internal/kobject: range over objects

For matching devices based on some criteria.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/kobject/kobject_test.go

@@ -2,6 +2,7 @@ package kobject_test
 
 import (
 	"bytes"
+	"context"
 	_ "embed"
 	"encoding/json"
 	"fmt"
@@ -10,7 +11,9 @@ import (
 	"reflect"
 	"slices"
 	"strings"
+	"sync"
 	"testing"
+	"testing/synctest"
 	"unsafe"
 
 	. "hakurei.app/internal/kobject"
@@ -335,6 +338,90 @@ func TestConsume(t *testing.T) {
 	}
 }
 
+func TestIter(t *testing.T) {
+	t.Parallel()
+	synctest.Test(t, func(t *testing.T) {
+		s := New(uevent.UUID{}, nil, nil)
+		var wg sync.WaitGroup
+		defer wg.Wait()
+		events := make(chan *uevent.Message)
+		defer close(events)
+		wg.Go(func() { s.Consume(t.Context(), events) })
+
+		events <- &uevent.Message{Action: uevent.KOBJ_ADD, DevPath: "\x00", Env: []string{
+			"V=\xfd",
+			"SEQNUM=0",
+		}}
+		events <- &uevent.Message{Action: uevent.KOBJ_ADD, DevPath: "\x01", Env: []string{
+			"V=\xfc",
+			"SEQNUM=1",
+		}}
+		synctest.Wait()
+		s.Range(t.Context(), func(o *Object) bool { return false })
+
+		var got []*Object
+		check := func(want []*Object) {
+			slices.SortFunc(got, func(a, b *Object) int {
+				return strings.Compare(a.DevPath, b.DevPath)
+			})
+			if !reflect.DeepEqual(got, want) {
+				t.Fatalf("Range: %#v, want %#v", got, want)
+			}
+			got = nil
+		}
+
+		ctx, cancel := context.WithCancel(t.Context())
+		defer cancel()
+		var done bool
+		wg.Go(func() {
+			s.Range(ctx, func(o *Object) bool {
+				got = append(got, new(o.Clone()))
+				return !done
+			})
+		})
+		synctest.Wait()
+		check([]*Object{
+			{
+				State:   StateNew,
+				DevPath: "\x00",
+				Env:     map[string]string{"V": "\xfd"},
+			},
+			{
+				State:   StateNew,
+				DevPath: "\x01",
+				Env:     map[string]string{"V": "\xfc"},
+			},
+		})
+
+		done = true
+		events <- &uevent.Message{Action: uevent.KOBJ_MOVE, DevPath: " ", Env: []string{
+			"DEVPATH_OLD=\x01",
+		}}
+		synctest.Wait()
+		check([]*Object{
+			{
+				State:   StateNew,
+				DevPath: " ",
+				Env:     map[string]string{"V": "\xfc"},
+			},
+		})
+
+		wg.Go(func() { s.Range(ctx, func(*Object) bool { return true }) })
+		synctest.Wait()
+
+		iter := reflect.ValueOf(s).Elem().FieldByName("iter")
+		if l := iter.Len(); l != 1 {
+			t.Errorf("len(s.iter): %d", l)
+		}
+
+		cancel()
+		synctest.Wait()
+		if l := iter.Len(); l != 0 {
+			t.Errorf("len(s.iter): %d", l)
+		}
+	})
+}
+
 func TestErrors(t *testing.T) {
 	t.Parallel()