neo4j-driver-core
Version:
Internals of neo4j-driver
641 lines (640 loc) • 27.8 kB
JavaScript
"use strict";
/**
* 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.
*/
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:
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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 __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
var _a;
Object.defineProperty(exports, "__esModule", { value: true });
/* eslint-disable @typescript-eslint/promise-function-async */
var result_summary_1 = __importDefault(require("./result-summary"));
var internal_1 = require("./internal");
var error_1 = require("./error");
var EMPTY_CONNECTION_HOLDER = internal_1.connectionHolder.EMPTY_CONNECTION_HOLDER;
/**
* @private
* @param {Error} error The error
* @returns {void}
*/
var DEFAULT_ON_ERROR = function (error) {
// eslint-disable-next-line @typescript-eslint/restrict-plus-operands, @typescript-eslint/no-base-to-string
console.log('Uncaught error when processing result: ' + error);
};
/**
* @private
* @param {ResultSummary} summary
* @returns {void}
*/
var DEFAULT_ON_COMPLETED = function (summary) { };
/**
* @private
* @param {string[]} keys List of keys of the record in the result
* @return {void}
*/
var DEFAULT_ON_KEYS = function (keys) { };
/**
* A stream of {@link Record} representing the result of a query.
* Can be consumed eagerly as {@link Promise} resolved with array of records and {@link ResultSummary}
* summary, or rejected with error that contains {@link string} code and {@link string} message.
* Alternatively can be consumed lazily using {@link Result#subscribe} function.
* @access public
*/
var Result = /** @class */ (function () {
/**
* Inject the observer to be used.
* @constructor
* @access private
* @param {Promise<observer.ResultStreamObserver>} streamObserverPromise
* @param {mixed} query - Cypher query to execute
* @param {Object} parameters - Map with parameters to use in query
* @param {ConnectionHolder} connectionHolder - to be notified when result is either fully consumed or error happened.
*/
function Result(streamObserverPromise, query, parameters, connectionHolder, watermarks) {
if (watermarks === void 0) { watermarks = { high: Number.MAX_VALUE, low: Number.MAX_VALUE }; }
/**
* Called when finally the result is done
*
* *Should not be combined with {@link Result#subscribe} function.*
* @param {function()|null} onfinally - function when the promise finished
* @return {Promise} promise.
*/
this[_a] = 'Result';
this._stack = captureStacktrace();
this._streamObserverPromise = streamObserverPromise;
this._p = null;
this._query = query;
this._parameters = parameters !== null && parameters !== void 0 ? parameters : {};
this._connectionHolder = connectionHolder !== null && connectionHolder !== void 0 ? connectionHolder : EMPTY_CONNECTION_HOLDER;
this._keys = null;
this._summary = null;
this._error = null;
this._watermarks = watermarks;
}
/**
* Returns a promise for the field keys.
*
* *Should not be combined with {@link Result#subscribe} function.*
*
* @public
* @returns {Promise<string[]>} - Field keys, in the order they will appear in records.
}
*/
Result.prototype.keys = function () {
var _this = this;
if (this._keys !== null) {
return Promise.resolve(this._keys);
}
else if (this._error !== null) {
return Promise.reject(this._error);
}
return new Promise(function (resolve, reject) {
_this._streamObserverPromise
.then(function (observer) {
return observer.subscribe(_this._decorateObserver({
onKeys: function (keys) { return resolve(keys); },
onError: function (err) { return reject(err); }
}));
})
.catch(reject);
});
};
/**
* Returns a promise for the result summary.
*
* *Should not be combined with {@link Result#subscribe} function.*
*
* @public
* @returns {Promise<ResultSummary>} - Result summary.
*
*/
Result.prototype.summary = function () {
var _this = this;
if (this._summary !== null) {
return Promise.resolve(this._summary);
}
else if (this._error !== null) {
return Promise.reject(this._error);
}
return new Promise(function (resolve, reject) {
_this._streamObserverPromise
.then(function (o) {
o.cancel();
o.subscribe(_this._decorateObserver({
onCompleted: function (summary) { return resolve(summary); },
onError: function (err) { return reject(err); }
}));
})
.catch(reject);
});
};
/**
* Create and return new Promise
*
* @private
* @return {Promise} new Promise.
