hamok/lib/raft/RaftEngine.js

Lightweight Distributed Object Storage on RAFT consensus algorithm

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.RaftEngine = void 0;
const RaftMessageEmitter_1 = require("../messages/RaftMessageEmitter");
const SyncedProperties_1 = require("./SyncedProperties");
const RaftEmptyState_1 = require("./RaftEmptyState");
const logger_1 = require("../common/logger");
const logger = (0, logger_1.createLogger)('RaftEngine');
class RaftEngine {
    config;
    logs;
    events;
    _state;
    props = new SyncedProperties_1.SyncedProperties();
    _leaderId;
    remotePeers = new Set();
    transport = new RaftMessageEmitter_1.RaftMessageEmitter();
    _failedElections = 0;
    constructor(config, logs, events) {
        this.config = config;
        this.logs = logs;
        this.events = events;
        if (this.config.heartbeatInMs < 1)
            throw new Error('Config error: heartbeatInMs must be greater than 0');
        this._state = (0, RaftEmptyState_1.createRaftEmptyState)({
            raftEngine: this,
        });
    }
    get localPeerId() {
        return this.config.peerId;
    }
    get leaderId() {
        return this._leaderId;
    }
    get failedElections() {
        return this._failedElections;
    }
    set leaderId(newLeaderId) {
        if (this._leaderId === newLeaderId)
            return;
        const prevLeaderId = this._leaderId;
        this._leaderId = newLeaderId;
        logger.info(`%s Leader changed from ${prevLeaderId} to ${newLeaderId}`, this.localPeerId);
        if (newLeaderId !== undefined) {
            this._failedElections = 0;
        }
        this.events.emit('leader-changed', newLeaderId, prevLeaderId);
    }
    get state() {
        return this._state;
    }
    set state(newState) {
        if (this._state.stateName === newState.stateName)
            return;
        const prevState = this._state;
        prevState.close();
        this._state = newState;
        logger.debug(`%s State changed from ${prevState.stateName} to ${newState.stateName}`, this.localPeerId);
        if (prevState.stateName === 'candidate' && newState.stateName === 'follower') {
            ++this._failedElections;
        }
        newState.init?.();
        this.events.emit('state-changed', newState.stateName, prevState.stateName);
        switch (newState.stateName) {
            case 'leader':
            case 'follower':
            case 'candidate':
                this.events.emit(newState.stateName);
                break;
        }
    }
    submit(message) {
        if (this._state.stateName !== 'leader') {
            return false;
        }
        this.logs.submit(this.props.currentTerm, message);
        return true;
    }
}
exports.RaftEngine = RaftEngine;