Bug 1654080 - Use PBackground for syncing SessionStorageCache and use LSWriteOptimizer to send data changes; r=dom-workers-and-storage-reviewers,janv,nika

This patch does:
- Use LSWriteOptimizer
- Remove SessionStorageService since it's unused.
- Move IPC from PContent to PBackground
(by SessionStorageManager{Child, Parent} and SessionStorageCache{Child, Parent}).
- Extract SessionStorageManagerBase and add PBackgroundSessionStorageManager.
- Expose a getter function to get a BackgroundParentManager for top context id
on the parent.

IPC
- Before this patch:
  - Copy from parent while loading a document.
    - Mark cache entry on the parent process as loaded by the child id.
  - Update change on checkpoint.
  - Unmark cache entry on the parent process as unloaded for the child id while
  the parent actor is destorying.
- After this patch:
  - Sync IPC load in the first SessionStorage operation.
  - Update change on checkpoint

`BackgroundSessionStorageManager`'s lifecycle on the parent process.
- Create by `SessionStorageManagerParent` and register to the `sManagers`.
- Hold by `SessionStorageManagerParent` and `sManagers`.
- Remove from the `sManagers` while the corresponding `BrowsingContext` is
destructed (on the parent process).

Depends on D89341

Differential Revision: https://phabricator.services.mozilla.com/D89342

Author: chihweitung

docshell/base/CanonicalBrowsingContext.cpp

@@ -20,6 +20,7 @@
 #include "mozilla/dom/MediaControlService.h"
 #include "mozilla/dom/ContentPlaybackController.h"
 #include "mozilla/dom/SessionHistoryEntry.h"
+#include "mozilla/dom/SessionStorageManager.h"
 #include "mozilla/ipc/ProtocolUtils.h"
 #include "mozilla/net/DocumentLoadListener.h"
 #include "mozilla/NullPrincipal.h"
@@ -744,6 +745,10 @@ void CanonicalBrowsingContext::CanonicalDiscard() {
     mTabMediaController->Shutdown();
     mTabMediaController = nullptr;
   }
+
+  if (IsTop()) {
+    BackgroundSessionStorageManager::RemoveManager(Id());
+  }
 }
 
 void CanonicalBrowsingContext::NotifyStartDelayedAutoplayMedia() {

dom/gamepad/ipc/GamepadEventChannelChild.h

@@ -4,6 +4,7 @@
  * 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 "mozilla/dom/PGamepadEventChannelChild.h"
+#include "nsRefPtrHashtable.h"
 
 #ifndef mozilla_dom_GamepadEventChannelChild_h_
 #  define mozilla_dom_GamepadEventChannelChild_h_

dom/ipc/ContentChild.cpp

@@ -3538,20 +3538,6 @@ mozilla::ipc::IPCResult ContentChild::RecvUpdateMediaControlAction(
   return IPC_OK();
 }
 
-mozilla::ipc::IPCResult ContentChild::RecvSessionStorageData(
-    const uint64_t aTopContextId, const nsACString& aOriginAttrs,
-    const nsACString& aOriginKey, const nsTArray<KeyValuePair>& aDefaultData,
-    const nsTArray<KeyValuePair>& aSessionData) {
-  if (const RefPtr<BrowsingContext> topContext =
-          BrowsingContext::Get(aTopContextId)) {
-    topContext->GetSessionStorageManager()->LoadSessionStorageData(
-        nullptr, aOriginAttrs, aOriginKey, aDefaultData, aSessionData);
-  } else {
-    NS_WARNING("Got session storage data for a discarded session");
-  }
-  return IPC_OK();
-}
-
 mozilla::ipc::IPCResult ContentChild::RecvOnAllowAccessFor(
     const MaybeDiscarded<BrowsingContext>& aContext,
     const nsCString& aTrackingOrigin, uint32_t aCookieBehavior,

dom/ipc/ContentChild.h

@@ -649,11 +649,6 @@ class ContentChild final : public PContentChild,
     return mBrowsingContextFieldEpoch;
   }
 
