git ssb

1
const Message = require('primea-message')
2
const PortManager = require('./portManager.js')
3
const DeleteMessage = require('./deleteMessage')
4
5
module.exports = class Kernel {
6
  /**
7
   * the Kernel 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 Kernel
11
   * @param {Object} opts.state - the state of the container
12
   * @param {Object} opts.hypervisor
13
   * @param {Object} opts.container - the container constuctor and argments
14
   */
15
  constructor (opts) {
16
    this.state = opts.state
17
    this.code = opts.code
18
    this.node = opts.node
19
    this.hypervisor = opts.hypervisor
20
    this.id = opts.id
21
    this.container = new opts.container.Constructor(this, opts.container.args)
22
23
    this.ticks = 0
24
    this.containerState = 'idle'
25
26
    // create the port manager
27
    this.ports = new PortManager(Object.assign({
28
      kernel: this
29
    }, opts))
30
  }
31
32
  /**
33
   * adds a message to this containers message queue
34
   * @param {string} portName
35
   * @param {object} message
36
   */
37
  queue (port, message) {
38
    this.ports.queue(port.destName, message)
39
    this._startMessageLoop()
40
  }
41
42
  async create (message) {
43
    await this.message(message, 'onCreation')
44
    this._startMessageLoop()
45
  }
46
47
  // waits for the next message
48
  async _startMessageLoop () {
49
    // this ensure we only every have one loop running at a time
50
    if (this.containerState !== 'running') {
51
      this.containerState = 'running'
52
      while (1) {
53
        const message = await this.ports.getNextMessage()
54
        if (!message) break
55
56
        // dequqe message
57
        message.fromPort.messages.shift()
58
        // if the message we recived had more ticks then we currently have then
59
        // update it
60
        if (message._fromTicks > this.ticks) {
61
          this.ticks = message._fromTicks
62
          this.hypervisor.scheduler.update(this)
63
        }
64
        // run the next message
65
        await this.message(message)
66
      }
67
68
      this.containerState = 'idle'
69
      this.container.onIdle()
70
    }
71
  }
72
73
  shutdown () {
74
    this.hypervisor.scheduler.done(this.id)
75
  }
76
77
  startup () {
78
    return this.container.onStartup()
79
  }
80
81
  /**
82
   * run the kernels code with a given enviroment
83
   * @param {object} message - the message to run
84
   * @param {boolean} init - whether or not to run the intialization routine
85
   * @returns {Promise}
86
   */
87
  async message (message, method = 'onMessage') {
88
    if (message.constructor === DeleteMessage) {
89
      this.ports._delete(message.fromName)
90
    } else {
91
      const responsePort = message.responsePort
92
      delete message.responsePort
93
94
      this.ports.addReceivedPorts(message)
95
      let result
96
      try {
97
        result = await this.container[method](message)
98
      } catch (e) {
99
        result = {
100
          exception: true,
101
          exceptionError: e
102
        }
103
      }
104
105
      if (responsePort) {
106
        this.ports._unboundPorts.add(responsePort)
107
        this.send(responsePort, new Message({
108
          data: result
109
        }))
110
      }
111
      await this.ports.clearUnboundedPorts()
112
    }
113
  }
114
115
  getResponsePort (message) {
116
    if (message.responsePort) {
117
      return message.responsePort.destPort
118
    } else {
119
      const [portRef1, portRef2] = this.ports.createChannel()
120
      message.responsePort = portRef2
121
      this.ports._unboundPorts.delete(portRef2)
122
      return portRef1
123
    }
124
  }
125
126
  /**
127
   * updates the number of ticks that the container has run
128
   * @param {Number} count - the number of ticks to add
129
   */
130
  incrementTicks (count) {
131
    this.ticks += count
132
    this.hypervisor.scheduler.update(this)
133
  }
134
135
  /**
136
   * creates a new message
137
   * @param {*} data
138
   */
139
  createMessage (opts) {
140
    const message = new Message(opts)
141
    this.ports.checkSendingPorts(message)
142
    return message
143
  }
144
145
  generateNextId () {
146
    const id = {
147
      nonce: this.state.nonce,
148
      parent: this.id
149
    }
150
151
    this.state.nonce++
152
    return id
153
  }
154
155
  /**
156
   * sends a message to a given port
157
   * @param {Object} portRef - the port
158
   * @param {Message} message - the message
159
   */
160
  send (port, message) {
161
    message._hops++
162
    message._fromTicks = this.ticks
163
    message.fromId = this.id
164
    this.ports.removeSentPorts(message)
165
166
    return this.hypervisor.send(port, message)
167
  }
168
}
169