*/
Result.prototype._getOrCreatePromise = function () {
var _this = this;
if (this._p == null) {
this._p = new Promise(function (resolve, reject) {
var records = [];
var observer = {
onNext: function (record) {
records.push(record);
},
onCompleted: function (summary) {
resolve({ records: records, summary: summary });
},
onError: function (error) {
reject(error);
}
};
_this.subscribe(observer);
});
}
return this._p;
};
/**
* Provides a async iterator over the records in the result.
*
* *Should not be combined with {@link Result#subscribe} or ${@link Result#then} functions.*
*
* @public
* @returns {PeekableAsyncIterator<Record<R>, ResultSummary>} The async iterator for the Results
*/
Result.prototype[Symbol.asyncIterator] = function () {
var _this = this;
if (!this.isOpen()) {
var error_2 = (0, error_1.newError)('Result is already consumed');
return {
next: function () { return Promise.reject(error_2); },
peek: function () { return Promise.reject(error_2); }
};
}
var state = { paused: true, firstRun: true, finished: false };
var controlFlow = function () {
var _b, _c;
if (state.streaming == null) {
return;
}
var size = (_c = (_b = state.queuedObserver) === null || _b === void 0 ? void 0 : _b.size) !== null && _c !== void 0 ? _c : 0;
var queueSizeIsOverHighOrEqualWatermark = size >= _this._watermarks.high;
var queueSizeIsBellowOrEqualLowWatermark = size <= _this._watermarks.low;
if (queueSizeIsOverHighOrEqualWatermark && !state.paused) {
state.paused = true;
state.streaming.pause();
}
else if ((queueSizeIsBellowOrEqualLowWatermark && state.paused) || (state.firstRun && !queueSizeIsOverHighOrEqualWatermark)) {
state.firstRun = false;
state.paused = false;
state.streaming.resume();
}
};
var initializeObserver = function () { return __awaiter(_this, void 0, void 0, function () {
var _b;
return __generator(this, function (_c) {
switch (_c.label) {
case 0:
if (!(state.queuedObserver === undefined)) return [3 /*break*/, 2];
state.queuedObserver = this._createQueuedResultObserver(controlFlow);
_b = state;
return [4 /*yield*/, this._subscribe(state.queuedObserver, true).catch(function () { return undefined; })];
case 1:
_b.streaming = _c.sent();
controlFlow();
_c.label = 2;
case 2: return [2 /*return*/, state.queuedObserver];
}
});
}); };
var assertSummary = function (summary) {
if (summary === undefined) {
throw (0, error_1.newError)('InvalidState: Result stream finished without Summary', error_1.PROTOCOL_ERROR);
}
return true;
};
return {
next: function () { return __awaiter(_this, void 0, void 0, function () {
var queuedObserver, next;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
if (state.finished) {
if (assertSummary(state.summary)) {
return [2 /*return*/, { done: true, value: state.summary }];
}
}
return [4 /*yield*/, initializeObserver()];
case 1:
queuedObserver = _b.sent();
return [4 /*yield*/, queuedObserver.dequeue()];
case 2:
next = _b.sent();
if (next.done === true) {
state.finished = next.done;
state.summary = next.value;
}
return [2 /*return*/, next];
}
});
}); },
return: function (value) { return __awaiter(_this, void 0, void 0, function () {
var queuedObserver, last;
var _b;
return __generator(this, function (_c) {
switch (_c.label) {
case 0:
if (state.finished) {
if (assertSummary(state.summary)) {
return [2 /*return*/, { done: true, value: value !== null && value !== void 0 ? value : state.summary }];
}
}
(_b = state.streaming) === null || _b === void 0 ? void 0 : _b.cancel();
return [4 /*yield*/, initializeObserver()];
case 1:
queuedObserver = _c.sent();
return [4 /*yield*/, queuedObserver.dequeueUntilDone()];
case 2:
last = _c.sent();
state.finished = true;
last.value = value !== null && value !== void 0 ? value : last.value;
state.summary = last.value;
return [2 /*return*/, last];
}
});
}); },
peek: function () { return __awaiter(_this, void 0, void 0, function () {
var queuedObserver;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
if (state.finished) {
if (assertSummary(state.summary)) {
return [2 /*return*/, { done: true, value: state.summary }];
}
}
return [4 /*yield*/, initializeObserver()];
case 1:
queuedObserver = _b.sent();
return [4 /*yield*/, queuedObserver.head()];
case 2: return [2 /*return*/, _b.sent()];
}
});
}); }
};
};
/**
* Waits for all results and calls the passed in function with the results.
*
* *Should not be combined with {@link Result#subscribe} function.*
*
* @param {function(result: {records:Array<Record>, summary: ResultSummary})} onFulfilled - function to be called
* when finished.
