xref: /sqlite-3.40.0/src/vtab.c (revision 63b3a64c)
1b9bb7c18Sdrh /*
2b9bb7c18Sdrh ** 2006 June 10
3b9bb7c18Sdrh **
4b9bb7c18Sdrh ** The author disclaims copyright to this source code.  In place of
5b9bb7c18Sdrh ** a legal notice, here is a blessing:
6b9bb7c18Sdrh **
7b9bb7c18Sdrh **    May you do good and not evil.
8b9bb7c18Sdrh **    May you find forgiveness for yourself and forgive others.
9b9bb7c18Sdrh **    May you share freely, never taking more than you give.
10b9bb7c18Sdrh **
11b9bb7c18Sdrh *************************************************************************
12b9bb7c18Sdrh ** This file contains code used to help implement virtual tables.
13b9bb7c18Sdrh */
14b9bb7c18Sdrh #ifndef SQLITE_OMIT_VIRTUALTABLE
15b9bb7c18Sdrh #include "sqliteInt.h"
16b9bb7c18Sdrh 
1763842415Sdrh /*
18b061d058Sdan ** Before a virtual table xCreate() or xConnect() method is invoked, the
19b061d058Sdan ** sqlite3.pVtabCtx member variable is set to point to an instance of
20b061d058Sdan ** this struct allocated on the stack. It is used by the implementation of
21b061d058Sdan ** the sqlite3_declare_vtab() and sqlite3_vtab_config() APIs, both of which
22b061d058Sdan ** are invoked only from within xCreate and xConnect methods.
23b061d058Sdan */
24b061d058Sdan struct VtabCtx {
2581028a45Sdrh   VTable *pVTable;    /* The virtual table being constructed */
2681028a45Sdrh   Table *pTab;        /* The Table object to which the virtual table belongs */
2775395ccdSdan   VtabCtx *pPrior;    /* Parent context (if any) */
2875395ccdSdan   int bDeclared;      /* True after sqlite3_declare_vtab() is called */
29b061d058Sdan };
30b061d058Sdan 
31b061d058Sdan /*
322fcc1590Sdrh ** Construct and install a Module object for a virtual table.  When this
332fcc1590Sdrh ** routine is called, it is guaranteed that all appropriate locks are held
342fcc1590Sdrh ** and the module is not already part of the connection.
35cc5979dbSdrh **
36cc5979dbSdrh ** If there already exists a module with zName, replace it with the new one.
37cc5979dbSdrh ** If pModule==0, then delete the module zName if it exists.
3863842415Sdrh */
sqlite3VtabCreateModule(sqlite3 * db,const char * zName,const sqlite3_module * pModule,void * pAux,void (* xDestroy)(void *))392fcc1590Sdrh Module *sqlite3VtabCreateModule(
40832a58a6Sdanielk1977   sqlite3 *db,                    /* Database in which module is registered */
41832a58a6Sdanielk1977   const char *zName,              /* Name assigned to this module */
42832a58a6Sdanielk1977   const sqlite3_module *pModule,  /* The definition of the module */
43832a58a6Sdanielk1977   void *pAux,                     /* Context pointer for xCreate/xConnect */
44832a58a6Sdanielk1977   void (*xDestroy)(void *)        /* Module destructor function */
45832a58a6Sdanielk1977 ){
46ca8b9bacSdan   Module *pMod;
47cc5979dbSdrh   Module *pDel;
48cc5979dbSdrh   char *zCopy;
49cc5979dbSdrh   if( pModule==0 ){
50cc5979dbSdrh     zCopy = (char*)zName;
51cc5979dbSdrh     pMod = 0;
52cc5979dbSdrh   }else{
532fcc1590Sdrh     int nName = sqlite3Strlen30(zName);
543ee1416bSdrh     pMod = (Module *)sqlite3Malloc(sizeof(Module) + nName + 1);
553ee1416bSdrh     if( pMod==0 ){
563ee1416bSdrh       sqlite3OomFault(db);
57cc5979dbSdrh       return 0;
58cc5979dbSdrh     }
