dweb-transports/TransportHTTP.js
2018-04-23 20:31:03 +10:00

335 lines
16 KiB
JavaScript

const errors = require('./Errors'); // Standard Dweb Errors
const Transport = require('./Transport'); // Base class for TransportXyz
const Transports = require('./Transports'); // Manage all Transports that are loaded
const nodefetch = require('node-fetch'); // Note, were using node-fetch-npm which had a warning in webpack see https://github.com/bitinn/node-fetch/issues/421 and is intended for clients
const Url = require('url');
//var fetch,Headers,Request;
//if (typeof(Window) === "undefined") {
if (typeof(fetch) === "undefined") {
//var fetch = require('whatwg-fetch').fetch; //Not as good as node-fetch-npm, but might be the polyfill needed for browser.safari
//XMLHttpRequest = require("xmlhttprequest").XMLHttpRequest; // Note this doesnt work if set to a var or const, needed by whatwg-fetch
console.log("Node loaded");
fetch = nodefetch;
Headers = fetch.Headers; // A class
Request = fetch.Request; // A class
} /* else {
// If on a browser, need to find fetch,Headers,Request in window
console.log("Loading browser version of fetch,Headers,Request");
fetch = window.fetch;
Headers = window.Headers;
Request = window.Request;
} */
//TODO-HTTP to work on Safari or mobile will require a polyfill, see https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch for comment
defaulthttpoptions = {
urlbase: 'https://gateway.dweb.me:443'
};
servercommands = { // What the server wants to see to return each of these
rawfetch: "content/rawfetch",
rawstore: "contenturl/rawstore",
rawadd: "void/rawadd",
rawlist: "metadata/rawlist",
get: "get/table",
set: "set/table",
delete: "delete/table",
keys: "keys/table",
getall: "getall/table"
};
class TransportHTTP extends Transport {
constructor(options, verbose) {
super(options, verbose);
this.options = options;
this.urlbase = options.http.urlbase;
this.supportURLs = ['contenthash', 'http','https'];
this.supportFunctions = ['fetch', 'store', 'add', 'list', 'reverse', 'newlisturls', "get", "set", "keys", "getall", "delete", "newtable", "newdatabase"]; //Does not support: listmonitor - reverse is disabled somewhere not sure if here or caller
this.supportFeatures = ['fetch.range']
this.name = "HTTP"; // For console log etc
this.status = Transport.STATUS_LOADED;
}
static setup0(options, verbose) {
let combinedoptions = Transport.mergeoptions({ http: defaulthttpoptions },options);
try {
let t = new TransportHTTP(combinedoptions, verbose);
Transports.addtransport(t);
return t;
} catch (err) {
console.log("Exception thrown in TransportHTTP.p_setup", err.message);
throw err;
}
}
async p_setup1(verbose, cb) {
this.status = Transport.STATUS_STARTING;
if (cb) cb(this);
await this.p_status(verbose);
if (cb) cb(this);
return this;
}
async p_status(verbose) {
/*
Return a numeric code for the status of a transport.
*/
try {
this.info = await this.p_info(verbose);
this.status = Transport.STATUS_CONNECTED;
} catch(err) {
console.log(this.name, ": Error in p_status.info",err.message);
this.status = Transport.STATUS_FAILED;
}
return super.p_status(verbose);
}
async p_httpfetch(httpurl, init, verbose) { // Embrace and extend "fetch" to check result etc.
/*
Fetch a url
url: optional (depends on command)
resolves to: data as text or json depending on Content-Type header
throws: TransportError if fails to fetch
*/
try {
if (verbose) console.log("httpurl=%s init=%o", httpurl, init);
//console.log('CTX=',init["headers"].get('Content-Type'))
// Using window.fetch, because it doesn't appear to be in scope otherwise in the browser.
let response = await fetch(new Request(httpurl, init));
// fetch throws (on Chrome, untested on Firefox or Node) TypeError: Failed to fetch)
// Note response.body gets a stream and response.blob gets a blob and response.arrayBuffer gets a buffer.
