vendor-ed skydns

vendor/github.com/skynetservices/skydns/cache/hit.go

@@ -0,0 +1,31 @@
+// Copyright (c) 2014 The SkyDNS Authors. All rights reserved.
+// Use of this source code is governed by The MIT License (MIT) that can be
+// found in the LICENSE file.
+
+package cache
+
+import (
+	"time"
+
+	"github.com/miekg/dns"
+)
+
+// Hit returns a dns message from the cache. If the message's TTL is expired nil
+// is returned and the message is removed from the cache.
+func (c *Cache) Hit(question dns.Question, dnssec, tcp bool, msgid uint16) *dns.Msg {
+	key := Key(question, dnssec, tcp)
+	m1, exp, hit := c.Search(key)
+	if hit {
+		// Cache hit! \o/
+		if time.Since(exp) < 0 {
+			m1.Id = msgid
+			m1.Compress = true
+			// Even if something ended up with the TC bit *in* the cache, set it to off
+			m1.Truncated = false
+			return m1
+		}
+		// Expired! /o\
+		c.Remove(key)
+	}
+	return nil
+}