59cc5979dbSdrh     zCopy = (char *)(&pMod[1]);
60832a58a6Sdanielk1977     memcpy(zCopy, zName, nName+1);
61832a58a6Sdanielk1977     pMod->zName = zCopy;
62832a58a6Sdanielk1977     pMod->pModule = pModule;
63832a58a6Sdanielk1977     pMod->pAux = pAux;
64832a58a6Sdanielk1977     pMod->xDestroy = xDestroy;
6551be3873Sdrh     pMod->pEpoTab = 0;
66cc5979dbSdrh     pMod->nRefModule = 1;
67cc5979dbSdrh   }
68acbcb7e0Sdrh   pDel = (Module *)sqlite3HashInsert(&db->aModule,zCopy,(void*)pMod);
69ca8b9bacSdan   if( pDel ){
70cc5979dbSdrh     if( pDel==pMod ){
714a642b60Sdrh       sqlite3OomFault(db);
72ca8b9bacSdan       sqlite3DbFree(db, pDel);
739a63f092Sdrh       pMod = 0;
74cc5979dbSdrh     }else{
7587ca8067Sdrh       sqlite3VtabEponymousTableClear(db, pDel);
76cc5979dbSdrh       sqlite3VtabModuleUnref(db, pDel);
7727a430ccSdanielk1977     }
78832a58a6Sdanielk1977   }
792fcc1590Sdrh   return pMod;
802fcc1590Sdrh }
812fcc1590Sdrh 
822fcc1590Sdrh /*
832fcc1590Sdrh ** The actual function that does the work of creating a new module.
842fcc1590Sdrh ** This function implements the sqlite3_create_module() and
852fcc1590Sdrh ** sqlite3_create_module_v2() interfaces.
862fcc1590Sdrh */
createModule(sqlite3 * db,const char * zName,const sqlite3_module * pModule,void * pAux,void (* xDestroy)(void *))872fcc1590Sdrh static int createModule(
882fcc1590Sdrh   sqlite3 *db,                    /* Database in which module is registered */
892fcc1590Sdrh   const char *zName,              /* Name assigned to this module */
902fcc1590Sdrh   const sqlite3_module *pModule,  /* The definition of the module */
912fcc1590Sdrh   void *pAux,                     /* Context pointer for xCreate/xConnect */
922fcc1590Sdrh   void (*xDestroy)(void *)        /* Module destructor function */
932fcc1590Sdrh ){
942fcc1590Sdrh   int rc = SQLITE_OK;
952fcc1590Sdrh 
962fcc1590Sdrh   sqlite3_mutex_enter(db->mutex);
972fcc1590Sdrh   (void)sqlite3VtabCreateModule(db, zName, pModule, pAux, xDestroy);
98ca8b9bacSdan   rc = sqlite3ApiExit(db, rc);
99ca8b9bacSdan   if( rc!=SQLITE_OK && xDestroy ) xDestroy(pAux);
10027641703Sdrh   sqlite3_mutex_leave(db->mutex);
10127641703Sdrh   return rc;
102832a58a6Sdanielk1977 }
103832a58a6Sdanielk1977 
104832a58a6Sdanielk1977 
105b9bb7c18Sdrh /*
106b9bb7c18Sdrh ** External API function used to create a new virtual-table module.
107b9bb7c18Sdrh */
sqlite3_create_module(sqlite3 * db,const char * zName,const sqlite3_module * pModule,void * pAux)108b9bb7c18Sdrh int sqlite3_create_module(
109b9bb7c18Sdrh   sqlite3 *db,                    /* Database in which module is registered */
110b9bb7c18Sdrh   const char *zName,              /* Name assigned to this module */
111d1ab1ba5Sdanielk1977   const sqlite3_module *pModule,  /* The definition of the module */
112d1ab1ba5Sdanielk1977   void *pAux                      /* Context pointer for xCreate/xConnect */
113b9bb7c18Sdrh ){
1149ca95730Sdrh #ifdef SQLITE_ENABLE_API_ARMOR
1159ca95730Sdrh   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
1169ca95730Sdrh #endif
117832a58a6Sdanielk1977   return createModule(db, zName, pModule, pAux, 0);
118d1ab1ba5Sdanielk1977 }
119832a58a6Sdanielk1977 
120832a58a6Sdanielk1977 /*
121832a58a6Sdanielk1977 ** External API function used to create a new virtual-table module.