* @param {function(error: {message:string, code:string})} onRejected - function to be called upon errors.
* @return {Promise} promise.
*/
Result.prototype.then = function (onFulfilled, onRejected) {
return this._getOrCreatePromise().then(onFulfilled, onRejected);
};
/**
* Catch errors when using promises.
*
* *Should not be combined with {@link Result#subscribe} function.*
*
* @param {function(error: Neo4jError)} onRejected - Function to be called upon errors.
* @return {Promise} promise.
*/
Result.prototype.catch = function (onRejected) {
return this._getOrCreatePromise().catch(onRejected);
};
Result.prototype.finally = function (onfinally) {
return this._getOrCreatePromise().finally(onfinally);
};
/**
* Stream records to observer as they come in, this is a more efficient method
* of handling the results, and allows you to handle arbitrarily large results.
*
* @param {Object} observer - Observer object
* @param {function(keys: string[])} observer.onKeys - handle stream head, the field keys.
* @param {function(record: Record)} observer.onNext - handle records, one by one.
* @param {function(summary: ResultSummary)} observer.onCompleted - handle stream tail, the result summary.
* @param {function(error: {message:string, code:string})} observer.onError - handle errors.
* @return {void}
*/
Result.prototype.subscribe = function (observer) {
this._subscribe(observer)
.catch(function () { });
};
/**
* Check if this result is active, i.e., neither a summary nor an error has been received by the result.
* @return {boolean} `true` when neither a summary or nor an error has been received by the result.
*/
Result.prototype.isOpen = function () {
return this._summary === null && this._error === null;
};
/**
* Stream records to observer as they come in, this is a more efficient method
* of handling the results, and allows you to handle arbitrarily large results.
*
* @access private
* @param {ResultObserver} observer The observer to send records to.
* @param {boolean} paused The flag to indicate if the stream should be started paused
* @returns {Promise<observer.ResultStreamObserver>} The result stream observer.
*/
Result.prototype._subscribe = function (observer, paused) {
if (paused === void 0) { paused = false; }
var _observer = this._decorateObserver(observer);
return this._streamObserverPromise
.then(function (o) {
if (paused) {
o.pause();
}
o.subscribe(_observer);
return o;
})
.catch(function (error) {
if (_observer.onError != null) {
_observer.onError(error);
}
return Promise.reject(error);
});
};
/**
* Decorates the ResultObserver with the necessary methods.
*
* @access private
* @param {ResultObserver} observer The ResultObserver to decorate.
* @returns The decorated result observer
*/
Result.prototype._decorateObserver = function (observer) {
var _this = this;
var _b, _c, _d;
var onCompletedOriginal = (_b = observer.onCompleted) !== null && _b !== void 0 ? _b : DEFAULT_ON_COMPLETED;
var onErrorOriginal = (_c = observer.onError) !== null && _c !== void 0 ? _c : DEFAULT_ON_ERROR;
var onKeysOriginal = (_d = observer.onKeys) !== null && _d !== void 0 ? _d : DEFAULT_ON_KEYS;
var onCompletedWrapper = function (metadata) {
_this._releaseConnectionAndGetSummary(metadata).then(function (summary) {
if (_this._summary !== null) {
return onCompletedOriginal.call(observer, _this._summary);
}
_this._summary = summary;
return onCompletedOriginal.call(observer, summary);
}).catch(onErrorOriginal);
};
var onErrorWrapper = function (error) {
// notify connection holder that the used connection is not needed any more because error happened
// and result can't bee consumed any further; call the original onError callback after that
_this._connectionHolder.releaseConnection().then(function () {
replaceStacktrace(error, _this._stack);
_this._error = error;
onErrorOriginal.call(observer, error);
}).catch(onErrorOriginal);
};
var onKeysWrapper = function (keys) {
_this._keys = keys;
return onKeysOriginal.call(observer, keys);
};
return {
onNext: (observer.onNext != null) ? observer.onNext.bind(observer) : undefined,
onKeys: onKeysWrapper,
onCompleted: onCompletedWrapper,
onError: onErrorWrapper
};
};
/**
* Signals the stream observer that the future records should be discarded on the server.
