index_scan.h

mini database sort-merge join

#ifndef __INDEX_SCAN__
#define __INDEX_SCAN__

#include "iterator.h"
#include "heapfile.h"
#include "scan.h"
#include "tuple_utils.h"
#include "projection.h"
#include "pred_eval.h"
#include "index.h"

/*

class Iterator {

        // All the relational operators and access methods are iterators.

public:
        virtual Status get_next(Tuple*& tuple) = 0;
        virtual ~Iterator(){};

//#ifdef TEST
Status get_buffer_pages(int n_pages, int *PageIds, char **bufs);
Status free_buffer_pages(int n_pages, int *PageIds );
//#endif


};
*/


class IndexScanIter : public Iterator {

// Index Scan iterator will directly access the required tuple using
// the provided key. It will also perform selections and projections.

public:

FldSpec *perm_mat;

        IndexScanIter(
                IndexType index,        // Type of the index
                const char* relName,  // Name of the input relation
                const char* indName,  // Name of the input index
                AttrType types[],       // Array of types in this relation
                short* str_sizes,       // Array of string sizes
                int noInFlds,           // Number of fields in input tuple
                int noOutFlds,          // Number of fields in output tuple
                FldSpec outFlds[],      // Fields to project
                CondExpr* selects[],// Conditions to apply, first one is primary
                const int fldNum,
                const int indexOnly,
                Status& s
        );

        Status get_next(Tuple*& tuple);
        ~IndexScanIter();

private:

//        IndexFileScan* BTree_scan(CondExpr* selects[], IndexFile* indFile);
//        void* IndexScanIter::getValue(CondExpr* cd, AttrType type, int choice);

        IndexFile*     indFile;
        IndexFileScan* indScan;
        AttrType* _types;
        CondExpr** _selects;
        int _noInFlds;
        int _noOutFlds;
        HeapFile *f;
        Tuple    * tuple1;
        Tuple    *Jtuple;
        int      t1_size;
        int _fldNum;       // added by BK
        int index_only;    // added by BK

};

class IndexUtils {

public:

  IndexFileScan* BTree_scan(CondExpr **selects, IndexFile *indFile);

private:
  void* getValue(CondExpr* cd, AttrType type, int choice);
};
#endif