typepool
Version:
Object pooling inspired by generic-pool - with Typing
367 lines • 14.6 kB
JavaScript
"use strict";
var __assign = (this && this.__assign) || function () {
__assign = Object.assign || function(t) {
for (var s, i = 1, n = arguments.length; i < n; i++) {
s = arguments[i];
for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
t[p] = s[p];
}
return t;
};
return __assign.apply(this, arguments);
};
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
var __generator = (this && this.__generator) || function (thisArg, body) {
var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
function verb(n) { return function (v) { return step([n, v]); }; }
function step(op) {
if (f) throw new TypeError("Generator is already executing.");
while (_) try {
if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
if (y = 0, t) op = [op[0] & 2, t.value];
switch (op[0]) {
case 0: case 1: t = op; break;
case 4: _.label++; return { value: op[1], done: false };
case 5: _.label++; y = op[1]; op = [0]; continue;
case 7: op = _.ops.pop(); _.trys.pop(); continue;
default:
if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
if (t[2]) _.ops.pop();
_.trys.pop(); continue;
}
op = body.call(thisArg, _);
} catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
}
};
var __importStar = (this && this.__importStar) || function (mod) {
if (mod && mod.__esModule) return mod;
var result = {};
if (mod != null) for (var k in mod) if (Object.hasOwnProperty.call(mod, k)) result[k] = mod[k];
result["default"] = mod;
return result;
};
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
var assert = __importStar(require("assert"));
var Deferred_1 = __importDefault(require("./Deferred"));
var PoolResourceStatus;
(function (PoolResourceStatus) {
PoolResourceStatus[PoolResourceStatus["Created"] = 0] = "Created";
PoolResourceStatus[PoolResourceStatus["Ready"] = 1] = "Ready";
PoolResourceStatus[PoolResourceStatus["Destroyed"] = 2] = "Destroyed";
})(PoolResourceStatus = exports.PoolResourceStatus || (exports.PoolResourceStatus = {}));
var Pool = /** @class */ (function () {
function Pool(factory, opts) {
var _this = this;
if (opts === void 0) { opts = {}; }
this.factory = factory;
this.resources = Array();
this.killed = false;
this.running = true;
/**
* Create a resource
*
* @returns {Promise<IPoolResource>}
*/
this.createResource = function () { return __awaiter(_this, void 0, void 0, function () {
var poolResource;
return __generator(this, function (_a) {
assert.ok(this.running, "Pool is not running");
poolResource = {
resource: null,
status: PoolResourceStatus.Created,
reserved: false,
createDeferred: new Deferred_1.default()
};
this.resources.push(poolResource);
this.factory
.create()
.then(function (resource) {
Object.assign(poolResource, {
resource: resource,
status: PoolResourceStatus.Ready
});
poolResource.createDeferred.resolve(resource);
return poolResource;
})
.catch(function (err) {
Object.assign(poolResource, {
status: PoolResourceStatus.Destroyed
});
poolResource.createDeferred.reject(err);
});
return [2 /*return*/, poolResource
.createDeferred
.promise
.then(function () { return poolResource; })];
});
}); };
this.opts = __assign({ min: 0, max: -1, limit: -1 }, opts);
this.checkInventory();
}
/**
* Start the pool
*/
Pool.prototype.checkInventory = function () {
var _a = this.opts, min = _a.min, max = _a.max, limit = _a.limit, activeResources = this.getActiveResources(), activeCount = activeResources.length, availableResources = this.getAvailableResources(), availableCount = availableResources.length, newCount = min < 1 || availableCount >= min ?
0 :
min - availableCount, destroyCount = max < 1 || availableCount <= max ?
