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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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