Bug 1347461 - Part 2: Always initialize all DataStorage classes in the content process at initialization time; r=keeler

dom/ipc/ContentParent.cpp

@@ -2236,9 +2236,6 @@ ContentParent::InitInternal(ProcessPriority aInitialPriority,
     }
   }
 
-  // Ensure the SSS is initialized before we try to use its storage.
-  nsCOMPtr<nsISiteSecurityService> sss = do_GetService("@mozilla.org/ssservice;1");
-
   DataStorage::GetAllChildProcessData(xpcomInit.dataStorage());
 
   // Must send screen info before send initialData

security/manager/ssl/DataStorage.cpp

@@ -191,8 +191,33 @@ DataStorage::SetCachedStorageEntries(
 {
   MOZ_ASSERT(XRE_IsContentProcess());
 
-  for (auto& entry : aEntries) {
-    RefPtr<DataStorage> storage = DataStorage::GetFromRawFileName(entry.filename());
+  // Make sure to initialize all DataStorage classes.
+  // For each one, we look through the list of our entries and if we find
+  // a matching DataStorage object, we initialize it.
+  //
+  // Note that this is an O(n^2) operation, but the n here is very small
+  // (currently 3).  There is a comment in the DataStorageList.h header
+  // about updating the algorithm here to something more fancy if the list
+  // of DataStorage items grows some day.
+  nsTArray<dom::DataStorageEntry> entries;
+#define DATA_STORAGE(_)                              \
+  {                                                  \
+    dom::DataStorageEntry entry;                     \
+    entry.filename() = NS_LITERAL_STRING(#_ ".txt"); \
+    for (auto& e : aEntries) {                       \
+      if (entry.filename().Equals(e.filename())) {   \
+        entry.items() = Move(e.items());             \
+        break;                                       \
+      }                                              \
+    }                                                \
+    entries.AppendElement(Move(entry));              \
+  }
+#include "mozilla/DataStorageList.h"
+#undef DATA_STORAGE
+
+  for (auto& entry : entries) {
+    RefPtr<DataStorage> storage =
+      DataStorage::GetFromRawFileName(entry.filename());
     bool dataWillPersist = false;
     storage->Init(dataWillPersist, &entry.items());
   }

security/manager/ssl/DataStorageList.h

@@ -7,6 +7,11 @@
 // This is the list of well-known PSM DataStorage classes that Gecko uses.
 // These are key value data stores that are backed by a simple text-based
 // storage in the profile directory.
+//
+// Please note that it is crucial for performance reasons for the number of
+// these classes to remain low.  If you need to add to this list, you may
+// need to update the algorithm in DataStorage::SetCachedStorageEntries()
+// to something faster.
 
 DATA_STORAGE(AlternateServices)
 DATA_STORAGE(SecurityPreloadState)