redis-semaphore
Version:
Distributed mutex and semaphore based on Redis
157 lines • 6.63 kB
JavaScript
"use strict";
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
var desc = Object.getOwnPropertyDescriptor(m, k);
if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
desc = { enumerable: true, get: function() { return m[k]; } };
}
Object.defineProperty(o, k2, desc);
}) : (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
o[k2] = m[k];
}));
var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
o["default"] = v;
});
var __importStar = (this && this.__importStar) || (function () {
var ownKeys = function(o) {
ownKeys = Object.getOwnPropertyNames || function (o) {
var ar = [];
for (var k in o) if (Object.prototype.hasOwnProperty.call(o, k)) ar[ar.length] = k;
return ar;
};
return ownKeys(o);
};
return function (mod) {
if (mod && mod.__esModule) return mod;
var result = {};
if (mod != null) for (var k = ownKeys(mod), i = 0; i < k.length; i++) if (k[i] !== "default") __createBinding(result, mod, k[i]);
__setModuleDefault(result, mod);
return result;
};
})();
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.Lock = void 0;
const debug_1 = __importDefault(require("debug"));
const crypto = __importStar(require("node:crypto"));
const LostLockError_1 = __importDefault(require("./errors/LostLockError"));
const TimeoutError_1 = __importDefault(require("./errors/TimeoutError"));
const misc_1 = require("./misc");
const REFRESH_INTERVAL_COEF = 0.8;
const debug = (0, debug_1.default)('redis-semaphore:instance');
class Lock {
constructor({ lockTimeout = misc_1.defaultTimeoutOptions.lockTimeout, acquireTimeout = misc_1.defaultTimeoutOptions.acquireTimeout, acquireAttemptsLimit = misc_1.defaultTimeoutOptions.acquireAttemptsLimit, retryInterval = misc_1.defaultTimeoutOptions.retryInterval, refreshInterval = Math.round(lockTimeout * REFRESH_INTERVAL_COEF), onLockLost = misc_1.defaultOnLockLost, externallyAcquiredIdentifier, identifierSuffix, identifier, acquiredExternally } = misc_1.defaultTimeoutOptions) {
this._refreshing = false;
this._acquired = false;
this._acquiredExternally = false;
this._processRefresh = async () => {
if (this._refreshing) {
debug(`already refreshing ${this._kind} (key: ${this._key}, identifier: ${this._identifier}) (skip)`);
return;
}
this._refreshing = true;
try {
debug(`refresh ${this._kind} (key: ${this._key}, identifier: ${this._identifier})`);
const refreshed = await this._refresh();
if (!refreshed) {
if (!this._acquired) {
debug(`refresh ${this._kind} (key: ${this._key}, identifier: ${this._identifier} failed, but lock was purposefully released`);
return;
}
this._acquired = false;
this.stopRefresh();
const lockLostError = new LostLockError_1.default(`Lost ${this._kind} for key ${this._key}`);
this._onLockLost(lockLostError);
}
}
finally {
this._refreshing = false;
}
};
if (identifier !== undefined &&
(!identifier || typeof identifier !== 'string')) {
throw new Error('identifier must be not empty random string');
}
if (acquiredExternally && !identifier) {
throw new Error('acquiredExternally=true meanless without custom identifier');
}
if (externallyAcquiredIdentifier && (identifier || acquiredExternally)) {
throw new Error('Invalid usage. Use custom identifier and acquiredExternally: true');
}
this._identifier =
identifier ||
externallyAcquiredIdentifier ||
this.getIdentifier(identifierSuffix);
this._acquiredExternally =
!!acquiredExternally || !!externallyAcquiredIdentifier;
this._acquireOptions = {
lockTimeout,
acquireTimeout,
acquireAttemptsLimit,
retryInterval,
identifier: this._identifier
};
this._refreshTimeInterval = refreshInterval;
this._onLockLost = onLockLost;
}
get identifier() {
return this._identifier;
}
get isAcquired() {
return this._acquired;
}
getIdentifier(identifierSuffix) {
const uuid = crypto.randomUUID();
return identifierSuffix ? `${uuid}-${identifierSuffix}` : uuid;
}
_startRefresh() {
this._refreshInterval = setInterval(this._processRefresh, this._refreshTimeInterval);
this._refreshInterval.unref();
}
stopRefresh() {
if (this._refreshInterval) {
debug(`clear refresh interval ${this._kind} (key: ${this._key}, identifier: ${this._identifier})`);
clearInterval(this._refreshInterval);
}
}
async acquire() {
debug(`acquire ${this._kind} (key: ${this._key})`);
const acquired = await this.tryAcquire();
if (!acquired) {
throw new TimeoutError_1.default(`Acquire ${this._kind} ${this._key} timeout`);
}
}
async tryAcquire() {
debug(`tryAcquire ${this._kind} (key: ${this._key})`);
const acquired = this._acquiredExternally
? await this._refresh()
: await this._acquire();
if (!acquired) {
return false;
}
this._acquired = true;
this._acquiredExternally = false;
if (this._refreshTimeInterval > 0) {
this._startRefresh();
}
return true;
}
async release() {
debug(`release ${this._kind} (key: ${this._key}, identifier: ${this._identifier})`);
if (this._refreshTimeInterval > 0) {
this.stopRefresh();
}
if (this._acquired || this._acquiredExternally) {
await this._release();
}
this._acquired = false;
this._acquiredExternally = false;
}
}
exports.Lock = Lock;
//# sourceMappingURL=Lock.js.map