Events mechanism

1 files changed, 20 insertions, 3 deletions

diff --git a/statemachine.py b/statemachine.py
index 3c63048..609da17 100644
--- a/statemachine.py
+++ b/statemachine.py
@@ -16,6 +16,17 @@ class StateMachine:
         """
         self.up = set()
         self.deps = []
+        self.event_triggers = []
+
+    def emit(self, event):
+        """
+        Emit an event.
+        """
+        retval = False
+        for evpat, cat in self.event_triggers:
+            if event.subset_of(evpat):
+                retval |= self.bring_up(cat.intersect_args(**event.args))
+        return retval
 
     def bring_up(self, cat):
         """
@@ -120,13 +131,19 @@ if __name__ == "__main__":
     sm.deps.append((Category("mounted", type=m("nfs")), Category("network_up")))
     sm.deps.append((Category("mounted", type=nm("nfs")), Category("found_disk")))
     sm.deps.append((Category("mounted"), Category("vol_conf")))
+
+    sm.event_triggers.append((Category("fstab_line"), Category("vol_conf", src=m("fstabd"))))
+
     sm.bring_up(Category("network_up"))
-    sm.bring_up(Category("vol_conf", label=m("myroot"), type=m("ext3"), mountpoint=m("/")))
-    sm.bring_up(Category("vol_conf", devname=m("foosrv.com:/vol/home"), type=m("nfs"), mountpoint=m("/home")))
-    sm.bring_up(Category("vol_conf", devname=m("foosrv.com:/vol/beefs"), type=m("nfs"), mountpoint=m("/beefs")))
     sm.bring_up(Category("found_disk", uuid=m("d3adb3ef"), devname=m("/dev/sda"), label=m("myroot")))
     sm.bring_up(Category("mounted", devname=any(), mountpoint=any()))
     print sm
     print "--"
+    sm.emit(Category("fstab_line", label=m("myroot"), type=m("ext3"), mountpoint=m("/")))
+    sm.emit(Category("fstab_line", devname=m("foosrv.com:/vol/home"), type=m("nfs"), mountpoint=m("/home")))
+    sm.emit(Category("fstab_line", devname=m("foosrv.com:/vol/beefs"), type=m("nfs"), mountpoint=m("/beefs")))
+    sm.bring_up(Category("mounted", devname=any(), mountpoint=any()))
+    print sm
+    print "--"
     sm.bring_down(Category("network_up"))
     print sm