Class: FiberConnectionPool

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

Constant Summary collapse

VERSION = 
'0.1.2'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts) ⇒ FiberConnectionPool

Initializes the pool with ‘size’ instances running the given block to get each one. Ex:

pool = FiberConnectionPool.new(:size => 5) { MyConnection.new }

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_connection_pool.rb', line 13

def initialize(opts)
  raise ArgumentError.new('size > 0 is mandatory') if opts[:size].to_i <= 0

  @saved_data = {} # placeholder for requested save data
  @reserved  = {}   # map of in-progress connections
  @reserved_backup = {}   # backup map of in-progress connections, to catch failures
  @available = []   # pool of free connections
  @pending   = []   # pending reservations (FIFO)

  @available = Array.new(opts[:size].to_i) { yield }
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args, &blk) ⇒ Object (private)

Allow the pool to behave as the underlying connection

If the requesting method begins with “a” prefix, then hijack the callbacks and errbacks to fire a connection pool release whenever the request is complete. Otherwise yield the connection within execute method and release once it is complete (assumption: fiber will yield until data is available, or request is complete)



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# File 'lib/fiber_connection_pool.rb', line 117

def method_missing(method, *args, &blk)
  async = (method[0,1] == "a")

  execute(async,method) do |conn|
    df = conn.send(method, *args, &blk)

    if async
      fiber = Fiber.current
      df.callback do
        release(fiber)
        release_backup(fiber)
      end
      df.errback { release(fiber) }
    end

    df
  end
end

Instance Attribute Details

#saved_data ⇒ Object

Returns the value of attribute saved_data.



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# File 'lib/fiber_connection_pool.rb', line 6

def saved_data
  @saved_data
end

Instance Method Details

#query(sql) ⇒ Object

avoid method_missing for most common methods



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# File 'lib/fiber_connection_pool.rb', line 36

def query(sql)
  execute(false,'query') do |conn|
    conn.query sql
  end
end

#recreate_connection(new_conn) ⇒ Object 



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# File 'lib/fiber_connection_pool.rb', line 43

def recreate_connection(new_conn)
  bad_conn = @reserved_backup[Fiber.current.object_id]
  release_backup Fiber.current
  @available.reject!{ |v| v == bad_conn }
  @reserved.reject!{ |k,v| v == bad_conn }
  @available.push new_conn
  # try to cleanup
  begin
    bad_conn.close
  rescue
  end
end

#save_data_for_fiber ⇒ Object 



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# File 'lib/fiber_connection_pool.rb', line 25

def save_data_for_fiber
  @saved_data[Fiber.current.object_id] ||= {}
end

#stop_saving_data_for_fiber ⇒ Object 



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# File 'lib/fiber_connection_pool.rb', line 29

def stop_saving_data_for_fiber
  @saved_data.delete Fiber.current.object_id
end