1 files changed, 115 insertions, 0 deletions
diff --git a/dom/base/nsMappedAttributes.h b/dom/base/nsMappedAttributes.h
new file mode 100644
index 0000000000..faf627478a
--- /dev/null
+++ b/dom/base/nsMappedAttributes.h
@@ -0,0 +1,115 @@
+/* -*- 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/. */
+
+/*
+ * A unique per-element set of attributes that is used as an
+ * nsIStyleRule; used to implement presentational attributes.
+ */
+
+#ifndef nsMappedAttributes_h___
+#define nsMappedAttributes_h___
+
+#include "AttrArray.h"
+#include "nsMappedAttributeElement.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/ServoBindingTypes.h"
+#include "mozilla/MemoryReporting.h"
+
+class nsAtom;
+class nsHTMLStyleSheet;
+
+class nsMappedAttributes final {
+  using InternalAttr = AttrArray::InternalAttr;
+
+ public:
+  nsMappedAttributes(nsHTMLStyleSheet* aSheet,
+                     nsMapRuleToAttributesFunc aMapRuleFunc);
+
+  // Do not return null.
+  void* operator new(size_t size, uint32_t aAttrCount = 1) noexcept(true);
+  nsMappedAttributes* Clone(bool aWillAddAttr);
+
+  NS_INLINE_DECL_REFCOUNTING_WITH_DESTROY(nsMappedAttributes, LastRelease())
+
+  void SetAndSwapAttr(nsAtom* aAttrName, nsAttrValue& aValue,
+                      bool* aValueWasSet);
+  const nsAttrValue* GetAttr(const nsAtom* aAttrName) const;
+  const nsAttrValue* GetAttr(const nsAString& aAttrName) const;
+
+  uint32_t Count() const { return mAttrCount; }
+
+  bool Equals(const nsMappedAttributes* aAttributes) const;
+  PLDHashNumber HashValue() const;
+
+  void DropStyleSheetReference() { mSheet = nullptr; }
+  void SetStyleSheet(nsHTMLStyleSheet* aSheet);
+  nsHTMLStyleSheet* GetStyleSheet() { return mSheet; }
+
+  void SetRuleMapper(nsMapRuleToAttributesFunc aRuleMapper) {
+    mRuleMapper = aRuleMapper;
+  }
+
+  auto Attrs() const {
+    return mozilla::Span<const InternalAttr>{mBuffer, mAttrCount};
+  }
+  auto Attrs() { return mozilla::Span<InternalAttr>{mBuffer, mAttrCount}; }
+  const nsAttrName* NameAt(uint32_t aPos) const {
+    NS_ASSERTION(aPos < mAttrCount, "out-of-bounds");
+    return &Attrs()[aPos].mName;
+  }
+  const nsAttrValue* AttrAt(uint32_t aPos) const {
+    NS_ASSERTION(aPos < mAttrCount, "out-of-bounds");
+    return &Attrs()[aPos].mValue;
+  }
+  // Remove the attr at position aPos.  The value of the attr is placed in
+  // aValue; any value that was already in aValue is destroyed.
+  void RemoveAttrAt(uint32_t aPos, nsAttrValue& aValue);
+  const nsAttrName* GetExistingAttrNameFromQName(const nsAString& aName) const;
+  int32_t IndexOfAttr(const nsAtom* aLocalName) const;
+
+  // Apply the contained mapper to the contained set of servo rules,
+  // unless the servo rules have already been initialized.
+  void LazilyResolveServoDeclaration(mozilla::dom::Document* aDocument);
+
+  // Obtain the contained servo declaration block
+  // May return null if called before the inner block
+  // has been (lazily) resolved
+  const mozilla::StyleLockedDeclarationBlock* GetServoStyle() const {
+    return mServoStyle;
+  }
+
+  void ClearServoStyle() {
+    MOZ_ASSERT(NS_IsMainThread());
+    mServoStyle = nullptr;
+  }
+
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
+
+  static void Shutdown();
+
+ private:
+  void LastRelease();
+
+  nsMappedAttributes(const nsMappedAttributes& aCopy);
+  ~nsMappedAttributes();
+
+  uint16_t mAttrCount;
+#ifdef DEBUG
+  uint16_t mBufferSize;
+#endif
+  nsHTMLStyleSheet* mSheet;  // weak
+  nsMapRuleToAttributesFunc mRuleMapper;
+  RefPtr<mozilla::StyleLockedDeclarationBlock> mServoStyle;
+  InternalAttr mBuffer[0];
+
+  static bool sShuttingDown;
+
+  // We're caching some memory to avoid trashing the allocator.
+  // The memory stored at index N can hold N attribute values.
+  static nsTArray<void*>* sCachedMappedAttributeAllocations;
+};
+
+#endif /* nsMappedAttributes_h___ */