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ndx.h

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00001 /* $Id: ndx.h,v 1.11 2003/08/16 19:59:39 gkunkel Exp $ 00002 00003 Xbase project source code 00004 00005 This file contains a header file for the xbNdx object, which is used 00006 for handling NDX type indices. 00007 00008 Copyright (C) 1997 Gary A. Kunkel 00009 00010 This library is free software; you can redistribute it and/or 00011 modify it under the terms of the GNU Lesser General Public 00012 License as published by the Free Software Foundation; either 00013 version 2.1 of the License, or (at your option) any later version. 00014 00015 This library is distributed in the hope that it will be useful, 00016 but WITHOUT ANY WARRANTY; without even the implied warranty of 00017 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00018 Lesser General Public License for more details. 00019 00020 You should have received a copy of the GNU Lesser General Public 00021 License along with this library; if not, write to the Free Software 00022 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 00023 00024 Contact: 00025 00026 Mail: 00027 00028 Technology Associates, Inc. 00029 XBase Project 00030 1455 Deming Way #11 00031 Sparks, NV 89434 00032 USA 00033 00034 Email: 00035 00036 xbase@techass.com 00037 xdb-devel@lists.sourceforge.net 00038 xdb-users@lists.sourceforge.net 00039 00040 See our website at: 00041 00042 xdb.sourceforge.net 00043 00044 */ 00045 00046 #ifndef __XB_NDX_H__ 00047 #define __XB_NDX_H__ 00048 00049 #ifdef __GNUG__ 00050 #pragma interface 00051 #endif 00052 00053 #include <xbase/xbase.h> 00054 #include <string.h> 00055 00059 // 00060 // Define the following to use inline versions of the respective methods. 00061 // 00062 #define XB_INLINE_COMPAREKEY 00063 #define XB_INLINE_GETDBFNO 00064 00065 #define XB_NDX_NODE_BASESIZE 24 // size of base header data 00066 00067 #define XB_VAR_NODESIZE // define to enable variable node sizes 00068 00069 #ifndef XB_VAR_NODESIZE 00070 #define XB_NDX_NODE_SIZE 2048 00071 //#define XB_NDX_NODE_SIZE 512 // standard dbase node size 00072 #else 00073 #define XB_DEFAULT_NDX_NODE_SIZE 512 00074 #define XB_MAX_NDX_NODE_SIZE 4096 00075 #define XB_NDX_NODE_SIZE NodeSize 00076 #define XB_NDX_NODE_MULTIPLE 512 00077 #endif // XB_VAR_NODESIZE 00078 00080 00083 struct XBDLLEXPORT xbNdxHeadNode { /* ndx header on disk */ 00084 xbLong StartNode; /* header node is node 0 */ 00085 xbLong TotalNodes; /* includes header node */ 00086 xbLong NoOfKeys; /* actual count + 1 */ 00087 xbUShort KeyLen; /* length of key data */ 00088 xbUShort KeysPerNode; 00089 xbUShort KeyType; /* 00 = Char, 01 = Numeric */ 00090 xbLong KeySize; /* key len + 8 bytes */ 00091 char Unknown2; 00092 char Unique; 00093 // char KeyExpression[488]; 00094 #ifndef XB_VAR_NODESIZE 00095 char KeyExpression[XB_NDX_NODE_SIZE - 24]; 00096 #else 00097 char KeyExpression[XB_MAX_NDX_NODE_SIZE - 24]; 00098 #endif // XB_VAR_NODESIZE 00099 }; 00100 00102 00105 struct XBDLLEXPORT xbNdxLeafNode { /* ndx node on disk */ 00106 xbLong NoOfKeysThisNode; 00107 #ifndef XB_VAR_NODESIZE 00108 char KeyRecs[XB_NDX_NODE_SIZE-4]; 00109 #else 00110 char KeyRecs[XB_MAX_NDX_NODE_SIZE - 4]; 00111 #endif // XB_VAR_NODESIZE 00112 }; 00113 00115 00118 struct XBDLLEXPORT xbNdxNodeLink { /* ndx