if (response.ok) {
let contenttype = response.headers.get('Content-Type');
if (contenttype === "application/json") {
return response.json(); // promise resolving to JSON
} else if (contenttype.startsWith("text")) { // Note in particular this is used for responses to store
return response.text();
} else { // Typically application/octetStream when don't know what fetching
return new Buffer(await response.arrayBuffer()); // Convert arrayBuffer to Buffer which is much more usable currently
}
}
// noinspection ExceptionCaughtLocallyJS
throw new errors.TransportError(`Transport Error ${response.status}: ${response.statusText}`);
} catch (err) {
// Error here is particularly unhelpful - if rejected during the COrs process it throws a TypeError
console.log("Note error from fetch might be misleading especially TypeError can be Cors issue:",httpurl);
if (err instanceof errors.TransportError) {
throw err;
} else {
throw new errors.TransportError(`Transport error thrown by ${httpurl}: ${err.message}`);
}
}
}
async p_GET(httpurl, opts={}) {
/* Locate and return a block, based on its url
Throws TransportError if fails
opts {
start, end, // Range of bytes wanted - inclusive i.e. 0,1023 is 1024 bytes
verbose }
resolves to: URL that can be used to fetch the resource, of form contenthash:/contenthash/Q123
*/
let headers = new Headers();
if (opts.start || opts.end) headers.append("range", `bytes=${opts.start || 0}-${opts.end || ""}`);
let init = { //https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch
method: 'GET',
headers: headers,
mode: 'cors',
cache: 'default',
redirect: 'follow', // Chrome defaults to manual
keepalive: true // Keep alive - mostly we'll be going back to same places a lot
};
return await this.p_httpfetch(httpurl, init, opts.verbose); // This s a real http url
}
async p_POST(httpurl, type, data, verbose) {
// Locate and return a block, based on its url
// Throws TransportError if fails
//let headers = new window.Headers();
//headers.set('content-type',type); Doesn't work, it ignores it
let init = {
//https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch
//https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_header_name for headers tat cant be set
method: 'POST',
headers: {}, //headers,
//body: new Buffer(data),
body: data,
mode: 'cors',
cache: 'default',
redirect: 'follow', // Chrome defaults to manual
keepalive: true // Keep alive - mostly we'll be going back to same places a lot
};
return await this.p_httpfetch(httpurl, init, verbose);
}
_cmdurl(command) {
return `${this.urlbase}/${command}`
}
_url(url, command, parmstr) {
if (!url) throw new errors.CodingError(`${command}: requires url`);
if (typeof url !== "string") { url = url.href }
url = url.replace('contenthash:/contenthash', this._cmdurl(command)) ; // Note leaves http: and https: urls unchanged
url = url.replace('getall/table', command);
url = url + (parmstr ? "?"+parmstr : "");
return url;
}
async p_rawfetch(url, opts={}) {
/*
Fetch from underlying transport,
Fetch is used both for contenthash requests and table as when passed to SmartDict.p_fetch may not know what we have
url: Of resource - which is turned into the HTTP url in p_httpfetch
opts: {start, end, verbose} see p_GET for documentation
throws: TransportError if fails
*/
//if (!(url && url.includes(':') ))
// throw new errors.CodingError("TransportHTTP.p_rawfetch bad url: "+url);
if (((typeof url === "string") ? url : url.href).includes('/getall/table')) {
console.log("XXX@176 - probably dont want to be calling p_rawfetch on a KeyValueTable, especially since dont know if its keyvaluetable or subclass"); //TODO-NAMING
return {
table: "keyvaluetable",
}
} else {
return await this.p_GET(this._url(url, servercommands.rawfetch), opts);
}
}
p_rawlist(url, {verbose=false}={}) {
// obj being loaded
// Locate and return a block, based on its url
if (!url) throw new errors.CodingError("TransportHTTP.p_rawlist: requires url");
return this.p_GET(this._url(url, servercommands.rawlist), {verbose});
}
rawreverse() { throw new errors.ToBeImplementedError("Undefined function TransportHTTP.rawreverse"); }
async p_rawstore(data, {verbose=false}={}) {
/*
Store data on http server,
data: string
resolves to: {string}: url
throws: TransportError on failure in p_POST > p_httpfetch
*/
//PY: res = self._sendGetPost(True, "rawstore", headers={"Content-Type": "application/octet-stream"}, urlargs=[], data=data, verbose=verbose)
console.assert(data, "TransportHttp.p_rawstore: requires data");
let res = await this.p_POST(this._cmdurl(servercommands.rawstore), "application/octet-stream", data, verbose); // resolves to URL
let parsedurl = Url.parse(res);
let pathparts = parsedurl.pathname.split('/');
return `contenthash:/contenthash/${pathparts.slice(-1)}`
}
p_rawadd(url, sig, {verbose=false}={}) { //TODO-BACKPORT turn date into ISO before adding
//verbose=true;
