include/Index.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 INDEX_H
  17 #define INDEX_H
  18 #include<DataType.h>
  19 #include<Debug.h>
  20 #include<Info.h>
  21
  22
  23 class Chunk;
  24 class Database;
  25 class Transaction;
  26 class TableImpl;
  27
  28 class Bucket
  29 {
  30     public:
  31     Mutex mutex_;
  32     void *bucketList_;
  33 };
  34 class HashIndexNode
  35 {
  36     public:
  37     void *ptrToKey_;
  38     void *ptrToTuple_;
  39     HashIndexNode *next_;
  40 };
  41 class BucketIter
  42 {
  43     HashIndexNode *iter;
  44     public:
  45     BucketIter(){}
  46     BucketIter(HashIndexNode *head) { iter = head;}
  47     HashIndexNode* next();
  48     friend class BucketList;
  49 };
  50 class BucketList
  51 {
  52     HashIndexNode *head;
  53     public:
  54     BucketList(){ head = NULL;}
  55     BucketList(HashIndexNode *h){ head = h; }
  56     DbRetVal insert(Chunk *chunk, Database *db, void *key, void *tuple);
  57     DbRetVal remove(Chunk *chunk, Database *db, void *key);
  58     BucketIter getIterator()
  59     {
  60         BucketIter it;
  61         it.iter = head;
  62         return it;
  63     }
  64
  65 };
  66 class HashIndex;
  67
  68 class Index
  69 {
  70     //create (one) object for each indexing mechanisms here
  71     static HashIndex *hIdx;
  72     public:
  73     static Index* getIndex(IndexType type);
  74     static void destroy() { delete hIdx; }
  75     virtual DbRetVal insert(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple)=0;
  76     virtual DbRetVal remove(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple)=0;
  77     virtual DbRetVal update(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple)=0;
  78 };
  79
  80 class HashIndex : public Index
  81 {
  82
  83     public:
  84     DbRetVal insert(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple);
  85     DbRetVal remove(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple);
  86     DbRetVal update(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple);
  87     static unsigned int computeHashBucket(DataType type, void *key, int noOfBuckets);
  88
  89 };
  90
  91 enum IndexIntType
  92 {
  93         hashOneField = 1,
  94         hash = 2,
  95         tree = 3
  96
  97 };
  98 class IndexInfo
  99 {
 100     public:
 101     IndexType type;
 102 };
 103
 104 //Used by TableImpl to cache information related to hash indexes on that table
 105 class SingleFieldHashIndexInfo :public IndexInfo
 106 {
 107     public:
 108     char  *fldName;
 109     DataType type ;
 110     char *indexPtr;
 111     int noOfBuckets;
 112     Bucket* buckets;
 113     int fldPos;
 114     bool isUnique;
 115 };
 116 #endif
 117