arweave-multihost/lib/index.js

JavaScript/TypeScript Arweave SDK with multiple host support

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
const arweave_1 = __importDefault(require("arweave"));
;
;
const DEFAULT_HOSTS = [
    {
        host: "arweave.net",
        protocol: "https",
        port: 443,
    },
    {
        host: "gateway.amplify.host",
        protocol: "https",
        port: 443,
    },
    {
        host: "arweave.dev",
        protocol: "https",
        port: 443,
    },
];
const defaultArweaveConfig = {
    timeout: 10000,
    logging: false,
    onError: console.error,
};
/**
   * Returns overrriden arweave instance
   * @param hosts - Array of hosts
   * @param config - Other configuration options
   * (timeout, logging, logger, onError callback)
   * @returns arweave instance
   */
function init(hosts, config = defaultArweaveConfig) {
    if (hosts.length === 0) {
        throw new Error("Multihost config should have at least one host");
    }
    const arweave = arweave_1.default.init(Object.assign(Object.assign({}, hosts[0]), config));
    let currentHostIndex = 0, lastFailedHost = 0;
    function updateHostParams(hostConfig) {
        arweave.api.config.host = hostConfig.host;
        arweave.api.config.port = hostConfig.port;
        arweave.api.config.protocol = hostConfig.protocol;
    }
    const originalApiRequestMethods = {
        get: arweave.api.get.bind(arweave.api),
        post: arweave.api.post.bind(arweave.api),
    };
    function switchHost() {
        const oldHost = getCurrentHost();
        currentHostIndex = (currentHostIndex + 1) % hosts.length;
        const newHost = hosts[currentHostIndex];
        if (config.logging && config.logger !== undefined) {
            config.logger("Request failed. Switching host and retrying. "
                + `Old host: ${JSON.stringify(oldHost)}. `
                + `New host: ${JSON.stringify(newHost)}.`);
        }
        updateHostParams(newHost);
    }
    function getCurrentHost() {
        return hosts[currentHostIndex];
    }
    function isHostActive(host) {
        const currentHost = getCurrentHost();
        return JSON.stringify(host) === JSON.stringify(currentHost);
    }
    async function overridenRequestMethod(sendOriginalRequest) {
        for (let i = 0; i < hosts.length; i++) {
            const hostUsedForRequest = getCurrentHost();
            try {
                const response = await sendOriginalRequest();
                if (response.status >= 500 && response.status < 600) {
                    throw new Error("Error while sending http request: "
                        + `Status: ${response.status}. `
                        + `Data: ${JSON.stringify(response.data)}`);
                }
                return response;
            }
            catch (err) {
                // config.onError callback may be used for error logging
                if (config.onError) {
                    config.onError(err);
                }
                if (i === hosts.length - 1) {
                    throw err;
                }
                else {
                    // We switch host only if it's still active.
                    // If it's not active it means that it was switched by
                    // another concurrent request
                    if (isHostActive(hostUsedForRequest)) {
                        switchHost();
                    }
                }
            }
        }
        throw new Error("Should never reach this");
    }
    arweave.api.get = async (endpoint, axiosConfig) => {
        return await overridenRequestMethod(() => originalApiRequestMethods.get(endpoint, axiosConfig));
    };
    arweave.api.post = async (endpoint, body, axiosConfig) => {
        return await overridenRequestMethod(() => originalApiRequestMethods.post(endpoint, body, axiosConfig));
    };
    return arweave;
}
/**
   * Returns overrriden arweave instance with default hosts
   * (arweave.net, gateway.amplify.host, arweave.dev)
   * @param config - Other configuration options
   * (timeout, logging, logger, onError callback)
   * @returns arweave instance
   */
function initWithDefaultHosts(config) {
    return init(DEFAULT_HOSTS, config);
}
module.exports = {
    init,
    initWithDefaultHosts,
};