use redis expire event to delete stored data immediately

server/storage.js

@@ -25,6 +25,13 @@ redis_client.on('error', err => {
   log.error('Redis:', err);
 });
 
+const redis_sub = redis_client.duplicate();
+
+const subKey = '__keyevent@0__:expired';
+redis_sub.psubscribe(subKey, function() {
+  log.info('Redis:', 'subscribed to expired key events');
+});
+
 let tempDir = null;
 
 if (config.s3_bucket) {
@@ -43,6 +50,11 @@ if (config.s3_bucket) {
     quit: quit,
     metadata
   };
+
+  redis_sub.on('pmessage', function(channel, message, id) {
+    log.info('RedisExpired:', id);
+    awsForceDelete(id);
+  });
 } else {
   tempDir = fs.mkdtempSync(`${tmpdir()}${path.sep}send-`);
   log.info('tempDir', tempDir);
@@ -61,6 +73,11 @@ if (config.s3_bucket) {
     quit: quit,
     metadata
   };
+
+  redis_sub.on('pmessage', function(channel, message, id) {
+    log.info('RedisExpired:', id);
+    localForceDelete(id);
+  });
 }
 
 function flushall() {
@@ -175,6 +192,7 @@ function localDelete(id, delete_token) {
 function localForceDelete(id) {
   return new Promise((resolve, reject) => {
     redis_client.del(id);
+    log.info('Deleted:', id);
     resolve(fs.unlinkSync(path.join(tempDir, id)));
   });
 }
@@ -270,6 +288,7 @@ function awsForceDelete(id) {
       Key: id
     };
 
+    log.info('Deleted:', id);
     s3.deleteObject(params, function(err, _data) {
       redis_client.del(id);
       err ? reject(err) : resolve();