add basic auth support (#23)

* add basic auth support

* bump version

bin/cli.ts

@@ -20,6 +20,7 @@ let verbose: boolean = false;
 let save: string | undefined;
 let onlyDefaultGraph: boolean = false;
 let loose: boolean = false;
+let basicAuth: string | undefined;
 
 program
   .arguments("<url>")
@@ -61,6 +62,7 @@ program
   )
   .option("-q --quiet", "be quiet")
   .option("-v --verbose", "be verbose")
+  .option("--basic-auth <username>:<password>", "HTTP basic auth information")
   .action((url: string, program) => {
     urlIsView = program.urlIsView;
     noShape = !program.shape;
@@ -74,6 +76,7 @@ program
     verbose = program.verbose;
     loose = program.loose;
     onlyDefaultGraph = program.onlyDefaultGraph;
+    basicAuth = program.basicAuth;
     if (program.after) {
       if (!isNaN(new Date(program.after).getTime())) {
         after = new Date(program.after);
@@ -94,11 +97,6 @@ program
 
 program.parse(process.argv);
 
-const f = global.fetch;
-global.fetch = (req, options) => {
-  console.log("Global fetch", req);
-  return f(req, options);
-};
 async function main() {
   const client = replicateLDES(
     intoConfig({
@@ -115,7 +113,7 @@ async function main() {
       onlyDefaultGraph,
       after,
       before,
-      // fetch: <typeof fetch>fetch_f,
+      basicAuth,
     }),
     undefined,
     undefined,

lib/client.ts

@@ -187,10 +187,9 @@ async function getInfo(
       config.shapes && config.shapes.length > 0 ? shapeConfigStore : store,
       dereferencer,
       {
-        // Updated upstream
         cbdDefaultGraph: config.onlyDefaultGraph,
         fetch: config.fetch,
-      }, //Stashed changes
+      },
     ),
     shapeMap: config.noShape ? undefined : shapeMap,
     timestampPath: timestampPaths[0],
@@ -430,7 +429,7 @@ export class Client {
       },
       cancel: async () => {
         this.stateFactory.write();
-        console.log("Cancled");
+        console.log("Canceled");
         this.strategy.cancle();
       },
     };

lib/config.ts

@@ -1,6 +1,10 @@
 import { NamedNode, Quad } from "@rdfjs/types";
 import { DefaultFetcherConfig, FetcherConfig } from "./pageFetcher";
-import { retry_fetch } from "./utils";
+import {
+  handle_basic_auth,
+  limit_fetch_per_domain,
+  retry_fetch,
+} from "./utils";
 
 export interface ShapeConfig {
   quads: Quad[];
@@ -34,6 +38,7 @@ export interface Config {
   shapeFiles?: string[];
   onlyDefaultGraph?: boolean;
   fetch?: typeof fetch;
+  basicAuth?: string;
   // Add flag to indicate in order (default true)
   // Make sure that slower pages to first emit the first members
   //
@@ -69,7 +74,14 @@ export async function getConfig(): Promise<Config & WithTarget> {
 
 export function intoConfig(config: Partial<Config>): Config {
   if (!config.fetch) {
-    config.fetch = retry_fetch(fetch, [408, 425, 429, 500, 502, 503, 504]);
+    const fetch_f = config.basicAuth
+      ? handle_basic_auth(fetch, config.basicAuth, new URL(config.url!))
+      : fetch;
+
+    config.fetch = limit_fetch_per_domain(
+      retry_fetch(fetch_f, [408, 425, 429, 500, 502, 503, 504, 404]),
+      1,
+    );
   }
 
   return Object.assign({}, defaultConfig, defaultTarget, config);

lib/utils.ts

@@ -1,8 +1,9 @@
-import { NamedNode, Quad_Subject, Stream, Term } from "@rdfjs/types";
+import { NamedNode, Stream, Term } from "@rdfjs/types";
 import { BaseQuad } from "n3";
 import { StateFactory, StateT } from "./state";
 import { RdfStore } from "rdf-stores";
 import { RDF, SHACL } from "@treecg/types";
+import debug from "debug";
 
