1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/base/src/nsContentList.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,569 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/*
1.10 + * nsBaseContentList is a basic list of content nodes; nsContentList
1.11 + * is a commonly used NodeList implementation (used for
1.12 + * getElementsByTagName, some properties on nsIDOMHTMLDocument, etc).
1.13 + */
1.14 +
1.15 +#ifndef nsContentList_h___
1.16 +#define nsContentList_h___
1.17 +
1.18 +#include "mozilla/Attributes.h"
1.19 +#include "nsContentListDeclarations.h"
1.20 +#include "nsISupports.h"
1.21 +#include "nsTArray.h"
1.22 +#include "nsString.h"
1.23 +#include "nsIHTMLCollection.h"
1.24 +#include "nsIDOMNodeList.h"
1.25 +#include "nsINodeList.h"
1.26 +#include "nsStubMutationObserver.h"
1.27 +#include "nsIAtom.h"
1.28 +#include "nsCycleCollectionParticipant.h"
1.29 +#include "nsNameSpaceManager.h"
1.30 +#include "nsWrapperCache.h"
1.31 +#include "nsHashKeys.h"
1.32 +#include "mozilla/HashFunctions.h"
1.33 +
1.34 +namespace mozilla {
1.35 +namespace dom {
1.36 +class Element;
1.37 +}
1.38 +}
1.39 +
1.40 +
1.41 +class nsBaseContentList : public nsINodeList
1.42 +{
1.43 +public:
1.44 + nsBaseContentList()
1.45 + {
1.46 + SetIsDOMBinding();
1.47 + }
1.48 + virtual ~nsBaseContentList();
1.49 +
1.50 + NS_DECL_CYCLE_COLLECTING_ISUPPORTS
1.51 +
1.52 + // nsIDOMNodeList
1.53 + NS_DECL_NSIDOMNODELIST
1.54 +
1.55 + // nsINodeList
1.56 + virtual int32_t IndexOf(nsIContent* aContent) MOZ_OVERRIDE;
1.57 + virtual nsIContent* Item(uint32_t aIndex) MOZ_OVERRIDE;
1.58 +
1.59 + uint32_t Length() const {
1.60 + return mElements.Length();
1.61 + }
1.62 +
1.63 + NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS(nsBaseContentList)
1.64 +
1.65 + void AppendElement(nsIContent *aContent)
1.66 + {
1.67 + mElements.AppendElement(aContent);
1.68 + }
1.69 + void MaybeAppendElement(nsIContent* aContent)
1.70 + {
1.71 + if (aContent)
1.72 + AppendElement(aContent);
1.73 + }
1.74 +
1.75 + /**
1.76 + * Insert the element at a given index, shifting the objects at
1.77 + * the given index and later to make space.
1.78 + * @param aContent Element to insert, must not be null
1.79 + * @param aIndex Index to insert the element at.
1.80 + */
1.81 + void InsertElementAt(nsIContent* aContent, int32_t aIndex)
1.82 + {
1.83 + NS_ASSERTION(aContent, "Element to insert must not be null");
1.84 + mElements.InsertElementAt(aIndex, aContent);
1.85 + }
1.86 +
1.87 + void RemoveElement(nsIContent *aContent)
1.88 + {
1.89 + mElements.RemoveElement(aContent);
1.90 + }
1.91 +
1.92 + void Reset() {
1.93 + mElements.Clear();
1.94 + }
1.95 +
1.96 + virtual int32_t IndexOf(nsIContent *aContent, bool aDoFlush);
1.97 +
1.98 + virtual JSObject* WrapObject(JSContext *cx)
1.99 + MOZ_OVERRIDE = 0;
1.100 +
1.101 + void SetCapacity(uint32_t aCapacity)
1.102 + {
1.103 + mElements.SetCapacity(aCapacity);
1.104 + }
1.105 +protected:
1.106 + /**
1.107 + * To be called from non-destructor locations (e.g. unlink) that want to
1.108 + * remove from caches. Cacheable subclasses should override.
