# HG changeset patch
# User Alain Leufroy
# Date 1573518243 -3600
#      Tue Nov 12 01:24:03 2019 +0100
# Node ID 036e3ee2ce42fa89809fccd142009c30db98d392
# Parent  0d84d4ff42a1da69902a7be9fa3df8b1672d2a84
🚸 reduce cpu usage

- kill subprocess in a better way
- call patch subprocess more sequentially

diff --git a/lairucrem/controler.py b/lairucrem/controler.py
--- a/lairucrem/controler.py
+++ b/lairucrem/controler.py
@@ -43,6 +43,9 @@
         await asyncio.gather(*(walker.wait() for walker in self.__sequences__))
         urwid.emit_signal(self, 'completed')
 
+    async def stop(self):
+        await asyncio.gather(*(walker.stop() for walker in self.__sequences__))
+
 
 class _hgwalker(ensurable, waitable, urwid.SimpleFocusListWalker):
     """An waitable walker though stdout of an async hg process.
@@ -61,6 +64,7 @@
         pass
 
     def __init__(self, *args, **kwargs):
+        self.hgproc = None
         super().__init__([urwid.Text('LOADING …')], *args, **kwargs)
 
     def get_cmd(self):
@@ -76,6 +80,8 @@
         cmd = self.get_cmd()
         if not cmd:
             return
+        if self.hgproc:
+            await self.hgproc.kill()
         self.hgproc = process.hg(*cmd)
         await self.hgproc.start()
         try:
@@ -110,11 +116,15 @@
         urwid.emit_signal(self, 'completed')
 
     def clear(self, full=False):
-        self.cancel()
         super().clear()
         if not full:
             self.append(urwid.Text('LOADING …'))
 
+    async def stop(self):
+        if self.hgproc:
+            await self.hgproc.kill()
+        super().cancel()
+
 
 class _listbox(ensurable, waitable, mixin.mouse_up_down, urwid.ListBox):
     """An waitable listbox that handle waitable walkers."""
@@ -153,6 +163,9 @@
     def cancel(self):
         self.body.cancel()
 
+    async def stop(self):
+        await self.body.stop()
+
     def set_focus(self, position, coming_from=None):
         try:
             return super().set_focus(position, coming_from)
@@ -597,8 +610,8 @@
             lambda *args: urwid.emit_signal(self, 'jump_diff', *args)
         )
 
-    def reset_node(self, node):
-        self.cancel()
+    async def reset_node(self, node):
+        await self.stop()
         self.node = node
         self._summary.node = node
         self._summaryextra.node = node
@@ -643,13 +656,13 @@
         except urwid.ListBoxError:
             pass
 
-    def reset_node(self, node):
+    async def reset_node(self, node):
         # resetonly if not CWD and changed. We always reset on cwd as
         # the user evently want to view changes while cset is expected
         # not to be modified outside the application.
         if node is not None and node == self.body.node:
             return
-        self.body.reset_node(node)
+        await self.body.reset_node(node)
         self.ensure()
 
     def _iter_widgets(self, startpos=None, forward=True):
@@ -723,8 +736,8 @@
             mainwidget.pane(self._patch, 'PATCH'),
         ]))
 
-    def _on_focus_patch(self, *args):
-        self._patch.reset_node(self._graph.current_node)
+    async def _on_focus_patch(self, *args):
+        await self._patch.reset_node(self._graph.current_node)
 
     def ensure(self):
         self._graph.ensure()
diff --git a/lairucrem/process.py b/lairucrem/process.py
--- a/lairucrem/process.py
+++ b/lairucrem/process.py
@@ -103,12 +103,13 @@
                 continue
 
     async def stop(self):
+        if not self.proc:
+            return
         try:
             await _wait_process(self.proc, cmd=self.cmd)
         except OSError as exc:
             if exc.errno == 255:
                 raise RepositoryNotFound(str(exc))
-
         self.proc = None
 
     async def kill(self):