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     char *val3;
  48     bool isBindBufSet;
  49     bool isNoLeftRight;
  50     bool dontEvaluate;
  51
  52     //opt for between queries
  53     ComparisionOp comp2Op;
  54     void *operand2;
  55     void **operand2Ptr;
  56     //This will be set before calling evaluate
  57     TableImpl *table;
  58
  59     public:
  60     PredicateImpl()
  61     {
  62         strcpy(fldName1, ""); strcpy(fldName2, "");
  63         operand = NULL; operandPtr = NULL; lhs = rhs = NULL;
  64         tuple = NULL; table = NULL;
  65         projList = NULL;
  66         parent = NULL;
  67         offset1 = -1;  offset2 =-1;
  68         type = typeUnknown;
  69         length = 0;
  70         isPushedDown=false;
  71         isBindBufSet = false;
  72         val1= NULL;
  73         val2=NULL;
  74         val3=NULL;
  75         isNoLeftRight=false;
  76         dontEvaluate=false;
  77     }
  78     ~PredicateImpl(){}
  79
  80     void setTerm(const char* fName1, ComparisionOp op, const char *fName2);
  81
  82     //Operand should be of the same type of the field.This is must
  83     void setTerm(const char* fName1, ComparisionOp op, void *opnd);
  84
  85     void setTerm(const char* fName1, ComparisionOp op, void **opnd);
  86     void setTerm(const char* fName1, ComparisionOp op, void **opnd,
  87                                      ComparisionOp op2, void **opnd2 );
  88
  89
  90     void setTerm(Predicate *p1, LogicalOp op, Predicate *p2 = NULL);
  91
  92     void* valPtrForIndexField(const char *name);
  93     ComparisionOp opForIndexField(const char *name);
  94
  95     DbRetVal evaluate(bool &result);
  96     void evaluateForTable(bool &result, char*tuple);
  97
  98     DbRetVal evaluateLogical(bool &result);
  99     DbRetVal evaluateLogicalForTable(bool &result, char *tuple);
 100
 101     void setTable(Table *tbl);
 102     void setTuple(void *tpl);
 103     void setProjectionList(List *list); //used by JoinTableImpl
 104     void setOffsetAndType();
 105     bool isSingleTerm();
 106     bool isNotOrInvolved();
 107     //check predicate, whether it has field name and == operator
 108     //and does not have OR, NOT operator
 109     // TODO:: expression like !(f1 !=100) wont be optimized for now
 110     bool pointLookupInvolved(const char *fName);
 111     bool rangeQueryInvolved(const char *fName);
 112     bool isBetweenInvolved(const char *fname);
 113     PredicateImpl *getTablePredicate();
 114     PredicateImpl *getJoinPredicate();
 115     void removeIfNotNecessary();
 116     bool isDummyPredicate();
 117     PredicateImpl* getIfOneSidedPredicate();
 118     void setParent(PredicateImpl *pImpl);
 119     char* getFldName1(){ return fldName1; }
 120     char* getFldName2(){ return fldName2; }
 121     ComparisionOp getCompOp() {return compOp; }
 122     void print(int space);
 123     void setIfNoLeftRight();
 124     void setDontEvaluate(){dontEvaluate = true;}
 125     bool appendIfSameFld(char *fname, ComparisionOp op, void* buf);
 126 };
 127
 128 #endif