neo4j-driver
Version:
The official Neo4j driver for Javascript
377 lines • 15.4 kB
JavaScript
"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
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) : adopt(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 (g && (g = 0, op[0] && (_ = 0)), _) 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 };
}
};
Object.defineProperty(exports, "__esModule", { value: true });
/**
* Copyright (c) "Neo4j"
* Neo4j Sweden AB [https://neo4j.com]
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* eslint-disable-next-line no-unused-vars */
var neo4j_driver_core_1 = require("neo4j-driver-core");
var rxjs_1 = require("rxjs");
var operators_1 = require("rxjs/operators");
var States = {
READY: 0,
STREAMING: 1,
COMPLETED: 2
};
/**
* The reactive result interface.
*/
var RxResult = /** @class */ (function () {
/**
* @constructor
* @protected
* @param {Observable<Result>} result - An observable of single Result instance to relay requests.
* @param {number} state - The streaming state
*/
function RxResult(result, state) {
var replayedResult = result.pipe((0, operators_1.publishReplay)(1), (0, operators_1.refCount)());
this._result = replayedResult;
this._keys = replayedResult.pipe((0, operators_1.mergeMap)(function (r) { return (0, rxjs_1.from)(r.keys()); }), (0, operators_1.publishReplay)(1), (0, operators_1.refCount)());
this._records = undefined;
this._controls = new StreamControl();
this._summary = new rxjs_1.ReplaySubject();
this._state = state || States.READY;
}
/**
* Returns an observable that exposes a single item containing field names
* returned by the executing query.
*
* Errors raised by actual query execution can surface on the returned
* observable stream.
*
* @public
* @returns {Observable<string[]>} - An observable stream (with exactly one element) of field names.
*/
RxResult.prototype.keys = function () {
return this._keys;
};
/**
* Returns an observable that exposes each record returned by the executing query.
*
* Errors raised during the streaming phase can surface on the returned observable stream.
*
* @public
* @returns {Observable<Record>} - An observable stream of records.
*/
RxResult.prototype.records = function () {
var _this = this;
var result = this._result.pipe((0, operators_1.mergeMap)(function (result) {
return new rxjs_1.Observable(function (recordsObserver) {
return _this._startStreaming({ result: result, recordsObserver: recordsObserver });
});
}));
result.push = function () { return _this._push(); };
return result;
};
/**
* Returns an observable that exposes a single item of {@link ResultSummary} that is generated by
* the server after the streaming of the executing query is completed.
*
* *Subscribing to this stream before subscribing to records() stream causes the results to be discarded on the server.*
*
* @public
* @returns {Observable<ResultSummary>} - An observable stream (with exactly one element) of result summary.
*/
RxResult.prototype.consume = function () {
var _this = this;
return this._result.pipe((0, operators_1.mergeMap)(function (result) {
return new rxjs_1.Observable(function (summaryObserver) {
return _this._startStreaming({ result: result, summaryObserver: summaryObserver });
});
}));
};
/**
* Pauses the automatic streaming of records.
*
* This method provides a way of control the flow of records
*
* @experimental
*/
RxResult.prototype.pause = function () {
this._controls.pause();
};
/**
* Resumes the automatic streaming of records.
*
* This method won't need to be called in normal stream operation. It only applies to the case when the stream is paused.
*
* This method is method won't start the consuming records if the {@link records} stream didn't get subscribed.
* @experimental
* @returns {Promise<void>} - A promise that resolves when the stream is resumed.
*/
RxResult.prototype.resume = function () {
return this._controls.resume();
};
/**
* Pushes the next record to the stream.
*
* This method automatic pause the auto-streaming of records and then push next record to the stream.
*
* For returning the automatic streaming of records, use {@link resume} method.
*
* @experimental
* @returns {Promise<void>} - A promise that resolves when the push is completed.
