1 files changed, 377 insertions, 0 deletions
diff --git a/dom/base/AttrArray.cpp b/dom/base/AttrArray.cpp
new file mode 100644
index 0000000000..83656ede89
--- /dev/null
+++ b/dom/base/AttrArray.cpp
@@ -0,0 +1,377 @@
+/* -*- 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/. */
+
+/*
+ * Storage of the children and attributes of a DOM node; storage for
+ * the two is unified to minimize footprint.
+ */
+
+#include "AttrArray.h"
+
+#include "mozilla/AttributeStyles.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/MathAlgorithms.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/ServoBindings.h"
+
+#include "nsString.h"
+#include "nsUnicharUtils.h"
+#include "nsContentUtils.h"  // nsAutoScriptBlocker
+
+using mozilla::CheckedUint32;
+
+AttrArray::Impl::~Impl() {
+  for (InternalAttr& attr : Attrs()) {
+    attr.~InternalAttr();
+  }
+  if (auto* decl = GetMappedDeclarationBlock()) {
+    Servo_DeclarationBlock_Release(decl);
+    mMappedAttributeBits = 0;
+  }
+}
+
+void AttrArray::SetMappedDeclarationBlock(
+    already_AddRefed<mozilla::StyleLockedDeclarationBlock> aBlock) {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mImpl);
+  MOZ_ASSERT(IsPendingMappedAttributeEvaluation());
+  if (auto* decl = GetMappedDeclarationBlock()) {
+    Servo_DeclarationBlock_Release(decl);
+  }
+  mImpl->mMappedAttributeBits = reinterpret_cast<uintptr_t>(aBlock.take());
+  MOZ_ASSERT(!IsPendingMappedAttributeEvaluation());
+}
+
+const nsAttrValue* AttrArray::GetAttr(const nsAtom* aLocalName) const {
+  NS_ASSERTION(aLocalName, "Must have attr name");
+  for (const InternalAttr& attr : Attrs()) {
+    if (attr.mName.Equals(aLocalName)) {
+      return &attr.mValue;
+    }
+  }
+  return nullptr;
+}
+
+const nsAttrValue* AttrArray::GetAttr(const nsAtom* aLocalName,
+                                      int32_t aNamespaceID) const {
+  NS_ASSERTION(aLocalName, "Must have attr name");
+  NS_ASSERTION(aNamespaceID != kNameSpaceID_Unknown, "Must have namespace");
+  if (aNamespaceID == kNameSpaceID_None) {
+    // This should be the common case so lets use the optimized loop
+    return GetAttr(aLocalName);
+  }
+  for (const InternalAttr& attr : Attrs()) {
+    if (attr.mName.Equals(aLocalName, aNamespaceID)) {
+      return &attr.mValue;
+    }
+  }
+  return nullptr;
+}
+
+const nsAttrValue* AttrArray::GetAttr(const nsAString& aLocalName) const {
+  for (const InternalAttr& attr : Attrs()) {
+    if (attr.mName.Equals(aLocalName)) {
+      return &attr.mValue;
+    }
+  }
+  return nullptr;
+}
+
+const nsAttrValue* AttrArray::GetAttr(const nsAString& aName,
+                                      nsCaseTreatment aCaseSensitive) const {
+  // Check whether someone is being silly and passing non-lowercase
+  // attr names.
+  if (aCaseSensitive == eIgnoreCase &&
+      nsContentUtils::StringContainsASCIIUpper(aName)) {
+    // Try again with a lowercased name, but make sure we can't reenter this
+    // block by passing eCaseSensitive for aCaseSensitive.
