Class: EventMachine::Postgres

Inherits:
Object
  • Object
show all
Defined in:
lib/em-postgres/postgres.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts) ⇒ Postgres

Returns a new instance of Postgres.



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# File 'lib/em-postgres/postgres.rb', line 45

def initialize(opts)
  unless EM.respond_to?(:watch) and PGconn.method_defined?(:socket)
    
    raise RuntimeError, 'pg and EM.watch are required for EventedPostgres'
  end

  @settings = { :debug => false }.merge!(opts)
  @connection = connect(@settings)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

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

behave as a normal postgres connection



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# File 'lib/em-postgres/postgres.rb', line 71

def method_missing(method, *args, &blk)
  @connection.send(method, *args)
end

Instance Attribute Details

#connection ⇒ Object (readonly)

self::Postgres = ::Postgres unless defined? self::Postgres



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# File 'lib/em-postgres/postgres.rb', line 43

def connection
  @connection
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/em-postgres/postgres.rb', line 55

def close
  @connection.close
end

#connect(opts) ⇒ Object 



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# File 'lib/em-postgres/postgres.rb', line 75

def connect(opts)
  if conn = connect_socket(opts)
    #debug [:connect, conn.socket, opts]
    #EM.watch(conn.socket, EventMachine::PostgresConnection, conn, opts, self)

    EM.watch(conn.socket, EventMachine::PostgresConnection,conn,opts,self)
  else
    # invokes :errback callback in opts before firing again
    debug [:reconnect]
    EM.add_timer(5) { connect opts }
  end
end

#connect_socket(opts) ⇒ Object

stolen from sequel



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# File 'lib/em-postgres/postgres.rb', line 89

def connect_socket(opts)
begin
  conn = PGconn.connect(
    opts[:host],
    (opts[:port]), #TODO deal with host and port
    nil,nil,
    opts[:database],
    opts[:user],
    opts[:password]
  )
  # set encoding _before_ connecting
  if encoding = opts[:encoding] || opts[:charset]
    if conn.respond_to?(:set_client_encoding)
      conn.set_client_encoding(encoding)
    else
      conn.async_exec("set client_encoding to '#{encoding}'")
    end
  end
  
  #conn.options(Mysql::OPT_LOCAL_INFILE, 'client')
 
  # increase timeout so mysql server doesn't disconnect us
  # this is especially bad if we're disconnected while EM.attach is
  # still in progress, because by the time it gets to EM, the FD is
  # no longer valid, and it throws a c++ 'bad file descriptor' error
  # (do not use a timeout of -1 for unlimited, it does not work on mysqld > 5.0.60)
  #conn.query("set @@wait_timeout = #{opts[:timeout] || 2592000}")

  # we handle reconnecting (and reattaching the new fd to EM)
  #conn.reconnect = false

  # By default, MySQL 'where id is null' selects the last inserted id
  # Turn this off. http://dev.rubyonrails.org/ticket/6778
  #conn.query("set SQL_AUTO_IS_NULL=0")

  # get results for queries
  #conn.query_with_result = true

  conn
rescue Exception => e
  puts "#{e} exception"
  if cb = opts[:errback]
    cb.call(e)
    nil
  else
    raise e
  end
end
end

#debug(data) ⇒ Object 



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# File 'lib/em-postgres/postgres.rb', line 139

def debug(data)
  p data if @settings[:debug]
end

#query(sql, &blk) ⇒ Object Also known as: real_query, execute 



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# File 'lib/em-postgres/postgres.rb', line 59

def query(sql, &blk)
  df = EventMachine::DefaultDeferrable.new
  cb = blk || Proc.new { |r| df.succeed(r) }
  eb = Proc.new { |r| df.fail(r) }

  @connection.execute(sql, cb, eb)

  df
end