*/
RxResult.prototype.push = function () {
return this._controls.push();
};
RxResult.prototype._startStreaming = function (_a) {
var _b = _a === void 0 ? {} : _a, result = _b.result, _c = _b.recordsObserver, recordsObserver = _c === void 0 ? null : _c, _d = _b.summaryObserver, summaryObserver = _d === void 0 ? null : _d;
var subscriptions = [];
if (summaryObserver) {
subscriptions.push(this._summary.subscribe(summaryObserver));
}
if (this._state < States.STREAMING) {
this._state = States.STREAMING;
this._setupRecordsStream(result);
if (recordsObserver) {
subscriptions.push(this._records.subscribe(recordsObserver));
}
else {
result._cancel();
}
subscriptions.push({
unsubscribe: function () {
if (result._cancel) {
result._cancel();
}
}
});
}
else if (recordsObserver) {
recordsObserver.error((0, neo4j_driver_core_1.newError)('Streaming has already started/consumed with a previous records or summary subscription.'));
}
return function () {
subscriptions.forEach(function (s) { return s.unsubscribe(); });
};
};
/**
* Create a {@link Observable} for the current {@link RxResult}
*
*
* @package
* @experimental
* @since 5.0
* @return {Observable<RxResult>}
*/
RxResult.prototype._toObservable = function () {
var _this = this;
function wrap(result) {
return new rxjs_1.Observable(function (observer) {
observer.next(result);
observer.complete();
});
}
return new rxjs_1.Observable(function (observer) {
_this._result.subscribe({
complete: function () { return observer.complete(); },
next: function (result) { return observer.next(new RxResult(wrap(result)), _this._state); },
error: function (e) { return observer.error(e); }
});
});
};
RxResult.prototype._setupRecordsStream = function (result) {
var _this = this;
if (this._records) {
return this._records;
}
this._records = createFullyControlledSubject(result[Symbol.asyncIterator](), {
complete: function () { return __awaiter(_this, void 0, void 0, function () {
var _a, _b;
return __generator(this, function (_c) {
switch (_c.label) {
case 0:
this._state = States.COMPLETED;
_b = (_a = this._summary).next;
return [4 /*yield*/, result.summary()];
case 1:
_b.apply(_a, [_c.sent()]);
this._summary.complete();
return [2 /*return*/];
}
});
}); },
error: function (error) {
_this._state = States.COMPLETED;
_this._summary.error(error);
}
}, this._controls);
return this._records;
};
return RxResult;
}());
exports.default = RxResult;
function createFullyControlledSubject(iterator, completeObserver, streamControl) {
var _this = this;
if (streamControl === void 0) { streamControl = new StreamControl(); }
var subject = new rxjs_1.Subject();
var pushNextValue = function (result) { return __awaiter(_this, void 0, void 0, function () {
var _a, done, value, error_1;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
_b.trys.push([0, 2, 3, 4]);
streamControl.pushing = true;
return [4 /*yield*/, result];
case 1:
_a = _b.sent(), done = _a.done, value = _a.value;
if (done) {
subject.complete();
completeObserver.complete();
}
else {
subject.next(value);
if (!streamControl.paused) {
pushNextValue(iterator.next())
.catch(function () { });
}
}
return [3 /*break*/, 4];
case 2:
error_1 = _b.sent();
subject.error(error_1);
completeObserver.error(error_1);
return [3 /*break*/, 4];
case 3:
streamControl.pushing = false;
return [7 /*endfinally*/];
case 4: return [2 /*return*/];
}
});
}); };
function push(value) {
return __awaiter(this, void 0, void 0, function () {
return __generator(this, function (_a) {
switch (_a.label) {
case 0: return [4 /*yield*/, pushNextValue(iterator.next(value))];
case 1:
_a.sent();
return [2 /*return*/];
}
});
});
}
streamControl.pusher = push;
push();
return subject;
}
var StreamControl = /** @class */ (function () {
function StreamControl(push) {
if (push === void 0) { push = function () { return __awaiter(_this, void 0, void 0, function () { return __generator(this, function (_a) {
return [2 /*return*/];
}); }); }; }
var _this = this;
this._paused = false;
this._pushing = false;
this._push = push;
}
StreamControl.prototype.pause = function () {
this._paused = true;
};
Object.defineProperty(StreamControl.prototype, "paused", {
get: function () {
return this._paused;
},
enumerable: false,
configurable: true
});
Object.defineProperty(StreamControl.prototype, "pushing", {
get: function () {
return this._pushing;
},
set: function (pushing) {
this._pushing = pushing;
},
enumerable: false,
configurable: true
});
StreamControl.prototype.resume = function () {
return __awaiter(this, void 0, void 0, function () {
var wasPaused;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
wasPaused = this._paused;
this._paused = false;
if (!(wasPaused && !this._pushing)) return [3 /*break*/, 2];
return [4 /*yield*/, this._push()];
case 1:
_a.sent();
_a.label = 2;
case 2: return [2 /*return*/];
}
});
});
};
StreamControl.prototype.push = function () {
return __awaiter(this, void 0, void 0, function () {
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
this.pause();
return [4 /*yield*/, this._push()];
case 1: return [2 /*return*/, _a.sent()];
}
});
});
};
Object.defineProperty(StreamControl.prototype, "pusher", {
get: function () {
return this._push;
},
set: function (push) {
this._push = push;
},
enumerable: false,
configurable: true
});
return StreamControl;
}());