Initial import of ideas around an automatic call distributor

.gitignore

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+*.swp
+Gemfile.lock

Gemfile

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+source :rubygems
+gemspec

LICENSE

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+Copyright (c) 2011 The Adhearsion Foundation
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

ahn_acd.gemspec

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+GEM_FILES = %w{
+  ahn_acd.gemspec
+  lib/ahn_acd.rb
+  lib/ahn_acd/queue_strategy.rb
+  lib/ahn_acd/round_robin.rb
+  lib/ahn_acd/round_robin_meetme.rb
+  config/ahn_acd.yml
+}
+
+Gem::Specification.new do |s|
+  s.name = "ahn_acd"
+  s.version = "0.0.1"
+
+  s.required_rubygems_version = Gem::Requirement.new(">= 0") if s.respond_to? :required_rubygems_version=
+  s.authors = ["Ben Klang"]
+
+  s.date = Date.today.to_s
+  s.description = "Automatic Call Distributor (ACD) for Adhearsion. Currently implements only Round Robin distribution strategies."
+  s.email = "dev&adhearsion.com"
+
+  s.files = GEM_FILES
+
+  s.has_rdoc = true
+  s.homepage = "http://github.com/adhearsion/ahn_acd"
+  s.require_paths = ["lib"]
+  s.rubygems_version = "1.2.0"
+  s.summary = "Automatic Call Distributor for Adhearsion"
+
+  s.add_runtime_dependency 'adhearsion', ['~> 1.2.0']
+
+  s.specification_version = 2
+end

config/ahn_acd.yml

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+# You can use this file for component-specific configuration.

lib/ahn_acd.rb

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+#methods_for :dialplan do
+#end
+#
+#initialization do
+#  COMPONENTS.ahn_acd[:queues].each do |q|
+#    AhnQueue.create q[:name], q[:queue_type], q[:agent_type]
+#  end
+#end
+
+class AhnQueue
+  include Singleton
+
+  def initialize
+    @queues = {}
+  end
+
+  def create(name, queue_type, agent_type = Agent)
+    synchronize do
+      @queues[name] = const_get(queue_type).new unless @queues.has_key?(name)
+      @queues[name].extend agent_type
+    end
+  end
+
+  def get_queue(name)
+    synchronize do
+      @queues[name]
+    end
+  end
+
+  def self.method_missing(method, *args, &block)
+    instance.send method, *args, &block
+  end
+
+  class QueuedCall
+    attr_accessor :call, :queued_time
+
+    def initialize(call)
+      @call = call
+      @queued_time = Time.now
+    end
+
+    def hold
+      call.execute 'StartMusicOnHold'
+      @latch = CountDownLatch.new 1
+      @latch.wait
+      call.execute 'StopMusicOnHold'
+    end
+
+    def make_ready!
+      @latch.countdown!
+    end
+  end
+
+  class Agent
+    def work(agent_call)
+      loop do
+        agent_call.execute 'Bridge', @queue.next_call
+      end
+    end
+  end
+
+  class CalloutAgent
+    def work(agent_channel)
+      @queue.next_call.each do |next_call|
+        next_call.dial agent_channel
+      end
+    end
+  end
+
+  class MeetMeAgent
+    include Agent
+
+    def work(agent_call)
+      loop do
+        agent_call.join agent_conf, @queue.next_call
+      end
+    end
+  end
+
+  class BridgeAgent
+    include Agent
+  end
+end

lib/ahn_acd/queue_strategy.rb

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+require 'countdownlatch'
+
+class AhnAcd
+  module QueueStrategy
+    def wrap_call(call)
+      QueuedCall.new(call) unless call.respond_to?(:queued_time)
+    end
+
+    def priority_enqueue(call)
+      enqueue call
+    end
+
+    def enqueue(call)
+      call.hold
+    end
+  end
+end

lib/ahn_acd/round_robin.rb

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+require 'thread'
+
+class AhnAcd
+  class RoundRobin
+    include QueueStrategy
+
+    def initialize
+      @queue = []
+      @conditional = ConditionVariable.new
+    end
+
+    def next_call
+      call = nil
+      synchronize do
+        @conditional.wait(@mutex) if @queue.length == 0
+        call = @queue.pop
+      end
+
+      call.make_ready!
+      call
+    end
+
+    # TODO: Add mechanism to add calls with higher priority to the front of the queue.
+
+    def enqueue(call)
+      call = wrap_call(call)
+      synchronize do
+        @queue << call
+        @conditional.signal if @queue.length == 1
+      end
+      super
+    end
+  end
+end
+

lib/ahn_acd/round_robin_meetme.rb

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+class AhnAcd
+  class RoundRobinMeetme
+    include QueueStrategy
+
+    def initialize(call)
+      @queue = []
+    end
+
+    def next_call
+      call = synchronize do
+        @queue.pop
+      end
+
+      call.make_ready!
+      call
+    end
+
+    def priority_enqueue(call)
+      call = wrap_call(call)
+
+      synchronize do
+        @queue.unshift call
+      end
+      super
+    end
+
+    def enqueue(call)
+      synchronize do
+        @queue << call
+      end
+    end
+  end
+end
+
+

spec/ahn_acd_spec.rb

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+require 'rubygems'
+require 'bundler'
+Bundler.setup
+Bundler.require
+
+require 'adhearsion/component_manager/spec_framework'
+
+component_name.upcase = ComponentTester.new("ahn_acd", File.dirname(__FILE__) + "/../..")