1.109 + */
1.110 + virtual void RemoveFromCaches()
1.111 + {
1.112 + }
1.113 +
1.114 + nsTArray< nsCOMPtr<nsIContent> > mElements;
1.115 +};
1.116 +
1.117 +
1.118 +class nsSimpleContentList : public nsBaseContentList
1.119 +{
1.120 +public:
1.121 + nsSimpleContentList(nsINode *aRoot) : nsBaseContentList(),
1.122 + mRoot(aRoot)
1.123 + {
1.124 + }
1.125 +
1.126 + NS_DECL_ISUPPORTS_INHERITED
1.127 + NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(nsSimpleContentList,
1.128 + nsBaseContentList)
1.129 +
1.130 + virtual nsINode* GetParentObject() MOZ_OVERRIDE
1.131 + {
1.132 + return mRoot;
1.133 + }
1.134 + virtual JSObject* WrapObject(JSContext *cx) MOZ_OVERRIDE;
1.135 +
1.136 +private:
1.137 + // This has to be a strong reference, the root might go away before the list.
1.138 + nsCOMPtr<nsINode> mRoot;
1.139 +};
1.140 +
1.141 +/**
1.142 + * Class that's used as the key to hash nsContentList implementations
1.143 + * for fast retrieval
1.144 + */
1.145 +struct nsContentListKey
1.146 +{
1.147 + nsContentListKey(nsINode* aRootNode,
1.148 + int32_t aMatchNameSpaceId,
1.149 + const nsAString& aTagname)
1.150 + : mRootNode(aRootNode),
1.151 + mMatchNameSpaceId(aMatchNameSpaceId),
1.152 + mTagname(aTagname),
1.153 + mHash(mozilla::AddToHash(mozilla::HashString(aTagname), mRootNode,
1.154 + mMatchNameSpaceId))
1.155 + {
1.156 + }
1.157 +
1.158 + nsContentListKey(const nsContentListKey& aContentListKey)
1.159 + : mRootNode(aContentListKey.mRootNode),
1.160 + mMatchNameSpaceId(aContentListKey.mMatchNameSpaceId),
1.161 + mTagname(aContentListKey.mTagname),
1.162 + mHash(aContentListKey.mHash)
1.163 + {
1.164 + }
1.165 +
1.166 + inline uint32_t GetHash(void) const
1.167 + {
1.168 + return mHash;
1.169 + }
1.170 +
1.171 + nsINode* const mRootNode; // Weak ref
1.172 + const int32_t mMatchNameSpaceId;
1.173 + const nsAString& mTagname;
1.174 + const uint32_t mHash;
1.175 +};
1.176 +
1.177 +/**
1.178 + * LIST_UP_TO_DATE means that the list is up to date and need not do
1.179 + * any walking to be able to answer any questions anyone may have.
1.180 + */
1.181 +#define LIST_UP_TO_DATE 0
1.182 +/**
1.183 + * LIST_DIRTY means that the list contains no useful information and
1.184 + * if anyone asks it anything it will have to populate itself before
1.185 + * answering.
1.186 + */
1.187 +#define LIST_DIRTY 1
1.188 +/**
1.189 + * LIST_LAZY means that the list has populated itself to a certain
1.190 + * extent and that that part of the list is still valid. Requests for
1.191 + * things outside that part of the list will require walking the tree
1.192 + * some more. When a list is in this state, the last thing in
1.193 + * mElements is the last node in the tree that the list looked at.
1.194 + */
1.195 +#define LIST_LAZY 2
1.196 +
1.197 +/**
1.198 + * Class that implements a live NodeList that matches Elements in the
1.199 + * tree based on some criterion.
1.200 + */
1.201 +class nsContentList : public nsBaseContentList,
1.202 + public nsIHTMLCollection,
1.203 + public nsStubMutationObserver
1.204 +{
1.205 +public:
1.206 + NS_DECL_ISUPPORTS_INHERITED
1.207 +
1.208 + /**
1.209 + * @param aRootNode The node under which to limit our search.
1.210 + * @param aMatchAtom An atom whose meaning depends on aMatchNameSpaceId.
