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 85