Begin WebSocket support for Broadcast and Player control

modules/React/Dns/Query/RecordCache.php

@@ -0,0 +1,82 @@
+<?php
+
+namespace React\Dns\Query;
+
+use React\Cache\CacheInterface;
+use React\Dns\Model\Message;
+use React\Dns\Model\Record;
+use React\Promise;
+
+class RecordCache
+{
+    private $cache;
+    private $expiredAt;
+
+    public function __construct(CacheInterface $cache)
+    {
+        $this->cache = $cache;
+    }
+
+    public function lookup(Query $query)
+    {
+        $id = $this->serializeQueryToIdentity($query);
+
+        $expiredAt = $this->expiredAt;
+
+        return $this->cache
+            ->get($id)
+            ->then(function ($value) use ($query, $expiredAt) {
+                $recordBag = unserialize($value);
+
+                if (null !== $expiredAt && $expiredAt <= $query->currentTime) {
+                    return Promise\reject();
+                }
+
+                return $recordBag->all();
+            });
+    }
+
+    public function storeResponseMessage($currentTime, Message $message)
+    {
+        foreach ($message->answers as $record) {
+            $this->storeRecord($currentTime, $record);
+        }
+    }
+
+    public function storeRecord($currentTime, Record $record)
+    {
+        $id = $this->serializeRecordToIdentity($record);
+
+        $cache = $this->cache;
+
+        $this->cache
+            ->get($id)
+            ->then(
+                function ($value) {
+                    return unserialize($value);
+                },
+                function ($e) {
+                    return new RecordBag();
+                }
+            )
+            ->then(function ($recordBag) use ($id, $currentTime, $record, $cache) {
+                $recordBag->set($currentTime, $record);
+                $cache->set($id, serialize($recordBag));
+            });
+    }
+
+    public function expire($currentTime)
+    {
+        $this->expiredAt = $currentTime;
+    }
+
+    public function serializeQueryToIdentity(Query $query)
+    {
+        return sprintf('%s:%s:%s', $query->name, $query->type, $query->class);
+    }
+
+    public function serializeRecordToIdentity(Record $record)
+    {
+        return sprintf('%s:%s:%s', $record->name, $record->type, $record->class);
+    }
+}