1.211 + * The special value "*" always matches whatever aMatchAtom
1.212 + * is matched against.
1.213 + * @param aMatchNameSpaceId If kNameSpaceID_Unknown, then aMatchAtom is the
1.214 + * tagName to match.
1.215 + * If kNameSpaceID_Wildcard, then aMatchAtom is the
1.216 + * localName to match.
1.217 + * Otherwise we match nodes whose namespace is
1.218 + * aMatchNameSpaceId and localName matches
1.219 + * aMatchAtom.
1.220 + * @param aDeep If false, then look only at children of the root, nothing
1.221 + * deeper. If true, then look at the whole subtree rooted at
1.222 + * our root.
1.223 + */
1.224 + nsContentList(nsINode* aRootNode,
1.225 + int32_t aMatchNameSpaceId,
1.226 + nsIAtom* aHTMLMatchAtom,
1.227 + nsIAtom* aXMLMatchAtom,
1.228 + bool aDeep = true);
1.229 +
1.230 + /**
1.231 + * @param aRootNode The node under which to limit our search.
1.232 + * @param aFunc the function to be called to determine whether we match.
1.233 + * This function MUST NOT ever cause mutation of the DOM.
1.234 + * The nsContentList implementation guarantees that everything
1.235 + * passed to the function will be IsElement().
1.236 + * @param aDestroyFunc the function that will be called to destroy aData
1.237 + * @param aData closure data that will need to be passed back to aFunc
1.238 + * @param aDeep If false, then look only at children of the root, nothing
1.239 + * deeper. If true, then look at the whole subtree rooted at
1.240 + * our root.
1.241 + * @param aMatchAtom an atom to be passed back to aFunc
1.242 + * @param aMatchNameSpaceId a namespace id to be passed back to aFunc
1.243 + * @param aFuncMayDependOnAttr a boolean that indicates whether this list is
1.244 + * sensitive to attribute changes.
1.245 + */
1.246 + nsContentList(nsINode* aRootNode,
1.247 + nsContentListMatchFunc aFunc,
1.248 + nsContentListDestroyFunc aDestroyFunc,
1.249 + void* aData,
1.250 + bool aDeep = true,
1.251 + nsIAtom* aMatchAtom = nullptr,
1.252 + int32_t aMatchNameSpaceId = kNameSpaceID_None,
1.253 + bool aFuncMayDependOnAttr = true);
1.254 + virtual ~nsContentList();
1.255 +
1.256 + // nsWrapperCache
1.257 + using nsWrapperCache::GetWrapperPreserveColor;
1.258 + virtual JSObject* WrapObject(JSContext* aCx) MOZ_OVERRIDE;
1.259 +protected:
1.260 + virtual JSObject* GetWrapperPreserveColorInternal() MOZ_OVERRIDE
1.261 + {
1.262 + return nsWrapperCache::GetWrapperPreserveColor();
1.263 + }
1.264 +public:
1.265 +
1.266 + // nsIDOMHTMLCollection
1.267 + NS_DECL_NSIDOMHTMLCOLLECTION
1.268 +
1.269 + // nsBaseContentList overrides
1.270 + virtual int32_t IndexOf(nsIContent *aContent, bool aDoFlush) MOZ_OVERRIDE;
1.271 + virtual int32_t IndexOf(nsIContent* aContent) MOZ_OVERRIDE;
1.272 + virtual nsINode* GetParentObject() MOZ_OVERRIDE
1.273 + {
1.274 + return mRootNode;
1.275 + }
1.276 +
1.277 + virtual nsIContent* Item(uint32_t aIndex) MOZ_OVERRIDE;
1.278 + virtual mozilla::dom::Element* GetElementAt(uint32_t index) MOZ_OVERRIDE;
1.279 + virtual mozilla::dom::Element*
1.280 + GetFirstNamedElement(const nsAString& aName, bool& aFound) MOZ_OVERRIDE
1.281 + {
1.282 + mozilla::dom::Element* item = NamedItem(aName, true);
1.283 + aFound = !!item;
1.284 + return item;
1.285 + }
1.286 + virtual void GetSupportedNames(unsigned aFlags,
1.287 + nsTArray<nsString>& aNames) MOZ_OVERRIDE;
1.288 +
