From 58840e2c00349d937ee6e83cb968845081662c11 Mon Sep 17 00:00:00 2001
From: Edmund Huggett <Edmund.Huggett@fsfe.org>
Date: Wed, 15 Nov 2017 12:31:22 +0000
Subject: [PATCH] use redis expire event to delete stored data immediately

---
 server/config.js  |  5 +++++
 server/storage.js | 14 ++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/server/config.js b/server/config.js
index e3e97b2a..ce2504bc 100644
--- a/server/config.js
+++ b/server/config.js
@@ -14,6 +14,11 @@ const conf = convict({
     default: 'localhost',
     env: 'REDIS_HOST'
   },
+  redis_event_expire: {
+    format: Boolean,
+    default: false,
+    env: 'REDIS_EVENT_EXPIRE'
+  },
   listen_port: {
     format: 'port',
     default: 1443,
diff --git a/server/storage.js b/server/storage.js
index 13bfeb47..27647032 100644
--- a/server/storage.js
+++ b/server/storage.js
@@ -61,6 +61,20 @@ if (config.s3_bucket) {
   };
 }
 
+if (config.redis_event_expire) {
+  const forceDelete = config.s3_bucket ? awsForceDelete : localForceDelete;
+  const redis_sub = redis_client.duplicate();
+  const subKey = '__keyevent@0__:expired';
+  redis_sub.psubscribe(subKey, function() {
+    log.info('Redis:', 'subscribed to expired key events');
+  });
+
+  redis_sub.on('pmessage', function(channel, message, id) {
+    log.info('RedisExpired:', id);
+    forceDelete(id);
+  });
+}
+
 function flushall() {
   redis_client.flushdb();
 }