Implement session caching.

lib/session.js

@@ -1,6 +1,6 @@
 import { getWebsiteByUuid, getSessionByUuid, createSession } from 'lib/queries';
 import { getClientInfo } from 'lib/request';
-import { uuid, isValidUuid } from 'lib/crypto';
+import { uuid, isValidUuid, parseToken } from 'lib/crypto';
 
 export async function getSession(req) {
   const { payload } = req.body;
@@ -9,7 +9,15 @@ export async function getSession(req) {
     throw new Error('Invalid request');
   }
 
-  const { website: website_uuid, hostname, screen, language } = payload;
+  const { website: website_uuid, hostname, screen, language, cache } = payload;
+
+  if (cache) {
+    const result = await parseToken(cache);
+
+    if (result) {
+      return result;
+    }
+  }
 
   if (!isValidUuid(website_uuid)) {
     throw new Error(`Invalid website: ${website_uuid}`);

package.json

@@ -1,6 +1,6 @@
 {
   "name": "umami",
-  "version": "0.72.0",
+  "version": "0.73.0",
   "description": "A simple, fast, website analytics alternative to Google Analytics. ",
   "author": "Mike Cao <mike@mikecao.com>",
   "license": "MIT",

pages/api/collect.js

@@ -1,7 +1,8 @@
+import isBot from 'isbot-fast';
 import { savePageView, saveEvent } from 'lib/queries';
 import { useCors, useSession } from 'lib/middleware';
 import { ok, badRequest } from 'lib/response';
-import isBot from 'isbot-fast';
+import { createToken } from 'lib/crypto';
 
 export default async (req, res) => {
   if (isBot(req.headers['user-agent'])) {
@@ -28,5 +29,7 @@ export default async (req, res) => {
     return badRequest(res);
   }
 
-  return ok(res);
+  const token = await createToken({ website_id, session_id });
+
+  return ok(res, token);
 };

tracker/index.js

@@ -6,6 +6,7 @@ import { removeTrailingSlash } from '../lib/url';
     screen: { width, height },
     navigator: { language },
     location: { hostname, pathname, search },
+    sessionStorage,
     document,
     history,
   } = window;
@@ -16,7 +17,8 @@ import { removeTrailingSlash } from '../lib/url';
   const website = attr('data-website-id');
   const hostUrl = attr('data-host-url');
   const autoTrack = attr('data-auto-track') !== 'false';
-  const dnt = attr('data-do-not-track') === 'true';
+  const dnt = attr('data-do-not-track');
+  const useCache = attr('data-cache');
 
   if (!script || (dnt && doNotTrack())) return;
 
@@ -37,7 +39,7 @@ import { removeTrailingSlash } from '../lib/url';
 
     req.onreadystatechange = () => {
       if (req.readyState === 4) {
-        callback && callback();
+        callback && callback(req.response);
       }
     };
 
@@ -45,11 +47,14 @@ import { removeTrailingSlash } from '../lib/url';
   };
 
   const collect = (type, params, uuid) => {
+    const key = 'umami.cache';
+
     const payload = {
       website: uuid,
       hostname,
       screen,
       language,
+      cache: useCache && sessionStorage.getItem(key),
     };
 
     if (params) {
@@ -58,10 +63,14 @@ import { removeTrailingSlash } from '../lib/url';
       });
     }
 
-    return post(`${root}/api/collect`, {
-      type,
-      payload,
-    });
+    return post(
+      `${root}/api/collect`,
+      {
+        type,
+        payload,
+      },
+      res => useCache && sessionStorage.setItem(key, res),
+    );
   };
 
   const trackView = (url = currentUrl, referrer = currentRef, uuid = website) =>