Exemple #1
0
//this function is useful for search and modify, and range-query 
ISNode*		//return the first key's position that >= *_key
ISTree::find(int _key, int* _store, bool ifmodify)
{											//to assign value for this->bstr, function shouldn't be const!
	if (this->root == NULL)
		return NULL;						//ISTree Is Empty
	ISNode* p = root;
	int i, j;
	while (!p->isLeaf())
	{
		if (ifmodify)
			p->setDirty();
		//j = p->getNum();
		//for(i = 0; i < j; ++i)				//BETTER(Binary-Search)
		//if(bstr < *(p->getKey(i)))
		//break;
		i = p->searchKey_less(_key);

		p = p->getChild(i);
		this->prepare(p);
	}

	j = p->getNum();
	//for(i = 0; i < j; ++i)
	//if(bstr <= *(p->getKey(i)))
	//break;
	i = p->searchKey_lessEqual(_key);

	if (i == j)
		*_store = -1;	//Not Found
	else
		*_store = i;
	return p;
}
Exemple #2
0
bool	//special case: not exist, one-edge-case
ISTree::range_query(int _key1, int _key2)
{		//the range is: *_key1 <= x < *_key2 	
		//if(_key1 <0 && _key2 <0)
		//return false;
		//ok to search one-edge, requiring only one be negative
		//find and write value
	int store1, store2;
	ISNode *p1, *p2;
	if (_key1 >= 0)
	{
		request = 0;
		p1 = this->find(_key1, &store1, false);
		if (p1 == NULL || store1 == -1)
			return false;	//no element
		this->TSM->request(request);
	}
	else
	{
		p1 = this->leaves_head;
		store1 = 0;
	}
	if (_key2 >= 0)
	{		//QUERY: another strategy is to getnext and compare every time to tell end
		request = 0;
		p2 = this->find(_key2, &store2, false);
		if (p2 == NULL)
			return false;
		else if (store2 == -1)
			store2 = p2->getNum();
		else if (store2 == 0)
		{
			p2 = p2->getPrev();
			if (p2 == NULL)
				return false;		//no element
			store2 = p2->getNum();
		}
		this->TSM->request(request);
	}
	else
	{
		p2 = this->leaves_tail;
		store2 = p2->getNum();
	}

	ISNode* p = p1;
	unsigned i, l, r;
	//get the num of answers first, not need to prepare the node
	unsigned ansNum = 0;
	while (true)
	{
		//request = 0;
		//this->prepare(p);
		if (p == p1)
			l = store1;
		else
			l = 0;
		if (p == p2)
			r = store2;
		else
			r = p->getNum();
		ansNum += (r - l);
		//this->TSM->request(request);
		if (p != p2)
			p = p->getNext();
		else
			break;
	}

	if (this->stream != NULL)
	{
		delete this->stream;
		this->stream = NULL;
	}
	vector<int> keys;
	vector<bool> desc;
	this->stream = new Stream(keys, desc, ansNum, 1, false);

	p = p1;
	while (1)
	{
		request = 0;
		this->prepare(p);
		if (p == p1)
			l = store1;
		else
			l = 0;
		if (p == p2)
			r = store2;
		else
			r = p->getNum();
		for (i = l; i < r; ++i)
		{
			//NOTICE:Bstr* in an array, used as Bstr[]
			this->stream->write(p->getValue(i));
		}
		this->TSM->request(request);
		if (p != p2)
			p = p->getNext();
		else
			break;
	}
	this->stream->setEnd();
	return true;
}
Exemple #3
0
bool
ISTree::remove(int _key)
{
	if (_key < 0)
	{
		printf("error in ISTree-remove: empty string\n");
		return false;
	}

	this->request = 0;
	ISNode* ret;
	if (this->root == NULL)	//tree is empty
		return false;

	ISNode* p = this->root;
	ISNode* q;
	int i, j;
	while (!p->isLeaf())
	{
		j = p->getNum();
		//for(i = 0; i < j; ++i)
		//if(bstr < *(p->getKey(i)))
		//break;
		i = p->searchKey_less(_key);