1.289 + // nsContentList public methods
1.290 + NS_HIDDEN_(uint32_t) Length(bool aDoFlush);
1.291 + NS_HIDDEN_(nsIContent*) Item(uint32_t aIndex, bool aDoFlush);
1.292 + NS_HIDDEN_(mozilla::dom::Element*)
1.293 + NamedItem(const nsAString& aName, bool aDoFlush);
1.294 +
1.295 + // nsIMutationObserver
1.296 + NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
1.297 + NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
1.298 + NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
1.299 + NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
1.300 + NS_DECL_NSIMUTATIONOBSERVER_NODEWILLBEDESTROYED
1.301 +
1.302 + static nsContentList* FromSupports(nsISupports* aSupports)
1.303 + {
1.304 + nsINodeList* list = static_cast<nsINodeList*>(aSupports);
1.305 +#ifdef DEBUG
1.306 + {
1.307 + nsCOMPtr<nsINodeList> list_qi = do_QueryInterface(aSupports);
1.308 +
1.309 + // If this assertion fires the QI implementation for the object in
1.310 + // question doesn't use the nsINodeList pointer as the nsISupports
1.311 + // pointer. That must be fixed, or we'll crash...
1.312 + NS_ASSERTION(list_qi == list, "Uh, fix QI!");
1.313 + }
1.314 +#endif
1.315 + return static_cast<nsContentList*>(list);
1.316 + }
1.317 +
1.318 + bool MatchesKey(const nsContentListKey& aKey) const
1.319 + {
1.320 + // The root node is most commonly the same: the document. And the
1.321 + // most common namespace id is kNameSpaceID_Unknown. So check the
1.322 + // string first.
1.323 + NS_PRECONDITION(mXMLMatchAtom,
1.324 + "How did we get here with a null match atom on our list?");
1.325 + return
1.326 + mXMLMatchAtom->Equals(aKey.mTagname) &&
1.327 + mRootNode == aKey.mRootNode &&
1.328 + mMatchNameSpaceId == aKey.mMatchNameSpaceId;
1.329 + }
1.330 +
1.331 + /**
1.332 + * Sets the state to LIST_DIRTY and clears mElements array.
1.333 + * @note This is the only acceptable way to set state to LIST_DIRTY.
1.334 + */
1.335 + void SetDirty()
1.336 + {
1.337 + mState = LIST_DIRTY;
1.338 + Reset();
1.339 + }
1.340 +
1.341 +protected:
1.342 + /**
1.343 + * Returns whether the element matches our criterion
1.344 + *
1.345 + * @param aElement the element to attempt to match
1.346 + * @return whether we match
1.347 + */
1.348 + bool Match(mozilla::dom::Element *aElement);
1.349 + /**
1.350 + * See if anything in the subtree rooted at aContent, including
1.351 + * aContent itself, matches our criterion.
1.352 + *
1.353 + * @param aContent the root of the subtree to match against
1.354 + * @return whether we match something in the tree rooted at aContent
1.355 + */
1.356 + bool MatchSelf(nsIContent *aContent);
1.357 +
1.358 + /**
1.359 + * Populate our list. Stop once we have at least aNeededLength
1.360 + * elements. At the end of PopulateSelf running, either the last
1.361 + * node we examined is the last node in our array or we have
1.362 + * traversed the whole document (or both).
1.363 + *
1.364 + * @param aNeededLength the length the list should have when we are
1.365 + * done (unless it exhausts the document)
1.366 + */
1.367 + void PopulateSelf(uint32_t aNeededLength);
1.368 +
1.369 + /**
1.370 + * @param aContainer a content node which must be a descendant of
1.371 + * mRootNode
1.372 + * @return true if children or descendants of aContainer could match our
1.373 + * criterion.
1.374 + * false otherwise.
