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 #define TRIE_SIZE 10
  22 #define TRIE_MAX_LENGTH 64
  23
  24 class Database;
  25 class Chunk;
  26 class Transaction;
  27 class TableImpl;
  28 class CINDEX;
  29
  30 class Bucket
  31 {
  32     public:
  33     Mutex mutex_;
  34     void *bucketList_;
  35 };
  36 class IndexNode
  37 {
  38     public:
  39     void *ptrToKey_;
  40     void *ptrToTuple_;
  41     IndexNode *next_;
  42 };
  43
  44 class TrieNode
  45 {
  46     public:
  47     IndexNode *head_[TRIE_SIZE];
  48     TrieNode *next_[TRIE_SIZE];
  49 };
  50
  51 class IndexInfo;
  52
  53 /**
  54 * @class TreeNode
  55 * @brief Represents node in tree index.
  56 *        It is actually a doubly linked list node which contains information such as minimum key value pointer, maximum key value pointer and total number of elements.
  57 *
  58 * TreeNode represents node in tree index and it is guarded by a mutex.
  59 * Any modifications to tree node should be done only after acquiring
  60 * its associated mutex. At the end array of pointers to next level tree nodes(in case of intermediate node) / tuple is stored(in case of leaf nodes)
  61 * <br/>
  62 *
  63 */
  64
  65 class TreeNode
  66 {
  67     public:
  68     Mutex mutex_;       /**< Mutex guarding this node */
  69     void *min_;         /**< Ptr to node having minimum value in this node */
  70     void *max_;         /**< Ptr to node having maximum value in this node */
  71     int noElements_;    /**< total number of elements in this node */
  72     TreeNode *next_;    /**< ptr to next tree node in same level */
  73     TreeNode *prev_;    /**< ptr to previous tree node in same level */
  74     int balance_;       /**< Reserved. Not currently used */
  75     //Note::after this array of pointer to tuples are stored
  76
  77     long long getTotalElements();
  78
  79
  80     /**
  81     *  @brief insert node into the tree, by traversing and locating the right node
  82     *
  83     *  Detailed description comes here
  84     *  Detailed desc continues here
  85     *  @param db  pointer to Database
  86     *  @param info pointer to tuple under search
  87     *  @param indexPtr  ptr to INDEX structure
  88     *  @param tuple pointer to tuple under search
  89     *  @return DbRetVal error code when function returns
  90     */
  91     DbRetVal insert(Database *db, IndexInfo *info, void *indexPtr, void *tuple);
  92
  93     /**
  94     *  @brief remove node from the tree, by traversing and locating the right node
  95     *
  96     *  @param db  pointer to Database
  97     *  @param info pointer to tuple under search
  98     *  @param indexPtr  ptr to INDEX structure
  99     *  @param tuple pointer to tuple to be removed
 100     *  @return DbRetVal error code when function returns
 101     */
 102     DbRetVal remove(Database *db, IndexInfo *info, void *indexPtr, void *tuple);
 103
 104     /**
 105     *  @brief update node in the tree, by traversing and locating the right node
 106     *
 107     *  @param db  pointer to Database
 108     *  @param info pointer to tuple under search
 109     *  @param indexPtr  ptr to INDEX structure
 110     *  @param tuple pointer to tuple to be updated
 111     *  @return DbRetVal error code when function returns
 112     */
 113     DbRetVal update(Database *db, IndexInfo *info, void *indexPtr, void *tuple);
 114
 115     void displayAll();
 116     void displayAll(int offset);
 117
 118     private:
 119
 120     /**
 121     *  @brief locate node where tuple resides by traversing the tree nodes
 122     *
 123     *  Detailed description comes here
 124     *  Detailed desc continues here
 125     *  @param db  pointer to Database
 126     *  @param iter  TreeNode pointer
 127     *  @param tuple pointer to tuple under search
