Module: LanGrove::Handler

Included in:
Base, Deferred, SocketBase
Defined in:
lib/langrove/handler/socket_multiplexer.rb,
lib/langrove/handler/base.rb,
lib/langrove/handler/socket.rb,
lib/langrove/handler/deferred.rb,
lib/langrove/handler/web_socket.rb,
lib/langrove/handler/socket_base.rb,
lib/langrove/handler/handler_base.rb,
lib/langrove/handler/http_servlet.rb

Overview

Occasionally a daemon is required to maintain multiple handlers in state, each receiving data asymetrically from an already aggregated source.

eg. A post accumulated syslog stream being forwarded

to the local daemon containing log events from 
the entire network.

This stream would arrive on a single socket to which there would therefore be only one attached Handler in the Daemon (per the pattern)

The purpose of this de-multiplexer is to re-align this situation back to pattern.

ie. To arrive at the situation where there is a representative 

entity present in the local Server for each connected Client, 
even if only connected 'virtually' via the remote proxy.

Allowing therefore the unmodified application of Behaviours
to these representative Handlers.

Defined Under Namespace

Modules: SocketBase Classes: Base, Deferred, HttpServlet, Socket, SocketMultiplexer, WebSocket

Constant Summary collapse

Default = 
LanGrove::Handler::Socket

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#capsule ⇒ Object

Handler contains a ‘capsule’ of data to be maniplulated by the implementor toward achieving their architected goal.

  • It is stored in the @capsule instance variable.

  • It is acted upon by certain of the built in Behaviours

  • Is is accessable through the following attribute



23
24
25
 
# File 'lib/langrove/handler/handler_base.rb', line 23

def capsule
  @capsule
end

#config ⇒ Object

Returns the value of attribute config.



11
12
13
 
# File 'lib/langrove/handler/handler_base.rb', line 11

def config
  @config
end

#key ⇒ Object

key contains the persistance storage address for the capsule



35
36
37
 
# File 'lib/langrove/handler/handler_base.rb', line 35

def key
  @key
end

#logger ⇒ Object

Returns the value of attribute logger.



10
11
12
 
# File 'lib/langrove/handler/handler_base.rb', line 10

def logger
  @logger
end

#pending_capsule ⇒ Object

pending_capsule is populated with the first received message and is used as source to construct the (storage) key



29
30
31
 
# File 'lib/langrove/handler/handler_base.rb', line 29

def pending_capsule
  @pending_capsule
end

#protocol ⇒ Object

Returns the value of attribute protocol.



8
9
10
 
# File 'lib/langrove/handler/handler_base.rb', line 8

def protocol
  @protocol
end

#scheduler ⇒ Object

Returns the value of attribute scheduler.



9
10
11
 
# File 'lib/langrove/handler/handler_base.rb', line 9

def scheduler
  @scheduler
end

#server ⇒ Object

Returns the value of attribute server.



7
8
9
 
# File 'lib/langrove/handler/handler_base.rb', line 7

def server
  @server
end

#type ⇒ Object

Returns the value of attribute type.



5
6
7
 
# File 'lib/langrove/handler/handler_base.rb', line 5

def type
  @type
end

Instance Method Details

#assign(parameters) ⇒ Object 



200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
 
# File 'lib/langrove/handler/handler_base.rb', line 200

def assign( parameters )
  
  @root = parameters[ :root ]
  
  @logger = @root.logger
  
  @type = :handler
  
  @capsule = {} if @capsule.nil?
  @key = nil
  @pending_capsule = nil
  
  
  #
  # Assigns daemon infrastructure
  # to sub process Handler (this)
  #
  
  self.config   = parameters[ :handler ][ :config ]
       
  #
  # Bind to (own instance) of Protocol + Protocol Config
  #
  
  self.protocol = parameters[ :protocol ][ :class ].new( 
  
    @root,
    parameters[ :protocol ][ :config ], 
    nil
  
  )
  
