Innertube

Innertube is a thread-safe, re-entrant resource pool, extracted from the Riak Ruby Client, where it was used to pool connections to Riak. It is free to use and modify, licensed under the Apache 2.0 License.

Example

# -------------------------------------------------------
# Basics
# -------------------------------------------------------

# Create a pool with open/close callables
pool = Innertube::Pool.new(proc { Connection.new },
                           proc {|c| c.disconnect })

# Optionally, fill the pool with existing resources
pool.fill([conn1, conn2, conn3])

# Grab a connection from the pool, returns the same value
# as the block
pool.take {|conn| conn.ping } # => true

# Raise the BadResource exception if the resource is no
# longer good
pool.take do |conn|
  raise Innertube::Pool::BadResource unless conn.connected?
  conn.ping
end

# Innertube helps your code be re-entrant! Take more resources
# while you have one checked out.
pool.take do |conn|
  conn.stream_tweets do |tweet|
    pool.take {|conn2| conn2.increment :tweets }
  end
end

# -------------------------------------------------------
# Iterations: These are slow because they have guarantees
# about visiting all current elements of the pool.
# -------------------------------------------------------

# Do something with every connection in the pool
pool.each {|conn| puts conn.get_stats }

# Expunge some expired connections from the pool
pool.delete_if {|conn| conn.idle_time > 5 }

Credits

The pool was originally implemented by Kyle Kingsbury and extracted by Sean Cribbs, when bugged about it by Pat Allan at EuRuKo 2012.