From 5f8de423f190bbb79a62f804151bc24824fa32d8 Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Fri, 2 Feb 2018 04:16:08 -0500 Subject: Add m-esr52 at 52.6.0 --- layout/style/nsNthIndexCache.h | 110 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 layout/style/nsNthIndexCache.h (limited to 'layout/style/nsNthIndexCache.h') diff --git a/layout/style/nsNthIndexCache.h b/layout/style/nsNthIndexCache.h new file mode 100644 index 000000000..e24d98737 --- /dev/null +++ b/layout/style/nsNthIndexCache.h @@ -0,0 +1,110 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* 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 nsContentIndexCache_h__ +#define nsContentIndexCache_h__ + +#include "js/HashTable.h" + +class nsIContent; + +namespace mozilla { +namespace dom { +class Element; +} // namespace dom +} // namespace mozilla + +/* + * A class that computes and caches the indices used for :nth-* pseudo-class + * matching. + */ + +class nsNthIndexCache { +private: + typedef mozilla::dom::Element Element; + +public: + /** + * Constructor and destructor out of line so that we don't try to + * instantiate the hashtable template all over the place. + */ + nsNthIndexCache(); + ~nsNthIndexCache(); + + // Returns a 1-based index of the child in its parent. If the child + // is not in its parent's child list (i.e., it is anonymous content), + // returns 0. + // If aCheckEdgeOnly is true, the function will return 1 if the result + // is 1, and something other than 1 (maybe or maybe not a valid + // result) otherwise. + // This must only be called on nodes which have a non-null parent. + int32_t GetNthIndex(Element* aChild, bool aIsOfType, bool aIsFromEnd, + bool aCheckEdgeOnly); + + void Reset(); + +private: + /** + * Returns true if aSibling and aElement should be considered in the same + * list for nth-index purposes, taking aIsOfType into account. + */ + inline bool SiblingMatchesElement(nsIContent* aSibling, Element* aElement, + bool aIsOfType); + + // This node's index for this cache. + // If -2, needs to be computed. + // If -1, needs to be computed but known not to be 1. + // If 0, the node is not at any index in its parent. + typedef int32_t CacheEntry; + + class SystemAllocPolicy { + public: + void *malloc_(size_t bytes) { return ::malloc(bytes); } + + template + T *maybe_pod_calloc(size_t numElems) { + return static_cast(::calloc(numElems, sizeof(T))); + } + + template + T *pod_calloc(size_t numElems) { + return maybe_pod_calloc(numElems); + } + + void *realloc_(void *p, size_t bytes) { return ::realloc(p, bytes); } + void free_(void *p) { ::free(p); } + void reportAllocOverflow() const {} + bool checkSimulatedOOM() const { return true; } + }; + + typedef js::HashMap, + SystemAllocPolicy> Cache; + + /** + * Returns true if aResult has been set to the correct value for aChild and + * no more work needs to be done. Returns false otherwise. + * + * aResult is an inout parameter. The in value is the number of elements + * that are in the half-open range (aSibling, aChild] (so including aChild + * but not including aSibling) that match aChild. The out value is the + * correct index for aChild if this function returns true and the number of + * elements in the closed range [aSibling, aChild] that match aChild + * otherwise. + */ + inline bool IndexDeterminedFromPreviousSibling(nsIContent* aSibling, + Element* aChild, + bool aIsOfType, + bool aIsFromEnd, + const Cache& aCache, + int32_t& aResult); + + // Caches of indices for :nth-child(), :nth-last-child(), + // :nth-of-type(), :nth-last-of-type(), keyed by Element*. + // + // The first subscript is 0 for -child and 1 for -of-type, the second + // subscript is 0 for nth- and 1 for nth-last-. + Cache mCaches[2][2]; +}; + +#endif /* nsContentIndexCache_h__ */ -- cgit v1.2.3