From cd2b80cd2a4a14aeb041244c386cab60b81978c7 Mon Sep 17 00:00:00 2001
From: sphinxrave <62570796+sphinxrave@users.noreply.github.com>
Date: Tue, 8 Dec 2020 04:08:01 -0800
Subject: [PATCH] add channel cache & fix etag

---
 apps/client-api/routes/v1/channels.js | 19 +++++++++++++++++--
 apps/client-api/routes/v1/live.js     |  4 ++--
 consts/index.js                       |  2 +-
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/apps/client-api/routes/v1/channels.js b/apps/client-api/routes/v1/channels.js
index 1551edf..286c2c4 100644
--- a/apps/client-api/routes/v1/channels.js
+++ b/apps/client-api/routes/v1/channels.js
@@ -1,16 +1,26 @@
 const { Op } = require('sequelize');
 const { Router } = require('express');
 const { db } = require('../../../../modules');
-const { ORGANIZATIONS } = require('../../../../consts');
+const { ORGANIZATIONS, CACHE_TTL } = require('../../../../consts');
 const { asyncMiddleware } = require('../../middleware/error');
 const { limitChecker } = require('../../middleware/filters');
 const { RESPONSE_FIELDS } = require('../../../../consts/v1_consts');
+const cacheService = require('../../services/CacheService');
 
 const router = new Router();
 
 router.get('/', limitChecker, asyncMiddleware(async (req, res) => {
   const { limit = 25, offset = 0, sort = 'id', order = 'asc', name } = req.query;
 
+  const cacheKey = (limit || offset || sort || order || name)
+    ? `channel-${limit}-${offset}-${sort}-${order}-${name}` : 'channel';
+
+  const cache = await cacheService.getStringFromCache(cacheKey); // nonnull indicates cached.
+  res.setHeader('Content-Type', 'application/json');
+  if (cache) {
+    return res.send(cache);
+  }
+
   const { rows, count } = await db.Channel.findAndCountAll({
     attributes: RESPONSE_FIELDS.CHANNEL,
     where: {
@@ -43,7 +53,12 @@ router.get('/', limitChecker, asyncMiddleware(async (req, res) => {
     });
   });
 
-  res.json(results);
+  const resultsJSON = JSON.stringify(results);
+  cacheService.saveStringToCache(cacheKey, resultsJSON, CACHE_TTL.CHANNELS);
+
+  res.send(
+    resultsJSON,
+  );
 }));
 
 router.get('/:id', asyncMiddleware(async (req, res) => {
diff --git a/apps/client-api/routes/v1/live.js b/apps/client-api/routes/v1/live.js
index 13b55d8..c3afa8a 100644
--- a/apps/client-api/routes/v1/live.js
+++ b/apps/client-api/routes/v1/live.js
@@ -22,9 +22,9 @@ router.get('/', asyncMiddleware(async (req, res) => {
   res.setHeader('Content-Type', 'application/json');
 
   if (cache) {
-    return res.end(cache);
+    return res.send(cache);
   }
-  return res.end(
+  return res.send(
     await computeLive(cacheKey, channel_id, max_upcoming_hours, lookback_hours, hide_channel_desc, channel_simple),
   );
 }));
diff --git a/consts/index.js b/consts/index.js
index 0b6ecf5..0b4dff8 100644
--- a/consts/index.js
+++ b/consts/index.js
@@ -23,7 +23,7 @@ exports.STATUSES = {
 
 exports.CACHE_TTL = {
   LIVE: 20,
-  CHANNELS: 6 * 60 * 60, // 1 hour
+  CHANNELS: 30 * 60, // 30 minutes
   COMMENTS: 2 * 60, // 2 minutes
 };