Bug 1696158 - Move CanSavePresentation to the parent process. Notify parent process of requests in the loadgroup. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D110233

docshell/base/nsDocShell.cpp

@@ -36,6 +36,7 @@
 #include "mozilla/SchedulerGroup.h"
 #include "mozilla/ScopeExit.h"
 #include "mozilla/ScrollTypes.h"
+#include "mozilla/SimpleEnumerator.h"
 #include "mozilla/StaticPrefs_browser.h"
 #include "mozilla/StaticPrefs_docshell.h"
 #include "mozilla/StaticPrefs_dom.h"
@@ -290,6 +291,7 @@ static mozilla::LazyLogModule gDocShellAndDOMWindowLeakLogging(
 static mozilla::LazyLogModule gDocShellLeakLog("nsDocShellLeak");
 extern mozilla::LazyLogModule gPageCacheLog;
 mozilla::LazyLogModule gSHLog("SessionHistory");
+extern mozilla::LazyLogModule gSHIPBFCacheLog;
 
 const char kBrandBundleURL[] = "chrome://branding/locale/brand.properties";
 const char kAppstringsBundleURL[] =
@@ -13589,3 +13591,102 @@ void nsDocShell::MoveLoadingToActiveEntry(bool aPersist) {
                                            hadActiveEntry, aPersist, false);
   }
 }
+
+void nsDocShell::RecordSingleChannelId() {
+  if (mLoadGroup && mBrowsingContext->GetCurrentWindowContext()) {
+    Maybe<uint64_t> singleChannelId;
+    nsCOMPtr<nsISimpleEnumerator> requests;
+    mLoadGroup->GetRequests(getter_AddRefs(requests));
+    for (const auto& request : SimpleEnumerator<nsIRequest>(requests)) {
+      nsCOMPtr<nsIChannel> channel = do_QueryInterface(request);
+
+      // Ignore favicon loads, they don't need to block caching.
+      nsCOMPtr<nsILoadInfo> li;
+      if (channel && (li = channel->LoadInfo()) &&
+          li->InternalContentPolicyType() ==
+              nsIContentPolicy::TYPE_INTERNAL_IMAGE_FAVICON) {
+        continue;
+      }
+
+      // If we already found a channel ID or this is not an nsIIdentChannel then
+      // we have more than one request in the loadgroup.
+      nsCOMPtr<nsIIdentChannel> identChannel;
+      if (singleChannelId.isSome() ||
+          !(identChannel = do_QueryInterface(channel))) {
+        // We really have three states: no request, one request with an id and
+        // eiher one request without an id or multiple requests. Nothing() is no
+        // request, Some(non-zero) is one request and Some(0) is one request
+        // without an id or multiple requests.
+        singleChannelId = Some(0);
+        break;
+      }
+
+      singleChannelId = Some(identChannel->ChannelId());
+    }
+
+    if (MOZ_UNLIKELY(MOZ_LOG_TEST(gSHIPBFCacheLog, LogLevel::Verbose))) {
+      nsAutoCString uri("[no uri]");
+      if (mCurrentURI) {
+        uri = mCurrentURI->GetSpecOrDefault();
+      }
+      if (singleChannelId.isNothing()) {
+        MOZ_LOG(gSHIPBFCacheLog, LogLevel::Verbose,
+                ("Loadgroup for %s doesn't have any requests relevant for "
+                 "blocking BFCache",
+                 uri.get()));
+      } else if (singleChannelId.value() == 0) {
+        MOZ_LOG(gSHIPBFCacheLog, LogLevel::Verbose,
+                ("Loadgroup for %s has multiple requests relevant for blocking "
+                 "BFCache",
+                 uri.get()));
+      } else {
+        MOZ_LOG(gSHIPBFCacheLog, LogLevel::Verbose,
+                ("Loadgroup for %s has one request with id %" PRIu64
+                 " relevant for blocking BFCache",
+                 uri.get(), singleChannelId.value()));
+      }
+    }
+
+    if (mSingleChannelId != singleChannelId) {
+      mSingleChannelId = singleChannelId;
+      WindowGlobalChild* wgc =
+          mBrowsingContext->GetCurrentWindowContext()->GetWindowGlobalChild();
+      if (wgc) {
+        wgc->SendSetSingleChannelId(singleChannelId);
+      }
+    }
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::OnStartRequest(nsIRequest* aRequest) {
+  if (MOZ_UNLIKELY(MOZ_LOG_TEST(gSHIPBFCacheLog, LogLevel::Verbose))) {
+    nsAutoCString uri("[no uri]");
+    if (mCurrentURI) {
+      uri = mCurrentURI->GetSpecOrDefault();
+    }
+    nsAutoCString name;
+    aRequest->GetName(name);
+    MOZ_LOG(gSHIPBFCacheLog, LogLevel::Verbose,
+            ("Adding request %s to loadgroup for %s", name.get(), uri.get()));
+  }
+  RecordSingleChannelId();
+  return nsDocLoader::OnStartRequest(aRequest);
+}
+
+NS_IMETHODIMP
+nsDocShell::OnStopRequest(nsIRequest* aRequest, nsresult aStatusCode) {
+  if (MOZ_UNLIKELY(MOZ_LOG_TEST(gSHIPBFCacheLog, LogLevel::Verbose))) {
+    nsAutoCString uri("[no uri]");
+    if (mCurrentURI) {
+      uri = mCurrentURI->GetSpecOrDefault();
+    }
+    nsAutoCString name;
+    aRequest->GetName(name);
+    MOZ_LOG(
+        gSHIPBFCacheLog, LogLevel::Verbose,
+        ("Removing request %s from loadgroup for %s", name.get(), uri.get()));
+  }
+  RecordSingleChannelId();
+  return nsDocLoader::OnStopRequest(aRequest, aStatusCode);
+}

docshell/base/nsDocShell.h

@@ -511,6 +511,10 @@ class nsDocShell final : public nsDocLoader,
   // This returns true only when using session history in parent.
   bool IsLoadingFromSessionHistory();
 
