Annotation of embedaddon/sqlite3/src/test_wsd.c, revision 1.1.1.1

1.1       misho       1: /*
                      2: ** 2008 September 1
                      3: **
                      4: ** The author disclaims copyright to this source code.  In place of
                      5: ** a legal notice, here is a blessing:
                      6: **
                      7: **    May you do good and not evil.
                      8: **    May you find forgiveness for yourself and forgive others.
                      9: **    May you share freely, never taking more than you give.
                     10: **
                     11: *************************************************************************
                     12: **
                     13: ** The code in this file contains sample implementations of the 
                     14: ** sqlite3_wsd_init() and sqlite3_wsd_find() functions required if the
                     15: ** SQLITE_OMIT_WSD symbol is defined at build time.
                     16: */
                     17: 
                     18: #if defined(SQLITE_OMIT_WSD) && defined(SQLITE_TEST)
                     19: 
                     20: #include "sqliteInt.h"
                     21: 
                     22: #define PLS_HASHSIZE 43
                     23: 
                     24: typedef struct ProcessLocalStorage ProcessLocalStorage;
                     25: typedef struct ProcessLocalVar ProcessLocalVar;
                     26: 
                     27: struct ProcessLocalStorage {
                     28:   ProcessLocalVar *aData[PLS_HASHSIZE];
                     29:   int nFree;
                     30:   u8 *pFree;
                     31: };
                     32: 
                     33: struct ProcessLocalVar {
                     34:   void *pKey;
                     35:   ProcessLocalVar *pNext;
                     36: };
                     37: 
                     38: static ProcessLocalStorage *pGlobal = 0;
                     39: 
                     40: int sqlite3_wsd_init(int N, int J){
                     41:   if( !pGlobal ){
                     42:     int nMalloc = N + sizeof(ProcessLocalStorage) + J*sizeof(ProcessLocalVar);
                     43:     pGlobal = (ProcessLocalStorage *)malloc(nMalloc);
                     44:     if( pGlobal ){
                     45:       memset(pGlobal, 0, sizeof(ProcessLocalStorage));
                     46:       pGlobal->nFree = nMalloc - sizeof(ProcessLocalStorage);
                     47:       pGlobal->pFree = (u8 *)&pGlobal[1];
                     48:     }
                     49:   }
                     50: 
                     51:   return pGlobal ? SQLITE_OK : SQLITE_NOMEM;
                     52: }
                     53: 
                     54: void *sqlite3_wsd_find(void *K, int L){
                     55:   int i;
                     56:   int iHash = 0;
                     57:   ProcessLocalVar *pVar;
                     58: 
                     59:   /* Calculate a hash of K */
                     60:   for(i=0; i<sizeof(void*); i++){
                     61:     iHash = (iHash<<3) + ((unsigned char *)&K)[i];
                     62:   }
                     63:   iHash = iHash%PLS_HASHSIZE;
                     64: 
                     65:   /* Search the hash table for K. */
                     66:   for(pVar=pGlobal->aData[iHash]; pVar && pVar->pKey!=K; pVar=pVar->pNext);
                     67: 
                     68:   /* If no entry for K was found, create and populate a new one. */
                     69:   if( !pVar ){
                     70:     int nByte = ROUND8(sizeof(ProcessLocalVar) + L);
                     71:     assert( pGlobal->nFree>=nByte );
                     72:     pVar = (ProcessLocalVar *)pGlobal->pFree;
                     73:     pVar->pKey = K;
                     74:     pVar->pNext = pGlobal->aData[iHash];
                     75:     pGlobal->aData[iHash] = pVar;
                     76:     pGlobal->nFree -= nByte;
                     77:     pGlobal->pFree += nByte;
                     78:     memcpy(&pVar[1], K, L);
                     79:   }
                     80: 
                     81:   return (void *)&pVar[1];
                     82: }
                     83: 
                     84: #endif

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