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     int offset1,offset2;
  37     DataType type;
  38     int length;
  39     //Members set during execution
  40     void *tuple; //pointer to the tuple
  41     List *projList;
  42     bool isPushedDown;
  43
  44     //optimization:caching val1 and val2 for evaluation
  45     char *val1;
  46     char *val2;
  47     bool isBindBufSet;
  48     bool isNoLeftRight;
  49
  50     //This will be set before calling evaluate
  51     TableImpl *table;
  52
  53     public:
  54     PredicateImpl()
  55     {
  56         strcpy(fldName1, ""); strcpy(fldName2, "");
  57         operand = NULL; operandPtr = NULL; lhs = rhs = NULL;
  58         tuple = NULL; table = NULL;
  59         projList = NULL;
  60         parent = NULL;
  61         offset1 = -1;  offset2 =-1;
  62         type = typeUnknown;
  63         length = 0;
  64         isPushedDown=false;
  65         isBindBufSet = false;
  66         val1= NULL;
  67         val2=NULL;
  68         isNoLeftRight=false;
  69     }
  70     ~PredicateImpl(){}
  71
  72     void setTerm(const char* fName1, ComparisionOp op, const char *fName2);
  73
  74     //Operand should be of the same type of the field.This is must
  75     void setTerm(const char* fName1, ComparisionOp op, void *opnd);
  76
  77     void setTerm(const char* fName1, ComparisionOp op, void **opnd);
  78
  79
  80     void setTerm(Predicate *p1, LogicalOp op, Predicate *p2 = NULL);
  81
  82     void* valPtrForIndexField(const char *name);
  83     ComparisionOp opForIndexField(const char *name);
  84
  85     DbRetVal evaluate(bool &result);
  86
  87     void setTable(Table *tbl);
  88     void setTuple(void *tpl);
  89     void setProjectionList(List *list); //used by JoinTableImpl
  90     void setOffsetAndType();
  91     bool isSingleTerm();
  92     bool isNotOrInvolved();
  93     //check predicate, whether it has field name and == operator
  94     //and does not have OR, NOT operator
  95     // TODO:: expression like !(f1 !=100) wont be optimized for now
  96     bool pointLookupInvolved(const char *fName);
  97     bool rangeQueryInvolved(const char *fName);
  98     bool isBetweenInvolved(const char *fname);
  99     PredicateImpl *getTablePredicate();
 100     PredicateImpl *getJoinPredicate();
 101     void removeIfNotNecessary();
 102     bool isDummyPredicate();
 103     PredicateImpl* getIfOneSidedPredicate();
 104     void setParent(PredicateImpl *pImpl);
 105     char* getFldName1(){ return fldName1; }
 106     char* getFldName2(){ return fldName2; }
 107     ComparisionOp getCompOp() {return compOp; }
 108     void print(int space);
 109     void setIfNoLeftRight();
 110 };
 111
 112 #endif