import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

netwerk/base/nsDNSPrefetch.cpp

@@ -0,0 +1,106 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#include "nsDNSPrefetch.h"
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsThreadUtils.h"
+
+#include "nsIDNSListener.h"
+#include "nsIDNSService.h"
+#include "nsICancelable.h"
+#include "nsIURI.h"
+
+static nsIDNSService *sDNSService = nullptr;
+
+nsresult
+nsDNSPrefetch::Initialize(nsIDNSService *aDNSService)
+{
+    NS_IF_RELEASE(sDNSService);
+    sDNSService =  aDNSService;
+    NS_IF_ADDREF(sDNSService);
+    return NS_OK;
+}
+
+nsresult
+nsDNSPrefetch::Shutdown()
+{
+    NS_IF_RELEASE(sDNSService);
+    return NS_OK;
+}
+
+nsDNSPrefetch::nsDNSPrefetch(nsIURI *aURI,
+                             nsIDNSListener *aListener,
+                             bool storeTiming)
+    : mStoreTiming(storeTiming)
+    , mListener(do_GetWeakReference(aListener))
+{
+    aURI->GetAsciiHost(mHostname);
+}
+
+nsresult 
+nsDNSPrefetch::Prefetch(uint16_t flags)
+{
+    if (mHostname.IsEmpty())
+        return NS_ERROR_NOT_AVAILABLE;
+  
+    if (!sDNSService)
+        return NS_ERROR_NOT_AVAILABLE;
+    
+    nsCOMPtr<nsICancelable> tmpOutstanding;  
+
+    if (mStoreTiming)
+        mStartTimestamp = mozilla::TimeStamp::Now();
+    // If AsyncResolve fails, for example because prefetching is disabled,
+    // then our timing will be useless. However, in such a case,
+    // mEndTimestamp will be a null timestamp and callers should check
+    // TimingsValid() before using the timing.
+    nsCOMPtr<nsIThread> mainThread = do_GetMainThread();
+    return sDNSService->AsyncResolve(mHostname,
+                                     flags | nsIDNSService::RESOLVE_SPECULATE,
+                                     this, mainThread,
+                                     getter_AddRefs(tmpOutstanding));
+}
+
+nsresult
+nsDNSPrefetch::PrefetchLow(bool refreshDNS)
+{
+    return Prefetch(nsIDNSService::RESOLVE_PRIORITY_LOW |
+      (refreshDNS ? nsIDNSService::RESOLVE_BYPASS_CACHE : 0));
+}
+
+nsresult
+nsDNSPrefetch::PrefetchMedium(bool refreshDNS)
+{
+    return Prefetch(nsIDNSService::RESOLVE_PRIORITY_MEDIUM |
+      (refreshDNS ? nsIDNSService::RESOLVE_BYPASS_CACHE : 0));
+}
+
+nsresult
+nsDNSPrefetch::PrefetchHigh(bool refreshDNS)
+{
+    return Prefetch(refreshDNS ?
+                    nsIDNSService::RESOLVE_BYPASS_CACHE : 0);
+}
+
+
+NS_IMPL_ISUPPORTS(nsDNSPrefetch, nsIDNSListener)
+
+NS_IMETHODIMP
+nsDNSPrefetch::OnLookupComplete(nsICancelable *request,
+                                nsIDNSRecord  *rec,
+                                nsresult       status)
+{
+    MOZ_ASSERT(NS_IsMainThread(), "Expecting DNS callback on main thread.");
+
+    if (mStoreTiming) {
+        mEndTimestamp = mozilla::TimeStamp::Now();
+    }
+    nsCOMPtr<nsIDNSListener> listener = do_QueryReferent(mListener);
+    if (listener) {
+      listener->OnLookupComplete(request, rec, status);
+    }
+    return NS_OK;
+}