Bug 1685677 - Don't unnecessarily materialize a flattened array of OriginInfo*. r=dom-workers-and-storage-reviewers,janv

Differential Revision: https://phabricator.services.mozilla.com/D101151

dom/quota/ActorsParent.cpp

@@ -7,6 +7,7 @@
 #include "ActorsParent.h"
 
 // Local includes
+#include "Flatten.h"
 #include "InitializationTypes.h"
 #include "OriginScope.h"
 #include "QuotaCommon.h"
@@ -7128,11 +7129,11 @@ QuotaManager::CollectLRUOriginInfosUntil(Collect&& aCollect, Pred&& aPred) {
   return originInfos;
 }
 
-QuotaManager::OriginInfosFlatTraversable
+QuotaManager::OriginInfosNestedTraversable
 QuotaManager::LockedGetOriginInfosExceedingGroupLimit() const {
   mQuotaMutex.AssertCurrentThreadOwns();
 
-  OriginInfosFlatTraversable originInfos;
+  OriginInfosNestedTraversable originInfos;
 
   for (const auto& entry : mGroupInfoPairs) {
     const auto& pair = entry.GetData();
@@ -7159,9 +7160,7 @@ QuotaManager::LockedGetOriginInfosExceedingGroupLimit() const {
       MOZ_ASSERT(quotaManager, "Shouldn't be null!");
 
       if (groupUsage > quotaManager->GetGroupLimit()) {
-        // XXX Instead of appending into a flat array, return an array of
-        // arrays.
-        originInfos.AppendElements(CollectLRUOriginInfosUntil(
+        originInfos.AppendElement(CollectLRUOriginInfosUntil(
             [&temporaryGroupInfo, &defaultGroupInfo](auto inserter) {
               MaybeInsertOriginInfos(std::move(inserter), temporaryGroupInfo,
                                      defaultGroupInfo,
@@ -7183,7 +7182,7 @@ QuotaManager::LockedGetOriginInfosExceedingGroupLimit() const {
 
 QuotaManager::OriginInfosFlatTraversable
 QuotaManager::LockedGetOriginInfosExceedingGlobalLimit(
-    const OriginInfosFlatTraversable& aAlreadyDoomedOriginInfos,
+    const OriginInfosNestedTraversable& aAlreadyDoomedOriginInfos,
     const uint64_t aAlreadyDoomedUsage) const {
   mQuotaMutex.AssertCurrentThreadOwns();
 
@@ -7199,7 +7198,13 @@ QuotaManager::LockedGetOriginInfosExceedingGlobalLimit(
               inserter, pair->LockedGetGroupInfo(PERSISTENCE_TYPE_TEMPORARY),
               pair->LockedGetGroupInfo(PERSISTENCE_TYPE_DEFAULT),
               [&aAlreadyDoomedOriginInfos](const auto& originInfo) {
-                return !aAlreadyDoomedOriginInfos.Contains(originInfo) &&
+                return !std::any_of(aAlreadyDoomedOriginInfos.cbegin(),
+                                    aAlreadyDoomedOriginInfos.cend(),
+                                    // XXX This should capture originInfo by
+                                    // value, but it can't due to Bug 1421435.
+                                    [&originInfo](const auto& array) {
+                                      return array.Contains(originInfo);
+                                    }) &&
                        !originInfo->LockedPersisted();
               });
         }
@@ -7216,24 +7221,28 @@ QuotaManager::LockedGetOriginInfosExceedingGlobalLimit(
       });
 }
 
-QuotaManager::OriginInfosFlatTraversable
+QuotaManager::OriginInfosNestedTraversable
 QuotaManager::GetOriginInfosExceedingLimits() const {
   MutexAutoLock lock(mQuotaMutex);
 
   auto originInfos = LockedGetOriginInfosExceedingGroupLimit();
 
-  const uint64_t doomedUsage =
-      std::accumulate(originInfos.cbegin(), originInfos.cend(), uint64_t(0),
+  const uint64_t doomedUsage = std::accumulate(
+      originInfos.cbegin(), originInfos.cend(), uint64_t(0),
+      [](uint64_t oldValue, const auto& currentOriginInfos) {
+        return std::accumulate(currentOriginInfos.cbegin(),
+                               currentOriginInfos.cend(), oldValue,
                                [](uint64_t oldValue, const auto& originInfo) {
                                  return oldValue + originInfo->LockedUsage();
                                });
+      });
 
   // Evicting origins that exceed their group limit also affects the global
   // temporary storage usage. If the global temporary storage limit would still
   // be exceeded after evicting the origins that were already selected, we need
   // to specifically evict origins to get below the global limit.
   if (mTemporaryStorageUsage - doomedUsage > mTemporaryStorageLimit) {
-    originInfos.AppendElements(
+    originInfos.AppendElement(
         LockedGetOriginInfosExceedingGlobalLimit(originInfos, doomedUsage));
   }
 