122832a58a6Sdanielk1977 */
sqlite3_create_module_v2(sqlite3 * db,const char * zName,const sqlite3_module * pModule,void * pAux,void (* xDestroy)(void *))123832a58a6Sdanielk1977 int sqlite3_create_module_v2(
124832a58a6Sdanielk1977   sqlite3 *db,                    /* Database in which module is registered */
125832a58a6Sdanielk1977   const char *zName,              /* Name assigned to this module */
126832a58a6Sdanielk1977   const sqlite3_module *pModule,  /* The definition of the module */
127832a58a6Sdanielk1977   void *pAux,                     /* Context pointer for xCreate/xConnect */
128832a58a6Sdanielk1977   void (*xDestroy)(void *)        /* Module destructor function */
129832a58a6Sdanielk1977 ){
1309ca95730Sdrh #ifdef SQLITE_ENABLE_API_ARMOR
1319ca95730Sdrh   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
1329ca95730Sdrh #endif
133832a58a6Sdanielk1977   return createModule(db, zName, pModule, pAux, xDestroy);
134b9bb7c18Sdrh }
135b9bb7c18Sdrh 
136b9bb7c18Sdrh /*
1375df84280Sdrh ** External API to drop all virtual-table modules, except those named
1385df84280Sdrh ** on the azNames list.
1395df84280Sdrh */
sqlite3_drop_modules(sqlite3 * db,const char ** azNames)1408c754a36Sdrh int sqlite3_drop_modules(sqlite3 *db, const char** azNames){
1415df84280Sdrh   HashElem *pThis, *pNext;
1425df84280Sdrh #ifdef SQLITE_ENABLE_API_ARMOR
1433722b3abSmistachkin   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1445df84280Sdrh #endif
1455df84280Sdrh   for(pThis=sqliteHashFirst(&db->aModule); pThis; pThis=pNext){
1465df84280Sdrh     Module *pMod = (Module*)sqliteHashData(pThis);
1475df84280Sdrh     pNext = sqliteHashNext(pThis);
1485df84280Sdrh     if( azNames ){
1495df84280Sdrh       int ii;
1505df84280Sdrh       for(ii=0; azNames[ii]!=0 && strcmp(azNames[ii],pMod->zName)!=0; ii++){}
1515df84280Sdrh       if( azNames[ii]!=0 ) continue;
1525df84280Sdrh     }
1535df84280Sdrh     createModule(db, pMod->zName, 0, 0, 0);
1545df84280Sdrh   }
1555df84280Sdrh   return SQLITE_OK;
1565df84280Sdrh }
1575df84280Sdrh 
1585df84280Sdrh /*
159cc5979dbSdrh ** Decrement the reference count on a Module object.  Destroy the
160cc5979dbSdrh ** module when the reference count reaches zero.
161cc5979dbSdrh */
sqlite3VtabModuleUnref(sqlite3 * db,Module * pMod)162cc5979dbSdrh void sqlite3VtabModuleUnref(sqlite3 *db, Module *pMod){
163cc5979dbSdrh   assert( pMod->nRefModule>0 );
164cc5979dbSdrh   pMod->nRefModule--;
165cc5979dbSdrh   if( pMod->nRefModule==0 ){
166cc5979dbSdrh     if( pMod->xDestroy ){
167cc5979dbSdrh       pMod->xDestroy(pMod->pAux);
168cc5979dbSdrh     }
169cc5979dbSdrh     assert( pMod->pEpoTab==0 );
170cc5979dbSdrh     sqlite3DbFree(db, pMod);
171cc5979dbSdrh   }
172cc5979dbSdrh }
173cc5979dbSdrh 
174cc5979dbSdrh /*
175189d4afaSdrh ** Lock the virtual table so that it cannot be disconnected.
176189d4afaSdrh ** Locks nest.  Every lock should have a corresponding unlock.
