Class: Brute::Hooks::Registry

Inherits:
Object
  • Object
show all
Defined in:
lib/brute/hooks.rb

Overview

The pub/sub registry a pipeline owns; use and run bind an emit to it.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Registry

Returns a new instance of Registry.



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# File 'lib/brute/hooks.rb', line 96

def initialize
  @subscribers = Hash.new { |hash, key| hash[key] = [] }
end

Instance Method Details

#any?(event) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/brute/hooks.rb', line 144

def any?(event) = @subscribers[event.to_sym].any?

#emit(event, env, *extras, &block) ⇒ Object

Fire an event. An emitter announces; it answers nothing, and what a subscriber's block happens to evaluate to is not a signal. A layer that wants to take part in a turn does it by mutating what it was handed, never by returning something.

Given a block, the event is timed instead: the block is the work, and subscribers fire once it is done, called as |env, started, finished, *extras| rather than |env, *extras|. Both stamps are monotonic, so a clock adjustment mid-turn cannot produce a negative duration.

The block is the work and nothing more: emit answers nothing in either form, so a caller that needs the work's value takes it inside the block.

result = nil
emit(DURATION_EVENT, env, self) { result = @app.call(env) }
# => .on(DURATION_EVENT) { |env, started, finished, layer| ... }

Subscribers fire from an ensure, so work that raises is still timed and still reported before the exception carries on up.



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# File 'lib/brute/hooks.rb', line 126

def emit(event, env, *extras, &block)
  unless block
    @subscribers[event.to_sym].each { |subscriber| subscriber.call(env, *extras) }
    return nil
  end

  started = Process.clock_gettime(Process::CLOCK_MONOTONIC)

  begin
    block.call
  ensure
    finished = Process.clock_gettime(Process::CLOCK_MONOTONIC)
    @subscribers[event.to_sym].each { |subscriber| subscriber.call(env, started, finished, *extras) }
  end

  nil
end

#on(event, &block) ⇒ Object 



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# File 'lib/brute/hooks.rb', line 100

def on(event, &block)
  @subscribers[event.to_sym] << block
  self
end