Bug 692255 - Get rid of prefetch files on Windows for faster startup. r=rstrong

browser/components/shell/src/nsWindowsShellService.cpp

@@ -26,6 +26,7 @@
 #include "nsUnicharUtils.h"
 #include "nsIWinTaskbar.h"
 #include "nsISupportsPrimitives.h"
+#include "nsThreadUtils.h"
 
 #include "windows.h"
 #include "shellapi.h"
@@ -52,6 +53,11 @@
 
 #define NS_TASKBAR_CONTRACTID "@mozilla.org/windows-taskbar;1"
 
+// We clear the prefetch files one time after the browser is started after
+// 60 seconds.  After this is done once we set a pref so this will never happen
+// again except in updater code.
+#define CLEAR_PREFETCH_TIMEOUT_MS 60000
+
 NS_IMPL_ISUPPORTS2(nsWindowsShellService, nsIWindowsShellService, nsIShellService)
 
 static nsresult
@@ -189,6 +195,16 @@ static SETTING gDDESettings[] = {
   { MAKE_KEY_NAME1("Software\\Classes\\HTTPS", SOD) }
 };
 
+#if defined(MOZ_MAINTENANCE_SERVICE)
+
+#define ONLY_SERVICE_LAUNCHING
+#include "updatehelper.h"
+#include "updatehelper.cpp"
+
+static const char kPrefetchClearedPref[] = "app.update.service.prefetchCleared";
+static nsCOMPtr<nsIThread> sThread;
+#endif
+
 nsresult
 GetHelperPath(nsAutoString& aPath)
 {
@@ -908,6 +924,123 @@ nsWindowsShellService::SetDesktopBackgroundColor(PRUint32 aColor)
   return regKey->Close();
 }
 
+nsWindowsShellService::nsWindowsShellService() : 
+  mCheckedThisSession(false) 
+{
+#if defined(MOZ_MAINTENANCE_SERVICE)
+
+  // Check to make sure the service is installed
+  PRUint32 installed = 0;
+  nsCOMPtr<nsIWindowsRegKey> regKey = 
+    do_CreateInstance("@mozilla.org/windows-registry-key;1");
+  if (!regKey || 
+      NS_FAILED(regKey->Open(nsIWindowsRegKey::ROOT_KEY_LOCAL_MACHINE,
+                             NS_LITERAL_STRING(
+                               "SOFTWARE\\Mozilla\\MaintenanceService"),
+                             nsIWindowsRegKey::ACCESS_READ |
+                             nsIWindowsRegKey::WOW64_64)) ||
+      NS_FAILED(regKey->ReadIntValue(NS_LITERAL_STRING("Installed"), 
+                &installed)) ||
+      !installed) {
+    return;
+  }
+
+  // check to see if we have attempted to do the one time operation of clearing
+  // the prefetch.
+  bool prefetchCleared;
+  nsCOMPtr<nsIPrefBranch> prefBranch;
+  nsCOMPtr<nsIPrefService> prefs =
+    do_GetService(NS_PREFSERVICE_CONTRACTID);
+  if (!prefs || 
+      NS_FAILED(prefs->GetBranch(nsnull, getter_AddRefs(prefBranch))) ||
+      (NS_SUCCEEDED(prefBranch->GetBoolPref(kPrefetchClearedPref, 
+                                            &prefetchCleared)) &&
+       prefetchCleared)) {
+    return;
+  }
+
+  // In a minute after startup is definitely complete, launch the
+  // service command.
+  mTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
+  if (mTimer) {
+    mTimer->InitWithFuncCallback(
+      nsWindowsShellService::LaunchPrefetchClearCommand, 
+      nsnull, CLEAR_PREFETCH_TIMEOUT_MS, nsITimer::TYPE_ONE_SHOT);
+  }
+#endif
+}
+
+nsWindowsShellService::~nsWindowsShellService()
+{
+#if defined(MOZ_MAINTENANCE_SERVICE)
+ if (mTimer) {
+    mTimer->Cancel();
+    mTimer = nsnull;
+  }
+  if (sThread) {
+    sThread->Shutdown();
+    sThread = nsnull;
+  }
+#endif
+}
+
+#if defined(MOZ_MAINTENANCE_SERVICE)
+
+class ClearPrefetchEvent : public nsRunnable {
+public:
+  ClearPrefetchEvent()
+  {
+  }
+
+  NS_IMETHOD Run() 
+  {
+    // Start the service command
+    LPCWSTR updaterServiceArgv[2];
+    updaterServiceArgv[0] = L"MozillaMaintenance";
+    updaterServiceArgv[1] = L"clear-prefetch";
+    // If this command fails, it is not critical as prefetch will be cleared
+    // on the next software update.
+    StartServiceCommand(NS_ARRAY_LENGTH(updaterServiceArgv), 
+                        updaterServiceArgv);
+    return NS_OK;
+  }
+};
+#endif
+
+/**
+ * For faster startup we attempt to clear the prefetch if the maintenance
+ * service is installed.  Please see the definition of ClearPrefetch()
+ * in toolkit/components/maintenanceservice/prefetch.cpp for more info.
+ * For now the only application that gets prefetch cleaned is Firefox
+ * since we have not done performance checking for other applications.
+ * This is done on every update but also there is a one time operation done
+ * from within the program for first time installs.
+ */ 
+#if defined(MOZ_MAINTENANCE_SERVICE)
+void
+nsWindowsShellService::LaunchPrefetchClearCommand(nsITimer *aTimer, void*)
+{
+  // Make sure we don't call this again from the application, it will be
+  // called on each application update instead.
+  nsCOMPtr<nsIPrefBranch> prefBranch;
+  nsCOMPtr<nsIPrefService> prefs =
+    do_GetService(NS_PREFSERVICE_CONTRACTID);
+  if (prefs) {
+    if (NS_SUCCEEDED(prefs->GetBranch(nsnull, getter_AddRefs(prefBranch)))) {
+      prefBranch->SetBoolPref(kPrefetchClearedPref, true);
+    }
+  }
+
+  // Starting the sevice can take a bit of time and we don't want to block the 
+  // main thread, so start an event on another thread to handle the operation
+  NS_NewThread(getter_AddRefs(sThread));
+  if (sThread) {
+    nsCOMPtr<nsIRunnable> prefetchEvent = new ClearPrefetchEvent();
+    sThread->Dispatch(prefetchEvent, NS_DISPATCH_NORMAL);
+  }
+}
+#endif
+
 NS_IMETHODIMP
 nsWindowsShellService::OpenApplicationWithURI(nsILocalFile* aApplication,
                                               const nsACString& aURI)