Bug 1546761 - Consolidate IPC calls to nsISHistory inside of nsDocShell::OnNewURI, r=peterv, r=nika for adding sync IPC messages

Inside of nsDocShell::OnNewURI there are 4 sync IPC calls
to nsSHistory that can be replaced with 1 sync IPC call
by adding a new method EnsureCorrectEntryAtCurrIndex to nsSHistory.

Differential Revision: https://phabricator.services.mozilla.com/D31539

--HG--
extra : rebase_source : 09d7738b2f2dc2334c8f6186e5918b9d0ea3e618
extra : source : 82a41bffcbbca24ad3e84b045d75e4cb01ae1445
extra : histedit_source : 96eb7d2dbed2ad8fe4cc2d37358ec2358f696442

docshell/base/nsDocShell.cpp

@@ -10855,16 +10855,8 @@ bool nsDocShell::OnNewURI(nsIURI* aURI, nsIChannel* aChannel,
   } else if (mSessionHistory && mLSHE && mURIResultedInDocument) {
     // Even if we don't add anything to SHistory, ensure the current index
     // points to the same SHEntry as our mLSHE.
-    int32_t index = mSessionHistory->LegacySHistory()->GetRequestedIndex();
-    if (index == -1) {
-      index = mSessionHistory->Index();
-    }
-    nsCOMPtr<nsISHEntry> currentSH;
-    mSessionHistory->LegacySHistory()->GetEntryAtIndex(
-        index, getter_AddRefs(currentSH));
-    if (currentSH != mLSHE) {
-      mSessionHistory->LegacySHistory()->ReplaceEntry(index, mLSHE);
-    }
+
+    mSessionHistory->LegacySHistory()->EnsureCorrectEntryAtCurrIndex(mLSHE);
   }
 
   // If this is a POST request, we do not want to include this in global

docshell/shistory/PSHistory.ipdl

@@ -56,6 +56,7 @@ parent:
   sync GetAllEntries() returns (MaybeNewPSHEntry[] entries);
   sync FindEntryForBFCache(uint64_t sharedID, bool includeCurrentEntry) returns (MaybeNewPSHEntry entries, int32_t startIndex);
   sync Evict(PSHEntry[] entry);
+  sync EnsureCorrectEntryAtCurrIndex(PSHEntry entry);
 
   async __delete__();
 };

docshell/shistory/SHistoryChild.cpp

@@ -304,6 +304,11 @@ SHistoryChild::RemoveDynEntries(int32_t aIndex, nsISHEntry* aEntry) {
   SendRemoveDynEntries(aIndex, static_cast<SHEntryChild*>(aEntry));
 }
 
+NS_IMETHODIMP_(void)
+SHistoryChild::EnsureCorrectEntryAtCurrIndex(nsISHEntry* aEntry) {
+  SendEnsureCorrectEntryAtCurrIndex(static_cast<SHEntryChild*>(aEntry));
+}
+
 NS_IMETHODIMP_(void)
 SHistoryChild::RemoveDynEntriesForBFCacheEntry(nsIBFCacheEntry* aBFEntry) {
   MaybeNewPSHEntry entry;

docshell/shistory/SHistoryParent.cpp

@@ -140,6 +140,12 @@ bool SHistoryParent::RecvRemoveDynEntries(int32_t aIndex,
   return true;
 }
 
+bool SHistoryParent::RecvEnsureCorrectEntryAtCurrIndex(PSHEntryParent* aEntry) {
+  mHistory->EnsureCorrectEntryAtCurrIndex(
+      static_cast<SHEntryParent*>(aEntry)->mEntry);
+  return true;
+}
+
 bool SHistoryParent::RecvRemoveEntries(nsTArray<nsID>&& aIds, int32_t aIndex,
                                        bool* aDidRemove) {
   mHistory->RemoveEntries(aIds, aIndex, aDidRemove);

docshell/shistory/SHistoryParent.h

@@ -79,6 +79,7 @@ class SHistoryParent final : public PSHistoryParent {
                                const bool& aIncludeCurrentEntry,
                                MaybeNewPSHEntry* aEntry, int32_t* aIndex);
   bool RecvEvict(nsTArray<PSHEntryParent*>&& aEntries);
+  bool RecvEnsureCorrectEntryAtCurrIndex(PSHEntryParent* aEntry);
 
   RefPtr<CanonicalBrowsingContext> mContext;
   RefPtr<LegacySHistory> mHistory;

docshell/shistory/nsISHistory.idl

@@ -260,4 +260,6 @@ interface nsISHistory: nsISupports
 
   [noscript]
   void Reload(in unsigned long aReloadFlags);
+
+  [notxpcom] void EnsureCorrectEntryAtCurrIndex(in nsISHEntry aEntry);
 };

docshell/shistory/nsSHistory.cpp

@@ -1358,6 +1358,15 @@ nsSHistory::GotoIndex(int32_t aIndex) {
   return LoadURI(loadResult);
 }
 
+NS_IMETHODIMP_(void)
+nsSHistory::EnsureCorrectEntryAtCurrIndex(nsISHEntry* aEntry) {
+  int index = mRequestedIndex == -1 ? mIndex : mRequestedIndex;
+  MOZ_ASSERT(mIndex > -1);
+  if (mEntries[index] != aEntry) {
+    ReplaceEntry(index, aEntry);
+  }
+}
+
 nsresult nsSHistory::GotoIndex(int32_t aIndex, LoadEntryResult& aLoadResult) {
   return LoadEntry(aIndex, LOAD_HISTORY, HIST_CMD_GOTOINDEX, aLoadResult);
 }

ipc/ipdl/sync-messages.ini

@@ -852,6 +852,8 @@ description = Standing up Fission
 description = Standing up Fission
 [PSHistory::Evict]
 description = Standing up Fission
+[PSHistory::EnsureCorrectEntryAtCurrIndex]
+description = Standing up Fission
 [PContent::PSHEntry]
 description = Standing up Fission
 [PSHEntry::GetURI]