 128     *  @param indInfo pointer to tuple under search
 129     *  @param rv OUT param which will contain error code when this function returns with any error
 130     *  @return TreeNode* pointer to TreeNode which contains the tuple under search
 131     */
 132     TreeNode* locateNode(Database *db,TreeNode *iter, void *tuple, IndexInfo *indInfo,DbRetVal &rv);
 133     TreeNode *locateNodeFromFirstLevel(TreeNode *ftnode,IndexInfo *indInfo,void *tuple,int *nodepos);
 134     DbRetVal insertRecordIntoNodeAndArrangeFirstLevel(Database * db, IndexInfo * indInfo, void* iptr, void * tuple, TreeNode * fstLevel,int nodepos);
 135     DbRetVal insertNodeIntoFirstLevel(Database * db, IndexInfo * indInfo, void* indexPtr, TreeNode * newNode,int nodepos);
 136 };
 137
 138 class BucketIter
 139 {
 140     IndexNode *iter;
 141     IndexNode *head;
 142     bool isUnique;
 143     bool recordsOver;
 144     public:
 145     BucketIter(){iter = head = NULL;
 146                  isUnique=false; recordsOver = false;}
 147     void setHead(IndexNode *hd) { iter = head = hd; recordsOver=false;}
 148     BucketIter(IndexNode *head) { iter = head = head;
 149                  isUnique=false; recordsOver = false;}
 150     void setUnique() { isUnique = true; }
 151     bool getUnique() { return isUnique; }
 152     IndexNode* next();
 153     void reset() { iter = head; recordsOver=false;}
 154     friend class BucketList;
 155 };
 156 class BucketList
 157 {
 158     IndexNode *head;
 159     public:
 160     BucketList(){ head = NULL;}
 161     BucketList(IndexNode *h){ head = h; }
 162     void *getBucketListHead(){ return head;}
 163     DbRetVal insert(Chunk *chunk, Database *db, void *key, void *tuple);
 164     DbRetVal remove(Chunk *chunk, Database *db, void *key);
 165     void print();
 166     BucketIter getIterator()
 167     {
 168         BucketIter it;
 169         it.iter = head;
 170         return it;
 171     }
 172 };
 173 class HashIndex;
 174 class IndexInfo;
 175 class HashIndexInfo;
 176 class TreeIndex;
 177 class TrieIndex;
 178 class Index
 179 {
 180     // create (one) object for each indexing mechanisms here
 181     // Also need to make changes to getIndex() and destroy() methods
 182     // accordingly for new index machanism.
 183     static HashIndex *hIdx;
 184     static TreeIndex *tIdx;
 185     static TrieIndex *iIdx;
 186     static long usageCount;
 187     public:
 188     static Index* getIndex(IndexType type);
 189     static void init() { usageCount++; }
 190     static void destroy();
 191     virtual DbRetVal insert(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag)=0;
 192     virtual DbRetVal remove(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag)=0;
 193     virtual DbRetVal update(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag)=0;
 194 };
 195 class HashIndex : public Index
 196 {
 197     //No members as it will be called by multiple threads
 198     public:
 199     DbRetVal insert(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag);
 200     DbRetVal remove(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag);
 201     DbRetVal update(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag);
 202     bool checkForUniqueKey(IndexNode *head,HashIndexInfo *info, void *tuple);
 203     static unsigned int computeHashBucket(DataType type, void *key, int noOfBuckets, int length=0);
 204     static DbRetVal insertLogicalUndoLog(Database *sysdb, void *info);
 205     static DbRetVal deleteLogicalUndoLog(Database *sysdb, void *info);
 206 };
 207
 208 class TreeIndex : public Index
 209 {
 210     //No members as it will be called by multiple threads
 211     DbRetVal removeElement(Database *db, TreeNode *iter, void *tuple, HashIndexInfo *info);
 212     void removeNode(Database *db,void *indexPtr,TreeNode *fltnode, TreeNode *node,int pos);
 213     public:
