git ssb

1
const Message = require('primea-message')
2
const CapsManager = require('./capsManager.js')
3
const Inbox = require('./inbox.js')
4
5
module.exports = class Actor {
6
  /**
7
   * the Actor manages the varous message passing functions and provides
8
   * an interface for the containers to use
9
   * @param {Object} opts
10
   * @param {Object} opts.id - the UUID of the Actor
11
   * @param {Object} opts.state - the state of the container
12
   * @param {Object} opts.hypervisor - the instance of the hypervisor
13
   * @param {Object} opts.container - the container constuctor and argments
14
   */
15
  constructor (opts) {
16
    this.state = opts.state.value
17
    this.code = opts.state.value.code
18
    this.treeNode = opts.state.node
19
    this.hypervisor = opts.hypervisor
20
    this.id = opts.id
21
    this.container = new opts.container.Constructor(this, opts.container.args)
22
    this.inbox = new Inbox({
23
      actor: this,
24
      hypervisor: opts.hypervisor
25
    })
26
27
    this.ticks = 0
28
    this.running = false
29
30
    this.caps = new CapsManager(opts.state.caps)
31
  }
32
33
  /**
34
   * Mints a new capabilitly with a given tag
35
   * @param {*} tag - a tag which can be used to identify caps
36
   * @return {Object}
37
   */
38
  mintCap (tag = 0) {
39
    return {
40
      destId: this.id,
41
      tag: tag
42
    }
43
  }
44
45
  /**
46
   * adds a message to this actor's message queue
47
   * @param {string} portName
48
   * @param {object} message
49
   */
50
  queue (message) {
51
    this.inbox.queue(message)
52
    this._startMessageLoop()
53
  }
54
55
  /**
56
   * runs the creation routine for the actor
57
   * @param {object} message
58
   * @returns {Promise}
59
   */
60
  create (message) {
61
    // start loop before running intializtion message so the the container state
62
    // will be "running" incase the actor recievse a message will running
63
    // creation code
64
    this._startMessageLoop()
65
    return this.runMessage(message, 'onCreation')
66
  }
67
68
  // waits for the next message
69
  async _startMessageLoop () {
70
    // this ensure we only every have one loop running at a time
71
    if (!this.running) {
72
      this.running = true
73
      while (1) {
74
        const message = await this.inbox.nextMessage()
75
        if (!message) break
76
77
        // if the message we recived had more ticks then we currently have then
78
        // update it
79
        if (message._fromTicks > this.ticks) {
80
          this.ticks = message._fromTicks
81
          this.hypervisor.scheduler.update(this)
82
        }
83
        // run the next message
84
        await this.runMessage(message)
85
      }
86
87
      this.running = false
88
      this.container.onIdle()
89
    }
90
  }
91
92
  /**
93
   * Runs the shutdown routine for the actor
94
   */
95
  shutdown () {
96
    this.hypervisor.scheduler.done(this.id)
97
  }
98
99
  /**
100
   * Runs the startup routine for the actor
101
   */
102
  startup () {
103
    return this.container.onStartup()
104
  }
105
106
  /**
107
   * run the Actor with a given message
108
   * @param {object} message - the message to run
109
   * @param {String} method - which method to run
110
   * @returns {Promise}
111
   */
112
  async runMessage (message, method = 'onMessage') {
113
    const responseCap = message.responseCap
114
    delete message.responseCap
115
116
    let result
117
    try {
118
      result = await this.container[method](message)
119
    } catch (e) {
120
      console.log(e)
121
      result = {
122
        exception: true,
123
        exceptionError: e
124
      }
125
    }
126
127
    if (responseCap) {
128
      this.send(responseCap, new Message({
129
        data: result
130
      }))
131
    }
132
  }
133
134
  /**
135
   * updates the number of ticks that the actor has run
136
   * @param {Number} count - the number of ticks to add
137
   */
138
  incrementTicks (count) {
139
    this.ticks += count
140
    this.hypervisor.scheduler.update(this)
141
  }
142
143
  /**
144
   * creates an actor
145
   * @param {Integer} type - the type id for the container
146
   * @param {Object} message - an intial [message](https://github.com/primea/js-primea-message) to send newly created actor
147
   */
148
  createActor (type, message) {
149
    const id = this._generateNextId()
150
    return this.hypervisor.createActor(type, message, id)
151
  }
152
153
  _generateNextId () {
154
    const id = {
155
      nonce: this.state.nonce,
156
      parent: this.id
157
    }
158
159
    this.state.nonce++
160
    return id
161
  }
162
163
  /**
164
   * sends a message to a given port
165
   * @param {Object} portRef - the port
166
   * @param {Message} message - the message
167
   */
168
  send (cap, message) {
169
    message._fromTicks = this.ticks
170
    message._fromId = this.id
171
    message.tag = cap.tag
172
173
    return this.hypervisor.send(cap, message)
174
  }
175
}
176