Bug 1585582 - Remove all pref observers in CacheService r=mayhemer

Differential Revision: https://phabricator.services.mozilla.com/D47960

--HG--
extra : moz-landing-system : lando

netwerk/cache/nsCacheService.cpp

@@ -39,6 +39,7 @@
 #include "mozilla/Services.h"
 #include "nsITimer.h"
 #include "mozIStorageService.h"
+#include "mozilla/StaticPrefs_browser.h"
 
 #include "mozilla/net/NeckoCommon.h"
 #include <algorithm>
@@ -49,8 +50,6 @@ using namespace mozilla::net;
 /******************************************************************************
  * nsCacheProfilePrefObserver
  *****************************************************************************/
-#define OFFLINE_CACHE_ENABLE_PREF "browser.cache.offline.enable"
-#define OFFLINE_CACHE_STORAGE_ENABLE_PREF "browser.cache.offline.storage.enable"
 #define OFFLINE_CACHE_DIR_PREF "browser.cache.offline.parent_directory"
 #define OFFLINE_CACHE_CAPACITY_PREF "browser.cache.offline.capacity"
 #define OFFLINE_CACHE_CAPACITY 512000
@@ -62,14 +61,6 @@ static const char* observerList[] = {
     NS_XPCOM_SHUTDOWN_OBSERVER_ID,  "last-pb-context-exited",
     "suspend_process_notification", "resume_process_notification"};
 
-static const char* prefList[] = {
-    OFFLINE_CACHE_ENABLE_PREF,
-    OFFLINE_CACHE_STORAGE_ENABLE_PREF,
-    OFFLINE_CACHE_CAPACITY_PREF,
-    OFFLINE_CACHE_DIR_PREF,
-    nullptr,
-};
-
 class nsCacheProfilePrefObserver : public nsIObserver {
   virtual ~nsCacheProfilePrefObserver() = default;
 
@@ -104,8 +95,6 @@ class nsCacheProfilePrefObserver : public nsIObserver {
     return mSanitizeOnShutdown && mClearCacheOnShutdown;
   }
 
-  void PrefChanged(const char* aPref);
-
  private:
   bool mHaveProfile;
 
@@ -153,10 +142,6 @@ nsresult nsCacheProfilePrefObserver::Install() {
   nsCOMPtr<nsIPrefBranch> branch = do_GetService(NS_PREFSERVICE_CONTRACTID);
   if (!branch) return NS_ERROR_FAILURE;
 
-  Preferences::RegisterCallbacks(
-      PREF_CHANGE_METHOD(nsCacheProfilePrefObserver::PrefChanged), prefList,
-      this);
-
   // Determine if we have a profile already
   //     Install() is called *after* the profile-after-change notification
   //     when there is only a single profile, or it is specified on the
@@ -183,13 +168,6 @@ void nsCacheProfilePrefObserver::Remove() {
       obs->RemoveObserver(this, observer);
     }
   }
-
-  // remove Pref Service observers
-  nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
-  if (!prefs) return;
-  Preferences::UnregisterCallbacks(
-      PREF_CHANGE_METHOD(nsCacheProfilePrefObserver::PrefChanged), prefList,
-      this);
 }
 
 NS_IMETHODIMP
@@ -236,40 +214,6 @@ nsCacheProfilePrefObserver::Observe(nsISupports* subject, const char* topic,
   return NS_OK;
 }
 
-void nsCacheProfilePrefObserver::PrefChanged(const char* aPref) {
-  // ignore pref changes until we're done switch profiles
-  if (!mHaveProfile) return;
-  // which preference changed?
-  nsresult rv;
-  if (!strcmp(OFFLINE_CACHE_ENABLE_PREF, aPref) ||
-      !strcmp(OFFLINE_CACHE_STORAGE_ENABLE_PREF, aPref)) {
-    rv = Preferences::GetBool(OFFLINE_CACHE_ENABLE_PREF, &mOfflineCacheEnabled);
-    if (NS_FAILED(rv)) {
-      return;
-    }
-    rv = Preferences::GetBool(OFFLINE_CACHE_STORAGE_ENABLE_PREF,
-                              &mOfflineStorageCacheEnabled);
-    if (NS_FAILED(rv)) {
-      return;
-    }
-    nsCacheService::SetOfflineCacheEnabled(OfflineCacheEnabled());
-
-  } else if (!strcmp(OFFLINE_CACHE_CAPACITY_PREF, aPref)) {
-    int32_t capacity = 0;
-    rv = Preferences::GetInt(OFFLINE_CACHE_CAPACITY_PREF, &capacity);
-    if (NS_FAILED(rv)) return;
-    mOfflineCacheCapacity = std::max(0, capacity);
-    nsCacheService::SetOfflineCacheCapacity(mOfflineCacheCapacity);
-#if 0
-    } else if (!strcmp(OFFLINE_CACHE_DIR_PREF, aPref)) {
-        // XXX We probaby don't want to respond to this pref except after
-        // XXX profile changes.  Ideally, there should be some kind of user
-        // XXX notification that the pref change won't take effect until
-        // XXX the next time the profile changes (browser launch)
-#endif
-  }
-}
-
 nsresult nsCacheProfilePrefObserver::ReadPrefs(nsIPrefBranch* branch) {
   nsresult rv = NS_OK;
 
@@ -303,13 +247,9 @@ nsresult nsCacheProfilePrefObserver::ReadPrefs(nsIPrefBranch* branch) {
   }
 
   // read offline cache device prefs
-  mOfflineCacheEnabled = true;  // presume offline cache is enabled
+  mOfflineCacheEnabled = StaticPrefs::browser_cache_offline_enable();
-  (void)branch->GetBoolPref(OFFLINE_CACHE_ENABLE_PREF, &mOfflineCacheEnabled);
-
   mOfflineStorageCacheEnabled =
-      true;  // presume offline storage cache is enabled
+      StaticPrefs::browser_cache_offline_storage_enable();
-  (void)branch->GetBoolPref(OFFLINE_CACHE_STORAGE_ENABLE_PREF,
-                            &mOfflineStorageCacheEnabled);
 
   mOfflineCacheCapacity = OFFLINE_CACHE_CAPACITY;
   (void)branch->GetIntPref(OFFLINE_CACHE_CAPACITY_PREF, &mOfflineCacheCapacity);