jam-cloud/ruby/lib/jam_ruby/models/icecast_server.rb

module JamRuby
  class IcecastServer < ActiveRecord::Base

    attr_accessor :skip_config_changed_flag

    attr_accessible :template_id, :mount_template_id, :limit_id, :admin_auth_id, :directory_id, :master_relay_id,
                    :path_id, :logging_id, :security_id, :config_changed, :config_updated_at, :hostname, :location,
                    :admin_email, :fileserve, :icecast_server_group_id, :server_id, as: :admin


    belongs_to :template, class_name: "JamRuby::IcecastTemplate", foreign_key: 'template_id', inverse_of: :servers
    belongs_to :mount_template, class_name: "JamRuby::IcecastMountTemplate", foreign_key: 'mount_template_id', inverse_of: :servers
    belongs_to :server_group, class_name: "JamRuby::IcecastServerGroup", foreign_key: 'icecast_server_group_id', inverse_of: :servers

    # all are overrides, because the template defines all of these as well.  When building the XML, we will prefer these if set
    belongs_to :limit, class_name: "JamRuby::IcecastLimit", foreign_key: 'limit_id', inverse_of: :servers
    belongs_to :admin_auth, class_name: "JamRuby::IcecastAdminAuthentication", foreign_key: 'admin_auth_id', inverse_of: :servers
    belongs_to :directory, class_name: "JamRuby::IcecastDirectory", foreign_key: 'directory_id', inverse_of: :servers
    belongs_to :master_relay,  class_name: "JamRuby::IcecastMasterServerRelay", foreign_key: 'master_relay_id', inverse_of: :servers
    belongs_to :path, class_name: "JamRuby::IcecastPath", foreign_key: 'path_id', inverse_of: :servers
    belongs_to :logging, class_name: "JamRuby::IcecastLogging", foreign_key: 'logging_id', inverse_of: :servers
    belongs_to :security, class_name: "JamRuby::IcecastSecurity", foreign_key: 'security_id', inverse_of: :servers
    has_many :listen_socket_servers, class_name: "JamRuby::IcecastServerSocket", inverse_of: :server
    has_many :listen_sockets, class_name: "JamRuby::IcecastListenSocket", :through => :listen_socket_servers, :source => :socket

    # mounts and relays are naturally server-specific, though
    #has_many :server_mounts, class_name: "JamRuby::IcecastServerMount", inverse_of: :server
    has_many :mounts, class_name: "JamRuby::IcecastMount", inverse_of: :server, :foreign_key => 'icecast_server_id'

    has_many :server_relays, class_name: "JamRuby::IcecastServerRelay", inverse_of: :relay
    has_many :relays, class_name: "JamRuby::IcecastRelay", :through => :server_relays, :source => :relay

    validates :config_changed, :inclusion => {:in => [0, 1]}
    validates :hostname, presence: true
    validates :fileserve, :inclusion => {:in => [0, 1]}, :if => lambda {|s| s.fileserve.present? }
    validates :server_id, presence: true

    validates :template, presence: true
    validates :mount_template, presence: true

    before_validation :before_validate
    before_save :before_save, unless: lambda { skip_config_changed_flag }
    before_save :sanitize_active_admin
    after_save  :after_save

    def before_validate
      self.server_id = self.hostname
    end

    def before_save
        self.config_changed = 1
    end

    def sanitize_active_admin
      self.template_id = nil if self.template_id == ''
      self.limit_id = nil if self.limit_id == ''
      self.admin_auth_id = nil if self.admin_auth_id == ''
      self.directory_id = nil if self.directory_id == ''
      self.master_relay_id = nil if self.master_relay_id == ''
      self.path_id = nil if self.path_id == ''
      self.logging_id = nil if self.logging_id == ''
      self.security_id = nil if self.security_id == ''
    end

    def after_save
      # if we set config_changed, then queue up a job
      if config_changed == 1
        IcecastConfigWriter.enqueue(self.server_id)
      end
    end

