From 2c8d138cbd7a9d040d23bbc2d209133d0e15b41b Mon Sep 17 00:00:00 2001
From: httpjamesm <github@httpjames.space>
Date: Mon, 31 Oct 2022 17:28:18 -0400
Subject: [PATCH] feat: cache media proxy data in redis for 30 mins

---
 package.json                 |  1 +
 src/pages/api/media_proxy.ts | 35 ++++++++++++++++++++++-------------
 src/utils/redis.ts           | 11 +++++++++++
 3 files changed, 34 insertions(+), 13 deletions(-)
 create mode 100644 src/utils/redis.ts

diff --git a/package.json b/package.json
index 9f880f6..f3755ba 100644
--- a/package.json
+++ b/package.json
@@ -15,6 +15,7 @@
   "dependencies": {
     "axios": "^0.27.2",
     "cheerio": "1.0.0-rc.12",
+    "ioredis": "^5.2.3",
     "next": "12.2.5",
     "node-fetch": "^3.2.10",
     "react": "18.2.0",
diff --git a/src/pages/api/media_proxy.ts b/src/pages/api/media_proxy.ts
index 98b9c93..78a75c1 100644
--- a/src/pages/api/media_proxy.ts
+++ b/src/pages/api/media_proxy.ts
@@ -1,5 +1,7 @@
 import { NextApiRequest, NextApiResponse } from 'next'
 import fetch from 'node-fetch'
+import redis from '../../utils/redis'
+import crypto from 'crypto'
 
 const acceptableExtensions = ['.jpg', '.png', '.gif', '.webp']
 
@@ -56,6 +58,22 @@ export default async function handler(
     return
   }
 
+  // hash mediaUrl with blake3
+  const mediaUrlHash = await crypto
+    .createHash('sha256')
+    .update(mediaUrl)
+    .digest('base64')
+
+  // try to find mediaUrlHash in redis
+  const cacheKey = `media_proxy:${mediaUrlHash}`
+
+  const cachedMedia = await redis.get(cacheKey)
+
+  if (cachedMedia) {
+    res.send(cachedMedia)
+    return
+  }
+
   // download media
   const mediaRes = await fetch(mediaUrl)
 
@@ -64,20 +82,11 @@ export default async function handler(
     return
   }
 
-  // get media type
-  const mediaType = mediaRes.headers.get('content-type')
+  const mediaBuffer = Buffer.from(await mediaRes.arrayBuffer())
 
-  if (!mediaType) {
-    res.status(500)
-    res.send(null)
-    return
-  }
-
-  // set media type
-  res.setHeader('content-type', mediaType)
-
-  const mediaBuffer = await mediaRes.arrayBuffer()
+  // save in redis for 30 minutes
+  await redis.setex(cacheKey, 60 * 30, mediaBuffer)
 
   // send media
-  res.send(Buffer.from(mediaBuffer))
+  res.send(mediaBuffer)
 }
diff --git a/src/utils/redis.ts b/src/utils/redis.ts
new file mode 100644
index 0000000..eb87c77
--- /dev/null
+++ b/src/utils/redis.ts
@@ -0,0 +1,11 @@
+import Redis from 'ioredis'
+
+const redisUrl = process.env.REDIS_URL
+
+if (!redisUrl) {
+  throw 'Please set the REDIS_URL environment variable.'
+}
+
+const redis = new Redis(redisUrl)
+
+export default redis