177189d4afaSdrh ** If an unlock is omitted, resources leaks will occur.
178189d4afaSdrh **
179189d4afaSdrh ** If a disconnect is attempted while a virtual table is locked,
180189d4afaSdrh ** the disconnect is deferred until all locks have been removed.
181189d4afaSdrh */
sqlite3VtabLock(VTable * pVTab)182595a523aSdanielk1977 void sqlite3VtabLock(VTable *pVTab){
183595a523aSdanielk1977   pVTab->nRef++;
184595a523aSdanielk1977 }
185595a523aSdanielk1977 
186595a523aSdanielk1977 
187595a523aSdanielk1977 /*
188595a523aSdanielk1977 ** pTab is a pointer to a Table structure representing a virtual-table.
189595a523aSdanielk1977 ** Return a pointer to the VTable object used by connection db to access
190595a523aSdanielk1977 ** this virtual-table, if one has been created, or NULL otherwise.
191595a523aSdanielk1977 */
sqlite3GetVTable(sqlite3 * db,Table * pTab)192595a523aSdanielk1977 VTable *sqlite3GetVTable(sqlite3 *db, Table *pTab){
193595a523aSdanielk1977   VTable *pVtab;
194595a523aSdanielk1977   assert( IsVirtual(pTab) );
195f38524d2Sdrh   for(pVtab=pTab->u.vtab.p; pVtab && pVtab->db!=db; pVtab=pVtab->pNext);
196595a523aSdanielk1977   return pVtab;
197189d4afaSdrh }
198189d4afaSdrh 
199189d4afaSdrh /*
200595a523aSdanielk1977 ** Decrement the ref-count on a virtual table object. When the ref-count
201595a523aSdanielk1977 ** reaches zero, call the xDisconnect() method to delete the object.
202189d4afaSdrh */
sqlite3VtabUnlock(VTable * pVTab)203595a523aSdanielk1977 void sqlite3VtabUnlock(VTable *pVTab){
204595a523aSdanielk1977   sqlite3 *db = pVTab->db;
205595a523aSdanielk1977 
206a04a34ffSdanielk1977   assert( db );
207595a523aSdanielk1977   assert( pVTab->nRef>0 );
2085f9de6ecSdrh   assert( db->eOpenState==SQLITE_STATE_OPEN
2095f9de6ecSdrh        || db->eOpenState==SQLITE_STATE_ZOMBIE );
210595a523aSdanielk1977 
211595a523aSdanielk1977   pVTab->nRef--;
212595a523aSdanielk1977   if( pVTab->nRef==0 ){
213595a523aSdanielk1977     sqlite3_vtab *p = pVTab->pVtab;
214cc5979dbSdrh     sqlite3VtabModuleUnref(pVTab->db, pVTab->pMod);
215595a523aSdanielk1977     if( p ){
216595a523aSdanielk1977       p->pModule->xDisconnect(p);
217189d4afaSdrh     }
218595a523aSdanielk1977     sqlite3DbFree(db, pVTab);
219595a523aSdanielk1977   }
220595a523aSdanielk1977 }
221595a523aSdanielk1977 
222595a523aSdanielk1977 /*
223595a523aSdanielk1977 ** Table p is a virtual table. This function moves all elements in the
224f38524d2Sdrh ** p->u.vtab.p list to the sqlite3.pDisconnect lists of their associated
225595a523aSdanielk1977 ** database connections to be disconnected at the next opportunity.
226595a523aSdanielk1977 ** Except, if argument db is not NULL, then the entry associated with
227f38524d2Sdrh ** connection db is left in the p->u.vtab.p list.