0 :
availableCount - max;
// CHECK THE MAX VALUES
if (limit > 0 && newCount + activeCount > limit)
newCount = limit - availableCount;
for (var i = 0; i < newCount; i++) {
this.createResource();
}
for (var i = 0; i < destroyCount; i++) {
this.destroy(availableResources[i].resource);
}
// Array
// .from(Array(this.opts.min).keys())
// .map(this.createResource)
};
Object.defineProperty(Pool.prototype, "isRunning", {
/**
* is running
*
* @returns {boolean}
*/
get: function () {
return this.running && !this.killed;
},
enumerable: true,
configurable: true
});
Object.defineProperty(Pool.prototype, "isShuttingDown", {
/**
* is shutting down
*
* @returns {boolean}
*/
get: function () {
return !this.running && !this.killed;
},
enumerable: true,
configurable: true
});
Object.defineProperty(Pool.prototype, "isShutdown", {
/**
* is completely shutdown
*
* @returns {boolean}
*/
get: function () {
return this.killed && !this.running;
},
enumerable: true,
configurable: true
});
/**
* Find a pooled resource record
*
* @param resource
* @returns {IPoolResource}
*/
Pool.prototype.getPoolResource = function (resource) {
return this.resources.find(function (it) { return it.resource === resource; });
};
/**
* Get all resources
*
* @returns {List<IPoolResource>}
*/
Pool.prototype.getResources = function () {
return this.resources;
};
/**
* Get active not destroyed resources
*
* @returns {List<IPoolResource>}
*/
Pool.prototype.getActiveResources = function () {
return this.resources.filter(function (it) { return it.status < PoolResourceStatus.Destroyed; });
};
/**
* Get available - active + not reserved instances
*
* @returns {any}
*/
Pool.prototype.getAvailableResources = function () {
return this.getActiveResources()
.filter(function (it) { return !it.reserved; });
};
Pool.prototype.canCreateResource = function () {
var limit = this.opts.limit;
return (limit < 1 || this.getActiveResources().length < limit);
};
/**
* Acquire a resource
*
* @returns {Promise<any>}
*/
Pool.prototype.acquire = function () {
return __awaiter(this, void 0, void 0, function () {
var resources, poolResource, _a, _b, resource, _c;
return __generator(this, function (_d) {
switch (_d.label) {
case 0:
assert.ok(this.running, "Pool is not running");
resources = this.getAvailableResources();
if (!(resources.length)) return [3 /*break*/, 1];
_a = resources[0];
return [3 /*break*/, 5];
case 1:
if (!this.canCreateResource()) return [3 /*break*/, 3];
return [4 /*yield*/, this.createResource()];
case 2:
_b = (_d.sent());
return [3 /*break*/, 4];
case 3:
_b = null;
_d.label = 4;
case 4:
_a = _b;
_d.label = 5;
case 5:
poolResource = _a;
assert.ok(poolResource, "Could not create pool resource, size=" + this.resources.length + " with max size=" + this.opts.max);
// MARK RESERVED
poolResource.reserved = true;
_c = poolResource.resource;
if (_c) return [3 /*break*/, 7];
return [4 /*yield*/, poolResource.createDeferred.promise];
case 6:
_c = (_d.sent());
_d.label = 7;
case 7:
resource = _c;
return [4 /*yield*/, this.validate(resource)];
case 8:
if (!!(_d.sent())) return [3 /*break*/, 10];
return [4 /*yield*/, this.destroy(resource)];
case 9:
_d.sent();
return [2 /*return*/, this.acquire()];
case 10:
this.checkInventory();
return [2 /*return*/, poolResource.resource];
}
});
});
};
/**
* Validate a resource is still valid
*
* @param resource
* @returns {boolean|Promise<boolean>}
*/
Pool.prototype.validate = function (resource) {
return __awaiter(this, void 0, void 0, function () {
var _a;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
_a = !this.factory.validate;
if (_a) return [3 /*break*/, 2];
return [4 /*yield*/, this.factory.validate(resource)];
case 1:
_a = (_b.sent());
_b.label = 2;
case 2: return [2 /*return*/, _a];
}
});
});
};
/**
* Release a resource
*
* @param resource
* @returns {Promise<void>}
*/
Pool.prototype.release = function (resource) {
return __awaiter(this, void 0, void 0, function () {
var poolResource;
return __generator(this, function (_a) {
assert.ok(this.running, "Pool is not running");
poolResource = this.getPoolResource(resource);
assert.ok(poolResource, "Unknown pool resource, can not release");
Object.assign(poolResource, {
reserved: false
});
this.checkInventory();
return [2 /*return*/];
});
});
};
/**
* Destroy a resource
*
* @param resource
* @returns {Promise<void>}
*/
Pool.prototype.destroy = function (resource) {
return __awaiter(this, void 0, void 0, function () {
var poolResource;
return __generator(this, function (_a) {
assert.ok(!this.killed, "Pool is not running");
poolResource = this.getPoolResource(resource);
if (!poolResource)
return [2 /*return*/];
Object.assign(resource, {
reserved: true,
status: PoolResourceStatus.Destroyed
});
// IF NOT ALREADY DESTROYED, START THE PROCESS
if (!poolResource.destroyDeferred) {
poolResource.destroyDeferred = new Deferred_1.default();
this.factory
.destroy(resource)
.then(function () {
poolResource.destroyDeferred.resolve();
});
}
this.checkInventory();
return [2 /*return*/];
});
});
};
/**
* Drain the pool
*/
Pool.prototype.drain = function () {
return __awaiter(this, void 0, void 0, function () {
var _this = this;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
if (!this.running)
return [2 /*return*/];
this.running = false;
return [4 /*yield*/, Promise.all(this.resources.map(function (it) { return _this.destroy(it.resource); }))];
case 1:
_a.sent();
this.killed = true;
return [2 /*return*/];
}
});
});
};
return Pool;
}());
exports.Pool = Pool;
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