saner interface & executable

.gitignore

@@ -13,6 +13,7 @@ lib/bundler/man
 pkg
 rdoc
 spec/reports
+zhong.rb
 test/tmp
 test/version_tmp
 tmp

README.md

@@ -15,14 +15,14 @@ gem 'zhong'
 ```ruby
 r = Redis.new
 
-Zhong.schedule(redis: r) do
-  category "stuff" do
-    every(5.seconds, "foo") { puts "foo" }
-    every(1.week, "baz", at: "mon 22:45") { puts "baz" }
+Zhong.schedule(redis: r) do |s|
+  s.category "stuff" do
+    s.every(5.seconds, "foo") { puts "foo" }
+    s.every(1.week, "baz", at: "mon 22:45") { puts "baz" }
   end
 
-  category "clutter" do
-    every(1.second, "compute", if: -> (t) { rand < 0.5 }) { puts "something happened" }
+  s.category "clutter" do
+    s.every(1.second, "compute", if: -> (t) { rand < 0.5 }) { puts "something happened" }
   end
 end
 ```

bin/zhong

@@ -0,0 +1,15 @@
+#!/usr/bin/env ruby
+
+STDERR.sync = STDOUT.sync = true
+
+require "bundler/setup"
+require "zhong"
+
+usage = "zhong <zhong.rb>"
+file = ARGV.shift || abort(usage)
+
+file = "./#{file}" unless file.match(/^[\/.]/)
+
+require file
+
+Zhong.start

lib/zhong.rb

@@ -5,6 +5,8 @@
 
 require "zhong/version"
 
+require "zhong/util"
+
 require "zhong/at"
 require "zhong/every"
 
@@ -13,10 +15,19 @@
 
 module Zhong
   class << self
-    def schedule(**opts, &block)
-      @scheduler = Scheduler.new(opts)
-      @scheduler.instance_eval(&block)
-      @scheduler.start
+    def schedule(**opts)
+      @scheduler = Scheduler.new(opts).tap do |s|
+        yield(s)
+      end
+    end
+
+    def start
+      fail "You must run `Zhong.schedule` first" unless scheduler
+      scheduler.start
+    end
+
+    def scheduler
+      @scheduler
     end
   end
 end

lib/zhong/job.rb

@@ -2,23 +2,26 @@ module Zhong
   class Job
     attr_reader :name, :category
 
-    def initialize(scheduler:, name:, every: nil, at: nil, only_if: nil, category: nil, &block)
+    def initialize(name, config = {}, &block)
       @name = name
-      @category = category
+      @category = config[:category]
 
-      @at = At.parse(at, grace: scheduler.config[:grace])
-      @every = Every.parse(every)
+      @at = At.parse(config[:at], grace: config.fetch(:grace, 15.minutes))
+      @every = Every.parse(config[:every])
 
       if @at && !@every
         @logger.error "warning: #{self} has `at` but no `every`; could run far more often than expected!"
       end
 
+      fail "must specific either `at` or `every` for a job" unless @at || @every
+
       @block = block
-      @redis = scheduler.config[:redis]
-      @logger = scheduler.config[:logger]
-      @tz = scheduler.config[:tz]
-      @if = only_if
-      @lock = Suo::Client::Redis.new(lock_key, client: @redis, stale_lock_expiration: scheduler.config[:long_running_timeout])
+
+      @redis = config[:redis]
+      @logger = config[:logger]
+      @tz = config[:tz]
+      @if = config[:if]
+      @lock = Suo::Client::Redis.new(lock_key, client: @redis, stale_lock_expiration: config[:long_running_timeout])
       @timeout = 5
 
       refresh_last_ran
@@ -36,6 +39,8 @@ def run(time = Time.now)
         return
       end
 
+      @thread = nil
+
       ran_set = @lock.lock do
         refresh_last_ran
 
@@ -85,7 +90,13 @@ def disabled?
     end
 
     def to_s
-      [@category, @name].compact.join(".")
+      [@category, @name].compact.join(".").freeze
+    end
+
+    def next_at
+      every_time = @every.next_at(@last_ran) if @last_ran && @every
+      at_time = @at.next_at(time) if @at
+      [every_time, at_time, Time.now].compact.max || "now"
     end
 
     private

lib/zhong/scheduler.rb

@@ -2,27 +2,37 @@ module Zhong
   class Scheduler
     attr_reader :config, :redis, :jobs
 
+    DEFAULT_CONFIG = {
+      timeout: 0.5,
+      grace: 15.minutes,
+      long_running_timeout: 5.minutes
+    }.freeze
+
+    TRAPPED_SIGNALS = %w(QUIT INT TERM).freeze
+
     def initialize(config = {})
       @jobs = {}
-      @config = {timeout: 0.5, grace: 15.minutes, long_running_timeout: 5.minutes}.merge(config)
-      @logger = @config[:logger] ||= self.class.default_logger
-      @redis = @config[:redis] ||= Redis.new
+      @config = DEFAULT_CONFIG.merge(config)
+      @logger = @config[:logger] ||= Util.default_logger
+      @redis = @config[:redis] ||= Redis.new(ENV["REDIS_URL"])
     end
 
     def category(name)
-      @category = name
+      fail "cannot nest categories: #{name} would be nested in #{@category}" if @category
+
+      @category = name.to_s
 
-      yield
+      yield(self)
 
       @category = nil
     end
 
     def every(period, name, opts = {}, &block)
-      add(Job.new(scheduler: self, name: name, every: period, at: opts[:at], only_if: opts[:if], category: @category, &block))
+      add(Job.new(name, opts.merge(@config).merge(every: period, category: @category), &block))
     end
 
     def start
-      %w(QUIT INT TERM).each do |sig|
+      TRAPPED_SIGNALS.each do |sig|
         Signal.trap(sig) { stop }
       end
 
@@ -66,11 +76,5 @@ def redis_time
       now = Time.at(s + ms / (10**6))
       config[:tz] ? now.in_time_zone(config[:tz]) : now
     end
-
-    def self.default_logger
-      Logger.new(STDOUT).tap do |logger|
-        logger.formatter = -> (_, datetime, _, msg) { "#{datetime}: #{msg}\n" }
-      end
-    end
   end
 end

lib/zhong/util.rb

@@ -0,0 +1,11 @@
+module Zhong
+  module Util
+    class << self
+      def default_logger
+        Logger.new(STDOUT).tap do |logger|
+          logger.formatter = -> (_, datetime, _, msg) { "#{datetime}: #{msg}\n" }
+        end
+      end
+    end
+  end
+end