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-rw-r--r--dom/base/nsAttrAndChildArray.h222
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diff --git a/dom/base/nsAttrAndChildArray.h b/dom/base/nsAttrAndChildArray.h
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+/* -*- 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.
+ */
+
+#ifndef nsAttrAndChildArray_h___
+#define nsAttrAndChildArray_h___
+
+#include "mozilla/Attributes.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/dom/BorrowedAttrInfo.h"
+
+#include "nscore.h"
+#include "nsAttrName.h"
+#include "nsAttrValue.h"
+#include "nsCaseTreatment.h"
+
+class nsINode;
+class nsIContent;
+class nsMappedAttributes;
+class nsHTMLStyleSheet;
+class nsRuleWalker;
+class nsMappedAttributeElement;
+
+#define ATTRCHILD_ARRAY_GROWSIZE 8
+#define ATTRCHILD_ARRAY_LINEAR_THRESHOLD 32
+
+#define ATTRCHILD_ARRAY_ATTR_SLOTS_BITS 10
+
+#define ATTRCHILD_ARRAY_MAX_ATTR_COUNT \
+ ((1 << ATTRCHILD_ARRAY_ATTR_SLOTS_BITS) - 1)
+
+#define ATTRCHILD_ARRAY_MAX_CHILD_COUNT \
+ (~uint32_t(0) >> ATTRCHILD_ARRAY_ATTR_SLOTS_BITS)
+
+#define ATTRCHILD_ARRAY_ATTR_SLOTS_COUNT_MASK \
+ ((1 << ATTRCHILD_ARRAY_ATTR_SLOTS_BITS) - 1)
+
+
+#define ATTRSIZE (sizeof(InternalAttr) / sizeof(void*))
+
+class nsAttrAndChildArray
+{
+ typedef mozilla::dom::BorrowedAttrInfo BorrowedAttrInfo;
+public:
+ nsAttrAndChildArray();
+ ~nsAttrAndChildArray();
+
+ uint32_t ChildCount() const
+ {
+ return mImpl ? (mImpl->mAttrAndChildCount >> ATTRCHILD_ARRAY_ATTR_SLOTS_BITS) : 0;
+ }
+ nsIContent* ChildAt(uint32_t aPos) const
+ {
+ NS_ASSERTION(aPos < ChildCount(), "out-of-bounds access in nsAttrAndChildArray");
+ return reinterpret_cast<nsIContent*>(mImpl->mBuffer[AttrSlotsSize() + aPos]);
+ }
+ nsIContent* GetSafeChildAt(uint32_t aPos) const;
+ nsIContent * const * GetChildArray(uint32_t* aChildCount) const;
+ nsresult AppendChild(nsIContent* aChild)
+ {
+ return InsertChildAt(aChild, ChildCount());
+ }
+ nsresult InsertChildAt(nsIContent* aChild, uint32_t aPos);
+ void RemoveChildAt(uint32_t aPos);
+ // Like RemoveChildAt but hands the reference to the child being
+ // removed back to the caller instead of just releasing it.
+ already_AddRefed<nsIContent> TakeChildAt(uint32_t aPos);
+ int32_t IndexOfChild(const nsINode* aPossibleChild) const;
+
+ bool HasAttrs() const
+ {
+ return MappedAttrCount() || (AttrSlotCount() && AttrSlotIsTaken(0));
+ }
+
+ uint32_t AttrCount() const;
+ const nsAttrValue* GetAttr(nsIAtom* aLocalName,
+ int32_t aNamespaceID = kNameSpaceID_None) const;
+ // As above but using a string attr name and always using
+ // kNameSpaceID_None. This is always case-sensitive.
+ const nsAttrValue* GetAttr(const nsAString& aName) const;
+ // Get an nsAttrValue by qualified name. Can optionally do
+ // ASCII-case-insensitive name matching.
+ const nsAttrValue* GetAttr(const nsAString& aName,
+ nsCaseTreatment aCaseSensitive) const;
+ const nsAttrValue* AttrAt(uint32_t aPos) const;
+ // SetAndSwapAttr swaps the current attribute value with aValue.
+ nsresult SetAndSwapAttr(nsIAtom* aLocalName, nsAttrValue& aValue);
+ nsresult SetAndSwapAttr(mozilla::dom::NodeInfo* aName, nsAttrValue& aValue);
+
+ // Remove the attr at position aPos. The value of the attr is placed in
+ // aValue; any value that was already in aValue is destroyed.
