git ssb

1
module.exports = class VM {
2
  /**
3
   * The interface API is the api the exposed to interfaces. All queries about
4
   * the enviroment and call to the kernel go through this API
5
   */
6
  constructor (code) {
7
    this._module = WebAssembly.Module(code)
8
  }
9
10
  /**
11
   * Runs the core VM with a given environment and imports
12
   */
13
  async run (environment, imports) {
14
    this._environment = environment
15
    // TODO, delete the instance once done.
16
    const instance = this._instance = WebAssembly.Instance(this._module, imports)
17
    if (instance.exports.main) {
18
      instance.exports.main()
19
    }
20
    await this.onDone()
21
    const env = this._environment
22
    delete this._environment
23
    return env
24
  }
25
26
  /**
27
   * returns a promise that resolves when the wasm instance is done running
28
   */
29
  async onDone () {
30
    let prevOps
31
    while (prevOps !== this._opsQueue) {
32
      prevOps = this._opsQueue
33
      await this._opsQueue
34
    }
35
  }
36
37
  /**
38
   * addes an aync operation to the operations queue
39
   */
40
  pushOpsQueue (promise, callbackIndex, intefaceCallback) {
41
    this._opsQueue = Promise.all([this._opsQueue, promise]).then(values => {
42
      const result = intefaceCallback(values.pop())
43
      this._instance.exports[callbackIndex.toString()](result)
44
    })
45
  }
46
47
  sendMessage (message) {
48
49
  }
50
51
  get environment () {
52
    return this._environment
53
  }
54
55
  get memory () {
56
    return this._instance.exports.memory.buffer
57
  }
58
}
59