include/PredicateImpl.h

   1 /***************************************************************************
   2  *   Copyright (C) 2007 by www.databasecache.com                           *
   3  *   Contact: praba_tuty@databasecache.com                                 *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15   ***************************************************************************/
  16 #ifndef PREDICATE_IMPL_H
  17 #define PREDICATE_IMPL_H
  18 #include<DataType.h>
  19 #include<Predicate.h>
  20 #include<ErrorType.h>
  21 class TableImpl;
  22 class Table;
  23 class List;
  24 class PredicateImpl:public Predicate
  25 {
  26     //Members set during initialization of the term
  27     char fldName1[IDENTIFIER_LENGTH];
  28     char fldName2[IDENTIFIER_LENGTH];
  29     ComparisionOp compOp;
  30     void *operand;
  31     void **operandPtr;
  32     LogicalOp logicalOp;
  33     PredicateImpl *lhs;
  34     PredicateImpl *rhs;
  35     PredicateImpl *parent;
  36
  37     //Members set during execution
  38     void *tuple; //pointer to the tuple
  39     List *projList;
  40
  41     //This will be set before calling evaluate
  42     TableImpl *table;
  43
  44     public:
  45     PredicateImpl()
  46     {
  47         strcpy(fldName1, ""); strcpy(fldName2, "");
  48         operand = NULL; operandPtr = NULL; lhs = rhs = NULL;
  49         tuple = NULL; table = NULL;
  50         projList = NULL;
  51         parent = NULL;
  52     }
  53     ~PredicateImpl(){}
  54
  55     void setTerm(const char* fName1, ComparisionOp op, const char *fName2);
  56
  57     //Operand should be of the same type of the field.This is must
  58     void setTerm(const char* fName1, ComparisionOp op, void *opnd);
  59
  60     void setTerm(const char* fName1, ComparisionOp op, void **opnd);
  61
  62
  63     void setTerm(Predicate *p1, LogicalOp op, Predicate *p2 = NULL);
  64
  65     void* valPtrForIndexField(const char *name);
  66     ComparisionOp opForIndexField(const char *name);
  67
  68     DbRetVal evaluate(bool &result);
  69
  70     void setTable(Table *tbl);
  71     void setTuple(void *tpl);
  72     void setProjectionList(List *list); //used by JoinTableImpl
  73
  74     bool isSingleTerm();
  75     bool isNotOrInvolved();
  76     //check predicate, whether it has field name and == operator
  77     //and does not have OR, NOT operator
  78     // TODO:: expression like !(f1 !=100) wont be optimized for now
  79     bool pointLookupInvolved(const char *fName);
  80     bool rangeQueryInvolved(const char *fName);
  81     bool isBetweenInvolved(const char *fname);
  82     PredicateImpl *getTablePredicate();
  83     PredicateImpl *getJoinPredicate();
  84     void removeIfNotNecessary();
  85     bool isDummyPredicate();
  86     PredicateImpl* getIfOneSidedPredicate();
  87     void setParent(PredicateImpl *pImpl);
  88     char* getFldName1(){ return fldName1; }
  89     char* getFldName2(){ return fldName2; }
  90     void print(int space);
  91 };
  92
  93 #endif