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     static HashIndex *hIdx;
  71     public:
  72     static Index* getIndex(IndexType type);
  73     static void destroy() { delete hIdx; }
  74     virtual DbRetVal insert(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple)=0;
  75     virtual DbRetVal remove(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple)=0;
  76     virtual DbRetVal update(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple)=0;
  77 };
  78
  79 class HashIndex : public Index
  80 {
  81
  82     public:
  83     DbRetVal insert(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple);
  84     DbRetVal remove(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple);
  85     DbRetVal update(TableImpl *tbl, Transaction *tr, void *indexPtr, void *tuple);
  86     static unsigned int computeHashBucket(DataType type, void *key, int noOfBuckets);
  87
  88 };
  89
  90 enum IndexIntType
  91 {
  92         hashOneField = 1,
  93         hash = 2,
  94         tree = 3
  95
  96 };
  97 class IndexInfo
  98 {
  99     public:
 100     IndexType type;
 101 };
 102
 103 //Used by TableImpl to cache information related to hash indexes on that table
 104 class SingleFieldHashIndexInfo :public IndexInfo
 105 {
 106     public:
 107     char  *fldName;
 108     DataType type ;
 109     char *indexPtr;
 110     int noOfBuckets;
 111     Bucket* buckets;
 112     int fldPos;
 113 };
 114 #endif
 115