Class: Pantry::Communication::ClientFilter

Inherits:
Object
  • Object
show all
Defined in:
lib/pantry/communication/client_filter.rb

Overview

ClientFilter handles and manages building filters that map configuration values to 0MQ stream names. A message stream is a period-delimited string that works with 0MQ’s Subscription prefix matcher, allowing Clients to choose which messages they want to receive. Streams are built to enable tiered delivery capability.

For example, a Client with the application ‘pantry’ and roles ‘app’ and ‘db’ will subscribe to the following streams:

pantry
pantry.app
pantry.db

Similarly to differentiate between environments, the environment is added inbetween the application and the role:

pantry
pantry.production
pantry.production.app
pantry.production.db

This class is also used to when sending messages, to choose which specific stream (e.g. the deepest buildable) to send a given message down.

A client identity token can also be given via identity. If identity is provided then that stream will be chosen above all others. Use this to send a message to specific clients.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(application: nil, environment: nil, roles: [], identity: nil) ⇒ ClientFilter 



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# File 'lib/pantry/communication/client_filter.rb', line 34

def initialize(application: nil, environment: nil, roles: [], identity: nil)
  @application = application
  @environment = environment
  @roles       = roles || []
  @identity    = identity
end

Instance Attribute Details

#application ⇒ Object (readonly)

Returns the value of attribute application.



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# File 'lib/pantry/communication/client_filter.rb', line 32

def application
  @application
end

#environment ⇒ Object (readonly)

Returns the value of attribute environment.



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# File 'lib/pantry/communication/client_filter.rb', line 32

def environment
  @environment
end

#identity ⇒ Object (readonly)

Returns the value of attribute identity.



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# File 'lib/pantry/communication/client_filter.rb', line 32

def identity
  @identity
end

#roles ⇒ Object (readonly)

Returns the value of attribute roles.



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# File 'lib/pantry/communication/client_filter.rb', line 32

def roles
  @roles
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/pantry/communication/client_filter.rb', line 77

def ==(other)
  return false unless other
  return false unless other.is_a?(ClientFilter)

  self.application   == other.application &&
    self.environment == other.environment &&
    self.roles       == other.roles &&
    self.identity    == other.identity
end

#includes?(filter) ⇒ Boolean

A filter includes another filter if the other filter matches. This does not look at identities.



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# File 'lib/pantry/communication/client_filter.rb', line 96

def includes?(filter)
  return true if self == filter
  return true if streams == [""]

  my_stream =    Set.new(streams)
  other_stream = Set.new(filter.streams)

  my_stream.subset?(other_stream)
end

#matches?(test_stream) ⇒ Boolean

Will this filter match on the given stream?



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# File 'lib/pantry/communication/client_filter.rb', line 88

def matches?(test_stream)
  self.streams.any? do |stream|
    stream.start_with?(test_stream)
  end
end

#stream ⇒ Object

Return the most specific stream that matches this ClientFilter. identity is chosen above all others.



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# File 'lib/pantry/communication/client_filter.rb', line 69

def stream
  if @identity
    @identity
  else
    [@application, @environment, @roles.first].compact.join(".")
  end
end

#streams ⇒ Object

List out all communication streams this ClientFilter is configured to know about.



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# File 'lib/pantry/communication/client_filter.rb', line 42

def streams
  list = []
  base_stream = []

  if @identity
    list << @identity
  end

  if @application
    list << @application
    base_stream = [@application]
  end

  if @environment
    list << [base_stream, @environment].flatten.compact.join(".")
  end

  @roles.each do |role|
    list << [base_stream, @environment, role].flatten.compact.join(".")
  end

  list = list.flatten.compact
  list.empty? ? [""] : list
end

#to_hash ⇒ Object 



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# File 'lib/pantry/communication/client_filter.rb', line 106

def to_hash
  {
    application: @application,
    environment: @environment,
    roles:       @roles,
    identity:    @identity
  }
end