txNodeSet.h (6687B)
1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* This Source Code Form is subject to the terms of the Mozilla Public 3 * License, v. 2.0. If a copy of the MPL was not distributed with this 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 5 6 /** 7 * Implementation of an XPath NodeSet 8 */ 9 10 #ifndef txNodeSet_h__ 11 #define txNodeSet_h__ 12 13 #include "nsError.h" 14 #include "txExprResult.h" 15 #include "txXPathNode.h" 16 17 class txNodeSet : public txAExprResult { 18 public: 19 /** 20 * Creates a new empty NodeSet 21 */ 22 explicit txNodeSet(txResultRecycler* aRecycler); 23 24 /** 25 * Creates a new NodeSet with one node. 26 */ 27 txNodeSet(const txXPathNode& aNode, txResultRecycler* aRecycler); 28 29 /** 30 * Creates a new txNodeSet, copying the node references from the source 31 * NodeSet. 32 */ 33 txNodeSet(const txNodeSet& aSource, txResultRecycler* aRecycler); 34 35 /** 36 * Destructor for txNodeSet, deletes the nodes. 37 */ 38 virtual ~txNodeSet(); 39 40 /** 41 * Adds the specified txXPathNode to this NodeSet if it is not already 42 * in this NodeSet. The node is inserted according to document order. 43 * 44 * @param aNode the txXPathNode to add to the NodeSet 45 * @return errorcode. 46 */ 47 nsresult add(const txXPathNode& aNode) { return add(txXPathNode(aNode)); } 48 nsresult add(txXPathNode&& aNode); 49 50 /** 51 * Adds the nodes in specified NodeSet to this NodeSet. The resulting 52 * NodeSet is sorted in document order and does not contain any duplicate 53 * nodes. 54 * 55 * @param aNodes the NodeSet to add, must be in document order. 56 * @return errorcode. 57 */ 58 nsresult add(const txNodeSet& aNodes); 59 nsresult addAndTransfer(txNodeSet* aNodes); 60 61 /** 62 * Append API 63 * These functions should be used with care. 64 * They are intended to be used when the caller assures that the resulting 65 * NodeSet remains in document order. 66 * Abuse will break document order, and cause errors in the result. 67 * These functions are significantly faster than the add API, as no 68 * order info operations will be performed. 69 */ 70 71 /** 72 * Appends the specified Node to the end of this NodeSet 73 * @param aNode the Node to append to the NodeSet 74 * @return errorcode. 75 */ 76 nsresult append(const txXPathNode& aNode) { 77 return append(txXPathNode(aNode)); 78 } 79 nsresult append(txXPathNode&& aNode); 80 81 /** 82 * Appends the nodes in the specified NodeSet to the end of this NodeSet 83 * @param aNodes the NodeSet to append to the NodeSet 84 * @return errorcode. 85 */ 86 nsresult append(const txNodeSet& aNodes); 87 88 /** 89 * API to implement reverse axes in LocationStep. 90 * 91 * Before adding nodes to the nodeset for a reversed axis, call 92 * setReverse(). This will make the append(aNode) and get() methods treat 93 * the nodeset as required. Do only call append(aNode), get(), mark() 94 * and sweep() while the nodeset is reversed. 95 * Afterwards, call unsetReverse(). The nodes are stored in document 96 * order internally. 97 */ 98 void setReverse() { mDirection = -1; } 99 void unsetReverse() { mDirection = 1; } 100 101 /** 102 * API to implement predicates in PredicateExpr 103 * 104 * mark(aIndex) marks the specified member of the nodeset. 105 * sweep() clears all members of the nodeset that haven't been 106 * marked before and clear the mMarks array. 107 */ 108 nsresult mark(int32_t aIndex); 109 nsresult sweep(); 110 111 /** 112 * Removes all nodes from this nodeset 113 */ 114 void clear(); 115 116 /** 117 * Returns the index of the specified Node, 118 * or -1 if the Node is not contained in the NodeSet 119 * @param aNode the Node to get the index for 120 * @param aStart index to start searching at 121 * @return index of specified node or -1 if the node does not exist 122 */ 123 int32_t indexOf(const txXPathNode& aNode, uint32_t aStart = 0) const; 124 125 /** 126 * Returns true if the specified Node is contained in the set. 127 * @param aNode the Node to search for 128 * @return true if specified Node is contained in the NodeSet 129 */ 130 bool contains(const txXPathNode& aNode) const { return indexOf(aNode) >= 0; } 131 132 /** 133 * Returns the Node at the specified node in this NodeSet. 134 * @param aIndex the node of the Node to return 135 * @return Node at specified node 136 */ 137 const txXPathNode& get(int32_t aIndex) const; 138 139 /** 140 * Returns true if there are no Nodes in the NodeSet. 141 * @return true if there are no Nodes in the NodeSet. 142 */ 143 bool isEmpty() const { return mStart ? mStart == mEnd : true; } 144 145 /** 146 * Returns the number of elements in the NodeSet 147 * @return the number of elements in the NodeSet 148 */ 149 int32_t size() const { return mStart ? mEnd - mStart : 0; } 150 151 TX_DECL_EXPRRESULT 152 153 private: 154 /** 155 * Ensure that this nodeset can take another aSize nodes. 156 * 157 * Changes mStart and mEnd as well as mBufferStart and mBufferEnd. 158 */ 159 bool ensureGrowSize(int32_t aSize); 160 161 /** 162 * Finds position in the buffer where a node should be inserted 163 * to keep the nodeset in document order. Searches the positions 164 * aFirst-aLast, including aFirst, but not aLast. 165 * @param aNode Node to find insert position for. 166 * @param aFirst First item of the search range, included. 167 * @param aLast Last item of the search range, excluded. 168 * @param aDupe out-param. Will be set to true if the node already 169 * exists in the NodeSet, false if it should be 170 * inserted. 171 * @return pointer where to insert the node. The node should be inserted 172 * before the given node. This value is always set, even if aNode 173 * already exists in the NodeSet 174 */ 175 txXPathNode* findPosition(const txXPathNode& aNode, txXPathNode* aFirst, 176 txXPathNode* aLast, bool& aDupe) const; 177 178 static void copyElements(txXPathNode* aDest, const txXPathNode* aStart, 179 const txXPathNode* aEnd); 180 static void transferElements(txXPathNode* aDest, const txXPathNode* aStart, 181 const txXPathNode* aEnd); 182 static void destroyElements(const txXPathNode* aStart, 183 const txXPathNode* aEnd) { 184 while (aStart < aEnd) { 185 aStart->~txXPathNode(); 186 ++aStart; 187 } 188 } 189 190 using transferOp = void (*)(txXPathNode* aDest, const txXPathNode* aStart, 191 const txXPathNode* aEnd); 192 using destroyOp = void (*)(const txXPathNode* aStart, 193 const txXPathNode* aEnd); 194 nsresult add(const txNodeSet& aNodes, transferOp aTransfer, 195 destroyOp aDestroy); 196 197 txXPathNode *mStart, *mEnd, *mStartBuffer, *mEndBuffer; 198 int32_t mDirection; 199 // used for mark() and sweep() in predicates 200 bool* mMarks; 201 }; 202 203 #endif