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
    if (this.parentPort !== undefined) {
42
      const id = await this.hypervisor.generateID(this.parentPort)
43
      this._portMap.set(id, new Port(ENTRY))
44
    }
45
  }
46
47
  async _mapPort (name, port) {
48
    const id = await this.hypervisor.generateID(port)
49
    port = new Port(name)
50
    this._portMap.set(id, port)
51
  }
52
53
  queue (message) {
54
    this._portMap.get(message.fromPort).queue(message)
55
  }
56
57
  set (name, port) {
58
    this.ports[name] = port
59
    return this._mapPort(name, port)
60
  }
61
62
  async get (port) {
63
    const id = await this.hypervisor.generateID(port)
64
    return this._portMap.get(id)
65
  }
66
67
  getRef (key) {
68
    return this.ports[key]
69
  }
70
71
  // waits till all ports have reached a threshold tick count
72
  async wait (threshold, fromPort) {
73
    // find the ports that have a smaller tick count then the threshold tick count
74
    const unkownPorts = [...this._portMap].filter(([id, port]) => {
75
      return (port.hasSent || port.name === ENTRY) &&
76
        port.ticks < threshold &&
77
        fromPort !== port
78
    })
79
80
    // console.log(unkownPorts, this.entryPort)
81
    const promises = unkownPorts.map(async ([id, port]) => {
82
      const portObj = port.name === ENTRY ? this.parentPort : this.ports[port.name]
83
      // update the port's tick count
84
      port.ticks = await this.hypervisor.wait(portObj, threshold, this.entryPort)
85
    })
86
    return Promise.all(promises)
87
  }
88
89
  async getNextMessage () {
90
    await this.wait(this.kernel.ticks, this.entryPort)
91
    const portMap = [...this._portMap].reduce(messageArbiter)
92
    if (portMap) {
93
      return portMap[1].shift()
94
    }
95
  }
96
}
97