load.h

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// ============================================================================
// Project:     Deductive Database
// Filename:    load.h
// Purpose:     Parse and load data.
// Last Change: 04.08.2017
// Language:    C++
// EMail:       brass@informatik.uni-halle.de
// WWW:         http://www.informatik.uni-halle.de/~brass/
// Address:     Feldschloesschen 15, D-06120 Halle (Saale), GERMANY
// Copyright:   (c) 2015-2017 by Stefan Brass
// License:     See file "LICENSE" for copying conditions.
// Note:        There is no warranty at all - this code may contain bugs.
// ============================================================================


//=============================================================================
// Include File Frame:
//=============================================================================

#ifndef LOAD_INCLUDED
#define LOAD_INCLUDED

//=============================================================================
// Used Types and Macros:
//=============================================================================

#ifndef VER_INCLUDED
#include "../base/ver.h"
#endif

#ifndef STR_INCLUDED
#include "../base/str.h"
#endif

#ifndef CHECK_INCLUDED
#include "../base/check.h"
#endif

#ifndef STRTAB_INCLUDED
#include "../dom/strtab.h"
#endif

#ifndef PRED_INCLUDED
#include "../pred/pred.h"
#endif

//=============================================================================
// Private Constants:
//=============================================================================

//-----------------------------------------------------------------------------
// LOAD_MAGIC: Magic number (identifies objects of this class).
//-----------------------------------------------------------------------------

static const long LOAD_MAGIC = 0x4C4F440AL;     // 'LOD\n'

//-----------------------------------------------------------------------------
// LOAD_HASHSIZE: Size of hash table.
//-----------------------------------------------------------------------------

static const int LOAD_HASHSIZE = 251; // Should be prime number

//=============================================================================
// Forward declaration for private type (predicate data):
//=============================================================================

class load_pred_c;

//=============================================================================
// Class for Data LOader:
//=============================================================================

class load_c {
        public:

//-----------------------------------------------------------------------------
// Constructor, Destructor:
//-----------------------------------------------------------------------------

        // Constructor:
        load_c();

        // Destructor:
        ~load_c();

//-----------------------------------------------------------------------------
// (Object) Methods:
//-----------------------------------------------------------------------------

        // add: Define predicate.
        void add(pred_t predicate);

        // Load data:
        bool load(str_t filename);

//-----------------------------------------------------------------------------
// Debugging Support:
//-----------------------------------------------------------------------------

#if     VER_DEBUG
        public:
        // Integrity check:
        str_t   check() const;

        private:
        // Magic number (identifies objects of this class for debugging).
        long    Magic;          // Must be "LOAD_MAGIC".
#endif

#if     VER_DUMP
        public:
        // Display data structure:
        void dump(str_t headline = STR_NULL) const;
#endif

//-----------------------------------------------------------------------------
// Copy-constructor and assignment operator are not supported for this class:
//-----------------------------------------------------------------------------

        private:

        load_c(const load_c& obj);              // Not implemented
        load_c& operator=(const load_c& obj);   // Not implemented

//-----------------------------------------------------------------------------
// Auxiliary Methods:
//-----------------------------------------------------------------------------

        private:

        // hash: Compute hash function for predicate name.
        int hash(str_t name_start, str_t name_end);

        // find_pred: Find predicate data for given predicate name.
        pred_t find_pred(str_t name_start, str_t name_end);


//-----------------------------------------------------------------------------
// Private Object Members:
//-----------------------------------------------------------------------------

        private:

        // Hash table:
        pred_t HashTab[LOAD_HASHSIZE];

//=============================================================================
// End of Class:
//=============================================================================

};


//=============================================================================
// End of Include File:
//=============================================================================

#endif