Class: Roby::Log::Server

Inherits:
Object show all
Extended by:
Logger::Forward
Defined in:
lib/roby/log/server.rb

Constant Summary collapse

RING_PORT = 
48904
POLLING_TIMEOUT =

Default value for #polling_timeout

0.1

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(port = RING_PORT, polling_timeout = POLLING_TIMEOUT) ⇒ Server

Returns a new instance of Server.



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# File 'lib/roby/log/server.rb', line 106

def initialize(port = RING_PORT, polling_timeout = POLLING_TIMEOUT)
		@ring_server = Distributed::RingServer.new(DRbObject.new(self), :port => port)
		@mutex   = Mutex.new
		@streams = Array.new
		@connections = Hash.new
		@subscriptions = Hash.new { |h, k| h[k] = Set.new }
		@polling_timeout = polling_timeout
		@polling = Thread.new(&method(:polling))
end

Class Attribute Details

.logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/roby/log/server.rb', line 13

def logger
  @logger
end

Instance Attribute Details

#connections ⇒ Object (readonly)

A remote_server => [queue, thread] hash which contains the set of connection parameters for each connected peer



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# File 'lib/roby/log/server.rb', line 95

def connections
  @connections
end

#polling_timeout ⇒ Object (readonly)

Returns the value of attribute polling_timeout.



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# File 'lib/roby/log/server.rb', line 104

def polling_timeout
  @polling_timeout
end

#ring_server ⇒ Object (readonly)

The Distributed::RingServer object which publishes this display server on the network



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# File 'lib/roby/log/server.rb', line 99

def ring_server
  @ring_server
end

#subscriptions ⇒ Object (readonly)

A stream_id => [remote_server, ...] hash containing the set of subscribed remote peer for each stream



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# File 'lib/roby/log/server.rb', line 92

def subscriptions
  @subscriptions
end

Class Method Details

.available_servers ⇒ Object

Returns the set of servers that have been discovered by the discovery mechanism at this time

See also enable_discovery and disable_discovery



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# File 'lib/roby/log/server.rb', line 30

def self.available_servers
		synchronize do
 @available_servers.dup
		end
end

.disable_discovery ⇒ Object

Stops the discovery thread if it is running



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# File 'lib/roby/log/server.rb', line 77

def self.disable_discovery
		Control.finalizers.delete(method(:disable_discovery))
		if @discovery_thread
 @discovery_thread.raise Interrupt, "quitting"
 @discovery_thread.join
 @discovery_thread = nil

 synchronize do
			@available_servers.clear
 end
		end
end

.enable_discovery(broadcast, port = RING_PORT, period = 10) ⇒ Object

Start an asynchronous discovery mechanism. This will fill the #available_servers set of servers. broadcast is an array of addresses on which discovery should be done and period is the discovery period in seconds



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# File 'lib/roby/log/server.rb', line 40

def self.enable_discovery(broadcast, port = RING_PORT, period = 10)
		if @discovery_thread
 raise ArgumentError, "already enabled discovery"
		end

		finger = Rinda::RingFinger.new(broadcast, port)

		discovered_displays = Array.new
		@available_servers  = Array.new

		# Add disable_discovery in the list of finalizers
		Control.finalizers << method(:disable_discovery)

		@discovery_thread = Thread.new do
 begin
			loop do
  finger.lookup_ring(period) do |remote|
				synchronize do
   unless @available_servers.include?(remote)
@available_servers << remote
   end
   discovered_displays << remote
				end
  end
  sleep(period)

  synchronize do
				@available_servers, discovered_displays = discovered_displays, @available_servers
				discovered_displays.clear
  end
			end
 rescue Interrupt
 end
		end
end

.synchronize ⇒ Object 



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# File 'lib/roby/log/server.rb', line 22

def self.synchronize
		@mutex.synchronize { yield }
end

Instance Method Details

#added_stream(stream) ⇒ Object

New stream



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# File 'lib/roby/log/server.rb', line 208

def added_stream(stream)
		synchronize do
 @streams << stream
 connections.each_value do |queue, _|
			queue.push [:added_stream, stream.class.name, stream.id, stream.name, stream.type]
 end
		end
end

#connect(remote) ⇒ Object 



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# File 'lib/roby/log/server.rb', line 120

def connect(remote)
		synchronize do
 queue = Queue.new
 receiver_thread = pushing_loop(remote, queue)
 connections[remote] = [queue, receiver_thread]

 Server.info "#{remote.__drburi} connected"
		end
		streams.map do |s|
 [s.class.name, s.id, s.name, s.type]
		end
end

#disconnect(remote) ⇒ Object 



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# File 'lib/roby/log/server.rb', line 133

def disconnect(remote)
		thread = synchronize do
 queue, thread = connections[remote]
 if thread
			thread.raise Interrupt, "quitting"
			thread
 end
		end
		thread.join if thread

		Server.info "#{remote.__drburi} disconnected"
end

#polling ⇒ Object

Polls all data sources and pushes the samples to the subscribed clients



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# File 'lib/roby/log/server.rb', line 148

def polling
		loop do
 s, data = nil
 done_sth = false
 synchronize do
			@streams.each do |s|
  done_sth ||= if s.reinit?
     Roby::Log::Server.info "reinitializing #{s}"
     s.reinit!
     reinit(s.id)
     true
 elsif s.has_sample?
     if Roby::Log::Server.logger.debug?
	 Roby::Log::Server.debug "new sample for #{s} at #{s.current_time.to_hms}"
     end
     push(s.id, s.current_time, s.read)
     true
 end
			end
 end
			
 unless done_sth
			sleep(polling_timeout)
 end
		end
rescue Interrupt
end

#quit ⇒ Object 



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# File 'lib/roby/log/server.rb', line 295

def quit
		if @polling
 @polling.raise Interrupt, "quitting"
 @polling.join
		end

		connections.each_value do |queue, thread|
 queue.push [:quit]
 thread.join
		end
end

#removed_stream(id) ⇒ Object

Stream id has stopped



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# File 'lib/roby/log/server.rb', line 218

def removed_stream(id)
		synchronize do
 found = false
 @streams.delete_if { |s| found ||= (s.id == id) }
 unless found
			raise ArgumentError, "no such stream"
 end

 connections.each_value do |queue, _|
			queue.push [:removed_stream, id]
 end
 subscriptions.delete(id)
		end
end

#streams ⇒ Object

Returns a set of Roby::Log::DataStream objects describing the available data sources on this stream



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# File 'lib/roby/log/server.rb', line 235

def streams
		synchronize do
 @streams.dup
		end
end

#subscribe(id, remote) ⇒ Object

Make remote subscribe to the stream identified by id. When new data is available, #push will be called on remote. The exact format of the pushed sample depends on the type of the stream

If the stream stop existing (because it source has quit for instance), #removed_stream will be called on the remote object



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# File 'lib/roby/log/server.rb', line 248

def subscribe(id, remote)
		synchronize do
 if s = @streams.find { |s| s.id == id }
			subscriptions[id] << remote
			if data = s.read_all
  remote.init(id, data)
			end
 else
			raise ArgumentError, "no such stream"
 end
		end
end

#synchronize ⇒ Object 



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# File 'lib/roby/log/server.rb', line 116

def synchronize
		@mutex.synchronize { yield }
end

#unsubscribe(id, remote) ⇒ Object

Rmoves a subscription of remote on id



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# File 'lib/roby/log/server.rb', line 262

def unsubscribe(id, remote)
		synchronize do
 if subscriptions.has_key?(id)
			subscriptions[id].delete(remote)
 end
		end
end