node memory */ 00119 xbNdxNodeLink * PrevNode; 00120 xbNdxNodeLink * NextNode; 00121 xbLong CurKeyNo; /* 0 - KeysPerNode-1 */ 00122 xbLong NodeNo; 00123 struct xbNdxLeafNode Leaf; 00124 }; 00125 00127 00130 class XBDLLEXPORT xbNdx : public xbIndex 00131 { 00132 // xbExpNode * ExpressionTree; /* Expression tree for index */ 00133 00134 public: 00135 xbNdx(); 00136 xbNdx(xbDbf *); 00137 virtual ~xbNdx(); 00138 00139 /* don't uncomment next line - it causes seg faults for some undiagnosed reason*/ 00140 // ~NDX() { if( NdxStatus ) CloseIndex(); } 00141 00142 xbShort OpenIndex ( const char * FileName ); 00143 xbShort CloseIndex(); 00144 xbShort CreateIndex( const char *IxName, const char *Exp, 00145 xbShort Unique, xbShort OverLay ); 00146 xbLong GetTotalNodes(); 00147 xbULong GetCurDbfRec() { return CurDbfRec; } 00148 xbShort CreateKey( xbShort, xbShort ); 00149 xbShort GetCurrentKey(char *key); 00150 xbShort AddKey( xbLong ); 00151 xbShort UniqueIndex() { return HeadNode.Unique; } 00152 xbShort DeleteKey( xbLong ); 00153 xbShort KeyWasChanged(); 00154 xbShort FindKey( const char *Key ); 00155 xbShort FindKey(); 00156 xbShort FindKey( xbDouble ); 00157 #ifdef XBASE_DEBUG 00158 void DumpHdrNode(); 00159 void DumpNodeRec( xbLong NodeNo ); 00160 void DumpNodeChain(); 00161 xbShort CheckIndexIntegrity( const xbShort Option ); 00162 #endif 00163 00164 00166 xbShort GetNextKey() { return GetNextKey( 1 ); } 00168 00170 xbShort GetLastKey() { return GetLastKey( 0, 1 ); } 00172 00174 xbShort GetFirstKey() { return GetFirstKey( 1 ); } 00176 00178 xbShort GetPrevKey() { return GetPrevKey( 1 ); } 00179 xbShort ReIndex(void (*statusFunc)(xbLong itemNum, xbLong numItems) = 0); 00180 xbShort KeyExists( const char * Key ) { return FindKey( Key, strlen( Key ), 0 ); } 00181 xbShort KeyExists( xbDouble ); 00182 00183 virtual void SetNodeSize(xbShort size); 00184 00185 virtual void GetExpression(char *buf, int len); 00186 00187 protected: 00188 xbNdxHeadNode HeadNode; 00189 xbNdxLeafNode LeafNode; 00190 xbLong xbNodeLinkCtr; 00191 xbLong ReusedxbNodeLinks; 00192 #if 0 // overrides IndexName in xbIndex 00193 xbString IndexName; 00194 #endif 00195 00196 #ifndef XB_VAR_NODESIZE 00197 char Node[XB_NDX_NODE_SIZE]; 00198 #else 00199 char Node[XB_MAX_NDX_NODE_SIZE]; 00200 #endif // XB_VAR_NODESIZE 00201 // FILE *ndxfp; 00202 // int NdxStatus; /* 0 = closed, 1 = open */ 00203 00204 xbNdxNodeLink * NodeChain; /* pointer to node chain of index nodes */ 00205 xbNdxNodeLink * FreeNodeChain; /* pointer to chain of free index nodes */ 00206 xbNdxNodeLink * CurNode; /* pointer to current node */ 00207 xbNdxNodeLink * DeleteChain; /* pointer to chain to delete */ 00208 xbNdxNodeLink * CloneChain; /* pointer to node chain copy (add dup) */ 00209 #if 0 // these override those in xbIndex 00210 xbLong CurDbfRec; /* current Dbf record number */ 00211 char *KeyBuf; /* work area key buffer */ 00212 char *KeyBuf2; /* work area key buffer */ 00213 #endif 00214 00215 /* private functions */ 00216 xbLong GetLeftNodeNo( xbShort, xbNdxNodeLink * ); 00217 #ifndef XB_INLINE_COMPAREKEY 00218 xbShort CompareKey( const char *Key1, const char *Key2, xbShort Klen ); 00219 #else 00220 00221 00223 inline xbShort CompareKey( const char *Key1, const char *Key2, xbShort Klen ) 00224 { 00225 #if 0 00226 const char *k1, *k2; 00227 xbShort i; 00228 #endif 00229 xbDouble d1, d2; 00230 int c; 00231 00232 if(!