228595a523aSdanielk1977 */
vtabDisconnectAll(sqlite3 * db,Table * p)229595a523aSdanielk1977 static VTable *vtabDisconnectAll(sqlite3 *db, Table *p){
230595a523aSdanielk1977   VTable *pRet = 0;
23178b2fa86Sdrh   VTable *pVTable;
23278b2fa86Sdrh 
23378b2fa86Sdrh   assert( IsVirtual(p) );
23478b2fa86Sdrh   pVTable = p->u.vtab.p;
235f38524d2Sdrh   p->u.vtab.p = 0;
236595a523aSdanielk1977 
237595a523aSdanielk1977   /* Assert that the mutex (if any) associated with the BtShared database
238595a523aSdanielk1977   ** that contains table p is held by the caller. See header comments
239595a523aSdanielk1977   ** above function sqlite3VtabUnlockList() for an explanation of why
240595a523aSdanielk1977   ** this makes it safe to access the sqlite3.pDisconnect list of any
241f38524d2Sdrh   ** database connection that may have an entry in the p->u.vtab.p list.
2429bbc2e28Sdrh   */
2439bbc2e28Sdrh   assert( db==0 || sqlite3SchemaMutexHeld(db, 0, p->pSchema) );
244595a523aSdanielk1977 
245595a523aSdanielk1977   while( pVTable ){
246595a523aSdanielk1977     sqlite3 *db2 = pVTable->db;
247595a523aSdanielk1977     VTable *pNext = pVTable->pNext;
248595a523aSdanielk1977     assert( db2 );
249595a523aSdanielk1977     if( db2==db ){
250595a523aSdanielk1977       pRet = pVTable;
251f38524d2Sdrh       p->u.vtab.p = pRet;
252595a523aSdanielk1977       pRet->pNext = 0;
253595a523aSdanielk1977     }else{
254595a523aSdanielk1977       pVTable->pNext = db2->pDisconnect;
255595a523aSdanielk1977       db2->pDisconnect = pVTable;
256595a523aSdanielk1977     }
257595a523aSdanielk1977     pVTable = pNext;
258595a523aSdanielk1977   }
259595a523aSdanielk1977 
260595a523aSdanielk1977   assert( !db || pRet );
261595a523aSdanielk1977   return pRet;
262595a523aSdanielk1977 }
263595a523aSdanielk1977 
264bba02a95Sdan /*
265bba02a95Sdan ** Table *p is a virtual table. This function removes the VTable object
266bba02a95Sdan ** for table *p associated with database connection db from the linked
267bba02a95Sdan ** list in p->pVTab. It also decrements the VTable ref count. This is
268bba02a95Sdan ** used when closing database connection db to free all of its VTable
269bba02a95Sdan ** objects without disturbing the rest of the Schema object (which may
270bba02a95Sdan ** be being used by other shared-cache connections).
271bba02a95Sdan */
sqlite3VtabDisconnect(sqlite3 * db,Table * p)272bba02a95Sdan void sqlite3VtabDisconnect(sqlite3 *db, Table *p){
273bba02a95Sdan   VTable **ppVTab;
274bba02a95Sdan 
275bba02a95Sdan   assert( IsVirtual(p) );
276bba02a95Sdan   assert( sqlite3BtreeHoldsAllMutexes(db) );
277bba02a95Sdan   assert( sqlite3_mutex_held(db->mutex) );
278bba02a95Sdan 
279f38524d2Sdrh   for(ppVTab=&p->u.vtab.p; *ppVTab; ppVTab=&(*ppVTab)->pNext){
280bba02a95Sdan     if( (*ppVTab)->db==db  ){
281bba02a95Sdan       VTable *pVTab = *ppVTab;
282bba02a95Sdan       *ppVTab = pVTab->pNext;
283bba02a95Sdan       sqlite3VtabUnlock(pVTab);
284bba02a95Sdan       break;
285bba02a95Sdan     }
286bba02a95Sdan   }
287bba02a95Sdan }
288bba02a95Sdan 
289595a523aSdanielk1977 
290595a523aSdanielk1977 /*
291595a523aSdanielk1977 ** Disconnect all the virtual table objects in the sqlite3.pDisconnect list.
292595a523aSdanielk1977 **
293595a523aSdanielk1977 ** This function may only be called when the mutexes associated with all
294595a523aSdanielk1977 ** shared b-tree databases opened using connection db are held by the
295595a523aSdanielk1977 ** caller. This is done to protect the sqlite3.pDisconnect list. The
296595a523aSdanielk1977 ** sqlite3.pDisconnect list is accessed only as follows:
297595a523aSdanielk1977 **
298595a523aSdanielk1977 **   1) By this function. In this case, all BtShared mutexes and the mutex
299595a523aSdanielk1977 **      associated with the database handle itself must be held.
