Class: Monga::Connections::EMProxyConnection

Inherits:
Object
  • Object
show all
Defined in:
lib/monga/connections/em_proxy_connection.rb

Overview

ProxyConnection accepts requests when ReplicaSetClient didn’t know where to send requests. I.E. when client is just initialized here is no any established connections, so client waits for the connection ready to accept requests. Also, when primary is down it will collect request while nodes are voting. Importaint to say, that requests will be stored in this object only for ‘timeout` period.

Direct Known Subclasses

FiberedProxyConnection

Constant Summary collapse

WAIT =

Pause while searching server in seconds

0.05

Instance Method Summary collapse

Constructor Details

#initialize(client) ⇒ EMProxyConnection

Returns a new instance of EMProxyConnection.



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# File 'lib/monga/connections/em_proxy_connection.rb', line 11

def initialize(client)
  @client = client
  @timeout = @client.timeout
  @requests = {}
end

Instance Method Details

#find_server!(i = 0) ⇒ Object

Find server unless server is found



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# File 'lib/monga/connections/em_proxy_connection.rb', line 54

def find_server!(i = 0)
  @pending_server = true
  if @pending_timeout && !@timeout_happend
    size = @client.clients.size
    client = @client.clients[i%size]
    client.force_status! do |status|
      if status == :primary && [:primary, :primary_preferred, :secondary_preferred].include?(@client.read_pref)
        server_found!
      elsif status == :secondary && [:secondary, :primary_preferred, :secondary_preferred].include?(@client.read_pref)
        server_found!
      else
        EM::Timer.new(WAIT) do
          find_server!(i+1)
        end
      end
    end
  else
    timeout_happend
  end
end

#send_command(msg, request_id = nil, &cb) ⇒ Object

If timeout is defined then collect request and start timeout. If timeout is not defined or zero then return exception.



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# File 'lib/monga/connections/em_proxy_connection.rb', line 23

def send_command(msg, request_id = nil, &cb)
  if @timeout && @timeout > 0 
    @requests[request_id] = [msg, cb] if cb
    set_timeout unless @pending_timeout
    find_server! unless @pending_server
  else
    error = Monga::Exceptions::Disconnected.new "Can't find appropriate server (all disconnected) without timeout"
    cb.call(error) if cb
  end
end

#server_found! ⇒ Object

YEEEHA! Send all collected requests back to client



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# File 'lib/monga/connections/em_proxy_connection.rb', line 76

def server_found!
  @pending_server = false
  @pending_timeout.cancel if @pending_timeout
  @pending_timeout = nil
  @timeout_happend = false
  @requests.keys.each do |request_id|
    msg, blk = @requests.delete request_id
    @client.aquire_connection.send_command(msg, request_id, &blk)
  end
end

#set_timeout ⇒ Object

If timeout happend send exception to all collected requests.



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# File 'lib/monga/connections/em_proxy_connection.rb', line 35

def set_timeout
  @pending_timeout = EM::Timer.new(@timeout) do
    @timeout_happend = true
  end
end

#timeout_happend ⇒ Object 



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# File 'lib/monga/connections/em_proxy_connection.rb', line 41

def timeout_happend
  @timeout_happend = false
  @pending_timeout.cancel  if @pending_timeout
  @pending_timeout = false
  @pending_server = false
  @requests.keys.each do |request_id|
    msg, cb = @requests.delete request_id
    error = Monga::Exceptions::Disconnected.new "Can't find appropriate server (all disconnected)"
    cb.call(error) if cb
  end
end

#type ⇒ Object 



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# File 'lib/monga/connections/em_proxy_connection.rb', line 17

def type
  :em
end