Class: EmSequelAsync::Mysql::ClientPool

Inherits:
Object
  • Object
show all
Defined in:
lib/em-sequel-async/mysql.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(db) ⇒ ClientPool

Instance Methods ===================================================



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# File 'lib/em-sequel-async/mysql.rb', line 28

def initialize(db)
  @options = {
    :symbolize_keys => true,
    :cast_booleans => true
  }

  db.opts.each do |key, value|
    case (key)
    when :database, :username, :password, :host, :port, :socket, :encoding, :charset, :compress, :timeout
      @options[key] = value
    when :user
      @options[:username] = value
    when :loggers
      if (value and !value.empty?)
        @options[:logging] = true
        @options[:logger] = value.first
      end
    end
  end
  
  @query_queue = [ ]

  @connections = { }
  @connection_pool = [ ]
  @connections_active = { }
  
  @connection_limit = @options[:connections] || self.class.size
  
  if (EventMachine.reactor_running? and self.class.trace?)
    EventMachine::PeriodicTimer.new(1) do
      dump_file = "#{self.class.trace}.#{@options[:database]}"
      
      File.open(dump_file, 'w') do |f|
        f.puts @options[:database]

        @connections.each do |c, x|
          f.puts "\t#{c.inspect} -> #{x.inspect}"
        end
        @connection_pool.each do |c|
          f.puts "\t#{c.inspect} (pool)"
        end
      
        @query_queue.each do |query, callback|
          f.puts "\t#{query}"
        end
      end
    end
  end
end

Class Method Details

.size ⇒ Object 



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# File 'lib/em-sequel-async/mysql.rb', line 10

def self.size
  @size ||= 4
end

.size=(value) ⇒ Object

Class Methods ======================================================



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# File 'lib/em-sequel-async/mysql.rb', line 5

def self.size=(value)
  @size = value.to_i
  @size = 1 if (@size <= 0)
end

.trace ⇒ Object 



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# File 'lib/em-sequel-async/mysql.rb', line 18

def self.trace
  @trace
end

.trace=(value) ⇒ Object 



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# File 'lib/em-sequel-async/mysql.rb', line 22

def self.trace=(value)
  @trace = value
end

.trace? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/em-sequel-async/mysql.rb', line 14

def self.trace?
  !!@trace
end

Instance Method Details

#add(connection) ⇒ Object 



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# File 'lib/em-sequel-async/mysql.rb', line 86

def add(connection)
  @connections[connection] = nil
  
  if (@query_queue.empty?)
    @connections_active.delete(connection)
    @connection_pool << connection
  else
    self.delegate_query(connection, *@query_queue.pop)
  end
end

#delegate_query(connection, query, callback) ⇒ Object 



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# File 'lib/em-sequel-async/mysql.rb', line 102

def delegate_query(connection, query, callback)
  @connections[connection] = [ query, callback ]

  start = Time.now
  deferrable = connection.query(query)
  
  deferrable.callback do |result|
    log(:debug, "(%.6fs) [OK] %s" % [ Time.now - start, query ])
    
    callback and callback.call(result, (Time.now - start).to_f, connection)

    self.add(connection)
  end
  deferrable.errback do |err|
    handled = false

    case (err)
    when Mysql2::Error
      case (err.message)
      when /^Deadlock/i
        self.delegate_query(connection, query, callback)

        handled = true
      when /Duplicate entry/i
        callback and callback.call(nil, (Time.now - start).to_f, connection, err)

        self.add(connection)

        handled = true
      when /MySQL server has gone away|Lost connection/i
        @query_queue << [ query, callback ]

        self.remove(connection)

        handled = true
      end
    end

    unless (handled)
      log(:error, "(%.6fs) [ERR] %s (%s: %s)" % [ Time.now - start, query, err.class, err ])
      log(:error, err.backtrace)

      callback and callback.call(false, (Time.now - start).to_f, connection, err)

      self.add(connection)
    end
  end
end

#log(level, *args) ⇒ Object 



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# File 'lib/em-sequel-async/mysql.rb', line 82

def log(level, *args)
  @options[:logger] and @options[:logger].send(level, *args)
end

#logger ⇒ Object 



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# File 'lib/em-sequel-async/mysql.rb', line 78

def logger
  @options[:logger]
end

#pool_connection ⇒ Object 



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# File 'lib/em-sequel-async/mysql.rb', line 151

def pool_connection
  connection = @connection_pool.pop
  
  if (!connection and @connections.length < @connection_limit)
    connection = Mysql2::EM::Client.new(@options)
  end

  @connections_active[connection] = true
  
  connection

rescue Mysql2::Error => err
  case (err.message)
  when /Too many connections/i
    return
  else
    raise err
  end
end

#query(query, callback = nil, &block) ⇒ Object 



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# File 'lib/em-sequel-async/mysql.rb', line 171

def query(query, callback = nil, &block)
  callback ||= block

  if (connection = self.pool_connection)
    self.delegate_query(connection, query, callback)
    
    :executing
  else
    @query_queue << [ query, callback ]

    :queued
  end
end

#remove(connection) ⇒ Object 



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# File 'lib/em-sequel-async/mysql.rb', line 97

def remove(connection)
  @connections.delete(connection)
  @connections_active.delete(connection)
end