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wanderer🌟 / js-primea-hypervisor



Tree: 7c1b9abb1401216b0a7325dfb2213933eda8826a

Files: 7c1b9abb1401216b0a7325dfb2213933eda8826a / index.js

4844 bytesRaw
1const Buffer = require('safe-buffer').Buffer
2const Actor = require('./actor.js')
3const Scheduler = require('./scheduler.js')
4const {decoder, generateId, ModuleRef, ActorRef} = require('primea-objects')
5
6const debug = require('debug')('lifecycle:createActor')
7
8module.exports = class Hypervisor {
9 /**
10 * The Hypervisor manages module instances by instantiating them and
11 * destroying them when possible. It also facilitates locating Containers
12 * @param {Object} opts
13 * @param {Object} opts.tree - a [radix tree](https://github.com/dfinity/js-dfinity-radix-tree) to store the state
14 * @param {Array} opts.modules - an array of modules to register
15 * @param {Array} opts.drivers - an array of drivers to install
16 * @param {boolean} [opts.meter=true] - whether to meter gas or not
17 */
18 constructor (opts) {
19 opts.tree.dag.decoder = decoder
20 this.tree = opts.tree
21 this.scheduler = new Scheduler(this)
22 this._modules = {}
23 this.nonce = opts.nonce || 0
24 this.meter = opts.meter !== undefined ? opts.meter : true;
25 (opts.modules || []).forEach(mod => this.registerModule(mod));
26 (opts.drivers || []).forEach(driver => this.registerDriver(driver))
27 }
28
29 /**
30 * sends a message(s). If an array of message is given the all the messages will be sent at once
31 * @param {Object} message - the [message](https://github.com/primea/js-primea-message) to send
32 * @returns {Promise} a promise that resolves once the receiving module is loaded
33 */
34 send (messages) {
35 if (!Array.isArray(messages)) {
36 messages = [messages]
37 }
38 this.scheduler.queue(messages)
39 }
40
41 /**
42 * loads an actor from the tree given its id
43 * @param {ID} id
44 * @returns {Promise<Actor>}
45 */
46 async loadActor (id) {
47 const state = await this.tree.get(id.id)
48 const [module, storage] = await Promise.all([
49 this.tree.graph.tree(state.node, '1'),
50 this.tree.graph.get(state.node, '2')
51 ])
52 await this.tree.graph.get(module[1][1], '')
53 const [type, nonce] = state.value
54 const Container = this._modules[type]
55
56 // create a new actor instance
57 const actor = new Actor({
58 hypervisor: this,
59 state,
60 Container,
61 id,
62 nonce,
63 module,
64 storage,
65 tree: this.tree
66 })
67
68 await actor.startup()
69 return actor
70 }
71
72 /**
73 * creates an actor from a module and code
74 * @param {Module} mod - the module
75 * @param {Buffer} code - the code
76 * @return {ActorRef}
77 */
78 newActor (mod, code) {
79 const modRef = this.createModule(mod, code)
80 return this.createActor(modRef)
81 }
82
83 /**
84 * creates a modref from a module and code
85 * @param {Module} mod - the module
86 * @param {Buffer} code - the code
87 * @param {id} id - the id for the module
88 * @return {ModuleRef}
89 */
90 createModule (mod, code, id = {nonce: this.nonce++, parent: null}) {
91 const moduleID = generateId(id)
92 const Module = this._modules[mod.typeId]
93 const {exports, state} = Module.onCreation(code)
94 return new ModuleRef(moduleID, mod.typeId, exports, state, code)
95 }
96
97 /**
98 * creates an instance of an Actor
99 * @param {ModuleRef} type - the modref
100 * @param {Object} id - the id for the actor
101 * @return {ActorRef}
102 */
103 createActor (modRef, id = {nonce: this.nonce++, parent: null}) {
104 const actorId = generateId(id)
105 const metaData = [modRef.type, 0]
106 debug('new id', actorId.toJSON())
107 debug(modRef.toJSON())
108
109 // save the container in the state
110 this.tree.set(actorId.id, metaData).then(node => {
111 // save the code
112 node[1] = [modRef.id.id, {
113 '/': modRef.code['/']
114 }]
115 // save the storage
116 node[2] = {
117 '/': modRef.state
118 }
119 })
120
121 return new ActorRef(actorId, modRef)
122 }
123
124 /**
125 * creates a state root when scheduler is idle
126 * @returns {Promise}
127 */
128 async createStateRoot () {
129 if (this.scheduler._running) {
130 await new Promise((resolve, reject) => {
131 this.scheduler.once('idle', resolve)
132 })
133 }
134
135 await this.tree.set(Buffer.from([0]), this.nonce)
136 return this.tree.flush()
137 }
138
139 /**
140 * set the state root. The promise must resolve before creating or sending any more messages to the hypervisor
141 * @param {Buffer} stateRoot
142 * @return {Promise}
143 */
144 async setStateRoot (stateRoot) {
145 this.tree.root = stateRoot
146 const node = await this.tree.get(Buffer.from([0]))
147 this.nonce = node.value
148 }
149
150 /**
151 * registers a module with the hypervisor
152 * @param {Function} Constructor - the module's constructor
153 */
154 registerModule (Constructor) {
155 this._modules[Constructor.typeId] = Constructor
156 }
157
158 /**
159 * register a driver with the hypervisor
160 * @param {Driver} driver
161 */
162 registerDriver (driver) {
163 driver.startup(this)
164 this.scheduler.drivers.set(driver.id.toString(), driver)
165 }
166}
167

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