-
Notifications
You must be signed in to change notification settings - Fork 3.4k
/
Node.js
578 lines (541 loc) · 17.3 KB
/
Node.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
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
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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
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
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
/**
* Copyright JS Foundation and other contributors, http://js.foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
**/
var util = require("util");
var EventEmitter = require("events").EventEmitter;
var redUtil = require("@node-red/util").util;
var Log = require("@node-red/util").log;
var context = require("./context");
var flows = require("../flows");
const hooks = require("@node-red/util").hooks;
const NOOP_SEND = function() {}
/**
* The Node object is the heart of a Node-RED flow. It is the object that all
* nodes extend.
*
* The Node object itself inherits from EventEmitter, although it provides
* custom implementations of some of the EE functions in order to handle
* `input` and `close` events properly.
*/
function Node(n) {
this.id = n.id;
this.type = n.type;
this.z = n.z;
this._closeCallbacks = [];
this._inputCallback = null;
this._inputCallbacks = null;
if (n.name) {
this.name = n.name;
}
if (n._alias) {
this._alias = n._alias;
}
if (n._flow) {
// Make this a non-enumerable property as it may cause
// circular references. Any existing code that tries to JSON serialise
// the object (such as dashboard) will not like circular refs
// The value must still be writable in the case that a node does:
// Object.assign(this,config)
// as part of its constructor - config._flow will overwrite this._flow
// which we can tolerate as they are the same object.
Object.defineProperty(this,'_flow', {value: n._flow, enumerable: false, writable: true })
}
this.updateWires(n.wires);
}
util.inherits(Node, EventEmitter);
/**
* Update the wiring configuration for this node.
*
* We try to optimise the message handling path. To do this there are three
* cases to consider:
* 1. this node is wired to nothing. In this case we replace node.send with a
* NO-OP function.
* 2. this node is wired to one other node. In this case we set `this._wire`
* as a reference to the node it is wired to. This means we avoid unnecessary
* iterations over what would otherwise be a 1-element array.
* 3. this node is wired to multiple things. The normal node.send processing of
* this.wires applies.
*
* @param {array} wires the new wiring configuration
*/
Node.prototype.updateWires = function(wires) {
//console.log("UPDATE",this.id);
this.wires = wires || [];
delete this._wire;
var wc = 0;
this.wires.forEach(function(w) {
wc+=w.length;
});
this._wireCount = wc;
if (wc === 0) {
// With nothing wired to the node, no-op send
this.send = NOOP_SEND
} else {
this.send = Node.prototype.send;
if (this.wires.length === 1 && this.wires[0].length === 1) {
// Single wire, so we can shortcut the send when
// a single message is sent
this._wire = this.wires[0][0];
}
}
}
/**
* Get the context object for this node.
*
* As most nodes do not use context, this is a lazy function that will only
* create a context instance for the node if it is needed.
* @return {object} the context object
*/
Node.prototype.context = function() {
if (!this._context) {
this._context = context.get(this._alias||this.id,this.z);
}
return this._context;
}
/**
* Handle the complete event for a message
*
* @param {object} msg The message that has completed
* @param {error} error (optional) an error hit whilst handling the message
*/
Node.prototype._complete = function(msg,error) {
this.metric("done",msg);
hooks.trigger("onComplete",{ msg: msg, error: error, node: { id: this.id, node: this }}, err => {
if (err) {
this.error(err);
}
})
if (error) {
// For now, delegate this to this.error
// But at some point, the timeout handling will need to know about
// this as well.
this.error(error,msg);
} else {
this._flow.handleComplete(this,msg);
}
}
/**
* An internal reference to the original EventEmitter.on() function
*/
Node.prototype._on = Node.prototype.on;
/**
* Register a callback function for a named event.
* 'close' and 'input' events are handled locally, other events defer to EventEmitter.on()
*/
Node.prototype.on = function(event, callback) {
var node = this;
if (event == "close") {
this._closeCallbacks.push(callback);
} else if (event === "input") {
if (this._inputCallback) {
this._inputCallbacks = [this._inputCallback, callback];
this._inputCallback = null;
} else if (this._inputCallbacks) {
this._inputCallbacks.push(callback);
} else {
this._inputCallback = callback;
}
} else {
this._on(event, callback);
}
};
/**
* An internal reference to the original EventEmitter.emit() function
*/
Node.prototype._emit = Node.prototype.emit;
/**
* Emit an event to all registered listeners.