300595a523aSdanielk1977 **
301595a523aSdanielk1977 **   2) By function vtabDisconnectAll(), when it adds a VTable entry to
302595a523aSdanielk1977 **      the sqlite3.pDisconnect list. In this case either the BtShared mutex
303595a523aSdanielk1977 **      associated with the database the virtual table is stored in is held
304595a523aSdanielk1977 **      or, if the virtual table is stored in a non-sharable database, then
305595a523aSdanielk1977 **      the database handle mutex is held.
306595a523aSdanielk1977 **
307595a523aSdanielk1977 ** As a result, a sqlite3.pDisconnect cannot be accessed simultaneously
308595a523aSdanielk1977 ** by multiple threads. It is thread-safe.
309595a523aSdanielk1977 */
sqlite3VtabUnlockList(sqlite3 * db)310595a523aSdanielk1977 void sqlite3VtabUnlockList(sqlite3 *db){
311595a523aSdanielk1977   VTable *p = db->pDisconnect;
312595a523aSdanielk1977 
313595a523aSdanielk1977   assert( sqlite3BtreeHoldsAllMutexes(db) );
314595a523aSdanielk1977   assert( sqlite3_mutex_held(db->mutex) );
315595a523aSdanielk1977 
316595a523aSdanielk1977   if( p ){
3171de92a64Sdrh     db->pDisconnect = 0;
318ba968dbfSdrh     sqlite3ExpirePreparedStatements(db, 0);
319595a523aSdanielk1977     do {
320595a523aSdanielk1977       VTable *pNext = p->pNext;
321595a523aSdanielk1977       sqlite3VtabUnlock(p);
322595a523aSdanielk1977       p = pNext;
323595a523aSdanielk1977     }while( p );
324595a523aSdanielk1977   }
325189d4afaSdrh }
326189d4afaSdrh 
327189d4afaSdrh /*
328b9bb7c18Sdrh ** Clear any and all virtual-table information from the Table record.
329b9bb7c18Sdrh ** This routine is called, for example, just before deleting the Table
330b9bb7c18Sdrh ** record.
331595a523aSdanielk1977 **
332595a523aSdanielk1977 ** Since it is a virtual-table, the Table structure contains a pointer
333595a523aSdanielk1977 ** to the head of a linked list of VTable structures. Each VTable
334595a523aSdanielk1977 ** structure is associated with a single sqlite3* user of the schema.
335595a523aSdanielk1977 ** The reference count of the VTable structure associated with database
336595a523aSdanielk1977 ** connection db is decremented immediately (which may lead to the
337595a523aSdanielk1977 ** structure being xDisconnected and free). Any other VTable structures
338595a523aSdanielk1977 ** in the list are moved to the sqlite3.pDisconnect list of the associated
339595a523aSdanielk1977 ** database connection.
340b9bb7c18Sdrh */
sqlite3VtabClear(sqlite3 * db,Table * p)3411feeaed2Sdan void sqlite3VtabClear(sqlite3 *db, Table *p){
34278b2fa86Sdrh   assert( IsVirtual(p) );
34341ce47c4Sdrh   assert( db!=0 );
34441ce47c4Sdrh   if( db->pnBytesFreed==0 ) vtabDisconnectAll(0, p);
345f38524d2Sdrh   if( p->u.vtab.azArg ){
346b9bb7c18Sdrh     int i;
347f38524d2Sdrh     for(i=0; i<p->u.vtab.nArg; i++){
348f38524d2Sdrh       if( i!=1 ) sqlite3DbFree(db, p->u.vtab.azArg[i]);
349b9bb7c18Sdrh     }
350f38524d2Sdrh     sqlite3DbFree(db, p->u.vtab.azArg);
351b9bb7c18Sdrh   }
352b9bb7c18Sdrh }
353b9bb7c18Sdrh 
354b9bb7c18Sdrh /*
355f38524d2Sdrh ** Add a new module argument to pTable->u.vtab.azArg[].