1.375 + */
1.376 + bool MayContainRelevantNodes(nsINode* aContainer)
1.377 + {
1.378 + return mDeep || aContainer == mRootNode;
1.379 + }
1.380 +
1.381 + /**
1.382 + * Remove ourselves from the hashtable that caches commonly accessed
1.383 + * content lists. Generally done on destruction.
1.384 + */
1.385 + void RemoveFromHashtable();
1.386 + /**
1.387 + * If state is not LIST_UP_TO_DATE, fully populate ourselves with
1.388 + * all the nodes we can find.
1.389 + */
1.390 + inline void BringSelfUpToDate(bool aDoFlush);
1.391 +
1.392 + /**
1.393 + * To be called from non-destructor locations that want to remove from caches.
1.394 + * Needed because if subclasses want to have cache behavior they can't just
1.395 + * override RemoveFromHashtable(), since we call that in our destructor.
1.396 + */
1.397 + virtual void RemoveFromCaches() MOZ_OVERRIDE
1.398 + {
1.399 + RemoveFromHashtable();
1.400 + }
1.401 +
1.402 + nsINode* mRootNode; // Weak ref
1.403 + int32_t mMatchNameSpaceId;
1.404 + nsCOMPtr<nsIAtom> mHTMLMatchAtom;
1.405 + nsCOMPtr<nsIAtom> mXMLMatchAtom;
1.406 +
1.407 + /**
1.408 + * Function to use to determine whether a piece of content matches
1.409 + * our criterion
1.410 + */
1.411 + nsContentListMatchFunc mFunc;
1.412 + /**
1.413 + * Cleanup closure data with this.
1.414 + */
1.415 + nsContentListDestroyFunc mDestroyFunc;
1.416 + /**
1.417 + * Closure data to pass to mFunc when we call it
1.418 + */
1.419 + void* mData;
1.420 + /**
1.421 + * The current state of the list (possible values are:
1.422 + * LIST_UP_TO_DATE, LIST_LAZY, LIST_DIRTY
1.423 + */
1.424 + uint8_t mState;
1.425 +
1.426 + // The booleans have to use uint8_t to pack with mState, because MSVC won't
1.427 + // pack different typedefs together. Once we no longer have to worry about
1.428 + // flushes in XML documents, we can go back to using bool for the
1.429 + // booleans.
1.430 +
1.431 + /**
1.432 + * True if we are looking for elements named "*"
1.433 + */
1.434 + uint8_t mMatchAll : 1;
1.435 + /**
1.436 + * Whether to actually descend the tree. If this is false, we won't
1.437 + * consider grandkids of mRootNode.
1.438 + */
1.439 + uint8_t mDeep : 1;
1.440 + /**
1.441 + * Whether the return value of mFunc could depend on the values of
1.442 + * attributes.
1.443 + */
1.444 + uint8_t mFuncMayDependOnAttr : 1;
1.445 + /**
1.446 + * Whether we actually need to flush to get our state correct.
