Initial commit

sys/apis/event.lua

@@ -0,0 +1,177 @@
+local Util = require('util')
+
+local Event = {
+  uid = 1,  -- unique id for handlers
+}
+
+local eventHandlers = {
+  namedTimers = {}
+}
+
+-- debug purposes
+function Event.getHandlers()
+  return eventHandlers
+end
+
+function Event.addHandler(type, f)
+  local event = eventHandlers[type]
+  if not event then
+    event = {}
+    event.handlers = {}
+    eventHandlers[type] = event
+  end
+
+  local handler = {
+    uid     = Event.uid,
+    event   = type,
+    f       = f,
+  }
+  Event.uid = Event.uid + 1
+  event.handlers[handler.uid] = handler
+
+  return handler
+end
+
+function Event.removeHandler(h)
+  if h and h.event then
+    eventHandlers[h.event].handlers[h.uid] = nil
+  end
+end
+
+function Event.queueTimedEvent(name, timeout, event, args)
+  Event.addNamedTimer(name, timeout, false,
+    function()
+      os.queueEvent(event, args)
+    end
+  )
+end
+
+function Event.addNamedTimer(name, interval, recurring, f)
+  Event.cancelNamedTimer(name)
+  eventHandlers.namedTimers[name] = Event.addTimer(interval, recurring, f)
+end
+
+function Event.getNamedTimer(name)
+  return eventHandlers.namedTimers[name]
+end
+
+function Event.cancelNamedTimer(name)
+  local timer = Event.getNamedTimer(name)
+  if timer then
+    timer.enabled = false
+    Event.removeHandler(timer)
+  end
+end
+
+function Event.isTimerActive(timer)
+  return timer.enabled and
+    os.clock() < timer.start + timer.interval
+end
+
+function Event.addTimer(interval, recurring, f)
+  local timer = Event.addHandler('timer',
+    function(t, id)
+      if t.timerId ~= id then
+        return
+      end
+      if t.enabled then
+        t.fired = true
+        t.cf(t, id)
+      end
+      if t.recurring then
+        t.fired = false
+        t.start = os.clock()
+        t.timerId = os.startTimer(t.interval)
+      else
+        Event.removeHandler(t)
+      end
+    end
+  )
+  timer.cf = f
+  timer.interval = interval
+  timer.recurring = recurring
+  timer.start = os.clock()
+  timer.enabled = true
+  timer.timerId = os.startTimer(interval)
+
+  return timer
+end
+
+function Event.removeTimer(h)
+  Event.removeHandler(h)
+end
+
+function Event.blockUntilEvent(event, timeout)
+  return Event.waitForEvent(event, timeout, os.pullEvent)
+end
+
+function Event.waitForEvent(event, timeout, pullEvent)
+  pullEvent = pullEvent or Event.pullEvent
+
+  local timerId = os.startTimer(timeout)
+  repeat
+    local e, p1, p2, p3, p4 = pullEvent()
+    if e == event then
+      return e, p1, p2, p3, p4
+    end 
+  until e == 'timer' and p1 == timerId
+end
+
+local exitPullEvents = false
+
+local function _pullEvents()
+
+  --exitPullEvents = false
+  while true do
+    local e = Event.pullEvent()
+    if exitPullEvents or e == 'terminate' then
+      break
+    end
+  end
+end
+
+function Event.sleep(t)
+  local timerId = os.startTimer(t or 0)
+  repeat
+    local event, id = Event.pullEvent()
+  until event == 'timer' and id == timerId
+end
+
+function Event.pullEvents(...)
+  local routines = { ... }
+  if #routines > 0 then
+    parallel.waitForAny(_pullEvents, ...)
+  else
+    _pullEvents()
+  end
+end
+
+function Event.exitPullEvents()
+  exitPullEvents = true
+  os.sleep(0)
+end
+
+function Event.pullEvent(eventType)
+  local e = { os.pullEventRaw(eventType) }
+  return Event.processEvent(e)
+end
+
+function Event.processEvent(pe)
+
+  local e, p1, p2, p3, p4, p5 = unpack(pe)
+
+  local event = eventHandlers[e]
+  if event then
+    local keys = Util.keys(event.handlers)
+    for _,key in pairs(keys) do
+      local h = event.handlers[key]
+      if h then
+        h.f(h, p1, p2, p3, p4, p5)
+      end
+    end
+  end
+  
+  return e, p1, p2, p3, p4, p5
+end
+
+return Event