@@ -7241,13 +7250,12 @@ QuotaManager::GetOriginInfosExceedingLimits() const {
 }
 
 void QuotaManager::ClearOrigins(
-    const OriginInfosFlatTraversable& aDoomedOriginInfos) {
+    const OriginInfosNestedTraversable& aDoomedOriginInfos) {
   AssertIsOnIOThread();
 
   // XXX Does this need to be done a) in order and/or b) sequentially?
-  // XXX We don't need to concatenate the results of the two steps. It would be
-  // sufficient to chain the ranges for iteration.
-  for (const auto& doomedOriginInfo : aDoomedOriginInfos) {
+  for (const auto& doomedOriginInfo :
+       Flatten<OriginInfosFlatTraversable::elem_type>(aDoomedOriginInfos)) {
 #ifdef DEBUG
     {
       MutexAutoLock lock(mQuotaMutex);
@@ -7269,7 +7277,8 @@ void QuotaManager::ClearOrigins(
   {
     MutexAutoLock lock(mQuotaMutex);
 
-    for (const auto& doomedOriginInfo : aDoomedOriginInfos) {
+    for (const auto& doomedOriginInfo :
+         Flatten<OriginInfosFlatTraversable::elem_type>(aDoomedOriginInfos)) {
       // LockedRemoveQuotaForOrigin might remove the group info;
       // OriginInfo::mGroupInfo is only a raw pointer, so we need to store the
       // information for calling OriginClearCompleted below in a separate array.

dom/quota/Flatten.h

@@ -0,0 +1,118 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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/. */
+
+#ifndef DOM_QUOTA_FLATTEN_H_
+#define DOM_QUOTA_FLATTEN_H_
+
+#include <iterator>
+#include <type_traits>
+#include <utility>
+
+// XXX This should be moved to MFBT.
+
+namespace mozilla::dom::quota {
+
+namespace detail {
+
+using std::begin;
+using std::end;
+
+template <typename T, typename NestedRange>
+auto Flatten(NestedRange&& aRange) -> std::enable_if_t<
+    std::is_same_v<T, std::decay_t<typename decltype(begin(
+                          std::declval<const NestedRange&>()))::value_type>>,
+    std::conditional_t<std::is_rvalue_reference_v<NestedRange>,
+                       std::decay_t<NestedRange>, NestedRange>> {
+  return std::forward<NestedRange>(aRange);
+}
+
+template <typename T, typename NestedRange>
+struct FlatIter {
+  using OuterIterator =
+      decltype(begin(std::declval<const std::decay_t<NestedRange>&>()));
+  using InnerIterator =
+      decltype(begin(*begin(std::declval<const std::decay_t<NestedRange>&>())));
+
+  explicit FlatIter(const NestedRange& aRange, OuterIterator aIter)
+      : mOuterIter{std::move(aIter)}, mOuterEnd{end(aRange)} {
+    InitInner();
+  }
+
+  const T& operator*() const { return *mInnerIter; }
+
+  FlatIter& operator++() {
+    ++mInnerIter;
+    if (mInnerIter == mInnerEnd) {
+      ++mOuterIter;
+      InitInner();
+    }
+    return *this;
+  }
+
+  bool operator!=(const FlatIter& aOther) const {
+    return mOuterIter != aOther.mOuterIter ||
+           (mOuterIter != mOuterEnd && mInnerIter != aOther.mInnerIter);
+  }
+
+ private:
+  void InitInner() {
+    while (mOuterIter != mOuterEnd) {
+      const typename OuterIterator::value_type& innerRange = *mOuterIter;
+
+      mInnerIter = begin(innerRange);
+      mInnerEnd = end(innerRange);
+
+      if (mInnerIter != mInnerEnd) {
+        break;
+      }
+
+      ++mOuterIter;
+    }
+  }
+
+  OuterIterator mOuterIter;
+  const OuterIterator mOuterEnd;
+
+  InnerIterator mInnerIter;
+  InnerIterator mInnerEnd;
+};
+
+template <typename T, typename NestedRange>
+struct FlatRange {
+  explicit FlatRange(NestedRange aRange) : mRange{std::move(aRange)} {}
+
+  auto begin() const {
+    using std::begin;
+    return FlatIter<T, NestedRange>{mRange, begin(mRange)};
+  }
+  auto end() const {
+    using std::end;
+    return FlatIter<T, NestedRange>{mRange, end(mRange)};
+  }
+
+ private:
+  NestedRange mRange;
+};
+
+template <typename T, typename NestedRange>
+auto Flatten(NestedRange&& aRange) -> std::enable_if_t<
+    !std::is_same_v<
+        T, std::decay_t<typename decltype(begin(
+               std::declval<const std::decay_t<NestedRange>&>()))::value_type>>,
+    FlatRange<T, NestedRange>> {
+  return FlatRange<T, NestedRange>{std::forward<NestedRange>(aRange)};
+}
+
+}  // namespace detail
+
+template <typename T, typename NestedRange>
+auto Flatten(NestedRange&& aRange) -> decltype(auto) {
+  return detail::Flatten<T>(std::forward<NestedRange>(aRange));
+}
+
+}  // namespace mozilla::dom::quota
+
+#endif