if (!url || !sig) throw new errors.CodingError("TransportHTTP.p_rawadd: invalid parms",url, sig);
if (verbose) console.log("rawadd", url, sig);
let value = JSON.stringify(sig.preflight(Object.assign({},sig)))+"\n";
return this.p_POST(this._url(url, servercommands.rawadd), "application/json", value, verbose); // Returns immediately
}
p_newlisturls(cl, {verbose=false}={}) {
let u = cl._publicurls.map(urlstr => Url.parse(urlstr))
.find(parsedurl =>
(parsedurl.protocol === "https" && parsedurl.host === "gateway.dweb.me" && parsedurl.pathname.includes('/content/rawfetch'))
|| (parsedurl.protocol === "contenthash:" && (parsedurl.pathname.split('/')[1] === "contenthash")));
if (!u) {
u = `contenthash:/contenthash/${ cl.keypair.verifyexportmultihashsha256_58() }`; // Pretty random, but means same test will generate same list and server is expecting base58 of a hash
}
return [u,u];
}
// ============================== Key Value support
// Support for Key-Value pairs as per
// https://docs.google.com/document/d/1yfmLRqKPxKwB939wIy9sSaa7GKOzM5PrCZ4W1jRGW6M/edit#
async p_newdatabase(pubkey, {verbose=false}={}) {
//if (pubkey instanceof Dweb.PublicPrivate)
if (pubkey.hasOwnProperty("keypair"))
pubkey = pubkey.keypair.signingexport()
// By this point pubkey should be an export of a public key of form xyz:abc where xyz
// specifies the type of public key (NACL VERIFY being the only kind we expect currently)
let u = `${this.urlbase}/getall/table/${encodeURIComponent(pubkey)}`;
return {"publicurl": u, "privateurl": u};
}
async p_newtable(pubkey, table, {verbose=false}={}) {
if (!pubkey) throw new errors.CodingError("p_newtable currently requires a pubkey");
let database = await this.p_newdatabase(pubkey, {verbose});
// If have use cases without a database, then call p_newdatabase first
return { privateurl: `${database.privateurl}/${table}`, publicurl: `${database.publicurl}/${table}`} // No action required to create it
}
//TODO-KEYVALUE needs signing with private key of list
async p_set(url, keyvalues, value, {verbose=false}={}) { // url = yjs:/yjs/database/table/key //TODO-KEYVALUE-API
if (!url || !keyvalues) throw new errors.CodingError("TransportHTTP.p_set: invalid parms",url, keyvalyes);
if (verbose) console.log("p_set", url, keyvalues, value);
if (typeof keyvalues === "string") {
let kv = JSON.stringify([{key: keyvalues, value: value}]);
await this.p_POST(this._url(url, servercommands.set), "application/json", kv, verbose); // Returns immediately
} else {
let kv = JSON.stringify(Object.keys(keyvalues).map((k) => ({"key": k, "value": keyvalues[k]})));
await this.p_POST(this._url(url, servercommands.set), "application/json", kv, verbose); // Returns immediately
}
}
_keyparm(key) {
return `key=${encodeURIComponent(key)}`
}
async p_get(url, keys, {verbose=false}={}) {
if (!url && keys) throw new errors.CodingError("TransportHTTP.p_get: requires url and at least one key");
let parmstr =Array.isArray(keys) ? keys.map(k => this._keyparm(k)).join('&') : this._keyparm(keys)
let res = await this.p_GET(this._url(url, servercommands.get, parmstr), {verbose});
return Array.isArray(keys) ? res : res[keys]
}
async p_delete(url, keys, {verbose=false}={}) { //TODO-KEYVALUE-API need to think this one through
if (!url && keys) throw new errors.CodingError("TransportHTTP.p_get: requires url and at least one key");
let parmstr = keys.map(k => this._keyparm(k)).join('&');
await this.p_GET(this._url(url, servercommands.delete, parmstr), {verbose});
}
async p_keys(url, {verbose=false}={}) {
if (!url && keys) throw new errors.CodingError("TransportHTTP.p_get: requires url and at least one key");
return await this.p_GET(this._url(url, servercommands.keys), {verbose});
}
async p_getall(url, {verbose=false}={}) {
if (!url && keys) throw new errors.CodingError("TransportHTTP.p_get: requires url and at least one key");
return await this.p_GET(this._url(url, servercommands.getall), {verbose});
}
/* Make sure doesnt shadow regular p_rawfetch
async p_rawfetch(url, verbose) {
return {
table: "keyvaluetable",
_map: await this.p_getall(url, {verbose})
}; // Data struc is ok as SmartDict.p_fetch will pass to KVT constructor
}
*/
p_info(verbose) { return this.p_GET(`${this.urlbase}/info`, {verbose}); }
static async p_test(opts={}, verbose=false) {
if (verbose) {console.log("TransportHTTP.test")}
try {
let transport = await this.p_setup(opts, verbose);
if (verbose) console.log("HTTP connected");
let res = await transport.p_info(verbose);
if (verbose) console.log("TransportHTTP info=",res);
res = await transport.p_status(verbose);
console.assert(res === Transport.STATUS_CONNECTED);
await transport.p_test_kvt("NACL%20VERIFY", verbose);
} catch(err) {
console.log("Exception thrown in TransportHTTP.test:", err.message);
throw err;
}
}
static async test() {
return this;
}
}
Transports._transportclasses["HTTP"] = TransportHTTP;
exports = module.exports = TransportHTTP;