Class: MsgpackRpcClient

Inherits:
Object
  • Object
show all
Defined in:
lib/msgpack_rpc_client.rb,
lib/msgpack_rpc_client/version.rb

Overview

MessagePack-RPC client

Defined Under Namespace

Classes: Error

Constant Summary collapse

DEFAULT_MAX_RETRIES = 
10
DEFAULT_MAX_CONNECT_RETRIES = 
5
DEFAULT_CONNECT_RETRY_WAIT =

seconds

0.1
MAX_MSGID = 
1_000_000_000
VERSION = 
"0.1.0"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ MsgpackRpcClient

Initialize client and establish connection to server.

(While it may seem beneficial to not connect in the constructor and wait for the first RPC call, I believe it’s better to fail early.

  • host, port, use_ssl - configure your connection

  • logger - logger (default nil, set to Rails.logger in a Rails app)

Parameters that are better left alone:

  • max_retries - number of times to retry sending a request

  • max_connect_retries - number of times to retry connecting to the server

  • connect_retry_wait - wait between connection retry attempts

TODO: once we are long past the <2.0.0 legacy, replace with named args



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# File 'lib/msgpack_rpc_client.rb', line 30

def initialize(options={})
  @host = options.fetch(:host)
  @port = options.fetch(:port)
  @use_ssl = options.fetch(:use_ssl, false)
  @logger = options.fetch(:logger, nil)
  @max_retries = options.fetch(:max_retries, DEFAULT_MAX_RETRIES)
  @max_connect_retries = options.fetch(:max_connect_retries, DEFAULT_MAX_CONNECT_RETRIES)
  @connect_retry_wait = options.fetch(:connect_retry_wait, DEFAULT_CONNECT_RETRY_WAIT)
  @msgid = 1
  @call_mutex = Mutex.new
  init_socket
end

Instance Attribute Details

#connect_retry_wait ⇒ Object (readonly)

Returns the value of attribute connect_retry_wait.



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# File 'lib/msgpack_rpc_client.rb', line 14

def connect_retry_wait
  @connect_retry_wait
end

#host ⇒ Object (readonly)

Returns the value of attribute host.



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# File 'lib/msgpack_rpc_client.rb', line 14

def host
  @host
end

#max_connect_retries ⇒ Object (readonly)

Returns the value of attribute max_connect_retries.



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# File 'lib/msgpack_rpc_client.rb', line 14

def max_connect_retries
  @max_connect_retries
end

#max_retries ⇒ Object (readonly)

Returns the value of attribute max_retries.



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# File 'lib/msgpack_rpc_client.rb', line 14

def max_retries
  @max_retries
end

#port ⇒ Object (readonly)

Returns the value of attribute port.



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# File 'lib/msgpack_rpc_client.rb', line 14

def port
  @port
end

#use_ssl ⇒ Object (readonly)

Returns the value of attribute use_ssl.



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# File 'lib/msgpack_rpc_client.rb', line 14

def use_ssl
  @use_ssl
end

Instance Method Details

#call(method_name, *params) ⇒ Object

Call an RPC method. Will reconnect if the server is down. Threadsafe.

  • Params is anything serializable with Messagepack.

  • Hashes in response will be deserialized with symbolized keys



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# File 'lib/msgpack_rpc_client.rb', line 47

def call(method_name, *params)
  request = nil
  response = nil

  @call_mutex.synchronize do
    request = [0, @msgid, method_name, params]
    @msgid = (@msgid % MAX_MSGID) + 1
    response = make_request_with_retries(request)
  end

  if response[0] != 1
    raise MsgpackRpcClient::Error, 'Response does not bear the proper type flag - something is very wrong'
  end
  if response[1] != request[1]
    raise MsgpackRpcClient::Error, 'Response message id does not match request message id - something is very wrong'
  end
  if response[2] != nil
    raise MsgpackRpcClient::Error, "Server responded with error: #{response[2]}"
  end

  response[3]
end