dom/quota/QuotaManager.h

@@ -561,15 +561,18 @@ class QuotaManager final : public BackgroundThreadObject {
   using OriginInfosFlatTraversable =
       nsTArray<NotNull<RefPtr<const OriginInfo>>>;
 
-  OriginInfosFlatTraversable LockedGetOriginInfosExceedingGroupLimit() const;
+  using OriginInfosNestedTraversable =
+      nsTArray<nsTArray<NotNull<RefPtr<const OriginInfo>>>>;
+
+  OriginInfosNestedTraversable LockedGetOriginInfosExceedingGroupLimit() const;
 
   OriginInfosFlatTraversable LockedGetOriginInfosExceedingGlobalLimit(
-      const OriginInfosFlatTraversable& aAlreadyDoomedOriginInfos,
+      const OriginInfosNestedTraversable& aAlreadyDoomedOriginInfos,
       uint64_t aAlreadyDoomedUsage) const;
 
-  OriginInfosFlatTraversable GetOriginInfosExceedingLimits() const;
+  OriginInfosNestedTraversable GetOriginInfosExceedingLimits() const;
 
-  void ClearOrigins(const OriginInfosFlatTraversable& aDoomedOriginInfos);
+  void ClearOrigins(const OriginInfosNestedTraversable& aDoomedOriginInfos);
 
   void CleanupTemporaryStorage();
 

dom/quota/test/gtest/TestFlatten.cpp

@@ -0,0 +1,74 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 "Flatten.h"
+
+#include "gtest/gtest.h"
+
+#include "mozilla/Unused.h"
+#include "nsTArray.h"
+
+namespace mozilla::dom::quota {
+
+TEST(Flatten, FlatEmpty)
+{
+  for (const auto& item : Flatten<int>(nsTArray<int>{})) {
+    Unused << item;
+    FAIL();
+  }
+}
+
+TEST(Flatten, NestedOuterEmpty)
+{
+  for (const auto& item : Flatten<int>(nsTArray<CopyableTArray<int>>{})) {
+    Unused << item;
+    FAIL();
+  }
+}
+
+TEST(Flatten, NestedInnerEmpty)
+{
+  for (const auto& item :
+       Flatten<int>(nsTArray<CopyableTArray<int>>{CopyableTArray<int>{}})) {
+    Unused << item;
+    FAIL();
+  }
+}
+
+TEST(Flatten, NestedInnerSingular)
+{
+  nsTArray<int> flattened;
+  for (const auto& item :
+       Flatten<int>(nsTArray<CopyableTArray<int>>{CopyableTArray<int>{1}})) {
+    flattened.AppendElement(item);
+  }
+
+  EXPECT_EQ(nsTArray{1}, flattened);
+}
+
+TEST(Flatten, NestedInnerSingulars)
+{
+  nsTArray<int> flattened;
+  for (const auto& item : Flatten<int>(nsTArray<CopyableTArray<int>>{
+           CopyableTArray<int>{1}, CopyableTArray<int>{2}})) {
+    flattened.AppendElement(item);
+  }
+
+  EXPECT_EQ((nsTArray{{1, 2}}), flattened);
+}
+
+TEST(Flatten, NestedInnerNonSingulars)
+{
+  nsTArray<int> flattened;
+  for (const auto& item : Flatten<int>(nsTArray<CopyableTArray<int>>{
+           CopyableTArray<int>{1, 2}, CopyableTArray<int>{3, 4}})) {
+    flattened.AppendElement(item);
+  }
+
+  EXPECT_EQ((nsTArray{{1, 2, 3, 4}}), flattened);
+}
+
+}  // namespace mozilla::dom::quota

dom/quota/test/gtest/moz.build

@@ -7,6 +7,7 @@
 UNIFIED_SOURCES = [
     "TestCheckedUnsafePtr.cpp",
     "TestEncryptedStream.cpp",
+    "TestFlatten.cpp",
     "TestQuotaCommon.cpp",
     "TestQuotaManager.cpp",
     "TestUsageInfo.cpp",