utils/LocHeap.cpp - platform/hardware/qcom/gps - Gitiles

 /* Copyright (c) 2015, 2020 The Linux Foundation. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *     * Redistributions of source code must retain the above copyright
  *       notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  *       copyright notice, this list of conditions and the following
  *       disclaimer in the documentation and/or other materials provided
  *       with the distribution.
  *     * Neither the name of The Linux Foundation, nor the names of its
  *       contributors may be used to endorse or promote products derived
  *       from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
 #include <LocHeap.h>

 namespace loc_util {

 class LocHeapNode {
     friend class LocHeap;

     // size of of the subtree, excluding self, 1 if no subtree
     int mSize;
     LocHeapNode* mLeft;
     LocHeapNode* mRight;
     LocRankable* mData;
 public:
     inline LocHeapNode(LocRankable& data) :
         mSize(1), mLeft(NULL), mRight(NULL), mData(&data) {}
     ~LocHeapNode();

     // this only swaps the data of the two nodes, so no
     // detach / re-attached is necessary
     void swap(LocHeapNode& node);

     LocRankable* detachData();

     // push a node into the tree stucture, keeping sorted by rank
     void push(LocHeapNode& node);

     // pop the head node out of the tree stucture. keeping sorted by rank
     static LocHeapNode* pop(LocHeapNode*& top);

     // remove a specific node from the tree
     // returns the pointer to the node removed, which would be either the
     //         same as input (if successfully removed); or NULL (if failed).
     static LocHeapNode* remove(LocHeapNode*& top, LocRankable& data);

     // convenience method to compare data ranking
     inline bool outRanks(LocHeapNode& node) { return mData->outRanks(*node.mData); }
     inline bool outRanks(LocRankable& data) { return mData->outRanks(data); }

     // checks if mSize is correct, AND this node is the highest ranking
     // of the entire subtree
     bool checkNodes();

     inline int getSize() { return mSize; }
 };

 inline
 LocHeapNode::~LocHeapNode() {
     if (mLeft) {
         delete mLeft;
         mLeft = NULL;
     }
     if (mRight) {
         delete mRight;
         mRight = NULL;
     }
     if (mData) {
         mData = NULL;
     }
 }

 inline
 void LocHeapNode::swap(LocHeapNode& node) {
     LocRankable* tmpData = node.mData;
     node.mData = mData;
     mData = tmpData;
 }

 inline
 LocRankable* LocHeapNode::detachData()  {
     LocRankable* data = mData;
     mData = NULL;
     return data;
 }

 // push keeps the tree sorted by rank, it also tries to balance the
 // tree by adding the new node to the smaller of the subtrees.
 // The pointer to the tree and internal links never change. If the
 // mData of tree top ranks lower than that of the incoming node,
 // mData will be swapped with that of the incoming node to ensure
 // ranking, no restructuring the container nodes.
 void LocHeapNode::push(LocHeapNode& node) {
     // ensure the current node ranks higher than in the incoming one
     if (node.outRanks(*this)) {
         swap(node);
     }

     // now drop the new node (ensured lower than *this) into a subtree
     if (NULL == mLeft) {
         mLeft = &node;
     } else if (NULL == mRight) {
         mRight = &node;
     } else if (mLeft->mSize <= mRight->mSize) {
         mLeft->push(node);
     } else {
         mRight->push(node);
     }
     mSize++;
 }

