Class: OMF::Web::Rack::WebsocketHandler

Inherits:
Rack::WebSocket::Application
  • Object
show all
Extended by:
Base::Loggable
Includes:
Base::Loggable
Defined in:
lib/omf-web/rack/websocket_handler.rb

Constant Summary collapse

MESSAGE_DELAY = 
0.5

Instance Method Summary collapse

Instance Method Details

#find_data_source(args) ⇒ Object 



147
148
149
150
151
152
153
154
155
 
# File 'lib/omf-web/rack/websocket_handler.rb', line 147

def find_data_source(args)
  ds_name = args['ds_name']
  unless dsp = OMF::Web::DataSourceProxy[ds_name]
    warn "Request for unknown datasource '#{ds_name}'."
    send_data({type: 'reply', status: 'error', err_msg: "Unknown datasource '#{ds_name}'"}.to_json)
    return nil
  end
  dsp
end

#on_close(env) ⇒ Object 



46
47
48
49
50
51
52
53
54
 
# File 'lib/omf-web/rack/websocket_handler.rb', line 46

def on_close(env)
  begin
    debug "client disconnected"
    @tab_inst.on_ws_close(self, @sub_path) if @tab_inst
    @tab_inst = nil
  rescue Exception => ex
    error(ex)
  end
end

#on_message(env, msg_s) ⇒ Object 



21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
 
# File 'lib/omf-web/rack/websocket_handler.rb', line 21

def on_message(env, msg_s)
  begin
    req = ::Rack::Request.new(env)
    sid = req.params['sid']
    Thread.current["sessionID"] = sid

    msg = JSON.parse(msg_s)
    debug("Msg(#{sid}): #{msg.inspect}")
    msg_type = msg['type']
    args = msg['args']
    msg_handler = "on_#{msg_type}".to_sym
    unless respond_to? msg_handler
      warn "Received unknonw request '#{msg_type}'"
      send_data({type: 'reply', status: 'error', err_msg: "Unknown message type '#{msg_type}'"}.to_json)
      return
    end
    context = OMF::Web::SessionStore[args['name'], :ws] ||= {}
    send(msg_handler, args, context)
  rescue Exception => ex
    error ex
    debug "#{ex.backtrace.join("\n")}"
    send_data({type: 'reply', status: 'exception', err_msg: ex.to_s}.to_json)
  end
end

#on_open(env) ⇒ Object

Delay in pushing action message to browser after receiving a ‘on_change’ from monitored data proxy



17
18
19
 
# File 'lib/omf-web/rack/websocket_handler.rb', line 17

def on_open(env)
  #puts ">>>>> OPEN"
end

#on_register_data_source(args, context) ⇒ Object 



56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
 
# File 'lib/omf-web/rack/websocket_handler.rb', line 56

def on_register_data_source(args, context)
  dsp = find_data_source(args)
  return unless dsp  # should define appropriate exception
  debug "Received registration for datasource proxy '#{dsp}'"
  send_data({type: 'reply', status: 'ok'}.to_json)

  mutex = Mutex.new
  semaphore = ConditionVariable.new
  action_queue = {}

  dsp.on_changed(args['offset']) do |action, rows|
    mutex.synchronize do
      (action_queue[action] ||= []).concat(rows)
      semaphore.signal
    end
  end

  # Send the rows in a separate thread, waiting a bit after the first one arriving
  # to 'bunch' things into more manageable number of messages
  Thread.new do
    begin
      loop do
        # Now lets send them
        mutex.synchronize do
          action_queue.each do |action, rows|
            next if rows.empty?
            debug "Sending '#{action}' message with #{rows.length} rows"
            msg = {
              type: 'datasource_update',
              datasource: dsp.name,
              rows: rows,
              action: action
              #offset: offset
            }
            # http://stackoverflow.com/questions/17022394/convert-string-to-utf8-in-ruby
            send_data(msg.to_json.encode("iso-8859-1").force_encoding("UTF-8"))
            rows.clear
          end

          # wait until there is more to send
          semaphore.wait(mutex)
        end

        # OK, there is something to do, but let's wait a bit, maybe there is more
        sleep MESSAGE_DELAY
      end
    rescue Exception => ex
      error "on_register_data_source - #{ex}"
      debug "#{ex.backtrace.join("\n")}"
    end
  end

end

#on_request_slice(args, context) ⇒ Object

args “col_value”=>“e8…”, “ds_name”=>“individual_link”}}



111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
 
# File 'lib/omf-web/rack/websocket_handler.rb', line 111

def on_request_slice(args, context)
  dsp = find_data_source(args)
  return unless dsp  # should define appropriate exception

  sargs = args['slice']
  col_name = sargs['col_name']
  col_value = sargs['col_value']
  debug "Creating slice '#{col_name}:#{col_value}' data source '#{dsp}'"

  if old_sdsp = context[:sliced_datasource]
    return if old_sdsp[:column_name] == col_name
    old_sdsp[:dsp].release
  end
  sdsp = dsp.create_slice(col_name, col_value)
  context[:sliced_datasource] = {:col_name => col_name, :dsp => sdsp}
  sdsp.on_changed(0) do |action, rows|
    msg = {
      type: 'datasource_update',
      datasource: args['ds_name'],
      rows: rows,
      action: action
      #offset: offset
    }
    send_data(msg.to_json.force_encoding("UTF-8"))
#
    # do |new_rows, offset|
    # msg = {
      # type: 'datasource_update',
      # datasource: args['ds_name'],
      # rows: new_rows,
      # offset: offset
    # }
    # send_data(msg.to_json)
  end
end