dworthjs
Version:
Wortheum blockchain RPC client library
137 lines (136 loc) • 5.53 kB
JavaScript
;
/**
* @file Misc utility functions.
* @author Johan Nordberg <code@johan-nordberg.com>
* @license
* Copyright (c) 2017 Johan Nordberg. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistribution of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistribution in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* You acknowledge that this software is not designed, licensed or intended for use
* in the design, construction, operation or maintenance of any military facility.
*/
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 __asyncValues = (this && this.__asyncIterator) || function (o) {
if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
var m = o[Symbol.asyncIterator];
return m ? m.call(o) : typeof __values === "function" ? __values(o) : o[Symbol.iterator]();
};
Object.defineProperty(exports, "__esModule", { value: true });
const stream_1 = require("stream");
const fetch = global['fetch']; // tslint:disable-line:no-string-literal
/**
* Return a promise that will resove when a specific event is emitted.
*/
function waitForEvent(emitter, eventName) {
return new Promise((resolve, reject) => {
emitter.once(eventName, resolve);
});
}
exports.waitForEvent = waitForEvent;
/**
* Sleep for N milliseconds.
*/
function sleep(ms) {
return new Promise((resolve) => {
setTimeout(resolve, ms);
});
}
exports.sleep = sleep;
/**
* Return a stream that emits iterator values.
*/
function iteratorStream(iterator) {
const stream = new stream_1.PassThrough({ objectMode: true });
const iterate = () => __awaiter(this, void 0, void 0, function* () {
try {
for (var iterator_1 = __asyncValues(iterator), iterator_1_1; iterator_1_1 = yield iterator_1.next(), !iterator_1_1.done;) {
const item = yield iterator_1_1.value;
if (!stream.write(item)) {
yield waitForEvent(stream, 'drain');
}
}
}
catch (e_1_1) { e_1 = { error: e_1_1 }; }
finally {
try {
if (iterator_1_1 && !iterator_1_1.done && (_a = iterator_1.return)) yield _a.call(iterator_1);
}
finally { if (e_1) throw e_1.error; }
}
var e_1, _a;
});
iterate().then(() => {
stream.end();
}).catch((error) => {
stream.emit('error', error);
stream.end();
});
return stream;
}
exports.iteratorStream = iteratorStream;
/**
* Return a deep copy of a JSON-serializable object.
*/
function copy(object) {
return JSON.parse(JSON.stringify(object));
}
exports.copy = copy;
/**
* Fetch API wrapper that retries until timeout is reached.
*/
function retryingFetch(url, opts, timeout, backoff, fetchTimeout) {
return __awaiter(this, void 0, void 0, function* () {
const start = Date.now();
let tries = 0;
do {
try {
if (fetchTimeout) {
opts.timeout = fetchTimeout(tries);
}
const response = yield fetch(url, opts);
if (!response.ok) {
throw new Error(`HTTP ${response.status}: ${response.statusText}`);
}
return yield response.json();
}
catch (error) {
if (timeout !== 0 && Date.now() - start > timeout) {
throw error;
}
yield sleep(backoff(tries++));
}
} while (true);
});
}
exports.retryingFetch = retryingFetch;