Commit the pile of initial work. Largely taken from company internal

repos, allowed to be newly released.  Portions already in production,
coverage still needs to be boosted.  Enjoy.

FossilOrigin-Name: 0f17fa483f55467bdf9e8f99dace58e6a90f5a8a7e595bdd79dfda5c92d16b7f

lib/symphony/tasks/scheduletask.rb

@@ -0,0 +1,81 @@
+#!/usr/bin/env ruby
+# vim: set nosta noet ts=4 sw=4:
+
+require 'symphony'
+require 'symphony/routing'
+require 'symphony/metronome'
+
+
+### Accept metronome scheduling events, translating them
+### to DB rows for persistence.
+###
+class Symphony::Metronome::ScheduleTask < Symphony::Task
+	include Symphony::Routing
+
+	queue_name 'metronome'
+	timeout 30
+
+	### Get a handle to the database.
+	###
+	def initialize( * )
+		@db = Symphony::Metronome::ScheduledEvent.db
+		@actions = @db[ :metronome ]
+		super
+	end
+
+	# The Sequel dataset of scheduled event actions.
+	attr_reader :actions
+
+
+	### Accept a new scheduled event.  The payload should be a free
+	### form hash of options, along with an expression string that
+	### conforms to IntervalExpression.
+	###
+	###   {
+	###       :expression  => 'run 25 times for an hour',
+	###       :payload     => { ... },
+	###   }
+	###
+	on 'metronome.create' do |payload, metadata|
+		raise ArgumentError, 'Invalid payload.' unless payload.is_a?( Hash )
+		exp = payload.delete( 'expression' )
+		raise ArgumentError, 'Missing time expression.' unless exp
+
+		self.actions.insert(
+			:created     => Time.now,
+			:expression  => exp,
+			:options     => Yajl.dump( payload )
+		)
+
+		self.signal_parent
+		return true
+	end
+
+
+	### Delete an existing scheduled event.
+	### The payload is the id of the action (row) to delete.
+	###
+	on 'metronome.delete' do |id, metadata|
+		self.actions.filter( :id => id.to_i ).delete
+		self.signal_parent
+		return true
+	end
+
+
+	### Tell our parent (the Metronome broadcaster) to re-read its event
+	### list.
+	###
+	def signal_parent
+		parent = Process.ppid
+
+		# Check to make sure we weren't orphaned.
+		#
+		if parent == 1
+			self.log.error "Lost my parent process?  Exiting."
+			exit 1
+		end
+
+		Process.kill( 'HUP', parent )
+	end
+end
+