gStore/KVstore/Btree.cpp

/*
 * Btree.cpp
 *
 *  Created on: 2014-4-18
 *      Author: liyouhuan
 */
#include "Btree.h"
Btree::Btree(const string& _store_path, const string& _file_name, const char* _mode){
	mode = string(_mode);
	storePath = _store_path;
	fileName = _file_name;
	btree = NULL;

	string _tmp_init = "1234567890";
	this->value_transfer = new bstr(_tmp_init.c_str(), _tmp_init.length());
	this->value_transfer_max_len = _tmp_init.length();

	string _btree_path = _store_path + "/" + fileName;
	bool _open_ok = false;
	if(strcmp(_mode, "r") == 0){//read-only, btree must exist
		_open_ok = openRead(_btree_path);
	}
	else
	if(strcmp(_mode, "rw") == 0){//read and write, btree must exist
		_open_ok = openReadWrite(_btree_path);
	}
	else
	if(strcmp(_mode, "w") == 0){//build a new btree, delete if exist
		_open_ok = openWrite(_btree_path);
	}
	else
	{
		cout << "[" << _mode << "] is error mode when open: " << _btree_path << endl;
	}
	{
		if(_open_ok)
		{
			btree ->log("new Btree\n");
		}
		else
		{
			btree ->log(("open failed: "+_file_name).c_str());
		}
	}
}
Btree::~Btree(){
	delete this->value_transfer;
	this->value_transfer_max_len = 0;
	delete btree;
	btree = NULL;
}
bool Btree::insert(const bstr& _key, const bstr& _val){
	mleafdata _mdata;
	_mdata.set_sKey_sValue(_key.str, _key.len, _val.str, _val.len);
	return btree ->Insert(_mdata);
}
bool Btree::insert(const char* _key, int _klen, const char* _val, int _vlen){
	mleafdata _mdata;
	_mdata.mData.sKey = (char*)_key;
	_mdata.mData.mLenKey = _klen;
	_mdata.pVal = new mValue();
	_mdata.pVal->Term[0] = (char*)_val;
	_mdata.pVal->lenTerm[0] = _vlen;


	bool _insert =  btree ->Insert(_mdata);

	_mdata.mData.sKey = NULL;
	_mdata.mData.mLenKey = 0;
	_mdata.pVal->Term[0] = NULL;
	_mdata.pVal->lenTerm[0] = 0;
	delete _mdata.pVal;
	_mdata.pVal = NULL;

	return _insert;
}
bool Btree::search(const char* _key, int _klen, char*& _val, int & _vlen)const{
	KeyType _k;
	_k.sKey = (char*)_key;
	_k.mLenKey = _klen;


	mleafdata _mdata;
	/* pVal of _mdata is got by assign_val_ptr,
	 * so in this function, we should not release pVal */
	bool _search = btree ->Search(_k, _mdata);
	if(!_search){
		_val = NULL;
		_vlen = 0;
		_k.sKey = NULL;
		_k.mLenKey = 0;
		_mdata.pVal = NULL;
		return false;
	}
	_vlen = _mdata.pVal->lenTerm[0];
	_val = new char[_vlen+1];
	memcpy(_val, _mdata.pVal->Term[0], _vlen);
	_val[_vlen]='\0';
	/* pVal is got by assign_val_ptr,
	 * so here should not release pVal */
	_mdata.pVal = NULL;
	_k.sKey = NULL;
	_k.mLenKey = 0;

	return true;
}

bool Btree::search(const char* _key, int _klen)
{

	KeyType _k;
	_k.sKey = (char*)_key;
	_k.mLenKey = _klen;


	mleafdata _mdata;
	/* pVal of _mdata is got by assign_val_ptr,
	 * so in this function, we should not release pVal */
	bool _search = btree ->Search(_k, _mdata);
	if(!_search){
		_k.sKey = NULL;
		_k.mLenKey = 0;
		return false;
	}

	if( this->value_transfer_max_len < _mdata.pVal->lenTerm[0] )
	{
		delete[] (this->value_transfer);
		this->value_transfer = new bstr(_mdata.pVal->Term[0], _mdata.pVal->lenTerm[0]);
		this->value_transfer_max_len = _mdata.pVal->lenTerm[0];
	}
	else
	{
		(this->value_transfer)->len = _mdata.pVal->lenTerm[0];
		memcpy((this->value_transfer)->str, _mdata.pVal->Term[0], _mdata.pVal->lenTerm[0]);
		( (this->value_transfer)->str )[(this->value_transfer)->len] = '\0';
	}

	/* pVal is got by assign_val_ptr,
	 * so here should not release pVal */
	_mdata.pVal = NULL;
	_k.sKey = NULL;
	_k.mLenKey = 0;

	return true;
}

const bstr* Btree::getValueTransfer()
{
	return this->value_transfer;
}
bool Btree::remove(const bstr& _kstr){
	KeyType _key;
	_key.set_sKey(_kstr.cstr(), _kstr.len);
	return btree ->Delete(_key);
}
bool Btree::remove(const char* _key, int _klen)
{
	KeyType _btree_key;
	_btree_key.set_sKey(_key, _klen);
	return btree->Delete(_btree_key);
}
bool Btree::flush(){
	if(this ->btree == NULL){
		return false;
	}
	(this ->btree) ->StoreTree();
	return true;
}
bool Btree::release(){
	this->flush();
	if (this->btree != NULL)
	{
	    delete btree;
	}


	btree = new BPlusTree((this->getBtreeFilePath()).c_str(), "rw");
	return true;
}
bool Btree::close(){
	btree ->log("before flush\n");
	this ->flush();
	btree ->log("after flush\n");
	delete btree;
	btree = NULL;
	return true;
}
/*
 * private
 */
bool Btree::deleteifExistPath(const string& _path){
	return true;
}
bool Btree::openRead(const string& _btree_path){
	{
		if(btree != NULL){
			cout << "err in openRead btree [" + _btree_path + "]: btree is not NULL" << endl;
			exit(0);
		}
	}
	this ->btree = new BPlusTree((_btree_path).c_str(), "open");
	return true;
}
bool Btree::openWrite(const string& _btree_path){
	this ->btree = new BPlusTree((_btree_path).c_str(), "build");
	return true;
}
bool Btree::openReadWrite(const string& _btree_path){
	{
		if(btree != NULL){
			cout << "err in openReadWrite btree [" + _btree_path + "]: btree is not NULL" << endl;
			exit(0);
		}
	}
	this ->btree = new BPlusTree((_btree_path).c_str(), "open");
	return true;
}