-  mozilla::ipc::IPCResult RecvSessionStorageData(
-      uint64_t aTopContextId, const nsACString& aOriginAttrs,
-      const nsACString& aOriginKey, const nsTArray<KeyValuePair>& aDefaultData,
-      const nsTArray<KeyValuePair>& aSessionData);
-
   mozilla::ipc::IPCResult RecvOnAllowAccessFor(
       const MaybeDiscarded<BrowsingContext>& aContext,
       const nsCString& aTrackingOrigin, uint32_t aCookieBehavior,

dom/ipc/ContentParent.cpp

@@ -5818,11 +5818,6 @@ nsresult ContentParent::AboutToLoadHttpFtpDocumentForChild(
   rv = loadInfo->GetTargetBrowsingContext(getter_AddRefs(browsingContext));
   NS_ENSURE_SUCCESS(rv, rv);
 
-  if (browsingContext && !browsingContext->IsDiscarded()) {
-    browsingContext->GetSessionStorageManager()
-        ->SendSessionStorageDataToContentProcess(this, principal);
-  }
-
   if (!NextGenLocalStorageEnabled()) {
     return NS_OK;
   }
@@ -6404,20 +6399,6 @@ mozilla::ipc::IPCResult ContentParent::RecvGetModulesTrust(
 #endif  // defined(XP_WIN)
 }
 
-mozilla::ipc::IPCResult ContentParent::RecvSessionStorageData(
-    const uint64_t aTopContextId, const nsACString& aOriginAttrs,
-    const nsACString& aOriginKey, const nsTArray<KeyValuePair>& aDefaultData,
-    const nsTArray<KeyValuePair>& aSessionData) {
-  if (const RefPtr<BrowsingContext> topContext =
-          BrowsingContext::Get(aTopContextId)) {
-    topContext->GetSessionStorageManager()->LoadSessionStorageData(
-        this, aOriginAttrs, aOriginKey, aDefaultData, aSessionData);
-  } else {
-    NS_WARNING("Got session storage data for a discarded session");
-  }
-  return IPC_OK();
-}
-
 mozilla::ipc::IPCResult ContentParent::RecvCreateBrowsingContext(
     uint64_t aGroupId, BrowsingContext::IPCInitializer&& aInit) {
   RefPtr<WindowGlobalParent> parent;

dom/ipc/ContentParent.h

@@ -1321,11 +1321,6 @@ class ContentParent final
       ModulePaths&& aModPaths, bool aRunAtNormalPriority,
       GetModulesTrustResolver&& aResolver);
 
-  mozilla::ipc::IPCResult RecvSessionStorageData(
-      uint64_t aTopContextId, const nsACString& aOriginAttrs,
-      const nsACString& aOriginKey, const nsTArray<KeyValuePair>& aDefaultData,
-      const nsTArray<KeyValuePair>& aSessionData);
-
   mozilla::ipc::IPCResult RecvReportServiceWorkerShutdownProgress(
       uint32_t aShutdownStateId,
       ServiceWorkerShutdownState::Progress aProgress);

dom/ipc/PContent.ipdl

@@ -365,12 +365,6 @@ struct PostMessageData
     uint64_t innerWindowId;
 };
 
-struct KeyValuePair
-{
-    nsString key;
-    nsString value;
-};
-
 union SyncedContextInitializer
 {
     BrowsingContextInitializer;
@@ -1790,13 +1784,6 @@ both:
                             ClonedOrErrorMessageData aMessage,
                             PostMessageData aData);
 