  #
  # Bind to Server
  #
  self.server = parameters[ :server ]
  parameters[ :server ].connect( self )
  
end

#connect ⇒ Object 



48
 
# File 'lib/langrove/handler/handler_base.rb', line 48

def connect; end

#disconnect ⇒ Object 



50
 
# File 'lib/langrove/handler/handler_base.rb', line 50

def disconnect; end

#error(err) ⇒ Object 



52
 
# File 'lib/langrove/handler/handler_base.rb', line 52

def error( err ); end

#event_filter(type, object) {|object| ... } ⇒ Object

Yields:

  • (object) 


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
 
# File 'lib/langrove/handler/handler_base.rb', line 67

def event_filter( type, object, &block )
  
  #
  #  OVERRIDE
  # 
  #  Certain behaviours call back through this filter 
  #  on the handler.
  # 
  #  The implementor can override this to affect control 
  #  over certain of the internal event pipelines.
  # 
  #  By not yielding into the block, the implementor can 
  #  prevent the <object> from traversing further. 
  #  
  # 
  #  <type>   
  # 
  #  Refers to which behaviour is calling back for 
  #  filtration.
  # 
  #  These include:
  #  
  #  :notification - A notification is about to be 
  #                  triggered. 
  # 
  #  <object>
  # 
  #  The notification.
  # 
  #  <&block> 
  # 
  #  This block to yield into after choosing to allow
  #  the event to traverse further.
  # 
  
  yield object if block
  
end

#receive(decoded_data) ⇒ Object 



54
55
56
57
58
59
60
61
62
 
# File 'lib/langrove/handler/handler_base.rb', line 54

def receive( decoded_data )

  #
  # OVERRIDE
  # 

  @capsule = decoded_data

end

#reload ⇒ Object 



46
 
# File 'lib/langrove/handler/handler_base.rb', line 46

def reload; end

#reload_handler ⇒ Object 



172
173
174
175
176
177
178
 
# File 'lib/langrove/handler/handler_base.rb', line 172

def reload_handler
  
  @root.trigger( self, :handler, :reload )
  
  reload
  
end

#start ⇒ Object

Event Callbacks



42
 
# File 'lib/langrove/handler/handler_base.rb', line 42

def start; end

#start_handler ⇒ Object 



146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
 
# File 'lib/langrove/handler/handler_base.rb', line 146

def start_handler
  
  @logger.debug "#{self}.start_handler()"
  
  #
  # trigger event
  #
  
  @root.trigger( self, :handler, :start )
  
  #
  # call overridable
  #
  
  start
  
end

#stop ⇒ Object 



44
 
# File 'lib/langrove/handler/handler_base.rb', line 44

def stop; end

#stop_handler ⇒ Object 



164
165
166
167
168
169
170
 
# File 'lib/langrove/handler/handler_base.rb', line 164

def stop_handler
  
  @root.trigger( self, :handler, :stop )
  
  stop
  
end

#transform(type, object) {|object| ... } ⇒ Object

Yields:

  • (object) 


106
107
108
109
110
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
 
# File 'lib/langrove/handler/handler_base.rb', line 106

def transform( type, object, &block )
  
  #
  # OVERRIDE
  #
  # Certain of the behaviours call through this transform
  # to adjust the data format of the capsule.
  # 
  # eg. The notifier requires a notification to be assembled
  #     into the format for the destination system.
  # 
  # <type>
  # 
  # Refers to which behaviour is calling back for 
  # transformation.
  #
  #  These include:
  #  
  #  :notification - A notification is about to be 
  #                  triggered. 
  #
  # 
  # 
  # <object>
  # 
  # The notification. Usually the 'capsule' and enqueued
  # 
  
  #
  # Default is no transform
  #
  yield object
  
  #
  # Return false if the notification should not go ahead
  #
  return true
  
end

#unique ⇒ Object

Raises:



180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
 
# File 'lib/langrove/handler/handler_base.rb', line 180

def unique

  raise LanGrove::DaemonConfigException.new(

    "Called unique without :unique: key specified"

  ) if @config[:unique].nil?

  unique = @capsule[@config[:unique]]

  raise LanGrove::RuntimeException.new(

    "Missing value for :unique: #{@config[:unique]}"

  ) if unique.nil?

  return unique

end