*/
Node.prototype.emit = function(event, ...args) {
var node = this;
if (event === "input") {
this._emitInput.apply(this,args);
} else {
this._emit.apply(this,arguments);
}
}
/**
* Handle the 'input' event.
*
* This will call all registered handlers for the 'input' event.
*/
Node.prototype._emitInput = function(arg) {
var node = this;
this.metric("receive", arg);
let receiveEvent = { msg:arg, destination: { id: this.id, node: this } }
// onReceive - a node is about to receive a message
hooks.trigger("onReceive",receiveEvent,(err) => {
if (err) {
node.error(err);
return
} else if (err !== false) {
if (node._inputCallback) {
// Just one callback registered.
try {
node._inputCallback(
arg,
function() { node.send.apply(node,arguments) },
function(err) { node._complete(arg,err); }
);
} catch(err) {
node.error(err,arg);
}
} else if (node._inputCallbacks) {
// Multiple callbacks registered. Call each one, tracking eventual completion
var c = node._inputCallbacks.length;
for (var i=0;i<c;i++) {
var cb = node._inputCallbacks[i];
if (cb.length === 2) {
c++;
}
try {
cb.call(
node,
arg,
function() { node.send.apply(node,arguments) },
function(err) {
c--;
if (c === 0) {
node._complete(arg,err);
}
}
);
} catch(err) {
node.error(err,arg);
}
}
}
// postReceive - the message has been passed to the node's input handler
hooks.trigger("postReceive",receiveEvent,(err) => {if (err) { node.error(err) }});
}
});
}
/**
* An internal reference to the original EventEmitter.removeListener() function
*/
Node.prototype._removeListener = Node.prototype.removeListener;
/**
* Remove a listener for an event
*/
Node.prototype.removeListener = function(name, listener) {
var index;
if (name === "input") {
if (this._inputCallback && this._inputCallback === listener) {
// Removing the only callback
this._inputCallback = null;
} else if (this._inputCallbacks) {
// Removing one of many callbacks
index = this._inputCallbacks.indexOf(listener);
if (index > -1) {
this._inputCallbacks.splice(index,1);
}
// Check if we can optimise back to a single callback
if (this._inputCallbacks.length === 1) {
this._inputCallback = this._inputCallbacks[0];
this._inputCallbacks = null;
}
}
} else if (name === "close") {
index = this._closeCallbacks.indexOf(listener);
if (index > -1) {
this._closeCallbacks.splice(index,1);
}
} else {
this._removeListener(name, listener);
}
}
/**
* An internal reference to the original EventEmitter.removeAllListeners() function
*/
Node.prototype._removeAllListeners = Node.prototype.removeAllListeners;
/**
* Remove all listeners for an event
*/
Node.prototype.removeAllListeners = function(name) {
if (name === "input") {
this._inputCallback = null;
this._inputCallbacks = null;
} else if (name === "close") {
this._closeCallbacks = [];
} else {
this._removeAllListeners(name);
}
}
/**
* Called when the node is being stopped
* @param {boolean} removed Whether the node has been removed, or just being stopped
* @return {Promise} resolves when the node has closed
*/
Node.prototype.close = function(removed) {
//console.log(this.type,this.id,removed);
var promises = [];
var node = this;
// Call all registered close callbacks.
for (var i=0;i<this._closeCallbacks.length;i++) {
var callback = this._closeCallbacks[i];
if (callback.length > 0) {
// The callback takes a 'done' callback and (maybe) the removed flag
promises.push(
new Promise((resolve) => {
try {
var args = [];
if (callback.length === 2) {
// The listener expects the removed flag
args.push(!!removed);
}
args.push(() => {
resolve();
});
callback.apply(node, args);
} catch(err) {
// TODO: error thrown in node async close callback
// We've never logged this properly.
resolve();
}
})
);
} else {
// No done callback so handle synchronously
try {
callback.call(node);
} catch(err) {
// TODO: error thrown in node sync close callback
// We've never logged this properly.
}
}
}
if (promises.length > 0) {
return Promise.all(promises).then(() => {
this.removeAllListeners("input")
if (this._context) {
return context.delete(this._alias||this.id,this.z);
}
});
} else {
this.removeAllListeners("input")
if (this._context) {
return context.delete(this._alias||this.id,this.z);
}
return Promise.resolve();
}
};
/**
* Send a message to the nodes wired.
