git ssb

1
const Port = require('./port.js')
2
const ENTRY = Symbol('entry')
3
4
// decides which message to go firts
5
function messageArbiter (pairA, pairB) {
6
  const a = pairA[1].peek()
7
  const b = pairB[1].peek()
8
9
  if (!a) {
10
    return pairB
11
  } else if (!b) {
12
    return pairA
13
  }
14
15
  const aGasPrice = a.resources.gasPrice
16
  const bGasPrice = b.resources.gasPrice
17
  if (a.ticks !== b.ticks) {
18
    return a.ticks < b.ticks ? pairA : pairB
19
  } else if (aGasPrice === bGasPrice) {
20
    return a.hash() > b.hash() ? pairA : pairB
21
  } else {
22
    return aGasPrice > bGasPrice ? pairA : pairB
23
  }
24
}
25
26
module.exports = class PortManager {
27
  constructor (opts) {
28
    Object.assign(this, opts)
29
    this._portMap = new Map()
30
  }
31
32
  async start () {
33
    // map ports to thier id's
34
    let ports = Object.keys(this.ports).map(name => {
35
      const port = this.ports[name]
36
      this._mapPort(name, port)
37
    })
38
39
    // create the parent port
40
    await Promise.all(ports)
41
    const id = await this.hypervisor.generateID(this.parentPort)
42
    this._portMap.set(id, new Port(ENTRY))
43
  }
44
45
  async _mapPort (name, port) {
46
    const id = await this.hypervisor.generateID(port)
47
    port = new Port(name)
48
    this._portMap.set(id, port)
49
  }
50
51
  queue (message) {
52
    this._portMap.get(message.fromPort).queue(message)
53
  }
54
55
  set (name, port) {
56
    this.ports[name] = port
57
    return this._mapPort(name, port)
58
  }
59
60
  async get (port) {
61
    const id = await this.hypervisor.generateID(port)
62
    return this._portMap.get(id)
63
  }
64
65
  getRef (key) {
66
    return this.ports[key]
67
  }
68
69
  // waits till all ports have reached a threshold tick count
70
  async wait (threshold, fromPort) {
71
    // console.log('wait', threshold, 'id', this.entryPort)
72
    // find the ports that have a smaller tick count then the threshold tick count
73
    const unkownPorts = [...this._portMap].filter(([id, port]) => {
74
      return (port.hasSent || port.name === ENTRY) &&
75
        port.ticks < threshold &&
76
        fromPort !== port
77
    })
78
79
    const promises = unkownPorts.map(async ([id, port]) => {
80
      const portObj = port.name === ENTRY ? this.parentPort : this.ports[port.name]
81
      // update the port's tick count
82
      port.ticks = await this.hypervisor.wait(portObj, threshold, this.entryPort)
83
    })
84
    return Promise.all(promises)
85
  }
86
87
  async getNextMessage () {
88
    await this.wait(this.kernel.ticks, this.entryPort)
89
    const portMap = [...this._portMap].reduce(messageArbiter)
90
    if (portMap) {
91
      return portMap[1].shift()
92
    }
93
  }
94
}
95