streamrow/row.go
@@ -0,0 +1,137 @@
+package streamrow
+
+import (
+	"sync/atomic"
+	"time"
+
+	"ior/internal/event"
+	"ior/internal/types"
+)
+
+// Row is the shared syscall stream row model used by live TUI views,
+// snapshot export, and future recording outputs.
+type Row struct {
+	Seq        uint64
+	TimeNs     uint64
+	Syscall    string
+	Comm       string
+	PID        uint32
+	TID        uint32
+	FileName   string
+	DurationNs uint64
+	GapNs      uint64
+	Bytes      uint64
+	RetVal     int64
+	IsError    bool
+	FD         int32
+}
+
+func (r Row) SyscallValue() string {
+	return r.Syscall
+}
+
+func (r Row) CommValue() string {
+	return r.Comm
+}
+
+func (r Row) FileValue() string {
+	return r.FileName
+}
+
+func (r Row) PIDValue() uint32 {
+	return r.PID
+}
+
+func (r Row) TIDValue() uint32 {
+	return r.TID
+}
+
+func (r Row) FDValue() int32 {
+	return r.FD
+}
+
+func (r Row) LatencyValue() uint64 {
+	return r.DurationNs
+}
+
+func (r Row) GapValue() uint64 {
+	return r.GapNs
+}
+
+func (r Row) BytesValue() uint64 {
+	return r.Bytes
+}
+
+func (r Row) ReturnValue() int64 {
+	return r.RetVal
+}
+
+func (r Row) ErrorValue() bool {
+	return r.IsError
+}
+
+// UnknownFD marks events that are not associated with a file descriptor.
+const UnknownFD int32 = -1
+
+// Sequencer hands out strictly increasing row sequence numbers.
+type Sequencer struct {
+	next atomic.Uint64
+}
+
+// NewSequencer constructs a monotonic sequence generator. The first call to
+// Next returns start+1.
+func NewSequencer(start uint64) *Sequencer {
+	s := &Sequencer{}
+	s.next.Store(start)
+	return s
+}
+
+// Next returns the next sequence number.
+func (s *Sequencer) Next() uint64 {
+	if s == nil {
+		return 0
+	}
+	return s.next.Add(1)
+}
+
+// New converts one syscall pair into the shared row model.
+func New(seq uint64, pair *event.Pair) Row {
+	row := Row{
+		Seq:        seq,
+		TimeNs:     pair.EnterEv.GetTime(),
+		Syscall:    pair.EnterEv.GetTraceId().Name(),
+		Comm:       pair.Comm,
+		PID:        pair.EnterEv.GetPid(),
+		TID:        pair.EnterEv.GetTid(),
+		FileName:   pair.FileName(),
+		DurationNs: pair.Duration,
+		GapNs:      pair.DurationToPrev,
+		Bytes:      pair.Bytes,
+		FD:         UnknownFD,
+	}
+	if fd, ok := pair.FileDescriptor(); ok {
+		row.FD = fd
+	}
+
+	if retEv, ok := pair.ExitEv.(*types.RetEvent); ok {
+		row.RetVal = retEv.Ret
+		row.IsError = retEv.Ret < 0
+	}
+
+	return row
+}
+
+// NewWarning creates a synthetic row for non-fatal runtime warnings.
+func NewWarning(seq uint64, message string) Row {
+	now := uint64(time.Now().UnixNano())
+	return Row{
+		Seq:      seq,
+		TimeNs:   now,
+		Syscall:  "warning",
+		Comm:     "ior",
+		FileName: message,
+		FD:       UnknownFD,
+		RetVal:   -1,
+		IsError:  true,
+	}
+}
diff --git a/internal/streamrow/row_test.go b/internal/streamrow/row_test.go
new file mode 100644
index 0000000..729ba94
--- /dev/null
+++ b/internal/streamrow/row_test.go
@@ -0,0 +1,48 @@
+package streamrow
+
+import (
+	"sync"
+	"testing"
+)
+
+func TestSequencerStartsAfterSeed(t *testing.T) {
+	seq := NewSequencer(41)
+	if got, want := seq.Next(), uint64(42); got != want {
+		t.Fatalf("first Next() = %d, want %d", got, want)
+	}
+	if got, want := seq.Next(), uint64(43); got != want {
+		t.Fatalf("second Next() = %d, want %d", got, want)
+	}
+}
+
+func TestSequencerIsMonotonicUnderConcurrency(t *testing.T) {
+	seq := NewSequencer(0)
+
+	const workers = 8
+	const perWorker = 64
+
+	got := make(chan uint64, workers*perWorker)
+	var wg sync.WaitGroup
+	for i := 0; i < workers; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for j := 0; j < perWorker; j++ {
+				got <- seq.Next()
+			}
+		}()
+	}
+	wg.Wait()
+	close(got)
+
+	seen := make(map[uint64]struct{}, workers*perWorker)
+	for n := range got {
+		if _, ok := seen[n]; ok {
+			t.Fatalf("duplicate sequence number %d", n)
+		}
+		seen[n] = struct{}{}
+	}
+	if got, want := len(seen), workers*perWorker; got != want {
+		t.Fatalf("unique sequence count = %d, want %d", got, want)
+	}
+}