+  NS_IMETHODIMP OnStartRequest(nsIRequest* aRequest) override;
+  NS_IMETHODIMP OnStopRequest(nsIRequest* aRequest,
+                              nsresult aStatusCode) override;
+
  private:  // member functions
   friend class nsDSURIContentListener;
   friend class FramingChecker;
@@ -713,6 +717,8 @@ class nsDocShell final : public nsDocLoader,
                 nsIContentSecurityPolicy* aCsp, bool aFireOnLocationChange,
                 bool aAddToGlobalHistory, bool aCloneSHChildren);
 
+  void RecordSingleChannelId();
+
  public:
   // Helper method that is called when a new document (including any
   // sub-documents - ie. frames) has been completely loaded.
@@ -1215,6 +1221,9 @@ class nsDocShell final : public nsDocLoader,
   // Possible values are defined as constants in nsIDocShell.idl.
   MetaViewportOverride mMetaViewportOverride;
 
+  // See WindowGlobalParent::mSingleChannelId.
+  mozilla::Maybe<uint64_t> mSingleChannelId;
+
   // The following two fields cannot be declared as bit fields
   // because of uses with AutoRestore.
   bool mCreatingDocument;  // (should be) debugging only

dom/ipc/PWindowGlobal.ipdl

@@ -186,6 +186,16 @@ parent:
   // enum for the valid flags.
   async UpdateBFCacheStatus(uint16_t aOnFlags, uint16_t aOffFlags);
 
+  /**
+   * Used to notify the parent when there's a change in the number of requests
+   * in the loadgroup. If there are no requests this will be set to Nothing().
+   * If there is one request this will be set to the ID of that request, if it
+   * implements nsIIdentChannel. If there are more than one requests this will
+   * be set to 0.
+   * Note that some requests are ignored (eg. favicon loads).
+   */
+  async SetSingleChannelId(uint64_t? singleChannelId);
+
   async Destroy();
 };
 

dom/ipc/WindowGlobalParent.cpp

@@ -1369,6 +1369,12 @@ mozilla::ipc::IPCResult WindowGlobalParent::RecvUpdateBFCacheStatus(
   return IPC_OK();
 }
 
+mozilla::ipc::IPCResult WindowGlobalParent::RecvSetSingleChannelId(
+    const Maybe<uint64_t>& aSingleChannelId) {
+  mSingleChannelId = aSingleChannelId;
+  return IPC_OK();
+}
+
 void WindowGlobalParent::ActorDestroy(ActorDestroyReason aWhy) {
   if (mPageUseCountersWindow) {
     mPageUseCountersWindow->FinishAccumulatingPageUseCounters();

dom/ipc/WindowGlobalParent.h

@@ -213,6 +213,8 @@ class WindowGlobalParent final : public WindowContext,
                               const Maybe<nsPoint>& aScrollPosition,
                               uint32_t aEpoch);
 
+  Maybe<uint64_t> GetSingleChannelId() { return mSingleChannelId; }
+
  protected:
   already_AddRefed<JSActor> InitJSActor(JS::HandleObject aMaybeActor,
                                         const nsACString& aName,
@@ -283,6 +285,10 @@ class WindowGlobalParent final : public WindowContext,
   mozilla::ipc::IPCResult RecvUpdateBFCacheStatus(const uint16_t& aOnFlags,
                                                   const uint16_t& aOffFlags);
 
+ public:
+  mozilla::ipc::IPCResult RecvSetSingleChannelId(
+      const Maybe<uint64_t>& aSingleChannelId);
+
  private:
   WindowGlobalParent(CanonicalBrowsingContext* aBrowsingContext,
                      uint64_t aInnerWindowId, uint64_t aOuterWindowId,
@@ -357,6 +363,17 @@ class WindowGlobalParent final : public WindowContext,
   bool mSentPageUseCounters = false;
 
   uint16_t mBFCacheStatus = 0;
+
+  // mSingleChannelId records whether the loadgroup contains a single request
+  // with an id. If there is one channel in the loadgroup and it has an id then
+  // mSingleChannelId is set to Some(id) (ids are non-zero). If there is one
+  // request in the loadgroup and it's not a channel or it doesn't have an id,
+  // or there are multiple requests in the loadgroup, then mSingleChannelId is
+  // set to Some(0). If there are no requests in the loadgroup then
+  // mSingleChannelId is set to Nothing().
+  // Note: We ignore favicon loads when considering the requests in the
+  // loadgroup.
+  Maybe<uint64_t> mSingleChannelId;
 };
 
 }  // namespace dom