Files: a728a4416ce9e9ab6ba38dc79dde2c7a294feb7e / portManager.js
3297 bytesRaw
1 | const Port = require('./port.js') |
2 | const BN = require('bn.js') |
3 | const ENTRY = Symbol('entry') |
4 | |
5 | // decides which message to go first |
6 | function messageArbiter (pairA, pairB) { |
7 | const portA = pairA[1] |
8 | const portB = pairB[1] |
9 | const a = portA.peek() |
10 | const b = portB.peek() |
11 | |
12 | if (!a) { |
13 | return pairB |
14 | } else if (!b) { |
15 | return pairA |
16 | } |
17 | |
18 | // order by number of ticks if messages have different number of ticks |
19 | if (portA.ticks !== portB.ticks) { |
20 | return portA.ticks < portB.ticks ? pairA : pairB |
21 | } else if (a.priority !== b.priority) { |
22 | // decide by priority |
23 | return a.priority > b.priority ? pairA : pairB |
24 | } else { |
25 | // insertion order |
26 | return pairA |
27 | } |
28 | } |
29 | |
30 | module.exports = class PortManager { |
31 | constructor (opts) { |
32 | Object.assign(this, opts) |
33 | this._portMap = new Map() |
34 | } |
35 | |
36 | async start () { |
37 | // skip the root, since it doesn't have a parent |
38 | if (this.parentPort !== undefined) { |
39 | this._bindRef(this.parentPort, ENTRY) |
40 | } |
41 | |
42 | // map ports to thier id's |
43 | this.ports = await this.hypervisor.graph.get(this.state, 'ports') |
44 | Object.keys(this.ports).map(name => { |
45 | const port = this.ports[name] |
46 | this._bindRef(port, name) |
47 | }) |
48 | } |
49 | |
50 | _bindRef (portRef, name) { |
51 | const port = new Port(name) |
52 | this._portMap.set(portRef, port) |
53 | } |
54 | |
55 | bind (port, name) { |
56 | // save the port instance |
57 | this.ports[name] = port |
58 | this._bindRef(port, name) |
59 | } |
60 | |
61 | queue (message) { |
62 | this._portMap.get(message.fromPort).queue(message) |
63 | } |
64 | |
65 | get (key) { |
66 | return this.ports[key] |
67 | } |
68 | |
69 | delete (key) { |
70 | const port = this.ports[key] |
71 | delete this.ports[key] |
72 | this._portMap.delete(port) |
73 | } |
74 | |
75 | isValidPort (port) { |
76 | return this._portMap.has(port) |
77 | } |
78 | |
79 | create (type) { |
80 | const Container = this.hypervisor._containerTypes[type] |
81 | const parentId = this.entryPort ? this.entryPort.id : null |
82 | let nonce = this.state['/'].nonce |
83 | |
84 | const portRef = { |
85 | 'messages': [], |
86 | 'id': { |
87 | '/': { |
88 | nonce: nonce, |
89 | parent: parentId |
90 | } |
91 | }, |
92 | 'type': type, |
93 | 'link': { |
94 | '/': Container.createState() |
95 | } |
96 | } |
97 | |
98 | // incerment the nonce |
99 | nonce = new BN(nonce) |
100 | nonce.iaddn(1) |
101 | this.state['/'].nonce = nonce.toArray() |
102 | return portRef |
103 | } |
104 | |
105 | // waits till all ports have reached a threshold tick count |
106 | wait (threshold, fromPort = this.entryPort, ports = this._portMap) { |
107 | // find the ports that have a smaller tick count then the threshold tick count |
108 | const unkownPorts = [...ports].filter(([portRef, port]) => { |
109 | return port.ticks < threshold && fromPort !== portRef |
110 | }) |
111 | |
112 | const promises = unkownPorts.map(async([portRef, port]) => { |
113 | // update the port's tick count |
114 | port.ticks = await this.hypervisor.wait(portRef, threshold, this.entryPort) |
115 | }) |
116 | |
117 | return Promise.all(promises) |
118 | } |
119 | |
120 | async getNextMessage () { |
121 | if (this._portMap.size) { |
122 | // find the oldest message |
123 | const ticks = [...this._portMap].map(([name, port]) => { |
124 | return port.size ? port.ticks : this.exoInterface.ticks |
125 | }).reduce((ticksA, ticksB) => { |
126 | return ticksA < ticksB ? ticksA : ticksB |
127 | }) |
128 | |
129 | await this.wait(ticks) |
130 | const portMap = [...this._portMap].reduce(messageArbiter) |
131 | return portMap[1].shift() |
132 | } |
133 | } |
134 | } |
135 |
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