 // pop keeps the tree sorted by rank, but it does not try to balance
 // the tree. It recursively swaps with the higher ranked top of the
 // subtrees.
 // The return is a popped out node from leaf level, that has the data
 // swapped all the way down from the top. The pinter to the tree and
 // internal links will not be changed or restructured, except for the
 // node that is popped out.
 // If the return pointer == this, this the last node in the tree.
 LocHeapNode* LocHeapNode::pop(LocHeapNode*& top) {
     // we know the top has the highest ranking at this point, else
     // the tree is broken. This top will be popped out.  But we need
     // a node from the left or right child, whichever ranks higher,
     // to replace the current top. This then will need to be done
     // recursively to the leaf level. So we swap the mData of the
     // current top node all the way down to the leaf level.
     LocHeapNode* poppedNode = top;
     // top is losing a node in its subtree
     top->mSize--;
     if (top->mLeft || top->mRight) {
         // if mLeft is NULL, mRight for sure is NOT NULL, take that;
         // else if mRight is NULL, mLeft for sure is NOT, take that;
         // else we take the address of whatever has higher ranking mData
         LocHeapNode*& subTop = (NULL == top->mLeft) ? top->mRight :
             ((NULL == top->mRight) ? top->mLeft :
              (top->mLeft->outRanks(*(top->mRight)) ? top->mLeft : top->mRight));
         // swap mData, the tree top gets updated with the new data.
         top->swap(*subTop);
         // pop out from the subtree
         poppedNode = pop(subTop);
     } else {
         // if the top has only single node
         // detach the poppedNode from the tree
         // subTop is the reference of ether mLeft or mRight
         // NOT a local stack pointer. so it MUST be NULL'ed here.
         top = NULL;
     }

     return poppedNode;
 }

 // navigating through the tree and find the node that hass the input
 // data. Since this is a heap, we do recursive linear search.
 // returns the pointer to the node removed, which would be either the
 //         same as input (if successfully removed); or NULL (if failed).
 LocHeapNode* LocHeapNode::remove(LocHeapNode*& top, LocRankable& data) {
     LocHeapNode* removedNode = NULL;
     // this is the node, by address
     if (&data == (LocRankable*)(top->mData)) {
         // pop this node out
         removedNode = pop(top);
     } else if (!data.outRanks(*top->mData)) {
         // subtrees might have this node
         if (top->mLeft) {
             removedNode = remove(top->mLeft, data);
         }
         // if we did not find in mLeft, and mRight is not empty
         if (!removedNode && top->mRight) {
             removedNode = remove(top->mRight, data);
         }

         // top lost a node in its subtree
         if (removedNode) {
             top->mSize--;
         }
     }

     return removedNode;
 }

 // checks if mSize is correct, AND this node is the highest ranking
 // of the entire subtree
 bool LocHeapNode::checkNodes() {
     // size of the current subtree
     int totalSize = mSize;
     if (mLeft) {
         // check the consistency of left subtree
         if (mLeft->outRanks(*this) || !mLeft->checkNodes()) {
             return false;
         }
         // subtract the size of left subtree (with subtree head)
         totalSize -= mLeft->mSize;
     }

     if (mRight) {
         // check the consistency of right subtree
         if (mRight->outRanks(*this) || !mRight->checkNodes()) {
             return false;
         }
         // subtract the size of right subtree (with subtree head)
         totalSize -= mRight->mSize;
     }

     // for the tree nodes to consistent, totalSize must be 1 now
     return totalSize == 1;
 }

 LocHeap::~LocHeap() {
     if (mTree) {
         delete mTree;
     }
 }

 void LocHeap::push(LocRankable& node) {
     LocHeapNode* heapNode = new LocHeapNode(node);
     if (!mTree) {
         mTree = heapNode;
     } else {
         mTree->push(*heapNode);
     }
 }

 LocRankable* LocHeap::peek() {
     LocRankable* top = NULL;
     if (mTree) {
         top = mTree->mData;
     }
     return top;
 }

 LocRankable* LocHeap::pop() {
     LocRankable* locNode = NULL;
     if (mTree) {
         // mTree may become NULL after this call
         LocHeapNode* heapNode = LocHeapNode::pop(mTree);
         locNode = heapNode->detachData();
         delete heapNode;
     }
     return locNode;
 }

 LocRankable* LocHeap::remove(LocRankable& rankable) {
     LocRankable* locNode = NULL;
     if (mTree) {
         // mTree may become NULL after this call
         LocHeapNode* heapNode = LocHeapNode::remove(mTree, rankable);
         if (heapNode) {
             locNode = heapNode->detachData();
             delete heapNode;
         }
     }
     return locNode;
 }

