Class: Sequel::SingleThreadedPool

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

Overview

A SingleThreadedPool acts as a replacement for a ConnectionPool for use in single-threaded applications. ConnectionPool imposes a substantial performance penalty, so SingleThreadedPool is used to gain some speed.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}, &block) ⇒ SingleThreadedPool

Initializes the instance with the supplied block as the connection_proc.

The single threaded pool takes the following options:

  • :disconnection_proc - The proc called when removing connections from the pool.

  • :pool_convert_exceptions - Whether to convert non-StandardError based exceptions to RuntimeError exceptions (default true)

  • :servers - A hash of servers to use. Keys should be symbols. If not present, will use a single :default server. The server name symbol will be passed to the connection_proc.



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# File 'lib/sequel/connection_pool.rb', line 218

def initialize(opts={}, &block)
  @connection_proc = block
  @disconnection_proc = opts[:disconnection_proc]
  @conns = {}
  @convert_exceptions = opts.include?(:pool_convert_exceptions) ? opts[:pool_convert_exceptions] : true
end

Instance Attribute Details

#connection_proc=(value) ⇒ Object (writeonly)

The proc used to create a new database connection



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# File 'lib/sequel/connection_pool.rb', line 203

def connection_proc=(value)
  @connection_proc = value
end

#disconnection_proc ⇒ Object

The proc used to disconnect a database connection.



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# File 'lib/sequel/connection_pool.rb', line 206

def disconnection_proc
  @disconnection_proc
end

Instance Method Details

#conn(server = :default) ⇒ Object

The connection for the given server.



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# File 'lib/sequel/connection_pool.rb', line 226

def conn(server=:default)
  @conns[server]
end

#disconnect(&block) ⇒ Object

Disconnects from the database. Once a connection is requested using #hold, the connection is reestablished.



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# File 'lib/sequel/connection_pool.rb', line 249

def disconnect(&block)
  block ||= @disconnection_proc
  @conns.values.each{|conn| block.call(conn) if block}
  @conns = {}
end

#hold(server = :default) ⇒ Object

Yields the connection to the supplied block for the given server. This method simulates the ConnectionPool#hold API.



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# File 'lib/sequel/connection_pool.rb', line 232

def hold(server=:default)
  begin
    begin
      yield(c = (@conns[server] ||= @connection_proc.call(server)))
    rescue Sequel::DatabaseDisconnectError => dde
      @conns.delete(server)
      @disconnection_proc.call(c) if @disconnection_proc
      raise
    end
  rescue Exception => e
    # if the error is not a StandardError it is converted into RuntimeError.
    raise(@convert_exceptions && !e.is_a?(StandardError) ? RuntimeError.new(e.message) : e)
  end
end