gStore/KVstore/SITree/SITree.cpp

/*=============================================================================
# Filename: SITree.cpp
# Author: syzz
# Mail: 1181955272@qq.com
# Last Modified: 2015-04-26 16:45
# Description: achieve functions in SITree.h
=============================================================================*/

#include "SITree.h"

using namespace std;

SITree::SITree()
{
	height = 0;
	mode = "";
	root = NULL;
	leaves_head = NULL;
	leaves_tail = NULL;
	TSM = NULL;
	storepath = "";
	filename = "";
	transfer_size[0] = transfer_size[1] = transfer_size[2] = 0;
	this->request = 0;
}

SITree::SITree(string _storepath, string _filename, string _mode, unsigned long long _buffer_size)
{
	storepath = _storepath;
	filename = _filename;
	this->height = 0;
	this->mode = string(_mode);
	string filepath = this->getFilePath();
	TSM = new SIStorage(filepath, this->mode, &this->height, _buffer_size);
	if (this->mode == "open")
		this->TSM->preRead(this->root, this->leaves_head, this->leaves_tail);
	else
		this->root = NULL;
	this->transfer[0].setStr((char*)malloc(Util::TRANSFER_SIZE));
	this->transfer[1].setStr((char*)malloc(Util::TRANSFER_SIZE));
	this->transfer[2].setStr((char*)malloc(Util::TRANSFER_SIZE));
	this->transfer_size[0] = this->transfer_size[1] = this->transfer_size[2] = Util::TRANSFER_SIZE;		//initialied to 1M
	this->request = 0;
}

string
SITree::getFilePath()
{
	return storepath + "/" + filename;
}

void			//WARN: not check _str and _len
SITree::CopyToTransfer(const char* _str, unsigned _len, unsigned _index)
{
	if (_index > 2)
		return;
	/*
	if(_str == NULL || _len == 0)
	{
	printf("error in CopyToTransfer: empty string\n");
	return;
	}
	*/
	//unsigned length = _bstr->getLen();
	unsigned length = _len;
	if (length + 1 > this->transfer_size[_index])
	{
		transfer[_index].release();
		transfer[_index].setStr((char*)malloc(length + 1));
		this->transfer_size[_index] = length + 1;	//one more byte: convenient to add \0
	}
	memcpy(this->transfer[_index].getStr(), _str, length);
	this->transfer[_index].getStr()[length] = '\0';	//set for string() in KVstore
	this->transfer[_index].setLen(length);
}

unsigned
SITree::getHeight() const
{
	return this->height;
}

void
SITree::setHeight(unsigned _h)
{
	this->height = _h;
}

SINode*
SITree::getRoot() const
{
	return this->root;
}

void
SITree::prepare(SINode* _np)
{
	//this->request = 0;
	bool flag = _np->inMem();
	if (!flag)
		this->TSM->readNode(_np, &request);	//readNode deal with request
}

bool
SITree::search(const char* _str, unsigned _len, unsigned* _val)
{
	if (_str == NULL || _len == 0)
	{
		printf("error in SITree-search: empty string\n");
		//*_val = -1;
		return false;
	}
	this->CopyToTransfer(_str, _len, 1);

	request = 0;
	Bstr bstr = this->transfer[1];	//not to modify its memory
	int store;
	SINode* ret = this->find(&transfer[1], &store, false);
	if (ret == NULL || store == -1 || bstr != *(ret->getKey(store)))	//tree is empty or not found
	{
		bstr.clear();
		return false;
	}
	*_val = ret->getValue(store);
	this->TSM->request(request);
	bstr.clear();

	return true;
}

bool
SITree::insert(const char* _str, unsigned _len, unsigned _val)
{
	if (_str == NULL || _len == 0)
	{
		printf("error in SITree-insert: empty string\n");
		return false;
	}
	this->CopyToTransfer(_str, _len, 1);

	this->request = 0;
	SINode* ret;
	if (this->root == NULL)	//tree is empty
	{
		leaves_tail = leaves_head = root = new SILeafNode;
		request += SINode::LEAF_SIZE;
		this->height = 1;
		root->setHeight(1);	//add to heap later
	}

	//this->prepare(this->root); //root must be in-mem
	if (root->getNum() == SINode::MAX_KEY_NUM)
	{
		SINode* father = new SIIntlNode;
		request += SINode::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 += SINode::LEAF_SIZE;
		else
			request += SINode::INTL_SIZE;
		this->height++;		//height rises only when root splits
		//WARN: height area in SINode: 4 bit!
		father->setHeight(this->height);	//add to heap later
		this->TSM->updateHeap(ret, ret->getRank(), false);
		this->root = father;
	}

	SINode* p = this->root;
	SINode* q;
	int i;
	const Bstr* _key = &transfer[1];
	Bstr bstr = *_key;
	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(bstr);

		q = p->getChild(i);
		this->prepare(q);
		if (q->getNum() == SINode::MAX_KEY_NUM)
		{
			ret = q->split(p, i);
			if (ret->isLeaf() && ret->getNext() == NULL)
				this->leaves_tail = ret;
			if (ret->isLeaf())
				request += SINode::LEAF_SIZE;
			else
				request += SINode::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 (bstr < *(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(bstr);

	//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 && bstr == *(p->getKey(i - 1)))
		ifexist = true;
	else
	{
		p->addKey(_key, i, true);
		p->addValue(_val, i);
		p->addNum();
		request += _key->getLen();
		p->setDirty();
		this->TSM->updateHeap(p, p->getRank(), true);
	}
	this->TSM->request(request);
	bstr.clear();		//NOTICE: must be cleared!

