git ssb

1
const Vertex = require('./deps/kernelVertex')
2
// The Kernel Exposes this Interface to VM instances it makes
3
const Interface = require('./interface.js')
4
const InterfaceAPI = require('./interfaceAPI.js')
5
const Environment = require('./environment.js')
6
7
module.exports = class Kernel {
8
  constructor (opts = {}) {
9
    this.state = opts.state || new Vertex()
10
    this.parent = opts.parent
11
12
    if (opts.code) {
13
      this.interfaceAPI = new InterfaceAPI(opts.code)
14
    }
15
    this.imports = this.buildImports(opts.interfaces)
16
  }
17
18
  /**
19
   * Builds a import map with an array of given interfaces
20
   */
21
  buildImports (interfaces = [Interface]) {
22
    return interfaces.reduce((obj, Interface) => {
23
      obj[Interface.name] = new Interface(this.interfaceAPI).exports
24
      return obj
25
    }, {})
26
  }
27
28
  /**
29
   * run the kernels code with a given enviroment
30
   * The Kernel Stores all of its state in the Environment. The Interface is used
31
   * to by the VM to retrive infromation from the Environment.
32
   */
33
  async run (environment = new Environment({state: this.state}), imports = this.imports) {
34
    await this.interfaceAPI.run(environment, imports)
35
    return environment
36
  }
37
38
  async messageReceiver (message) {
39
    // let the code handle the message if there is code
40
    if (this.code) {
41
      const environment = new Environment(message)
42
      let result = await this.run(environment)
43
      if (!result.execption) {
44
        this.state = result.state
45
      }
46
    } else if (message.to.length) {
47
      // else forward the message on to the destination contract
48
      let [vertex, done] = await this.state.update(message.to)
49
      message.to = []
50
      await vertex.kernel.messageReceiver(message)
51
      done(vertex)
52
    }
53
  }
54
55
  copy () {
56
    return new Kernel({
57
      state: this.state.copy(),
58
      code: this.code,
59
      interfaces: this.interfaces,
60
      parent: this.parent
61
    })
62
  }
63
}
64