 export type Notifier<Events, S> = {
   [K in keyof Events]: (event: Events[K], state: S) => void;
@@ -227,7 +228,6 @@ class ModulatorInstance<T> implements Modulator<T> {
     this.notifier = notifier;
     this.factory = factory;
     for (let item of readd) {
-      console.log("Readding");
       this.push(item.item);
     }
   }
@@ -289,19 +289,113 @@ class ModulatorInstance<T> implements Modulator<T> {
   }
 }
 
+function urlToUrl(input: Parameters<typeof fetch>[0]): URL {
+  if (typeof input === "string") {
+    return new URL(input);
+  } else if (input instanceof URL) {
+    return input;
+  } else if (input instanceof Request) {
+    return new URL(input.url);
+  } else {
+    throw "Not a real url";
+  }
+}
+
+const log = debug("fetch");
+
+export function limit_fetch_per_domain(
+  fetch_f: typeof fetch,
+  concurrent: number,
+): typeof fetch {
+  const logger = log.extend("limit");
+  const domain_dict: { [domain: string]: Array<(value: void) => void> } = {};
+
+  const out: typeof fetch = async (input, init) => {
+    let url: URL = urlToUrl(input);
+    const domain = url.origin;
+
+    if (!(domain in domain_dict)) {
+      domain_dict[domain] = [];
+    }
+
+    const requests = domain_dict[domain];
+    await new Promise((res) => {
+      logger("%s capacity %d/%d", domain, requests.length, concurrent);
+      if (requests.length < concurrent) {
+        requests.push(res);
+        res({});
+      } else {
+        requests.push(res);
+      }
+    });
+    const resp = await fetch_f(input, init);
+
+    requests.shift();
+    for (let i = 0; i < concurrent; i++) {
+      if (requests[i]) {
+        requests[i]();
+      }
+    }
+
+    return resp;
+  };
+
+  return out;
+}
+
+export function handle_basic_auth(
+  fetch_f: typeof fetch,
+  basicAuth: string,
+  domain: URL,
+): typeof fetch {
+  const logger = log.extend("auth");
+  let authRequired = false;
+
+  const basicAuthValue = `Basic ${Buffer.from(basicAuth).toString("base64")}`;
+  const setHeader = (init?: RequestInit): RequestInit => {
+    const reqInit = init || {};
+    const headers = new Headers(reqInit.headers);
+    headers.set("Authorization", basicAuthValue);
+    reqInit.headers = headers;
+    return reqInit;
+  };
+
+  const auth_f: typeof fetch = async (input, init) => {
+    let url: URL = urlToUrl(input);
+    if (authRequired && url.host === domain.host) {
+      return await fetch_f(input, setHeader(init));
+    }
+
+    const resp = await fetch_f(input, init);
+    if (resp.status === 401) {
+      logger("Unauthorized, adding basic auth");
+      if (url.host === domain.host) {
+        authRequired = true;
+        return await fetch_f(input, setHeader(init));
+      }
+    }
+
+    return resp;
+  };
+
+  return auth_f;
+}
+
 export function retry_fetch(
   fetch_f: typeof fetch,
   httpCodes: number[],
   base = 500,
   maxRetries = 5,
 ): typeof fetch {
+  const logger = log.extend("retry");
   const retry: typeof fetch = async (input, init) => {
     let tryCount = 0;
     let retryTime = base;
     while (tryCount < maxRetries) {
       const resp = await fetch_f(input, init);
       if (!resp.ok) {
         if (httpCodes.some((x) => x == resp.status)) {
+          logger("Retry %s %d/%d", input, tryCount, maxRetries);
           // Wait 500ms, 1 second, 2 seconds, 4 seconds, 8 seconds, fail
           tryCount += 1;
           await new Promise((res) => setTimeout(res, retryTime));