70 lines
1.6 KiB
Ruby
70 lines
1.6 KiB
Ruby
require 'connection_pool/timed_queue'
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# Generic connection pool class for e.g. sharing a limited number of network connections
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# among many threads. Note: Connections are eager created.
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#
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# Example usage with block (faster):
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#
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# @pool = ConnectionPool.new { Redis.new }
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#
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# @pool.with do |redis|
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# redis.lpop('my-list') if redis.llen('my-list') > 0
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# end
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#
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# Example usage replacing a global connection (slower):
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#
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# REDIS = ConnectionPool.new { Redis.new }
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#
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# def do_work
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# REDIS.lpop('my-list') if REDIS.llen('my-list') > 0
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# end
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#
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# Accepts the following options:
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# - :size - number of connections to pool, defaults to 5
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# - :timeout - amount of time to wait for a connection if none currently available, defaults to 5 seconds
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#
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class ConnectionPool
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DEFAULTS = { :size => 5, :timeout => 5 }
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def initialize(options={})
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raise ArgumentError, 'Connection pool requires a block' unless block_given?
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@available = TimedQueue.new
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@options = DEFAULTS.merge(options)
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@options[:size].times do
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@available << yield
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end
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@busy = []
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end
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def with(&block)
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yield checkout
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ensure
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checkin
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end
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def method_missing(name, *args)
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checkout.send(name, *args)
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ensure
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checkin
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end
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private
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def checkout
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Thread.current[:"current-#{self.object_id}"] ||= begin
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conn = @available.timed_pop(@options[:timeout])
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@busy << conn
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conn
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end
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end
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def checkin
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conn = Thread.current[:"current-#{self.object_id}"]
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Thread.current[:"current-#{self.object_id}"] = nil
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@busy.delete(conn)
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@available << conn
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nil
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end
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end |