*
* @protected
* @since 4.0.0
* @returns {void}
*/
Result.prototype._cancel = function () {
if (this._summary === null && this._error === null) {
this._streamObserverPromise.then(function (o) { return o.cancel(); })
.catch(function () { });
}
};
/**
* @access private
* @param metadata
* @returns
*/
Result.prototype._releaseConnectionAndGetSummary = function (metadata) {
var _b = internal_1.util.validateQueryAndParameters(this._query, this._parameters, {
skipAsserts: true
}), query = _b.validatedQuery, parameters = _b.params;
var connectionHolder = this._connectionHolder;
return connectionHolder
.getConnection()
.then(
// onFulfilled:
function (connection) {
return connectionHolder
.releaseConnection()
.then(function () {
return connection === null || connection === void 0 ? void 0 : connection.getProtocolVersion();
});
},
// onRejected:
function (_) { return undefined; })
.then(function (protocolVersion) {
return new result_summary_1.default(query, parameters, metadata, protocolVersion);
});
};
/**
* @access private
*/
Result.prototype._createQueuedResultObserver = function (onQueueSizeChanged) {
var _this = this;
function createResolvablePromise() {
var resolvablePromise = {};
resolvablePromise.promise = new Promise(function (resolve, reject) {
resolvablePromise.resolve = resolve;
resolvablePromise.reject = reject;
});
return resolvablePromise;
}
function isError(elementOrError) {
return elementOrError instanceof Error;
}
function dequeue() {
var _b;
return __awaiter(this, void 0, void 0, function () {
var element;
return __generator(this, function (_c) {
switch (_c.label) {
case 0:
if (buffer.length > 0) {
element = (_b = buffer.shift()) !== null && _b !== void 0 ? _b : (0, error_1.newError)('Unexpected empty buffer', error_1.PROTOCOL_ERROR);
onQueueSizeChanged();
if (isError(element)) {
throw element;
}
return [2 /*return*/, element];
}
promiseHolder.resolvable = createResolvablePromise();
return [4 /*yield*/, promiseHolder.resolvable.promise];
case 1: return [2 /*return*/, _c.sent()];
}
});
});
}
var buffer = [];
var promiseHolder = { resolvable: null };
var observer = {
onNext: function (record) {
observer._push({ done: false, value: record });
},
onCompleted: function (summary) {
observer._push({ done: true, value: summary });
},
onError: function (error) {
observer._push(error);
},
_push: function (element) {
if (promiseHolder.resolvable !== null) {
var resolvable = promiseHolder.resolvable;
promiseHolder.resolvable = null;
if (isError(element)) {
resolvable.reject(element);
}
else {
resolvable.resolve(element);
}
}
else {
buffer.push(element);
onQueueSizeChanged();
}
},
dequeue: dequeue,
dequeueUntilDone: function () { return __awaiter(_this, void 0, void 0, function () {
var element;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
if (!true) return [3 /*break*/, 2];
return [4 /*yield*/, dequeue()];
case 1:
element = _b.sent();
if (element.done === true) {
return [2 /*return*/, element];
}
return [3 /*break*/, 0];
case 2: return [2 /*return*/];
}
});
}); },
head: function () { return __awaiter(_this, void 0, void 0, function () {
var element, element, error_3;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
if (buffer.length > 0) {
element = buffer[0];
if (isError(element)) {
throw element;
}
return [2 /*return*/, element];
}
promiseHolder.resolvable = createResolvablePromise();
_b.label = 1;
case 1:
_b.trys.push([1, 3, 4, 5]);
return [4 /*yield*/, promiseHolder.resolvable.promise];
case 2:
element = _b.sent();
buffer.unshift(element);
return [2 /*return*/, element];
case 3:
error_3 = _b.sent();
buffer.unshift(error_3);
throw error_3;
case 4:
onQueueSizeChanged();
return [7 /*endfinally*/];
case 5: return [2 /*return*/];
}
});
}); },
get size() {
return buffer.length;
}
};
return observer;
};
return Result;
}());
_a = Symbol.toStringTag;
function captureStacktrace() {
var error = new Error('');
if (error.stack != null) {
return error.stack.replace(/^Error(\n\r)*/, ''); // we don't need the 'Error\n' part, if only it exists
}
return null;
}
/**
* @private
* @param {Error} error The error
* @param {string| null} newStack The newStack
* @returns {void}
*/
function replaceStacktrace(error, newStack) {
if (newStack != null) {
// Error.prototype.toString() concatenates error.name and error.message nicely
// then we add the rest of the stack trace
// eslint-disable-next-line @typescript-eslint/no-base-to-string
error.stack = error.toString() + '\n' + newStack;
}
}
exports.default = Result;