-    /**
-     * Move sessionStorage data between parent and content processes. See
-     * SessionStorageManager documentation for more details.
-     */
-    async SessionStorageData(uint64_t aTopContextId, nsCString aOriginAttrs,
-                             nsCString aOriginKey, KeyValuePair[] aDefaultData,
-                             KeyValuePair[] aSessionData);
     async CommitWindowContextTransaction(MaybeDiscardedWindowContext aContext,
                                          WindowContextTransaction aTransaction,
                                          uint64_t aEpoch);

dom/localstorage/ActorsParent.cpp

@@ -21,7 +21,7 @@
 #include "mozilla/dom/ContentParent.h"
 #include "mozilla/dom/ClientManagerService.h"
 #include "mozilla/dom/FlippedOnce.h"
-#include "mozilla/dom/LSWriteOptimizer.h"
+#include "mozilla/dom/LSWriteOptimizerImpl.h"
 #include "mozilla/dom/PBackgroundLSDatabaseParent.h"
 #include "mozilla/dom/PBackgroundLSObserverParent.h"
 #include "mozilla/dom/PBackgroundLSRequestParent.h"

dom/localstorage/LSSnapshot.cpp

@@ -9,7 +9,7 @@
 #include "ActorsChild.h"
 #include "LocalStorageCommon.h"
 #include "LSDatabase.h"
-#include "LSWriteOptimizer.h"
+#include "LSWriteOptimizerImpl.h"
 #include "mozilla/dom/PBackgroundLSSnapshot.h"
 #include "nsContentUtils.h"
 

dom/localstorage/LSWriteOptimizer.cpp

@@ -63,52 +63,5 @@ void LSWriteOptimizerBase::GetSortedWriteInfos(
   }
 }
 
-template <typename T, typename U>
-void LSWriteOptimizer<T, U>::InsertItem(const nsAString& aKey, const T& aValue,
-                                        int64_t aDelta) {
-  AssertIsOnOwningThread();
-
-  WriteInfo* existingWriteInfo;
-  UniquePtr<WriteInfo> newWriteInfo;
-  if (mWriteInfos.Get(aKey, &existingWriteInfo) &&
-      existingWriteInfo->GetType() == WriteInfo::DeleteItem) {
-    // We could just simply replace the deletion with ordinary update, but that
-    // would preserve item's original position/index. Imagine a case when we
-    // have only one existing key k1. Now let's create a new optimizer and
-    // remove k1, add k2 and add k1 back. The final order should be k2, k1
-    // (ordinary update would produce k1, k2). So we need to differentiate
-    // between normal update and "optimized" update which resulted from a
-    // deletion followed by an insertion. We use the UpdateWithMove flag for
-    // this.
-
-    newWriteInfo = MakeUnique<UpdateItemInfo>(NextSerialNumber(), aKey, aValue,
-                                              /* aUpdateWithMove */ true);
-  } else {
-    newWriteInfo = MakeUnique<InsertItemInfo>(NextSerialNumber(), aKey, aValue);
-  }
-  mWriteInfos.Put(aKey, std::move(newWriteInfo));
-
-  mTotalDelta += aDelta;
-}
-
-template <typename T, typename U>
-void LSWriteOptimizer<T, U>::UpdateItem(const nsAString& aKey, const T& aValue,
-                                        int64_t aDelta) {
-  AssertIsOnOwningThread();
-
-  WriteInfo* existingWriteInfo;
-  UniquePtr<WriteInfo> newWriteInfo;
-  if (mWriteInfos.Get(aKey, &existingWriteInfo) &&
-      existingWriteInfo->GetType() == WriteInfo::InsertItem) {
-    newWriteInfo = MakeUnique<InsertItemInfo>(NextSerialNumber(), aKey, aValue);
-  } else {
-    newWriteInfo = MakeUnique<UpdateItemInfo>(NextSerialNumber(), aKey, aValue,
-                                              /* aUpdateWithMove */ false);
-  }
-  mWriteInfos.Put(aKey, std::move(newWriteInfo));
-
-  mTotalDelta += aDelta;
-}
-
 }  // namespace dom
 }  // namespace mozilla