*
*
* @param {object} msg A message or array of messages to send
*/
Node.prototype.send = function(msg) {
var msgSent = false;
var node;
if (msg === null || typeof msg === "undefined") {
return;
} else if (!util.isArray(msg)) {
if (this._wire) {
// A single message and a single wire on output 0
// TODO: pre-load flows.get calls - cannot do in constructor
// as not all nodes are defined at that point
if (!msg._msgid) {
msg._msgid = redUtil.generateId();
}
this.metric("send",msg);
this._flow.send([{
msg: msg,
source: {
id: this.id,
node: this,
port: 0
},
destination: {
id: this._wire,
node: undefined
},
cloneMessage: false
}]);
return;
} else {
msg = [msg];
}
}
var numOutputs = this.wires.length;
// Build a list of send events so that all cloning is done before
// any calls to node.receive
var sendEvents = [];
var sentMessageId = null;
var hasMissingIds = false;
// for each output of node eg. [msgs to output 0, msgs to output 1, ...]
for (var i = 0; i < numOutputs; i++) {
var wires = this.wires[i]; // wires leaving output i
/* istanbul ignore else */
if (i < msg.length) {
var msgs = msg[i]; // msgs going to output i
if (msgs !== null && typeof msgs !== "undefined") {
if (!util.isArray(msgs)) {
msgs = [msgs];
}
var k = 0;
// for each recipent node of that output
for (var j = 0; j < wires.length; j++) {
// for each msg to send eg. [[m1, m2, ...], ...]
for (k = 0; k < msgs.length; k++) {
var m = msgs[k];
if (m !== null && m !== undefined) {
if (!m._msgid) {
hasMissingIds = true;
}
/* istanbul ignore else */
if (!sentMessageId) {
sentMessageId = m._msgid;
}
sendEvents.push({
msg: m,
source: {
id: this.id,
node: this,
port: i
},
destination: {
id: wires[j],
node: undefined
},
cloneMessage: msgSent
});
msgSent = true;
}
}
}
}
}
}
/* istanbul ignore else */
if (!sentMessageId) {
sentMessageId = redUtil.generateId();
}
this.metric("send",{_msgid:sentMessageId});
if (hasMissingIds) {
for (i=0;i<sendEvents.length;i++) {
var ev = sendEvents[i];
/* istanbul ignore else */
if (!ev.msg._msgid) {
ev.msg._msgid = sentMessageId;
}
}
}
this._flow.send(sendEvents);
};
/**
* Receive a message.
*
* This will emit the `input` event with the provided message.
*/
Node.prototype.receive = function(msg) {
if (!msg) {
msg = {};
}
if (!msg._msgid) {
msg._msgid = redUtil.generateId();
}
this.emit("input",msg);
};
function log_helper(self, level, msg) {
var o = {
level: level,
id: self.id,
type: self.type,
msg: msg
};
if (self._alias) {
o._alias = self._alias;
}
if (self.z) {
o.z = self.z;
}
if (self.name) {
o.name = self.name;
}
self._flow.log(o);
}
/**
* Log an INFO level message
*/
Node.prototype.log = function(msg) {
log_helper(this, Log.INFO, msg);
};
/**
* Log a WARN level message
*/
Node.prototype.warn = function(msg) {
log_helper(this, Log.WARN, msg);
};
/**
* Log an ERROR level message
*/
Node.prototype.error = function(logMessage,msg) {
if (typeof logMessage != 'boolean') {
logMessage = logMessage || "";
}
var handled = false;
if (msg && typeof msg === 'object') {
handled = this._flow.handleError(this,logMessage,msg);
}
if (!handled) {
log_helper(this, Log.ERROR, logMessage);
}
};
/**
* Log an DEBUG level message
*/
Node.prototype.debug = function(msg) {
log_helper(this, Log.DEBUG, msg);
}
/**
* Log an TRACE level message
*/
Node.prototype.trace = function(msg) {
log_helper(this, Log.TRACE, msg);
}
/**
* Log a metric event.
* If called with no args, returns whether metric collection is enabled
*/
Node.prototype.metric = function(eventname, msg, metricValue) {
if (typeof eventname === "undefined") {
return Log.metric();
}
var metrics = {};
metrics.level = Log.METRIC;
metrics.nodeid = this.id;
metrics.event = "node."+this.type+"."+eventname;
metrics.msgid = msg._msgid;
metrics.value = metricValue;
Log.log(metrics);
}
/**
* Set the node's status object
*
* status: { fill:"red|green", shape:"dot|ring", text:"blah" }
* or
* status: "simple text status"
*/
Node.prototype.status = function(status) {
switch (typeof status) {
case "string":
case "number":
case "boolean":
status = {text:""+status}
}
this._flow.handleStatus(this,status);
};
module.exports = Node;