+ nsresult RemoveAttrAt(uint32_t aPos, nsAttrValue& aValue);
+
+ // Returns attribute name at given position, *not* out-of-bounds safe
+ const nsAttrName* AttrNameAt(uint32_t aPos) const;
+
+ // Returns the attribute info at a given position, *not* out-of-bounds safe
+ BorrowedAttrInfo AttrInfoAt(uint32_t aPos) const;
+
+ // Returns attribute name at given position or null if aPos is out-of-bounds
+ const nsAttrName* GetSafeAttrNameAt(uint32_t aPos) const;
+
+ const nsAttrName* GetExistingAttrNameFromQName(const nsAString& aName) const;
+ int32_t IndexOfAttr(nsIAtom* aLocalName, int32_t aNamespaceID = kNameSpaceID_None) const;
+
+ nsresult SetAndTakeMappedAttr(nsIAtom* aLocalName, nsAttrValue& aValue,
+ nsMappedAttributeElement* aContent,
+ nsHTMLStyleSheet* aSheet);
+ nsresult SetMappedAttrStyleSheet(nsHTMLStyleSheet* aSheet) {
+ if (!mImpl || !mImpl->mMappedAttrs) {
+ return NS_OK;
+ }
+ return DoSetMappedAttrStyleSheet(aSheet);
+ }
+ void WalkMappedAttributeStyleRules(nsRuleWalker* aRuleWalker);
+
+ void Compact();
+
+ bool CanFitMoreAttrs() const
+ {
+ return AttrSlotCount() < ATTRCHILD_ARRAY_MAX_ATTR_COUNT ||
+ !AttrSlotIsTaken(ATTRCHILD_ARRAY_MAX_ATTR_COUNT - 1);
+ }
+
+ size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
+ bool HasMappedAttrs() const
+ {
+ return MappedAttrCount();
+ }
+
+private:
+ nsAttrAndChildArray(const nsAttrAndChildArray& aOther) = delete;
+ nsAttrAndChildArray& operator=(const nsAttrAndChildArray& aOther) = delete;
+
+ void Clear();
+
+ uint32_t NonMappedAttrCount() const;
+ uint32_t MappedAttrCount() const;
+
+ // Returns a non-null zero-refcount object.
+ nsMappedAttributes*
+ GetModifiableMapped(nsMappedAttributeElement* aContent,
+ nsHTMLStyleSheet* aSheet,
+ bool aWillAddAttr);
+ nsresult MakeMappedUnique(nsMappedAttributes* aAttributes);
+
+ uint32_t AttrSlotsSize() const
+ {
+ return AttrSlotCount() * ATTRSIZE;
+ }
+
+ uint32_t AttrSlotCount() const
+ {
+ return mImpl ? mImpl->mAttrAndChildCount & ATTRCHILD_ARRAY_ATTR_SLOTS_COUNT_MASK : 0;
+ }
+
+ bool AttrSlotIsTaken(uint32_t aSlot) const
+ {
+ NS_PRECONDITION(aSlot < AttrSlotCount(), "out-of-bounds");
+ return mImpl->mBuffer[aSlot * ATTRSIZE];
+ }
+
+ void SetChildCount(uint32_t aCount)
+ {
+ mImpl->mAttrAndChildCount =
+ (mImpl->mAttrAndChildCount & ATTRCHILD_ARRAY_ATTR_SLOTS_COUNT_MASK) |
+ (aCount << ATTRCHILD_ARRAY_ATTR_SLOTS_BITS);
+ }
+
+ void SetAttrSlotCount(uint32_t aCount)
+ {
+ mImpl->mAttrAndChildCount =
+ (mImpl->mAttrAndChildCount & ~ATTRCHILD_ARRAY_ATTR_SLOTS_COUNT_MASK) |
+ aCount;
+ }
+
+ void SetAttrSlotAndChildCount(uint32_t aSlotCount, uint32_t aChildCount)
+ {
+ mImpl->mAttrAndChildCount = aSlotCount |
+ (aChildCount << ATTRCHILD_ARRAY_ATTR_SLOTS_BITS);
+ }
+
+ bool GrowBy(uint32_t aGrowSize);
+ bool AddAttrSlot();
+
+ /**
+ * Set *aPos to aChild and update sibling pointers as needed. aIndex is the
+ * index at which aChild is actually being inserted. aChildCount is the
+ * number of kids we had before the insertion.
+ */
+ inline void SetChildAtPos(void** aPos, nsIContent* aChild, uint32_t aIndex,
+ uint32_t aChildCount);
+
+ /**
+ * Guts of SetMappedAttrStyleSheet for the rare case when we have mapped attrs
+ */
+ nsresult DoSetMappedAttrStyleSheet(nsHTMLStyleSheet* aSheet);
+
+ struct InternalAttr
+ {
+ nsAttrName mName;
+ nsAttrValue mValue;
+ };
+
+ struct Impl {
+ uint32_t mAttrAndChildCount;
+ uint32_t mBufferSize;
+ nsMappedAttributes* mMappedAttrs;
+ void* mBuffer[1];
+ };
+
+ Impl* mImpl;
+};
+
+#endif