ydb-sdk
Version:
Node.js bindings for working with YDB API over gRPC
81 lines (80 loc) • 4 kB
JavaScript
;
var __await = (this && this.__await) || function (v) { return this instanceof __await ? (this.v = v, this) : new __await(v); }
var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _arguments, generator) {
if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
var g = generator.apply(thisArg, _arguments || []), i, q = [];
return i = Object.create((typeof AsyncIterator === "function" ? AsyncIterator : Object).prototype), verb("next"), verb("throw"), verb("return", awaitReturn), i[Symbol.asyncIterator] = function () { return this; }, i;
function awaitReturn(f) { return function (v) { return Promise.resolve(v).then(f, reject); }; }
function verb(n, f) { if (g[n]) { i[n] = function (v) { return new Promise(function (a, b) { q.push([n, v, a, b]) > 1 || resume(n, v); }); }; if (f) i[n] = f(i[n]); } }
function resume(n, v) { try { step(g[n](v)); } catch (e) { settle(q[0][3], e); } }
function step(r) { r.value instanceof __await ? Promise.resolve(r.value.v).then(fulfill, reject) : settle(q[0][2], r); }
function fulfill(value) { resume("next", value); }
function reject(value) { resume("throw", value); }
function settle(f, v) { if (f(v), q.shift(), q.length) resume(q[0][0], q[0][1]); }
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.buildAsyncQueueIterator = buildAsyncQueueIterator;
const QUEUE_END = Symbol('QUEUE_END');
function buildAsyncQueueIterator() {
let waitNextItemPromiseResolve;
let waitNextItemPromiseReject;
const queue = [];
let isQueueOver;
let error;
let isGeneratorInstantiated;
return {
push(value) {
if (error)
return; // queue is already droped
if (isQueueOver)
throw new Error('The queue has already been closed by calling end()');
if (waitNextItemPromiseResolve) {
waitNextItemPromiseResolve(value);
waitNextItemPromiseResolve = waitNextItemPromiseReject = undefined;
}
else {
queue.push(value);
}
},
end() {
if (isQueueOver)
throw new Error('The queue has already been closed by calling end()');
isQueueOver = true;
if (waitNextItemPromiseResolve)
waitNextItemPromiseResolve(QUEUE_END);
waitNextItemPromiseResolve = waitNextItemPromiseReject = undefined;
},
error(err) {
error = err;
queue.length = 0; // drop queue
if (waitNextItemPromiseReject)
waitNextItemPromiseReject(err);
waitNextItemPromiseResolve = waitNextItemPromiseReject = undefined;
},
[Symbol.asyncIterator]() {
return __asyncGenerator(this, arguments, function* _a() {
if (isGeneratorInstantiated)
throw new Error('Сan be only ONE instance of the generator');
isGeneratorInstantiated = true;
while (true) {
if (error)
throw error;
if (queue.length > 0)
yield yield __await(queue.shift());
else if (isQueueOver)
return yield __await(void 0);
else { // nothing in the queue and it is not ended
const waitNextItemPromise = new Promise((resolve, reject) => {
waitNextItemPromiseResolve = resolve;
waitNextItemPromiseReject = reject;
});
const value = yield __await(waitNextItemPromise);
if (value === QUEUE_END)
return yield __await(void 0);
yield yield __await(value);
}
}
});
},
};
}