Class: RDKit::Server

Inherits:
Object show all
Extended by:
ClassMethods
Includes:
Callbacks, MemoryMonitoring
Defined in:
lib/rdkit/server.rb

Defined Under Namespace

Modules: ClassMethods

Constant Summary collapse

HZ = 
10
HANDLED_SIGNALS = 
[ :TERM, :INT, :HUP ]

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from ClassMethods

instance, register

Methods included from Callbacks

#client_block_resumed, #client_blocked, #client_command_processed, #client_connected, #client_disconnected, #server_started

Methods included from MemoryMonitoring

#used_memory_peak_in_mb, #used_memory_rss_in_mb

Constructor Details

#initialize(host, port) ⇒ Server

Returns a new instance of Server.



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# File 'lib/rdkit/server.rb', line 24

def initialize(host, port)
  @host, @port = host, port

  @cycles = 0
  @peak_connected_clients = 0
  @client_id_seq = 0

  @clients = Hash.new
  @blocked_clients = Hash.new
  @monitors = []

  @logger = Logger.new(ENV['RDKIT_LOG_PATH'])
  @current_db = DB.new(0)
  @all_dbs = [@current_db]

  Introspection.register(self)

  @server_up_since = Time.now

  @parser_class = RESPParser

  register_notification_observers!

  Server.register(self)

  # Self-pipe for deferred signal-handling http://www.sitepoint.com/the-self-pipe-trick-explained/
  # Borrowed from `Foreman::Engine`
  reader, writer = create_pipe
  @selfpipe      = { :reader => reader, :writer => writer }
  @signal_queue  = []
end

Instance Attribute Details

#core ⇒ Object (readonly)

Returns the value of attribute core.



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# File 'lib/rdkit/server.rb', line 13

def core
  @core
end

#current_client ⇒ Object (readonly)

Returns the value of attribute current_client.



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# File 'lib/rdkit/server.rb', line 11

def current_client
  @current_client
end

#current_db ⇒ Object (readonly)

Returns the value of attribute current_db.



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# File 'lib/rdkit/server.rb', line 12

def current_db
  @current_db
end

#cycles ⇒ Object (readonly)

Returns the value of attribute cycles.



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# File 'lib/rdkit/server.rb', line 17

def cycles
  @cycles
end

#host ⇒ Object (readonly)

Returns the value of attribute host.



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# File 'lib/rdkit/server.rb', line 14

def host
  @host
end

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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# File 'lib/rdkit/server.rb', line 15

def logger
  @logger
end

#monitors ⇒ Object (readonly)

Returns the value of attribute monitors.



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# File 'lib/rdkit/server.rb', line 16

def monitors
  @monitors
end

#parser_class ⇒ Object

Returns the value of attribute parser_class.



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# File 'lib/rdkit/server.rb', line 18

def parser_class
  @parser_class
end

#port ⇒ Object (readonly)

Returns the value of attribute port.



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# File 'lib/rdkit/server.rb', line 14

def port
  @port
end

#server_up_since ⇒ Object (readonly)

Returns the value of attribute server_up_since.



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# File 'lib/rdkit/server.rb', line 10

def server_up_since
  @server_up_since
end

Instance Method Details

#blocking(on_success = nil, &block) ⇒ Object 



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# File 'lib/rdkit/server.rb', line 199

def blocking(on_success=nil, &block)
  @blocked_clients[current_client.socket] = current_client
  @clients.delete(current_client.socket)

  current_client.blocking(on_success, &block)
end

#clients ⇒ Object 



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# File 'lib/rdkit/server.rb', line 175

def clients
  @clients.values
end

#create_pipe ⇒ Object 



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# File 'lib/rdkit/server.rb', line 71

def create_pipe
  IO.method(:pipe).arity.zero? ? IO.pipe : IO.pipe("BINARY")
end

#delete(socket) ⇒ Object 



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# File 'lib/rdkit/server.rb', line 171

def delete(socket)
  @clients.delete(socket)
end

#flushall! ⇒ Object 



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# File 'lib/rdkit/server.rb', line 193

def flushall!
  flushdb!

