added yaml address book example, wrapped some potentially shared acce…

…ss calls with a mutex. Updated csv address book to actually read from a csv

address_books/csv_address_book.rb

@@ -1,10 +1,19 @@
+require 'singleton'
+require 'thread'
 require 'csv'
 
 class AddressBook
+  include Singleton
+
   def initialize
-    @servers = [
-      {:host => 'localhost', :port => 80}
-    ]
+    @servers = []
+    @mutex = Mutex.new
+  end
+
+  def configure(config)
+    CSV.open(config['file']) do |row|
+      @servers << {:host => row[1], :port => row[2].to_i}
+    end
   end
 
   # this method should return an array of hosts which this request is qualified to connect to.

address_books/yaml_address_book.rb

@@ -0,0 +1,25 @@
+require 'singleton'
+require 'thread'
+require 'yaml'
+
+class AddressBook
+  include Singleton
+
+  def initialize
+    @servers = []
+    @mutex = Mutex.new
+  end
+
+  def configure(config)
+    servers = YAML.load_file(config['file'])
+    servers.each do |server|
+      @servers << server
+    end
+  end
+
+  # this method should return an array of hosts which this request is qualified to connect to.
+  # which is determined based on the contents of the data passed
+  def lookup_addresses(data)
+    return @servers
+  end
+end

config.yml

@@ -1,10 +1,13 @@
 panel:
-    name: eventmachine
+    name: rev
     max_connections: 1024
     options:
         addr: 0.0.0.0
         port: 8000
 operator:
     name: random
+    options:
 address_book:
-    name: csv
+    name: csv
+    options:
+        file: "examples/servers.csv"

examples/servers.csv

@@ -0,0 +1 @@
+4.0,localhost,80

examples/servers.yml

@@ -0,0 +1,3 @@
+---
+    - :host: localhost
+      :port: 80

operators/random_operator.rb

@@ -1,12 +1,23 @@
+require 'singleton'
+require 'thread'
+
 class Operator
+  include Singleton
+
   def initialize
-    @address_book = AddressBook.new
+    @address_book = AddressBook.instance
+    @mutex = Mutex.new
+  end
+
+  def configure(config)
   end
 
   # the purpose of this method is to return a *single* host for the backend connection
   # which is determined by this operators method of load-balancing
   def lookup_jack(data)
-    addresses = @address_book.lookup_addresses(data)
+    @mutex.synchronize {
+      addresses = @address_book.lookup_addresses(data)
+    }
     return addresses[rand(addresses.size)] unless addresses.nil?
     return nil
   end

panels/eventmachine_panel.rb

@@ -63,7 +63,7 @@ class BrowserRequest < EventMachine::Connection
   attr_reader :backend
 
   def initialize
-    @operator = Operator.new
+    @operator = Operator.instance
     super
   end
 

panels/rev_panel.rb

@@ -51,7 +51,7 @@ class BrowserRequest < Rev::TCPSocket
   attr_reader :backend
 
   def initialize(*args)
-    @operator = Operator.new
+    @operator = Operator.instance
     super
   end
 
@@ -111,11 +111,21 @@ def self.start(options)
 
     trap ('SIGHUP') {
       LOGGER.warn 'Hangup caught, restarting'
+      # TODO: reload config
+      # tell AddressBook and Operator to reconfigure themselves based on the "new" config
     }
 
     server = Rev::TCPServer.new(options['host'], options['port'], BrowserRequest)
     server.attach(@@rev_loop)
-
+
+    # timer = Rev::TimerWatcher.new(5, true)
+    # timer.instance_eval do
+    #   def on_timer
+    #     LOGGER.info("This will check for failed backends, and attempt to bring them back online")
+    #   end
+    # end
+    # timer.attach(@@rev_loop)
+
     LOGGER.info "Rev panel listening on #{options['host']}:#{options['port']}"
     @@rev_loop.run
   end

panels/threaded_panel.rb

@@ -39,7 +39,7 @@ class BrowserRequest
   attr_reader :backend
 
   def initialize(sock)
-    @operator = Operator.new
+    @operator = Operator.instance
 
     @socket = sock
     LOGGER.info "#{@socket.peeraddr[3]}:#{@socket.peeraddr[1]} connected"

switchboard.rb

@@ -18,6 +18,8 @@
 LOGGER.info("Max connections to: #{CONFIG['panel']['max_connections'].to_i}")
 
 begin
+  AddressBook.instance.configure(CONFIG['address_book']['options'])
+  Operator.instance.configure(CONFIG['operator']['options'])
   Panel.start(CONFIG['panel']['options'])
 rescue Exception => e
   LOGGER.fatal e.inspect