( Key1 && Key2 )) return -1; 00233 00234 if( Klen > HeadNode.KeyLen ) Klen = HeadNode.KeyLen; 00235 00236 if( HeadNode.KeyType == 0 ) 00237 { 00238 c = memcmp(Key1, Key2, Klen); 00239 if(c < 0) 00240 return 2; 00241 else if(c > 0) 00242 return 1; 00243 return 0; 00244 } 00245 else /* key is numeric */ 00246 { 00247 d1 = dbf->xbase->GetDouble( Key1 ); 00248 d2 = dbf->xbase->GetDouble( Key2 ); 00249 if( d1 == d2 ) return 0; 00250 else if( d1 > d2 ) return 1; 00251 else return 2; 00252 } 00253 } 00254 #endif 00255 #ifndef XB_INLINE_GETDBFNO 00256 xbLong GetDbfNo( xbShort, xbNdxNodeLink * ); 00257 #else 00258 00259 00261 inline xbLong GetDbfNo( xbShort RecNo, xbNdxNodeLink *n ) 00262 { 00263 xbNdxLeafNode *temp; 00264 char *p; 00265 if( !n ) return 0L; 00266 temp = &n->Leaf; 00267 if( RecNo < 0 || RecNo > ( temp->NoOfKeysThisNode - 1 )) return 0L; 00268 p = temp->KeyRecs + 4; 00269 p += RecNo * ( 8 + HeadNode.KeyLen ); 00270 return( dbf->xbase->GetLong( p )); 00271 } 00272 #endif 00273 char * GetKeyData( xbShort, xbNdxNodeLink * ); 00274 xbUShort GetKeysPerNode(); 00275 xbShort GetHeadNode(); 00276 xbShort GetLeafNode( xbLong, xbShort ); 00277 xbNdxNodeLink * GetNodeMemory(); 00278 void ReleaseNodeMemory(xbNdxNodeLink *n, bool doFree = false); 00279 xbShort BSearchNode(const char *key, xbShort klen, 00280 const xbNdxNodeLink *node, 00281 xbShort *comp); 00282 xbLong GetLeafFromInteriorNode( const char *Tkey, xbShort Klen ); 00283 xbShort CalcKeyLen(); 00284 xbShort PutKeyData( xbShort, xbNdxNodeLink * ); 00285 xbShort PutLeftNodeNo( xbShort, xbNdxNodeLink *, xbLong ); 00286 xbShort PutLeafNode( xbLong, xbNdxNodeLink * ); 00287 xbShort PutHeadNode( xbNdxHeadNode *, FILE *, xbShort ); 00288 xbShort PutDbfNo( xbShort, xbNdxNodeLink *, xbLong ); 00289 xbShort PutKeyInNode( xbNdxNodeLink *, xbShort, xbLong, xbLong, xbShort ); 00290 xbShort SplitLeafNode( xbNdxNodeLink *, xbNdxNodeLink *, xbShort, xbLong ); 00291 xbShort SplitINode( xbNdxNodeLink *, xbNdxNodeLink *, xbLong ); 00292 xbShort AddToIxList(); 00293 xbShort RemoveFromIxList(); 00294 xbShort RemoveKeyFromNode( xbShort, xbNdxNodeLink * ); 00295 xbShort FindKey( const char *Tkey, xbShort Klen, xbShort RetrieveSw ); 00296 xbShort UpdateParentKey( xbNdxNodeLink * ); 00297 xbShort GetFirstKey( xbShort ); 00298 xbShort GetNextKey( xbShort ); 00299 xbShort GetLastKey( xbLong, xbShort ); 00300 xbShort GetPrevKey( xbShort ); 00301 void UpdateDeleteList( xbNdxNodeLink * ); 00302 void ProcessDeleteList(); 00303 xbNdxNodeLink * LeftSiblingHasSpace( xbNdxNodeLink * ); 00304 xbNdxNodeLink * RightSiblingHasSpace( xbNdxNodeLink * ); 00305 xbShort DeleteSibling( xbNdxNodeLink * ); 00306 xbShort MoveToLeftNode( xbNdxNodeLink *, xbNdxNodeLink * ); 00307 xbShort MoveToRightNode( xbNdxNodeLink *, xbNdxNodeLink * ); 00308 xbShort FindKey( const char *Tkey, xbLong DbfRec ); /* for a specific dbf no */ 00309 00310 xbShort CloneNodeChain(); 00311 xbShort UncloneNodeChain(); 00312 00313 //#ifdef XB_LOCKING_ON 00314 // xbShort LockIndex( const xbShort, const xbShort ) const; 00315 //#else 00316 // xbShort LockIndex( const xbShort, const xbShort ) const { return NO_ERROR; } 00317 //#endif 00318 00319 }; 00320 #endif /* __XB_NDX_H__ */

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