MyItr * Table::index_find(int op, string key_to_btree, Tuple to_find )
{
//cout << op << endl;
map<string, BTree*>::iterator map_itr = keys.find( key_to_btree );
MyItr * itr = NULL;
//tuples.push_back( myItr->first() ); // get the headers
// if there is not index for the column, should never happen
if ( map_itr == keys.end() )
{
return NULL;
}
BTree * btree = map_itr->second;
if ( op == OP_EQUAL )
{
//cout << "euql " << endl;
BTreeNode * node = btree->find( to_find );
if ( node == NULL )
return NULL;
for ( int i = 0; i < node->getCount(); i++ )
{
if ( to_find == ( (LeafNode *) node )->get_values()[i] )
{
vector<streampos> offset = ( (LeafNode *) node )->get_values()[i].offset;
//cout << offset.size() << endl;
itr = index_fetch( offset );
}
}
}
else if ( op == OP_LEQ )
{
BTreeNode * node = btree->find_leq( to_find );
if ( node == NULL )
return NULL;
BTreeNode * cur_node = node;
vector<string> tuples;
myItr->open();
tuples.push_back( myItr->first() );
myItr->close();
itr = new MyItr( name, tuples );
while( node )
{
for ( int i = node->getCount() - 1; i >= 0; i-- )
{
if ( ( (LeafNode *) node )->get_values()[i] <= to_find)
{
vector<streampos> offset = ( (LeafNode *) node )->get_values()[i].offset;
*itr += *( index_fetch( offset ) );
}
}
node = node->getLeftSibling();
}
}
else if ( op == OP_LT )
{
BTreeNode * node = btree->find_leq( to_find );
if ( node == NULL )
return NULL;
BTreeNode * cur_node = node;
vector<string> tuples;
myItr->open();
tuples.push_back( myItr->first() );
myItr->close();
itr = new MyItr( name, tuples );
//cout << " at least here" << endl;
while( node )
{
for ( int i = node->getCount() - 1; i >= 0; i-- )
{
if ( ( (LeafNode *) node )->get_values()[i] < to_find)
{
vector<streampos> offset = ( (LeafNode *) node )->get_values()[i].offset;
*itr += *( index_fetch( offset ) );
}
}
node = node->getLeftSibling();
}
}
else if ( op == OP_GEQ )
{
BTreeNode * node = btree->find_geq( to_find );
if ( node == NULL )
return NULL;
BTreeNode * cur_node = node;
vector<string> tuples;
myItr->open();
tuples.push_back( myItr->first() );
myItr->close();
itr = new MyItr( name, tuples );
//cout << " at least here" << endl;
while( node )
{
for ( int i = 0; i < node->getCount(); i++ )
{
if ( ( (LeafNode *) node )->get_values()[i] >= to_find)
{
vector<streampos> offset = ( (LeafNode *) node )->get_values()[i].offset;
*itr += *( index_fetch( offset ) );
}
}
node = node->getRightSibling();
}
}
else if ( op == OP_GT )
{
//cout << "GT" << endl;
BTreeNode * node = btree->find_geq( to_find );
if ( node == NULL )
return NULL;
BTreeNode * cur_node = node;
vector<string> tuples;
myItr->open();
tuples.push_back( myItr->first() );
myItr->close();
itr = new MyItr( name, tuples );
//cout << " at least here" << endl;
//cout << node << endl;
while( node )
{
for ( int i = 0; i < node->getCount(); i++ )
{
if ( ( (LeafNode *) node )->get_values()[i] > to_find)
{
vector<streampos> offset = ( (LeafNode *) node )->get_values()[i].offset;
*itr += *( index_fetch( offset ) );
}
}
node = node->getRightSibling();
}
}
else
{
cerr << "Error in Table::index_find(): should never be here." << endl;
return NULL;
}
return itr;
}
