git ssb

1
const Vertex = require('merkle-trie')
2
const Cache = require('imperative-trie')
3
const imports = require('./EVMinterface.js')
4
const codeHandler = require('./codeHandler.js')
5
const MessageQueue = require('./messageQueue')
6
const common = require('./common.js')
7
8
module.exports = class Kernel {
9
  constructor (opts = {}) {
10
    const state = this.state = opts.state || new Vertex()
11
    state.value = opts.code || state.value
12
    this.imports = opts.imports || [imports]
13
    // RENAME agent
14
    this._vm = (opts.codeHandler || codeHandler).init(state.value)
15
    this._messageQueue = new MessageQueue(this)
16
    this._instanceCache = new Cache()
17
  }
18
19
  /**
20
   * run the kernels code with a given enviroment
21
   * The Kernel Stores all of its state in the Environment. The Interface is used
22
   * to by the VM to retrive infromation from the Environment.
23
   */
24
  async run (message, imports = this.imports) {
25
    const state = this.state.copy()
26
    const result = await this._vm.run(message, this, imports, state)
27
    if (!result.execption) {
28
      // update the state
29
      this.state.set([], state)
30
    }
31
    return result
32
  }
33
34
  async recieve (message) {
35
    if (message.isCyclic(this)) {
36
      const result = await this.run(message)
37
      message.finished()
38
      return result
39
    } else {
40
      return this._messageQueue.add(message)
41
    }
42
  }
43
44
  async send (port, message) {
45
    message.sending(this, this._messageQueue.currentMessage)
46
    // replace root with parent path to root
47
    if (port === common.ROOT) {
48
      port = common.PARENT
49
      message.to = new Array(this.state.path.length - 1).fill(common.PARENT).concat(message.to)
50
    }
51
52
    if (port === common.PARENT) {
53
      message.from.push(this.state.name)
54
    } else {
55
      message.from.push(common.PARENT)
56
    }
57
58
    const dest = await this.getPort(port)
59
    return dest.recieve(message)
60
  }
61
62
  setValue (name, value) {
63
    return this.state.set(name, value)
64
  }
65
66
  getValue (name) {
67
    return this.state.get(name)
68
  }
69
70
  async getPort (name) {
71
    let kernel
72
    if (name === common.PARENT) {
73
      kernel = this.parent
74
    } else {
75
      kernel = this._instanceCache.get(name)
76
    }
77
78
    if (kernel) {
79
      return kernel
80
    } else {
81
      const destState = await (
82
        name === common.PARENT
83
        ? this.state.getParent()
84
        : this.state.get([name]))
85
86
      const kernel = new Kernel({
87
        state: destState
88
      })
89
90
      const cache = new Cache({value: kernel})
91
      kernel._instanceCache = cache
92
93
      this._instanceCache.set(name, kernel)
94
      return kernel
95
    }
96
  }
97
}
98