1.447 + */
1.448 + uint8_t mFlushesNeeded : 1;
1.449 +
1.450 +#ifdef DEBUG_CONTENT_LIST
1.451 + void AssertInSync();
1.452 +#endif
1.453 +};
1.454 +
1.455 +/**
1.456 + * A class of cacheable content list; cached on the combination of aRootNode + aFunc + aDataString
1.457 + */
1.458 +class nsCacheableFuncStringContentList;
1.459 +
1.460 +class MOZ_STACK_CLASS nsFuncStringCacheKey {
1.461 +public:
1.462 + nsFuncStringCacheKey(nsINode* aRootNode,
1.463 + nsContentListMatchFunc aFunc,
1.464 + const nsAString& aString) :
1.465 + mRootNode(aRootNode),
1.466 + mFunc(aFunc),
1.467 + mString(aString)
1.468 + {}
1.469 +
1.470 + uint32_t GetHash(void) const
1.471 + {
1.472 + uint32_t hash = mozilla::HashString(mString);
1.473 + return mozilla::AddToHash(hash, mRootNode, mFunc);
1.474 + }
1.475 +
1.476 +private:
1.477 + friend class nsCacheableFuncStringContentList;
1.478 +
1.479 + nsINode* const mRootNode;
1.480 + const nsContentListMatchFunc mFunc;
1.481 + const nsAString& mString;
1.482 +};
1.483 +
1.484 +// aDestroyFunc is allowed to be null
1.485 +// aDataAllocator must always return a non-null pointer
1.486 +class nsCacheableFuncStringContentList : public nsContentList {
1.487 +public:
1.488 + virtual ~nsCacheableFuncStringContentList();
1.489 +
1.490 + bool Equals(const nsFuncStringCacheKey* aKey) {
1.491 + return mRootNode == aKey->mRootNode && mFunc == aKey->mFunc &&
1.492 + mString == aKey->mString;
1.493 + }
1.494 +
1.495 +#ifdef DEBUG
1.496 + enum ContentListType {
1.497 + eNodeList,
1.498 + eHTMLCollection
1.499 + };
1.500 + ContentListType mType;
1.501 +#endif
1.502 +
1.503 +protected:
1.504 + nsCacheableFuncStringContentList(nsINode* aRootNode,
1.505 + nsContentListMatchFunc aFunc,
1.506 + nsContentListDestroyFunc aDestroyFunc,
1.507 + nsFuncStringContentListDataAllocator aDataAllocator,
1.508 + const nsAString& aString) :
1.509 + nsContentList(aRootNode, aFunc, aDestroyFunc, nullptr),
1.510 + mString(aString)
1.511 + {
1.512 + mData = (*aDataAllocator)(aRootNode, &mString);
1.513 + MOZ_ASSERT(mData);
1.514 + }
1.515 +
1.516 + virtual void RemoveFromCaches() MOZ_OVERRIDE {
1.517 + RemoveFromFuncStringHashtable();
1.518 + }
1.519 + void RemoveFromFuncStringHashtable();
1.520 +
1.521 + nsString mString;
1.522 +};
1.523 +
1.524 +class nsCacheableFuncStringNodeList
1.525 + : public nsCacheableFuncStringContentList
1.526 +{
1.527 +public:
1.528 + nsCacheableFuncStringNodeList(nsINode* aRootNode,
1.529 + nsContentListMatchFunc aFunc,
1.530 + nsContentListDestroyFunc aDestroyFunc,
1.531 + nsFuncStringContentListDataAllocator aDataAllocator,
1.532 + const nsAString& aString)
1.533 + : nsCacheableFuncStringContentList(aRootNode, aFunc, aDestroyFunc,
1.534 + aDataAllocator, aString)
1.535 + {
1.536 +#ifdef DEBUG
1.537 + mType = eNodeList;
1.538 +#endif
1.539 + }
1.540 +
1.541 + virtual JSObject* WrapObject(JSContext *cx) MOZ_OVERRIDE;
1.542 +
1.543 +#ifdef DEBUG
1.544 + static const ContentListType sType;
1.545 +#endif
1.546 +};
1.547 +
1.548 +class nsCacheableFuncStringHTMLCollection
1.549 + : public nsCacheableFuncStringContentList
1.550 +{
1.551 +public:
1.552 + nsCacheableFuncStringHTMLCollection(nsINode* aRootNode,
1.553 + nsContentListMatchFunc aFunc,
1.554 + nsContentListDestroyFunc aDestroyFunc,
1.555 + nsFuncStringContentListDataAllocator aDataAllocator,
1.556 + const nsAString& aString)
1.557 + : nsCacheableFuncStringContentList(aRootNode, aFunc, aDestroyFunc,
1.558 + aDataAllocator, aString)
1.559 + {
1.560 +#ifdef DEBUG
1.561 + mType = eHTMLCollection;
1.562 +#endif
1.563 + }
1.564 +
1.565 + virtual JSObject* WrapObject(JSContext *cx) MOZ_OVERRIDE;
1.566 +
1.567 +#ifdef DEBUG
1.568 + static const ContentListType sType;
1.569 +#endif
1.570 +};
1.571 +
1.572 +#endif // nsContentList_h___
