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Class: Bundler::ConnectionPool

Overview

Generic connection pool class for e.g. sharing a limited number of network connections among many threads. Note: Connections are lazily created.

Example usage with block (faster):

@pool = Bundler::ConnectionPool.new { Redis.new }

@pool.with do |redis|
  redis.lpop('my-list') if redis.llen('my-list') > 0
end

Using optional timeout override (for that single invocation)

@pool.with(timeout: 2.0) do |redis|
  redis.lpop('my-list') if redis.llen('my-list') > 0
end

Example usage replacing an existing connection (slower):

$redis = Bundler::ConnectionPool.wrap { Redis.new }

def do_work
  $redis.lpop('my-list') if $redis.llen('my-list') > 0
end

Accepts the following options:

  • :size - number of connections to pool, defaults to 5

  • :timeout - amount of time to wait for a connection if none currently available, defaults to 5 seconds

Constant Summary

Class Method Summary

Instance Method Summary

Constructor Details

.new(options = {}, &block) ⇒ ConnectionPool

Raises:

  • (ArgumentError)
[ GitHub ] 

  


# File 'lib/bundler/vendor/connection_pool/lib/connection_pool.rb', line 44



def initialize(options = {}, &block)
  raise ArgumentError, 'Connection pool requires a block' unless block

  options = DEFAULTS.merge(options)

  @size = options.fetch(:size)
  @timeout = options.fetch(:timeout)

  @available = TimedStack.new(@size, &block)
  @key = :"current-#{@available.object_id}"
  @key_count = :"current-#{@available.object_id}-count"
end


  







Class Method Details



  

    .monotonic_time  ⇒ Float 
  



  

    

Returns the current time a tracked by the application monotonic clock.


  





  
Returns:


    
  
  • 
    (Float)
—    
    

    The current monotonic time when since not given else the elapsed monotonic time between ‘since` and the current time
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/bundler/vendor/connection_pool/lib/connection_pool/monotonic_time.rb', line 62



def monotonic_time
  GLOBAL_MONOTONIC_CLOCK.get_time
end


  








  

    .wrap(options, &block)  
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/connection_pool/lib/connection_pool.rb', line 40



def self.wrap(options, &block)
  Wrapper.new(options, &block)
end


  







Instance Method Details



  

    #available  
  



  

    

Number of pool entries available for checkout at this instant.


  



  [ GitHub ]


  

  


# File 'lib/bundler/vendor/connection_pool/lib/connection_pool.rb', line 122



def available
  @available.length
end


  








  

    #checkin  
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/connection_pool/lib/connection_pool.rb', line 97



def checkin
  if ::Thread.current[@key]
    if ::Thread.current[@key_count] == 1
      @available.push(::Thread.current[@key])
      ::Thread.current[@key]= nil
    else
      ::Thread.current[@key_count]-= 1
    end
  else
    raise Bundler::ConnectionPool::Error, 'no connections are checked out'
  end

  nil
end


  








  

    #checkout(options = {})  
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/connection_pool/lib/connection_pool.rb', line 87



def checkout(options = {})
  if ::Thread.current[@key]
    ::Thread.current[@key_count]+= 1
    ::Thread.current[@key]
  else
    ::Thread.current[@key_count]= 1
    ::Thread.current[@key]= @available.pop(options[:timeout] || @timeout)
  end
end


  








  

    #shutdown(&block)  
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/connection_pool/lib/connection_pool.rb', line 112



def shutdown(&block)
  @available.shutdown(&block)
end


  








  

    #size  
  



  

    

Size of this connection pool


  



  [ GitHub ]


  

  


# File 'lib/bundler/vendor/connection_pool/lib/connection_pool.rb', line 117



def size
  @size
end


  








  

    #with(options = {})  
  



  

    

jruby 1.7.x



See additional method definition at line 60.


  



  [ GitHub ]


  

  


# File 'lib/bundler/vendor/connection_pool/lib/connection_pool.rb', line 76



def with(options = {})
  Thread.handle_interrupt(Exception => :never) do
    conn = checkout(options)
    begin
      Thread.handle_interrupt(Exception => :immediate) do
        yield conn
      end
    ensure
      checkin
    end
  end
end