1 files changed, 89 insertions, 0 deletions
diff --git a/internal/system/dispatcher.go b/internal/system/dispatcher.go
new file mode 100644
index 00000000..86aebcaa
--- /dev/null
+++ b/internal/system/dispatcher.go
@@ -0,0 +1,89 @@
+package system
+
+import (
+	"io"
+	"io/fs"
+	"log"
+	"os"
+
+	"hakurei.app/hst"
+	"hakurei.app/internal/system/acl"
+	"hakurei.app/internal/system/dbus"
+	"hakurei.app/internal/system/xcb"
+)
+
+type osFile interface {
+	Name() string
+	io.Writer
+	fs.File
+}
+
+// syscallDispatcher provides methods that make state-dependent system calls as part of their behaviour.
+// syscallDispatcher is embedded in [I], so all methods must be unexported.
+type syscallDispatcher interface {
+	// new starts a goroutine with a new instance of syscallDispatcher.
+	// A syscallDispatcher must never be used in any goroutine other than the one owning it,
+	// just synchronising access is not enough, as this is for test instrumentation.
+	new(f func(k syscallDispatcher))
+
+	// stat provides os.Stat.
+	stat(name string) (os.FileInfo, error)
+	// open provides [os.Open].
+	open(name string) (osFile, error)
+	// mkdir provides os.Mkdir.
+	mkdir(name string, perm os.FileMode) error
+	// chmod provides os.Chmod.
+	chmod(name string, mode os.FileMode) error
+	// link provides os.Link.
+	link(oldname, newname string) error
+	// remove provides os.Remove.
+	remove(name string) error
+
+	// println provides [log.Println].
+	println(v ...any)
+
+	// aclUpdate provides [acl.Update].
+	aclUpdate(name string, uid int, perms ...acl.Perm) error
+
+	// xcbChangeHosts provides [xcb.ChangeHosts].
+	xcbChangeHosts(mode xcb.HostMode, family xcb.Family, address string) error
+
+	// dbusFinalise provides [dbus.Finalise].
+	dbusFinalise(sessionBus, systemBus dbus.ProxyPair, session, system *hst.BusConfig) (final *dbus.Final, err error)
+	// dbusProxyStart provides the Start method of [dbus.Proxy].
+	dbusProxyStart(proxy *dbus.Proxy) error
+	// dbusProxyClose provides the Close method of [dbus.Proxy].
+	dbusProxyClose(proxy *dbus.Proxy)
+	// dbusProxyWait provides the Wait method of [dbus.Proxy].
+	dbusProxyWait(proxy *dbus.Proxy) error
+}
+
+// direct implements syscallDispatcher on the current kernel.
+type direct struct{}
+
+func (k direct) new(f func(k syscallDispatcher)) { go f(k) }
+
+func (k direct) stat(name string) (os.FileInfo, error)     { return os.Stat(name) }
+func (k direct) open(name string) (osFile, error)          { return os.Open(name) }
+func (k direct) mkdir(name string, perm os.FileMode) error { return os.Mkdir(name, perm) }
+func (k direct) chmod(name string, mode os.FileMode) error { return os.Chmod(name, mode) }
+func (k direct) link(oldname, newname string) error        { return os.Link(oldname, newname) }
+func (k direct) remove(name string) error                  { return os.Remove(name) }
+
+func (k direct) println(v ...any) { log.Println(v...) }
+
+func (k direct) aclUpdate(name string, uid int, perms ...acl.Perm) error {
+	return acl.Update(name, uid, perms...)
+}
+
+func (k direct) xcbChangeHosts(mode xcb.HostMode, family xcb.Family, address string) error {
+	return xcb.ChangeHosts(mode, family, address)
+}
+
+func (k direct) dbusFinalise(sessionBus, systemBus dbus.ProxyPair, session, system *hst.BusConfig) (final *dbus.Final, err error) {
+	return dbus.Finalise(sessionBus, systemBus, session, system)
+}
+
+func (k direct) dbusProxyStart(proxy *dbus.Proxy) error { return proxy.Start() }
+func (k direct) dbusProxyClose(proxy *dbus.Proxy)       { proxy.Close() }
+func (k direct) dbusProxyWait(proxy *dbus.Proxy) error  { return proxy.Wait() }