/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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/. */
/**
* Implementation of an XPath NodeSet
*/
#ifndef txNodeSet_h__
#define txNodeSet_h__
#include "txExprResult.h"
#include "nsError.h"
#include "txXPathNode.h"
class txNodeSet : public txAExprResult
{
public:
/**
* Creates a new empty NodeSet
*/
explicit txNodeSet(txResultRecycler* aRecycler);
/**
* Creates a new NodeSet with one node.
*/
txNodeSet(const txXPathNode& aNode, txResultRecycler* aRecycler);
/**
* Creates a new txNodeSet, copying the node references from the source
* NodeSet.
*/
txNodeSet(const txNodeSet& aSource, txResultRecycler* aRecycler);
/**
* Destructor for txNodeSet, deletes the nodes.
*/
virtual ~txNodeSet();
/**
* Adds the specified txXPathNode to this NodeSet if it is not already
* in this NodeSet. The node is inserted according to document order.
*
* @param aNode the txXPathNode to add to the NodeSet
* @return errorcode.
*/
nsresult add(const txXPathNode& aNode);
/**
* Adds the nodes in specified NodeSet to this NodeSet. The resulting
* NodeSet is sorted in document order and does not contain any duplicate
* nodes.
*
* @param aNodes the NodeSet to add, must be in document order.
* @return errorcode.
*/
nsresult add(const txNodeSet& aNodes);
nsresult addAndTransfer(txNodeSet* aNodes);
/**
* Append API
* These functions should be used with care.
* They are intended to be used when the caller assures that the resulting
* NodeSet remains in document order.
* Abuse will break document order, and cause errors in the result.
* These functions are significantly faster than the add API, as no
* order info operations will be performed.
*/
/**
* Appends the specified Node to the end of this NodeSet
* @param aNode the Node to append to the NodeSet
* @return errorcode.
*/
nsresult append(const txXPathNode& aNode);
/**
* Appends the nodes in the specified NodeSet to the end of this NodeSet
* @param aNodes the NodeSet to append to the NodeSet
* @return errorcode.
*/
nsresult append(const txNodeSet& aNodes);
/**
* API to implement reverse axes in LocationStep.
*
* Before adding nodes to the nodeset for a reversed axis, call
* setReverse(). This will make the append(aNode) and get() methods treat
* the nodeset as required. Do only call append(aNode), get(), mark()
* and sweep() while the nodeset is reversed.
* Afterwards, call unsetReverse(). The nodes are stored in document
* order internally.
*/
void setReverse()
{
mDirection = -1;
}
void unsetReverse()
{
mDirection = 1;
}
/**
* API to implement predicates in PredicateExpr
*
* mark(aIndex) marks the specified member of the nodeset.
* sweep() clears all members of the nodeset that haven't been
* marked before and clear the mMarks array.
*/
nsresult mark(int32_t aIndex);
nsresult sweep();
/**
* Removes all nodes from this nodeset
*/
void clear();
/**
* Returns the index of the specified Node,
* or -1 if the Node is not contained in the NodeSet
* @param aNode the Node to get the index for
* @param aStart index to start searching at
* @return index of specified node or -1 if the node does not exist
*/
int32_t indexOf(const txXPathNode& aNode, uint32_t aStart = 0) const;
/**
* Returns true if the specified Node is contained in the set.
* @param aNode the Node to search for
* @return true if specified Node is contained in the NodeSet
*/
bool contains(const txXPathNode& aNode) const
{
return indexOf(aNode) >= 0;
}
/**
* Returns the Node at the specified node in this NodeSet.
* @param aIndex the node of the Node to return
* @return Node at specified node
*/
const txXPathNode& get(int32_t aIndex) const;
/**
* Returns true if there are no Nodes in the NodeSet.
* @return true if there are no Nodes in the NodeSet.
*/
bool isEmpty() const
{
return mStart ? mStart == mEnd : true;
}
/**
* Returns the number of elements in the NodeSet
* @return the number of elements in the NodeSet
*/
int32_t size() const
{
return mStart ? mEnd - mStart : 0;
}
TX_DECL_EXPRRESULT
private:
/**
* Ensure that this nodeset can take another aSize nodes.
*
* Changes mStart and mEnd as well as mBufferStart and mBufferEnd.
*/
bool ensureGrowSize(int32_t aSize);
/**
* Finds position in the buffer where a node should be inserted
* to keep the nodeset in document order. Searches the positions
* aFirst-aLast, including aFirst, but not aLast.
* @param aNode Node to find insert position for.
* @param aFirst First item of the search range, included.
* @param aLast Last item of the search range, excluded.
* @param aDupe out-param. Will be set to true if the node already
* exists in the NodeSet, false if it should be
* inserted.
* @return pointer where to insert the node. The node should be inserted
* before the given node. This value is always set, even if aNode
* already exists in the NodeSet
*/
txXPathNode* findPosition(const txXPathNode& aNode,
txXPathNode* aFirst,
txXPathNode* aLast, bool& aDupe) const;
static void copyElements(txXPathNode* aDest, const txXPathNode* aStart,
const txXPathNode* aEnd);
static void transferElements(txXPathNode* aDest, const txXPathNode* aStart,
const txXPathNode* aEnd);
static void destroyElements(const txXPathNode* aStart,
const txXPathNode* aEnd)
{
while (aStart < aEnd) {
aStart->~txXPathNode();
++aStart;
}
}
typedef void (*transferOp) (txXPathNode* aDest, const txXPathNode* aStart,
const txXPathNode* aEnd);
typedef void (*destroyOp) (const txXPathNode* aStart,
const txXPathNode* aEnd);
nsresult add(const txNodeSet& aNodes, transferOp aTransfer,
destroyOp aDestroy);
txXPathNode *mStart, *mEnd, *mStartBuffer, *mEndBuffer;
int32_t mDirection;
// used for mark() and sweep() in predicates
bool* mMarks;
};
#endif