+    nsAutoString lowercase;
+    nsContentUtils::ASCIIToLower(aName, lowercase);
+    return GetAttr(lowercase, eCaseMatters);
+  }
+
+  for (const InternalAttr& attr : Attrs()) {
+    if (attr.mName.QualifiedNameEquals(aName)) {
+      return &attr.mValue;
+    }
+  }
+
+  return nullptr;
+}
+
+const nsAttrValue* AttrArray::AttrAt(uint32_t aPos) const {
+  NS_ASSERTION(aPos < AttrCount(), "out-of-bounds access in AttrArray");
+  return &mImpl->Attrs()[aPos].mValue;
+}
+
+template <typename Name>
+inline nsresult AttrArray::AddNewAttribute(Name* aName, nsAttrValue& aValue) {
+  MOZ_ASSERT(!mImpl || mImpl->mCapacity >= mImpl->mAttrCount);
+  if (!mImpl || mImpl->mCapacity == mImpl->mAttrCount) {
+    if (!GrowBy(1)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+  }
+
+  InternalAttr& attr = mImpl->mBuffer[mImpl->mAttrCount++];
+  new (&attr.mName) nsAttrName(aName);
+  new (&attr.mValue) nsAttrValue();
+  attr.mValue.SwapValueWith(aValue);
+  return NS_OK;
+}
+
+nsresult AttrArray::SetAndSwapAttr(nsAtom* aLocalName, nsAttrValue& aValue,
+                                   bool* aHadValue) {
+  *aHadValue = false;
+
+  for (InternalAttr& attr : Attrs()) {
+    if (attr.mName.Equals(aLocalName)) {
+      attr.mValue.SwapValueWith(aValue);
+      *aHadValue = true;
+      return NS_OK;
+    }
+  }
+
+  return AddNewAttribute(aLocalName, aValue);
+}
+
+nsresult AttrArray::SetAndSwapAttr(mozilla::dom::NodeInfo* aName,
+                                   nsAttrValue& aValue, bool* aHadValue) {
+  int32_t namespaceID = aName->NamespaceID();
+  nsAtom* localName = aName->NameAtom();
+  if (namespaceID == kNameSpaceID_None) {
+    return SetAndSwapAttr(localName, aValue, aHadValue);
+  }
+
+  *aHadValue = false;
+  for (InternalAttr& attr : Attrs()) {
+    if (attr.mName.Equals(localName, namespaceID)) {
+      attr.mName.SetTo(aName);
+      attr.mValue.SwapValueWith(aValue);
+      *aHadValue = true;
+      return NS_OK;
+    }
+  }
+
+  return AddNewAttribute(aName, aValue);
+}
+
+nsresult AttrArray::RemoveAttrAt(uint32_t aPos, nsAttrValue& aValue) {
+  NS_ASSERTION(aPos < AttrCount(), "out-of-bounds");
+
+  mImpl->mBuffer[aPos].mValue.SwapValueWith(aValue);
+  mImpl->mBuffer[aPos].~InternalAttr();
+
+  memmove(mImpl->mBuffer + aPos, mImpl->mBuffer + aPos + 1,
+          (mImpl->mAttrCount - aPos - 1) * sizeof(InternalAttr));
+
+  --mImpl->mAttrCount;
+  return NS_OK;
+}
+
+mozilla::dom::BorrowedAttrInfo AttrArray::AttrInfoAt(uint32_t aPos) const {
+  NS_ASSERTION(aPos < AttrCount(), "out-of-bounds access in AttrArray");
+  InternalAttr& attr = mImpl->mBuffer[aPos];
+  return BorrowedAttrInfo(&attr.mName, &attr.mValue);
+}
+
+const nsAttrName* AttrArray::AttrNameAt(uint32_t aPos) const {
+  NS_ASSERTION(aPos < AttrCount(), "out-of-bounds access in AttrArray");
+  return &mImpl->mBuffer[aPos].mName;
+}
+
+const nsAttrName* AttrArray::GetSafeAttrNameAt(uint32_t aPos) const {
+  if (aPos >= AttrCount()) {
+    return nullptr;
+  }
+  return &mImpl->mBuffer[aPos].mName;
+}
+
+const nsAttrName* AttrArray::GetExistingAttrNameFromQName(
+    const nsAString& aName) const {
+  for (const InternalAttr& attr : Attrs()) {
+    if (attr.mName.QualifiedNameEquals(aName)) {
+      return &attr.mName;
+    }
+  }
+  return nullptr;
+}
+
+int32_t AttrArray::IndexOfAttr(const nsAtom* aLocalName) const {
+  int32_t i = 0;
+  for (const InternalAttr& attr : Attrs()) {
+    if (attr.mName.Equals(aLocalName)) {
+      return i;
+    }
+    ++i;
+  }
+  return -1;
+}
+
+int32_t AttrArray::IndexOfAttr(const nsAtom* aLocalName,
+                               int32_t aNamespaceID) const {
+  if (aNamespaceID == kNameSpaceID_None) {
+    // This should be the common case so lets use the optimized loop
+    return IndexOfAttr(aLocalName);
+  }
+  int32_t i = 0;
+  for (const InternalAttr& attr : Attrs()) {
+    if (attr.mName.Equals(aLocalName, aNamespaceID)) {
+      return i;
+    }
+    ++i;
+  }
+  return -1;
+}
+
+void AttrArray::Compact() {
+  if (!mImpl) {
+    return;
+  }
+
+  if (!mImpl->mAttrCount && !mImpl->mMappedAttributeBits) {
+    mImpl.reset();
+    return;
+  }
+
+  // Nothing to do.