 214     DbRetVal insert(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag);
 215     DbRetVal remove(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag);
 216     DbRetVal update(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag);
 217     static DbRetVal insertLogicalUndoLog(Database *sysdb, void *info);
 218     static DbRetVal deleteLogicalUndoLog(Database *sysdb, void *info);
 219     static DbRetVal getTreeNodeMutex(TreeNode*, int procSlot, bool isX=false);
 220     static DbRetVal upgradeTreeNodeMutex(TreeNode*, int procSlot);
 221
 222 };
 223
 224 class TrieIndex: public Index
 225 {
 226     public:
 227     DbRetVal insert(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag);
 228     DbRetVal remove(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag);
 229     DbRetVal update(TableImpl *tbl, Transaction *tr, void *indexPtr, IndexInfo *info, void *tuple, bool undoFlag);
 230     bool checkForUniqueKey(IndexNode *head, IndexInfo *info, void *tuple);
 231     static void computeHashValues(DataType type, void *key, char *in, int length=0);
 232     static DbRetVal insertLogicalUndoLog(Database *sysdb, void *info);
 233     static DbRetVal deleteLogicalUndoLog(Database *sysdb, void *info);
 234     static void displayAll(TrieNode *node, int level =1);
 235     static void printTrieNode(TrieNode *node, int level);
 236     private:
 237     DbRetVal addToValueList(Database*, void**, Chunk*, IndexInfo*, void*, void*);
 238     DbRetVal removeFromValueList(Database*, void**, Chunk*, void*, void*);
 239
 240 };
 241 class TreeIter
 242 {
 243     TreeNode *iter;
 244     TreeNode *head;
 245     int fldOffset;
 246     DataType type;
 247     int length;
 248     ComparisionOp op;
 249     bool asc;
 250     void *searchKey;
 251     bool firstCall;
 252     int nodeOffset;
 253     bool recordsOver;
 254     void *fstLTnode;
 255     void* locateNode();
 256     void* locateElement();
 257     int procSlot;
 258     bool isUnique;
 259
 260     public:
 261     TreeIter(){ iter=head=NULL; searchKey=fstLTnode=NULL;isUnique = false;}
 262     TreeIter(TreeNode *hd,void *fTnode, int slot ) { fstLTnode = fTnode; iter = head = hd; firstCall = true; recordsOver=false; procSlot=slot; isUnique=false;}
 263     void set(TreeNode *hd,void *fTnode, int slot ) { fstLTnode = fTnode; iter = head = hd; firstCall = true; recordsOver=false; procSlot=slot; isUnique=false;}
 264     void setSearchKey(void *key, ComparisionOp cop, bool ascending = true)
 265     {
 266         searchKey = key; op = cop; asc =ascending;
 267     }
 268     void setUnique() { isUnique = true; }
 269     bool getUnique() { return isUnique; }
 270     void setFldOffset(int off) { fldOffset = off; }
 271     void setTypeLength(DataType t, int l) { type =t ; length =l; }
 272     void* prev();
 273     void* next();
 274     void nextNode();
 275     void* getFirstElement();
 276     void* getLastElement();
 277     void reset();// { iter = head; firstCall = true; recordsOver=false; }
 278 };
 279
 280 enum IndexIntType
 281 {
 282         hashOneField = 1,
 283         hash = 2,
 284         tree = 3,
 285         trie = 4
 286
 287 };
 288 class IndexInfo
 289 {
 290     public:
 291     IndexType indType;
 292     int fldOffset;
 293     bool isUnique;
 294     DataType type;
 295     int compLength;
 296     virtual ~IndexInfo() {}
 297 };
 298
 299 //Used by TableImpl to cache information related to hash indexes on that table
 300 class HashIndexInfo :public IndexInfo
 301 {
 302     public:
 303     FieldList idxFldList;
 304     char *indexPtr;
 305     int noOfBuckets;
 306     Bucket* buckets;
 307     void print()
 308     {
 309         printf("HashIndexInfo indexPtr:%x noOfBuckets:%d buckets:%x \n",indexPtr, noOfBuckets, buckets);
 310     }
 311     ~HashIndexInfo() { idxFldList.removeAll(); }
 312 };
 313 #endif
 314