firebase-admin/lib/messaging/batch-request-internal.js

/*! firebase-admin v12.0.0 */
"use strict";
/*!
 * Copyright 2019 Google Inc.
 *
 * 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.
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.BatchRequestClient = void 0;
const api_request_1 = require("../utils/api-request");
const error_1 = require("../utils/error");
const PART_BOUNDARY = '__END_OF_PART__';
const TEN_SECONDS_IN_MILLIS = 15000;
/**
 * An HTTP client that can be used to make batch requests. This client is not tied to any service
 * (FCM or otherwise). Therefore it can be used to make batch requests to any service that allows
 * it. If this requirement ever arises we can move this implementation to the utils module
 * where it can be easily shared among other modules.
 */
class BatchRequestClient {
    /**
     * @param {HttpClient} httpClient The client that will be used to make HTTP calls.
     * @param {string} batchUrl The URL that accepts batch requests.
     * @param {object=} commonHeaders Optional headers that will be included in all requests.
     *
     * @constructor
     */
    constructor(httpClient, batchUrl, commonHeaders) {
        this.httpClient = httpClient;
        this.batchUrl = batchUrl;
        this.commonHeaders = commonHeaders;
    }
    /**
     * Sends the given array of sub requests as a single batch, and parses the results into an array
     * of HttpResponse objects.
     *
     * @param requests - An array of sub requests to send.
     * @returns A promise that resolves when the send operation is complete.
     */
    send(requests) {
        requests = requests.map((req) => {
            req.headers = Object.assign({}, this.commonHeaders, req.headers);
            return req;
        });
        const requestHeaders = {
            'Content-Type': `multipart/mixed; boundary=${PART_BOUNDARY}`,
        };
        const request = {
            method: 'POST',
            url: this.batchUrl,
            data: this.getMultipartPayload(requests),
            headers: Object.assign({}, this.commonHeaders, requestHeaders),
            timeout: TEN_SECONDS_IN_MILLIS,
        };
        return this.httpClient.send(request).then((response) => {
            if (!response.multipart) {
                throw new error_1.FirebaseAppError(error_1.AppErrorCodes.INTERNAL_ERROR, 'Expected a multipart response.');
            }
            return response.multipart.map((buff) => {
                return (0, api_request_1.parseHttpResponse)(buff, request);
            });
        });
    }
    getMultipartPayload(requests) {
        let buffer = '';
        requests.forEach((request, idx) => {
            buffer += createPart(request, PART_BOUNDARY, idx);
        });
        buffer += `--${PART_BOUNDARY}--\r\n`;
        return Buffer.from(buffer, 'utf-8');
    }
}
exports.BatchRequestClient = BatchRequestClient;
/**
 * Creates a single part in a multipart HTTP request body. The part consists of several headers
 * followed by the serialized sub request as the body. As per the requirements of the FCM batch
 * API, sets the content-type header to application/http, and the content-transfer-encoding to
 * binary.
 *
 * @param request - A sub request that will be used to populate the part.
 * @param boundary - Multipart boundary string.
 * @param idx - An index number that is used to set the content-id header.
 * @returns The part as a string that can be included in the HTTP body.
 */
function createPart(request, boundary, idx) {
    const serializedRequest = serializeSubRequest(request);
    let part = `--${boundary}\r\n`;
    part += `Content-Length: ${serializedRequest.length}\r\n`;
    part += 'Content-Type: application/http\r\n';
    part += `content-id: ${idx + 1}\r\n`;
    part += 'content-transfer-encoding: binary\r\n';
    part += '\r\n';
    part += `${serializedRequest}\r\n`;
    return part;
}
/**
 * Serializes a sub request into a string that can be embedded in a multipart HTTP request. The
 * format of the string is the wire format of a typical HTTP request, consisting of a header and a
 * body.
 *
 * @param request - The sub request to be serialized.
 * @returns String representation of the SubRequest.
 */
function serializeSubRequest(request) {
    const requestBody = JSON.stringify(request.body);
    let messagePayload = `POST ${request.url} HTTP/1.1\r\n`;
    messagePayload += `Content-Length: ${requestBody.length}\r\n`;
    messagePayload += 'Content-Type: application/json; charset=UTF-8\r\n';
    if (request.headers) {
        Object.keys(request.headers).forEach((key) => {
            messagePayload += `${key}: ${request.headers[key]}\r\n`;
        });
    }
    messagePayload += '\r\n';
    messagePayload += requestBody;
    return messagePayload;
}