include/Field.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 FIELD_H
  17 #define FIELD_H
  18 #include<os.h>
  19 #include<DataType.h>
  20 #include<ErrorType.h>
  21
  22 //used by FieldNameList
  23 class FieldNameNode
  24 {
  25     public:
  26     char  fldName[IDENTIFIER_LENGTH];
  27     FieldNameNode *next;
  28 };
  29
  30
  31 class FieldDef
  32 {
  33     public:
  34     FieldDef()
  35     {
  36         init();
  37     }
  38     void init() {
  39         type_ = typeUnknown;
  40         length_ = 0;
  41         offset_ = 0;
  42         bindVal_ = NULL;
  43         isDefault_ = false;
  44         isNull_ = false;
  45         isPrimary_ = false;
  46         isUnique_ = false;
  47         strcpy(fldName_, "");
  48     }
  49     char fldName_[IDENTIFIER_LENGTH];
  50     DataType type_;
  51     size_t length_;
  52     size_t offset_;
  53     //currently default value is supported for string and binary
  54     //less than length 32 bytes
  55     char defaultValueBuf_[DEFAULT_VALUE_BUF_LENGTH];
  56
  57     //used only in case of binding fields
  58     void *bindVal_;
  59
  60     bool isNull_;
  61     bool isPrimary_;
  62     bool isDefault_;
  63     bool isUnique_;
  64     //TODO::width and scale
  65 };
  66
  67 class FieldNode
  68 {
  69     public:
  70     FieldDef fldDef;
  71     FieldNode *next;
  72 };
  73
  74
  75 class FieldIterator
  76 {
  77     public:
  78     FieldNode *iter;
  79     FieldIterator(FieldNode *ptr) { iter = ptr; }
  80     bool hasElement()
  81     {
  82         if (iter == NULL) return false; else return true;
  83     }
  84     FieldDef* nextElement()
  85     {
  86         if (iter == NULL) { return NULL;}
  87         FieldNode *node = iter;
  88         iter = iter ->next;
  89         return &(node->fldDef);
  90     }
  91 };
  92
  93 class FieldInfo;
  94
  95 //Internal class used to implement the field list information
  96 //to create the table
  97 class FieldList
  98 {
  99     public:
 100     FieldNode *head;
 101     FieldList(){ head = NULL;}
 102
 103     //TODO::pass by reference instead of value
 104     DbRetVal append(FieldDef fDef);
 105
 106     DbRetVal remove(const char* fldName);
 107
 108     DbRetVal removeAll();
 109
 110     DbRetVal updateBindVal(const char *fldName, void *val);
 111     void * getBindField(const char *fldName);
 112     int getFieldOffset(const char *fldName);
 113     int getFieldOffset(int fldpos);
 114
 115     //Returns position of field in the list:count starting from 1
 116     int getFieldPosition(const char *fldName);
 117
 118     DataType getFieldType(const char *fldName);
 119
 120     size_t getFieldLength(const char *fldName);
 121
 122     DbRetVal getFieldInfo(const char *fldName, FieldInfo *&info);
 123
 124     int getTupleSize();
 125
 126     FieldIterator getIterator()
 127     {
 128         FieldIterator iter(head);
 129         return iter;
 130     }
 131 };
 132 #endif