1 files changed, 125 insertions, 0 deletions
diff --git a/dom/html/nsHTMLDNSPrefetch.h b/dom/html/nsHTMLDNSPrefetch.h
new file mode 100644
index 000000000..18da98f26
--- /dev/null
+++ b/dom/html/nsHTMLDNSPrefetch.h
@@ -0,0 +1,125 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsHTMLDNSPrefetch_h___
+#define nsHTMLDNSPrefetch_h___
+
+#include "nsCOMPtr.h"
+#include "nsString.h"
+
+#include "nsIDNSListener.h"
+#include "nsIWebProgressListener.h"
+#include "nsWeakReference.h"
+#include "nsIObserver.h"
+
+class nsIDocument;
+class nsITimer;
+namespace mozilla {
+namespace dom {
+class Link;
+} // namespace dom
+} // namespace mozilla
+
+namespace mozilla {
+namespace net {
+class NeckoParent;
+} // namespace net
+} // namespace mozilla
+
+class nsHTMLDNSPrefetch 
+{
+public:
+  // The required aDocument parameter is the context requesting the prefetch - under
+  // certain circumstances (e.g. headers, or security context) associated with
+  // the context the prefetch will not be performed. 
+  static bool     IsAllowed(nsIDocument *aDocument);
+ 
+  static nsresult Initialize();
+  static nsresult Shutdown();
+  
+  // Call one of the Prefetch* methods to start the lookup.
+  //
+  // The URI versions will defer DNS lookup until pageload is
+  // complete, while the string versions submit the lookup to 
+  // the DNS system immediately. The URI version is somewhat lighter
+  // weight, but its request is also more likely to be dropped due to a 
+  // full queue and it may only be used from the main thread.
+
+  static nsresult PrefetchHigh(mozilla::dom::Link *aElement);
+  static nsresult PrefetchMedium(mozilla::dom::Link *aElement);
+  static nsresult PrefetchLow(mozilla::dom::Link *aElement);
+  static nsresult PrefetchHigh(const nsAString &host);
+  static nsresult PrefetchMedium(const nsAString &host);
+  static nsresult PrefetchLow(const nsAString &host);
+  static nsresult CancelPrefetchLow(const nsAString &host, nsresult aReason);
+  static nsresult CancelPrefetchLow(mozilla::dom::Link *aElement,
+                                    nsresult aReason);
+
+private:
+  static nsresult Prefetch(const nsAString &host, uint16_t flags);
+  static nsresult Prefetch(mozilla::dom::Link *aElement, uint16_t flags);
+  static nsresult CancelPrefetch(const nsAString &hostname,
+                                 uint16_t flags,
+                                 nsresult aReason);
+  static nsresult CancelPrefetch(mozilla::dom::Link *aElement,
+                                 uint16_t flags,
+                                 nsresult aReason);
+  
+public:
+  class nsListener final : public nsIDNSListener
+  {
+    // This class exists to give a safe callback no-op DNSListener
+  public:
+    NS_DECL_THREADSAFE_ISUPPORTS
+    NS_DECL_NSIDNSLISTENER
+
+    nsListener()  {}
+  private:
+    ~nsListener() {}
+  };
+  
+  class nsDeferrals final: public nsIWebProgressListener
+                         , public nsSupportsWeakReference
+                         , public nsIObserver
+  {
+  public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIWEBPROGRESSLISTENER
+    NS_DECL_NSIOBSERVER
+
+    nsDeferrals();
+    
+    void Activate();
+    nsresult Add(uint16_t flags, mozilla::dom::Link *aElement);
+    
+  private:
+    ~nsDeferrals();
+    void Flush();
+    
+    void SubmitQueue();
+    
+    uint16_t                  mHead;
+    uint16_t                  mTail;
+    uint32_t                  mActiveLoaderCount;
+
+    nsCOMPtr<nsITimer>        mTimer;
+    bool                      mTimerArmed;
+    static void Tick(nsITimer *aTimer, void *aClosure);
+    
+    static const int          sMaxDeferred = 512;  // keep power of 2 for masking
+    static const int          sMaxDeferredMask = (sMaxDeferred - 1);
+    
+    struct deferred_entry
+    {
+      uint16_t                         mFlags;
+      nsWeakPtr                        mElement;
+    } mEntries[sMaxDeferred];
+  };
+
+  friend class mozilla::net::NeckoParent;
+};
+
+#endif