  @all_dbs = [@current_db]
end

#flushdb! ⇒ Object 



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# File 'lib/rdkit/server.rb', line 189

def flushdb!
  @current_db.flush!
end

#handle_hangup ⇒ Object

Handle a HUP signal



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# File 'lib/rdkit/server.rb', line 132

def handle_hangup
  @logger.warn "SIGHUP received"
  terminate_gracefully
end

#handle_interrupt ⇒ Object

Handle an INT signal



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# File 'lib/rdkit/server.rb', line 125

def handle_interrupt
  @logger.warn "SIGINT received"
  terminate_gracefully
end

#handle_signal(sig) ⇒ Object

Invoke the real handler for signal sig. This shouldn’t be called directly by signal handlers, as it might invoke code which isn’t re-entrant.

Parameters:

  • sig (Symbol) —

    the name of the signal to be handled



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# File 'lib/rdkit/server.rb', line 103

def handle_signal(sig)
  case sig
  when :TERM
    handle_term_signal
  when :INT
    handle_interrupt
  when :HUP
    handle_hangup
  else
    system "unhandled signal #{sig}"
  end
end

#handle_signals ⇒ Object 



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# File 'lib/rdkit/server.rb', line 92

def handle_signals
  while sig = @signal_queue.shift
    handle_signal(sig)
  end
end

#handle_term_signal ⇒ Object

Handle a TERM signal



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# File 'lib/rdkit/server.rb', line 118

def handle_term_signal
  @logger.warn "SIGTERM received"
  terminate_gracefully
end

#introspection ⇒ Object 



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# File 'lib/rdkit/server.rb', line 147

def introspection
  {
    server: {
      ruby_version: "#{RUBY_VERSION}p#{RUBY_PATCHLEVEL}",
      rdkit_version: RDKit::VERSION,
      multiplexing_api: 'select',
      process_id: Process.pid,
      tcp_port: @port,
      uptime_in_seconds: (Time.now - @server_up_since).to_i,
      uptime_in_days: ((Time.now - @server_up_since) / (24 * 60 * 60)).to_i,
      hz: HZ,
    },
    clients: {
      blocked_clients: @blocked_clients.size,
      connected_clients: @clients.size,
      connected_clients_peak: @peak_connected_clients
    },
    memory: {
      used_memory_rss: used_memory_rss_in_mb,
      used_memory_peak: used_memory_peak_in_mb
    },
  }
end

#notice_signal ⇒ Object 



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# File 'lib/rdkit/server.rb', line 83

def notice_signal
  @selfpipe[:writer].write_nonblock('.')
rescue Errno::EAGAIN
  # Ignore writes that would block
rescue Errno::EINT
  # Retry if another signal arrived while writing
  retry
end

#pool ⇒ Object 



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# File 'lib/rdkit/server.rb', line 206

def pool
  @pool ||= Thread.pool((ENV['RDKIT_SERVER_THREAD_POOL_SIZE'] || 10).to_i)
end

#register_signal_handlers ⇒ Object 



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# File 'lib/rdkit/server.rb', line 75

def register_signal_handlers
  HANDLED_SIGNALS.each do |sig|
    if ::Signal.list.include? sig.to_s
      trap(sig) { @signal_queue << sig ; notice_signal }
    end
  end
end

#responder ⇒ Object 



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# File 'lib/rdkit/server.rb', line 20

def responder
  @responder ||= (( @runner && $stderr.puts("@runner is deprecated, use @responder instead") ) || @runner)
end

#select_db!(index) ⇒ Object 



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# File 'lib/rdkit/server.rb', line 179

def select_db!(index)
  if db = @all_dbs.find { |db| db.index == index }
    @current_db = db
  else
    @all_dbs << DB.new(index)

    @current_db = @all_dbs.last
  end
end

#start ⇒ Object 



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# File 'lib/rdkit/server.rb', line 56

def start
  sanity_check!

  register_signal_handlers

  @server_socket = TCPServer.new(@host, @port)

  run_acceptor
end

#stop ⇒ Object 



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# File 'lib/rdkit/server.rb', line 66

def stop
  @logger.warn "shutting down..."
  exit
end

#terminate_gracefully ⇒ Object 



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# File 'lib/rdkit/server.rb', line 137

def terminate_gracefully
  return if @terminating

  @terminating = true

  stop
end