 } // namespace loc_util

 #ifdef __LOC_UNIT_TEST__
 bool LocHeap::checkTree() {
     return ((NULL == mTree) || mTree->checkNodes());
 }
 uint32_t LocHeap::getTreeSize() {
     return (NULL == mTree) ? 0 : mTree->getSize();
 }
 #endif
	/* Copyright (c) 2015, 2020 The Linux Foundation. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met:
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following
	* disclaimer in the documentation and/or other materials provided
	* with the distribution.
	* * Neither the name of The Linux Foundation, nor the names of its
	* contributors may be used to endorse or promote products derived
	* from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
	* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
	* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
	* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*
	*/
	#include <LocHeap.h>

	namespace loc_util {

	class LocHeapNode {
	friend class LocHeap;

	// size of of the subtree, excluding self, 1 if no subtree
	int mSize;
	LocHeapNode* mLeft;
	LocHeapNode* mRight;
	LocRankable* mData;
	public:
	inline LocHeapNode(LocRankable& data) :
	mSize(1), mLeft(NULL), mRight(NULL), mData(&data) {}
	~LocHeapNode();

	// this only swaps the data of the two nodes, so no
	// detach / re-attached is necessary
	void swap(LocHeapNode& node);

	LocRankable* detachData();

	// push a node into the tree stucture, keeping sorted by rank
	void push(LocHeapNode& node);

	// pop the head node out of the tree stucture. keeping sorted by rank
	static LocHeapNode* pop(LocHeapNode*& top);

	// remove a specific node from the tree
	// returns the pointer to the node removed, which would be either the
	// same as input (if successfully removed); or NULL (if failed).
	static LocHeapNode* remove(LocHeapNode*& top, LocRankable& data);

	// convenience method to compare data ranking
	inline bool outRanks(LocHeapNode& node) { return mData->outRanks(*node.mData); }
	inline bool outRanks(LocRankable& data) { return mData->outRanks(data); }

	// checks if mSize is correct, AND this node is the highest ranking
	// of the entire subtree
	bool checkNodes();

	inline int getSize() { return mSize; }
	};

	inline
	LocHeapNode::~LocHeapNode() {
	if (mLeft) {
	delete mLeft;
	mLeft = NULL;
	}
	if (mRight) {
	delete mRight;
	mRight = NULL;
	}
	if (mData) {
	mData = NULL;
	}
	}

	inline
	void LocHeapNode::swap(LocHeapNode& node) {
	LocRankable* tmpData = node.mData;
	node.mData = mData;
	mData = tmpData;
	}

	inline
	LocRankable* LocHeapNode::detachData() {
	LocRankable* data = mData;
	mData = NULL;
	return data;
	}

	// push keeps the tree sorted by rank, it also tries to balance the
	// tree by adding the new node to the smaller of the subtrees.
	// The pointer to the tree and internal links never change. If the
	// mData of tree top ranks lower than that of the incoming node,
	// mData will be swapped with that of the incoming node to ensure
	// ranking, no restructuring the container nodes.
	void LocHeapNode::push(LocHeapNode& node) {
	// ensure the current node ranks higher than in the incoming one
	if (node.outRanks(*this)) {
	swap(node);
	}

	// now drop the new node (ensured lower than *this) into a subtree
	if (NULL == mLeft) {
	mLeft = &node;
	} else if (NULL == mRight) {
	mRight = &node;
	} else if (mLeft->mSize <= mRight->mSize) {
	mLeft->push(node);
	} else {
	mRight->push(node);
	}
	mSize++;
	}

	// pop keeps the tree sorted by rank, but it does not try to balance
	// the tree. It recursively swaps with the higher ranked top of the
	// subtrees.
	// The return is a popped out node from leaf level, that has the data
	// swapped all the way down from the top. The pinter to the tree and
	// internal links will not be changed or restructured, except for the
	// node that is popped out.
	// If the return pointer == this, this the last node in the tree.
	LocHeapNode* LocHeapNode::pop(LocHeapNode*& top) {
	// we know the top has the highest ranking at this point, else
	// the tree is broken. This top will be popped out. But we need
	// a node from the left or right child, whichever ranks higher,
	// to replace the current top. This then will need to be done
	// recursively to the leaf level. So we swap the mData of the
	// current top node all the way down to the leaf level.
	LocHeapNode* poppedNode = top;
	// top is losing a node in its subtree
	top->mSize--;
	if (top->mLeft \|\| top->mRight) {
	// if mLeft is NULL, mRight for sure is NOT NULL, take that;
	// else if mRight is NULL, mLeft for sure is NOT, take that;
	// else we take the address of whatever has higher ranking mData
	LocHeapNode*& subTop = (NULL == top->mLeft) ? top->mRight :
	((NULL == top->mRight) ? top->mLeft :
	(top->mLeft->outRanks(*(top->mRight)) ? top->mLeft : top->mRight));
	// swap mData, the tree top gets updated with the new data.
	top->swap(*subTop);
	// pop out from the subtree
	poppedNode = pop(subTop);
	} else {
	// if the top has only single node
	// detach the poppedNode from the tree
	// subTop is the reference of ether mLeft or mRight
	// NOT a local stack pointer. so it MUST be NULL'ed here.
	top = NULL;
	}

