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