Class: Async::HTTP::Pool

Inherits:
Object
  • Object
show all
Defined in:
lib/async/http/pool.rb

Overview

Pool behaviours

  • Single request per connection (HTTP/1 without keep-alive)

  • Multiple sequential requests per connection (HTTP1 with keep-alive)

  • Multiplex requests per connection (HTTP2)

In general we don’t know the policy until connection is established.

This pool doesn’t impose a maximum number of open resources, but it WILL block if there are no available resources and trying to allocate another one fails.

Resources must respond to #multiplex -> 1 or more. #reusable? -> can be used again.

Instance Method Summary collapse

Constructor Details

#initialize(limit = nil, &block) ⇒ Pool

Returns a new instance of Pool.



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# File 'lib/async/http/pool.rb', line 38

def initialize(limit = nil, &block)
  @available = {} # resource => count
  @waiting = []
  
  @limit = limit
  
  @constructor = block
end

Instance Method Details

#acquire ⇒ Object 



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# File 'lib/async/http/pool.rb', line 47

def acquire
  resource = wait_for_next_available
  
  return resource unless block_given?
  
  begin
    yield resource
  ensure
    release(resource)
  end
end

#close ⇒ Object 



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# File 'lib/async/http/pool.rb', line 75

def close
  @available.each_key(&:close)
  @available.clear
end

#release(resource) ⇒ Object

Make the resource available and let waiting tasks know that there is something available.



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# File 'lib/async/http/pool.rb', line 60

def release(resource)
  if resource.reusable?
    Async.logger.debug(self) {"Reusing resource #{resource}"}
    
    @available[resource] -= 1
    
    if task = @waiting.pop
      task.resume
    end
  else
    Async.logger.debug(self) {"Closing resource: #{resource}"}
    resource.close
  end
end