	return !ifexist;		//QUERY(which case:return false)
}

bool
SITree::modify(const char* _str, unsigned _len, unsigned _val)
{
	if (_str == NULL || _len == 0)
	{
		printf("error in SITree-modify: empty string\n");
		return false;
	}
	this->CopyToTransfer(_str, _len, 1);

	this->request = 0;
	const Bstr* _key = &transfer[1];
	Bstr bstr = *_key;
	int store;
	SINode* ret = this->find(_key, &store, true);
	if (ret == NULL || store == -1 || bstr != *(ret->getKey(store)))	//tree is empty or not found
	{
		bstr.clear();
		return false;
	}
	ret->setValue(_val, store);
	ret->setDirty();
	this->TSM->request(request);
	bstr.clear();

	return true;
}

//this function is useful for search and modify, and range-query 
SINode*		//return the first key's position that >= *_key
SITree::find(const Bstr* _key, int* _store, bool ifmodify)
{											//to assign value for this->bstr, function shouldn't be const!
	if (this->root == NULL)
		return NULL;						//SITree Is Empty
	SINode* p = root;
	int i, j;
	Bstr bstr = *_key;					//local Bstr: multiple delete
	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(bstr);

		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(bstr);

	if (i == j)
		*_store = -1;	//Not Found
	else
		*_store = i;
	bstr.clear();

	return p;
}

/*
SINode*
SITree::find(unsigned _len, const char* _str, int* store) const
{
}
*/

bool
SITree::remove(const char* _str, unsigned _len)
{
	if (_str == NULL || _len == 0)
	{
		printf("error in SITree-remove: empty string\n");
		return false;
	}
	this->CopyToTransfer(_str, _len, 1);

	request = 0;
	const Bstr* _key = &transfer[1];
	SINode* ret;
	if (this->root == NULL)	//tree is empty
		return false;
	SINode* p = this->root;
	SINode* q;
	int i, j;
	Bstr bstr = *_key;
	while (!p->isLeaf())
	{
		j = p->getNum();
		//for(i = 0; i < j; ++i)
		//if(bstr < *(p->getKey(i)))
		//break;
		i = p->searchKey_less(bstr);

		q = p->getChild(i);
		this->prepare(q);
		if (q->getNum() < SINode::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;
	i = p->searchKey_equal(bstr);
	//WARN+NOTICE:here must check, because the key to remove maybe not exist
	if (i != (int)p->getNum())
	{
		request -= p->getKey(i)->getLen();
		p->subKey(i, true);		//to release
		p->subValue(i);	//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);
	bstr.clear();

	return flag;		//i == j, not found		
}

bool
SITree::save()	//save the whole tree to disk
{
#ifdef DEBUG_KVSTORE
	printf("now to save tree!\n");
#endif
	if (TSM->writeTree(this->root))
		return true;
	else
		return false;
}

void
SITree::release(SINode* _np) const
{
	if (_np == NULL)	return;
	if (_np->isLeaf())
	{
		delete _np;
		return;
	}
	int cnt = _np->getNum();
	for (; cnt >= 0; --cnt)
		release(_np->getChild(cnt));
	delete _np;
}

SITree::~SITree()
{
	delete TSM;
#ifdef DEBUG_KVSTORE
	printf("already empty the buffer, now to delete all nodes in tree!\n");
#endif
	//recursively delete each SINode
	release(root);
}

void
SITree::print(string s)
{
#ifdef DEBUG_KVSTORE
	fputs(Util::showtime().c_str(), Util::debug_kvstore);
	fputs("Class SITree\n", Util::debug_kvstore);
	fputs("Message: ", Util::debug_kvstore);
	fputs(s.c_str(), Util::debug_kvstore);
	fputs("\n", Util::debug_kvstore);
	fprintf(Util::debug_kvstore, "Height: %d\n", this->height);
	if (s == "tree" || s == "TREE")
	{
		if (this->root == NULL)
		{
			fputs("Null SITree\n", Util::debug_kvstore);
			return;
		}
		SINode** ns = new SINode*[this->height];
		int* ni = new int[this->height];
		SINode* np;
		int i, pos = 0;
		ns[pos] = this->root;
		ni[pos] = this->root->getNum();
		pos++;
		while (pos > 0)
		{
			np = ns[pos - 1];
			i = ni[pos - 1];
			this->prepare(np);
			if (np->isLeaf() || i < 0)	//LeafSINode or ready IntlNode
			{							//child-num ranges: 0~num
				if (s == "tree")
					np->print("node");
				else
					np->print("NODE");	//print full node-information
				pos--;
				continue;
			}
			else
			{
				ns[pos] = np->getChild(i);
				ni[pos - 1]--;
				ni[pos] = ns[pos]->getNum();
				pos++;
			}
		}
		delete[] ns;
		delete[] ni;
	}
	else if (s == "LEAVES" || s == "leaves")
	{
		SINode* np;
		for (np = this->leaves_head; np != NULL; np = np->getNext())
		{
			this->prepare(np);
			if (s == "leaves")
				np->print("node");
			else
				np->print("NODE");
		}
	}
	else if (s == "check tree")
	{
		//check the tree, if satisfy B+ definition
		//TODO	
	}
	else;
#endif
}