		q = p->getChild(i);
		this->prepare(q);
		if (q->getNum() < ISNode::MIN_CHILD_NUM)	//==MIN_KEY_NUM
		{
			if (i > 0)
				this->prepare(p->getChild(i - 1));
			if (i < j)
				this->prepare(p->getChild(i + 1));
			ret = q->coalesce(p, i);
			if (ret != NULL)
				this->TSM->updateHeap(ret, 0, true);//non-sense node
			this->TSM->updateHeap(q, q->getRank(), true);
			if (q->isLeaf())
			{
				if (q->getPrev() == NULL)
					this->leaves_head = q;
				if (q->getNext() == NULL)
					this->leaves_tail = q;
			}
			if (p->getNum() == 0)		//root shrinks
			{
				//this->leaves_head = q;
				this->root = q;
				this->TSM->updateHeap(p, 0, true);	//instead of delete p				
				this->height--;
			}
		}
		else
			p->setDirty();
		this->TSM->updateHeap(p, p->getRank(), true);
		p = q;
	}
	bool flag = false;
	//j = p->getNum();		//LeafNode(maybe root)
	//for(i = 0; i < j; ++i)
	//	if(bstr == *(p->getKey(i)))
	//	{
	//		request -= p->getKey(i)->getLen();
	//		request -= p->getValue(i)->getLen();
	//		p->subKey(i, true);		//to release
	//		p->subValue(i, true);	//to release
	//		p->subNum();
	//		if(p->getNum() == 0)	//root leaf 0 key
	//		{
	//			this->root = NULL;
	//			this->leaves_head = NULL;
	//			this->leaves_tail = NULL;
	//			this->height = 0;
	//			this->TSM->updateHeap(p, 0, true);	//instead of delete p
	//		}
	//		p->setDirty();
	//		flag = true;
	//		break;
	//	}
	i = p->searchKey_equal(_key);
	//WARN+NOTICE:here must check, because the key to remove maybe not exist
	if (i != (int)p->getNum())
	{
		request -= p->getValue(i)->getLen();
		p->subKey(i);		//to release
		p->subValue(i, true);	//to release
		p->subNum();
		if (p->getNum() == 0)	//root leaf 0 key
		{
			this->root = NULL;
			this->leaves_head = NULL;
			this->leaves_tail = NULL;
			this->height = 0;
			this->TSM->updateHeap(p, 0, true);	//instead of delete p
		}
		p->setDirty();
		flag = true;
	}

	this->TSM->request(request);
	return flag;		//i == j, not found		
}
Exemple #4
0
bool
ISTree::insert(int _key, const char* _str, unsigned _len)
{
	if (_key < 0)
	{
		printf("error in ISTree-insert: empty string\n");
		return false;
	}

	this->CopyToTransfer(_str, _len, 2);
	const Bstr* val = &(this->transfer[2]);
	this->request = 0;
	ISNode* ret;
	if (this->root == NULL)	//tree is empty
	{
		leaves_tail = leaves_head = root = new ISLeafNode;
		request += ISNode::LEAF_SIZE;
		this->height = 1;
		root->setHeight(1);	//add to heap later
	}

	//this->prepare(this->root); //root must be in-mem
	if (root->getNum() == ISNode::MAX_KEY_NUM)
	{
		ISNode* father = new ISIntlNode;
		request += ISNode::INTL_SIZE;
		father->addChild(root, 0);
		ret = root->split(father, 0);
		if (ret->isLeaf() && ret->getNext() == NULL)
			this->leaves_tail = ret;
		if (ret->isLeaf())
			request += ISNode::LEAF_SIZE;
		else
			request += ISNode::INTL_SIZE;
		this->height++;		//height rises only when root splits
							//WARN: height area in Node: 4 bit!
		father->setHeight(this->height);	//add to heap later
		this->TSM->updateHeap(ret, ret->getRank(), false);
		this->root = father;
	}

	ISNode* p = this->root;
	ISNode* q;
	int i;
	while (!p->isLeaf())
	{
		//j = p->getNum();
		//for(i = 0; i < j; ++i)
		//if(bstr < *(p->getKey(i)))
		//break;
		//NOTICE: using binary search is better here
		i = p->searchKey_less(_key);

		q = p->getChild(i);
		this->prepare(q);
		if (q->getNum() == ISNode::MAX_KEY_NUM)
		{
			ret = q->split(p, i);
			if (ret->isLeaf() && ret->getNext() == NULL)
				this->leaves_tail = ret;
			if (ret->isLeaf())
				request += ISNode::LEAF_SIZE;
			else
				request += ISNode::INTL_SIZE;
			//BETTER: in loop may update multiple times
			this->TSM->updateHeap(ret, ret->getRank(), false);
			this->TSM->updateHeap(q, q->getRank(), true);
			this->TSM->updateHeap(p, p->getRank(), true);
			if (_key < p->getKey(i))
				p = q;
			else
				p = ret;
		}
		else
		{
			p->setDirty();
			this->TSM->updateHeap(p, p->getRank(), true);
			p = q;
		}
	}
	//j = p->getNum();
	//for(i = 0; i < j; ++i)
	//if(bstr < *(p->getKey(i)))
	//break;
	i = p->searchKey_less(_key);

	//insert existing key is ok, but not inserted in
	//however, the tree-shape may change due to possible split in former code
	bool ifexist = false;
	if (i > 0 && _key == p->getKey(i - 1))
		ifexist = true;
	else
	{
		p->addKey(_key, i);
		p->addValue(val, i, true);
		p->addNum();
		request += val->getLen();
		p->setDirty();
		this->TSM->updateHeap(p, p->getRank(), true);
		//_key->clear();
		//_value->clear();
	}
	this->TSM->request(request);
	return !ifexist;		//QUERY(which case:return false)
}