    # this method is the correct way to set config_changed to false
    # if you don't do it this way, then likely you'll get into a loop
    # config_changed = true, enqueued job, job executes, job accidentally flags config_changed by touching the model, and repeat
    def config_updated
      self.skip_config_changed_flag = true

      self.config_changed = 0
      self.config_updated_at = Time.now
      begin
        self.save!
      rescue
        raise
      ensure
        self.skip_config_changed_flag = false
      end
    end


    def pick_listen_socket(field)
      current_listen_sockets = listen_sockets.length > 0 ? listen_sockets : template.listen_sockets
      socket = current_listen_sockets.first
      socket[field] if socket
    end


    # pick an icecast server with the least listeners * sources
    def self.find_best_server_for_user(user)
      chosen_server_id = nil
      chosen_server_weight = nil

      ActiveRecord::Base.connection_pool.with_connection do |connection|
        result = connection.execute('select SUM(listeners), SUM(sourced::int), icecast_servers.id
                                            FROM icecast_servers
                                            LEFT JOIN icecast_mounts ON icecast_servers.id = icecast_mounts.icecast_server_id
                                            WHERE icecast_server_group_id = \'' + user.icecast_server_group_id + '\'
                                            GROUP BY icecast_servers.id;')

        result.cmd_tuples.times do |i|
          listeners = result.getvalue(i, 0).to_i
          sourced = result.getvalue(i, 1).to_i
          icecast_server_id = result.getvalue(i, 2)

          # compute weight.  source is much more intensive than listener, based on load tests again 2.3.0
          # http://icecast.org/loadtest2.php

          weight = sourced * 10 + listeners

          if !chosen_server_id || (weight < chosen_server_weight)
            chosen_server_id = icecast_server_id
            chosen_server_weight = weight
          end
        end
      end

      IcecastServer.find(chosen_server_id) if chosen_server_id
    end

    def to_s
      server_id
    end

    def dumpXml (output=$stdout, indent=1)

      builder = ::Builder::XmlMarkup.new(:target => output, :indent => indent)

      builder.tag! 'icecast' do |root|
        root.tag! 'hostname',   hostname
        root.tag! 'server-id',  server_id
        root.tag! 'location',   resolve_string(:location)       if string_present?(:location)
        root.tag! 'admin',      resolve_string(:admin_email)    if string_present?(:admin_email)
        root.tag! 'fileserve',  resolve_int(:fileserve)         if int_present?(:fileserve)

        resolve_association(:limit).dumpXml(builder)            if association_present?(:limit)
        resolve_association(:admin_auth).dumpXml(builder)       if association_present?(:admin_auth)
        resolve_association(:directory).dumpXml(builder)        if association_present?(:directory)
        resolve_association(:master_relay).dumpXml(builder)     if association_present?(:master_relay)
        resolve_association(:path).dumpXml(builder)             if association_present?(:path)
        resolve_association(:logging).dumpXml(builder)          if association_present?(:logging)
        resolve_association(:security).dumpXml(builder)         if association_present?(:security)

        current_listen_sockets = listen_sockets.length > 0 ? listen_sockets : template.listen_sockets
        current_listen_sockets.each do  |listen_socket|
          listen_socket.dumpXml(builder)
        end

        relays.each do  |relay|
          relay.dumpXml(builder)
        end

        mounts.each do  |mount|
          mount.dumpXml(builder)
        end
      end
    end

    def resolve_string(field)
      self[field].present? ? self[field] : template && template[field]
    end

    def string_present?(field)
      val = resolve_string(field)
      val ? val.present? : false
    end

    def resolve_int(field)
      self[field] ? self[field]: template && template[field]
    end

    def int_present?(field)
      resolve_int(field)
    end

    def resolve_association(field)
      self.send(field) ? self.send(field) : template && template.send(field)
    end

    def association_present?(field)
      resolve_association(field)
    end


  end
end