Class: Concurrent::Actor::Utils::Balancer — Concurrent Ruby

# Class: Concurrent::Actor::Utils::Balancer

Inherits:
  RestartingContext
  - Object
  - AbstractContext
  - RestartingContext
  - Concurrent::Actor::Utils::Balancer
  show all

Defined in:
  lib/concurrent-ruby-edge/concurrent/actor/utils/balancer.rb

## Overview

Distributes messages between subscribed actors. Each actor'll get only one message then it's unsubscribed. The actor needs to resubscribe when it's ready to receive next message. It will buffer the messages if there is no worker registered.

See Also:

- Pool

## Instance Method Summary collapse

- #distribute ⇒ undocumented
- #initialize ⇒ Balancer constructor

  A new instance of Balancer.

- #on_message(message) ⇒ undocumented

## Constructor Details

### #initialize ⇒ `Balancer`

Returns a new instance of Balancer.

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    # File 'lib/concurrent-ruby-edge/concurrent/actor/utils/balancer.rb', line 11

    def initialize
      @receivers = []
      @buffer    = []
    end

## Instance Method Details

### #distribute ⇒ `undocumented`

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    # File 'lib/concurrent-ruby-edge/concurrent/actor/utils/balancer.rb', line 35

    def distribute
      while !@receivers.empty? && !@buffer.empty?
        redirect @receivers.shift, @buffer.shift
      end
    end

### #on_message(message) ⇒ `undocumented`

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    # File 'lib/concurrent-ruby-edge/concurrent/actor/utils/balancer.rb', line 16

    def on_message(message)
      command, who = message
      case command
      when :subscribe
        @receivers << (who || envelope.sender)
        distribute
        true
      when :unsubscribe
        @receivers.delete(who || envelope.sender)
        true
      when :subscribed?
        @receivers.include?(who || envelope.sender)
      else
        @buffer << envelope
        distribute
        Behaviour::MESSAGE_PROCESSED
      end
    end