	return poppedNode;
	}

	// navigating through the tree and find the node that hass the input
	// data. Since this is a heap, we do recursive linear search.
	// returns the pointer to the node removed, which would be either the
	// same as input (if successfully removed); or NULL (if failed).
	LocHeapNode* LocHeapNode::remove(LocHeapNode*& top, LocRankable& data) {
	LocHeapNode* removedNode = NULL;
	// this is the node, by address
	if (&data == (LocRankable*)(top->mData)) {
	// pop this node out
	removedNode = pop(top);
	} else if (!data.outRanks(*top->mData)) {
	// subtrees might have this node
	if (top->mLeft) {
	removedNode = remove(top->mLeft, data);
	}
	// if we did not find in mLeft, and mRight is not empty
	if (!removedNode && top->mRight) {
	removedNode = remove(top->mRight, data);
	}

	// top lost a node in its subtree
	if (removedNode) {
	top->mSize--;
	}
	}

	return removedNode;
	}

	// checks if mSize is correct, AND this node is the highest ranking
	// of the entire subtree
	bool LocHeapNode::checkNodes() {
	// size of the current subtree
	int totalSize = mSize;
	if (mLeft) {
	// check the consistency of left subtree
	if (mLeft->outRanks(*this) \|\| !mLeft->checkNodes()) {
	return false;
	}
	// subtract the size of left subtree (with subtree head)
	totalSize -= mLeft->mSize;
	}

	if (mRight) {
	// check the consistency of right subtree
	if (mRight->outRanks(*this) \|\| !mRight->checkNodes()) {
	return false;
	}
	// subtract the size of right subtree (with subtree head)
	totalSize -= mRight->mSize;
	}

	// for the tree nodes to consistent, totalSize must be 1 now
	return totalSize == 1;
	}

	LocHeap::~LocHeap() {
	if (mTree) {
	delete mTree;
	}
	}

	void LocHeap::push(LocRankable& node) {
	LocHeapNode* heapNode = new LocHeapNode(node);
	if (!mTree) {
	mTree = heapNode;
	} else {
	mTree->push(*heapNode);
	}
	}

	LocRankable* LocHeap::peek() {
	LocRankable* top = NULL;
	if (mTree) {
	top = mTree->mData;
	}
	return top;
	}

	LocRankable* LocHeap::pop() {
	LocRankable* locNode = NULL;
	if (mTree) {
	// mTree may become NULL after this call
	LocHeapNode* heapNode = LocHeapNode::pop(mTree);
	locNode = heapNode->detachData();
	delete heapNode;
	}
	return locNode;
	}

	LocRankable* LocHeap::remove(LocRankable& rankable) {
	LocRankable* locNode = NULL;
	if (mTree) {
	// mTree may become NULL after this call
	LocHeapNode* heapNode = LocHeapNode::remove(mTree, rankable);
	if (heapNode) {
	locNode = heapNode->detachData();
	delete heapNode;
	}
	}
	return locNode;
	}

	} // namespace loc_util

	#ifdef __LOC_UNIT_TEST__
	bool LocHeap::checkTree() {
	return ((NULL == mTree) \|\| mTree->checkNodes());
	}
	uint32_t LocHeap::getTreeSize() {
	return (NULL == mTree) ? 0 : mTree->getSize();
	}
	#endif