+  if (mImpl->mAttrCount == mImpl->mCapacity) {
+    return;
+  }
+
+  Impl* oldImpl = mImpl.release();
+  Impl* impl = static_cast<Impl*>(
+      realloc(oldImpl, Impl::AllocationSizeForAttributes(oldImpl->mAttrCount)));
+  if (!impl) {
+    mImpl.reset(oldImpl);
+    return;
+  }
+  impl->mCapacity = impl->mAttrCount;
+  mImpl.reset(impl);
+}
+
+nsresult AttrArray::EnsureCapacityToClone(const AttrArray& aOther) {
+  MOZ_ASSERT(!mImpl,
+             "AttrArray::EnsureCapacityToClone requires the array be empty "
+             "when called");
+
+  uint32_t attrCount = aOther.AttrCount();
+  if (!attrCount) {
+    return NS_OK;
+  }
+
+  // No need to use a CheckedUint32 because we are cloning. We know that we
+  // have already allocated an AttrArray of this size.
+  mImpl.reset(
+      static_cast<Impl*>(malloc(Impl::AllocationSizeForAttributes(attrCount))));
+  NS_ENSURE_TRUE(mImpl, NS_ERROR_OUT_OF_MEMORY);
+
+  mImpl->mMappedAttributeBits = 0;
+  mImpl->mCapacity = attrCount;
+  mImpl->mAttrCount = 0;
+
+  return NS_OK;
+}
+
+bool AttrArray::GrowBy(uint32_t aGrowSize) {
+  const uint32_t kLinearThreshold = 16;
+  const uint32_t kLinearGrowSize = 4;
+
+  CheckedUint32 capacity = mImpl ? mImpl->mCapacity : 0;
+  CheckedUint32 minCapacity = capacity;
+  minCapacity += aGrowSize;
+  if (!minCapacity.isValid()) {
+    return false;
+  }
+
+  if (capacity.value() <= kLinearThreshold) {
+    do {
+      capacity += kLinearGrowSize;
+      if (!capacity.isValid()) {
+        return false;
+      }
+    } while (capacity.value() < minCapacity.value());
+  } else {
+    uint32_t shift = mozilla::CeilingLog2(minCapacity.value());
+    if (shift >= 32) {
+      return false;
+    }
+    capacity = 1u << shift;
+  }
+
+  return GrowTo(capacity.value());
+}
+
+bool AttrArray::GrowTo(uint32_t aCapacity) {
+  uint32_t oldCapacity = mImpl ? mImpl->mCapacity : 0;
+  if (aCapacity <= oldCapacity) {
+    return true;
+  }
+
+  CheckedUint32 sizeInBytes = aCapacity;
+  sizeInBytes *= sizeof(InternalAttr);
+  if (!sizeInBytes.isValid()) {
+    return false;
+  }
+
+  sizeInBytes += sizeof(Impl);
+  if (!sizeInBytes.isValid()) {
+    return false;
+  }
+
+  MOZ_ASSERT(sizeInBytes.value() ==
+             Impl::AllocationSizeForAttributes(aCapacity));
+
+  const bool needToInitialize = !mImpl;
+  Impl* oldImpl = mImpl.release();
+  Impl* newImpl = static_cast<Impl*>(realloc(oldImpl, sizeInBytes.value()));
+  if (!newImpl) {
+    mImpl.reset(oldImpl);
+    return false;
+  }
+
+  mImpl.reset(newImpl);
+
+  // Set initial counts if we didn't have a buffer before
+  if (needToInitialize) {
+    mImpl->mMappedAttributeBits = 0;
+    mImpl->mAttrCount = 0;
+  }
+
+  mImpl->mCapacity = aCapacity;
+  return true;
+}
+
+size_t AttrArray::SizeOfExcludingThis(
+    mozilla::MallocSizeOf aMallocSizeOf) const {
+  if (!mImpl) {
+    return 0;
+  }
+  size_t n = aMallocSizeOf(mImpl.get());
+  for (const InternalAttr& attr : Attrs()) {
+    n += attr.mValue.SizeOfExcludingThis(aMallocSizeOf);
+  }
+  return n;
+}
+
+int32_t AttrArray::FindAttrValueIn(int32_t aNameSpaceID, const nsAtom* aName,
+                                   AttrValuesArray* aValues,
+                                   nsCaseTreatment aCaseSensitive) const {
+  NS_ASSERTION(aName, "Must have attr name");
+  NS_ASSERTION(aNameSpaceID != kNameSpaceID_Unknown, "Must have namespace");
+  NS_ASSERTION(aValues, "Null value array");
+
+  const nsAttrValue* val = GetAttr(aName, aNameSpaceID);
+  if (val) {
+    for (int32_t i = 0; aValues[i]; ++i) {
+      if (val->Equals(aValues[i], aCaseSensitive)) {
+        return i;
+      }
+    }
+    return ATTR_VALUE_NO_MATCH;
+  }
+  return ATTR_MISSING;
+}