356b9bb7c18Sdrh ** The string is not copied - the pointer is stored.  The
357b9bb7c18Sdrh ** string will be freed automatically when the table is
358b9bb7c18Sdrh ** deleted.
359b9bb7c18Sdrh */
addModuleArgument(Parse * pParse,Table * pTable,char * zArg)3600aa3231fSdrh static void addModuleArgument(Parse *pParse, Table *pTable, char *zArg){
36178b2fa86Sdrh   sqlite3_int64 nBytes;
362b7a2f2e8Sdanielk1977   char **azModuleArg;
3630aa3231fSdrh   sqlite3 *db = pParse->db;
36478b2fa86Sdrh 
36578b2fa86Sdrh   assert( IsVirtual(pTable) );
36678b2fa86Sdrh   nBytes = sizeof(char *)*(2+pTable->u.vtab.nArg);
367f38524d2Sdrh   if( pTable->u.vtab.nArg+3>=db->aLimit[SQLITE_LIMIT_COLUMN] ){
3680aa3231fSdrh     sqlite3ErrorMsg(pParse, "too many columns on %s", pTable->zName);
3690aa3231fSdrh   }
370f38524d2Sdrh   azModuleArg = sqlite3DbRealloc(db, pTable->u.vtab.azArg, nBytes);
371b7a2f2e8Sdanielk1977   if( azModuleArg==0 ){
372633e6d57Sdrh     sqlite3DbFree(db, zArg);
373b7a2f2e8Sdanielk1977   }else{
374f38524d2Sdrh     int i = pTable->u.vtab.nArg++;
375b7a2f2e8Sdanielk1977     azModuleArg[i] = zArg;
376b7a2f2e8Sdanielk1977     azModuleArg[i+1] = 0;
377f38524d2Sdrh     pTable->u.vtab.azArg = azModuleArg;
378b9bb7c18Sdrh   }
3790e07f6aeSdrh }
380b9bb7c18Sdrh 
381b9bb7c18Sdrh /*
382b9bb7c18Sdrh ** The parser calls this routine when it first sees a CREATE VIRTUAL TABLE
383b9bb7c18Sdrh ** statement.  The module name has been parsed, but the optional list
384b9bb7c18Sdrh ** of parameters that follow the module name are still pending.
385b9bb7c18Sdrh */
sqlite3VtabBeginParse(Parse * pParse,Token * pName1,Token * pName2,Token * pModuleName,int ifNotExists)386b9bb7c18Sdrh void sqlite3VtabBeginParse(
387b9bb7c18Sdrh   Parse *pParse,        /* Parsing context */
388b9bb7c18Sdrh   Token *pName1,        /* Name of new table, or database name */
389b9bb7c18Sdrh   Token *pName2,        /* Name of new table or NULL */
390b421b894Sdrh   Token *pModuleName,   /* Name of the module for the virtual table */
391b421b894Sdrh   int ifNotExists       /* No error if the table already exists */
392b9bb7c18Sdrh ){
393b9bb7c18Sdrh   Table *pTable;        /* The new virtual table */
39417435752Sdrh   sqlite3 *db;          /* Database connection */
395b9bb7c18Sdrh 
396b421b894Sdrh   sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, ifNotExists);
397b9bb7c18Sdrh   pTable = pParse->pNewTable;
398748ce211Sdrh   if( pTable==0 ) return;
399f1a381e7Sdanielk1977   assert( 0==pTable->pIndex );
400f38524d2Sdrh   pTable->eTabType = TABTYP_VTAB;
401f1a381e7Sdanielk1977 
40217435752Sdrh   db = pParse->db;
40370ba1640Sdanielk1977 
404f38524d2Sdrh   assert( pTable->u.vtab.nArg==0 );
4050aa3231fSdrh   addModuleArgument(pParse, pTable, sqlite3NameFromToken(db, pModuleName));
4060aa3231fSdrh   addModuleArgument(pParse, pTable, 0);
4070aa3231fSdrh   addModuleArgument(pParse, pTable, sqlite3DbStrDup(db, pTable->zName));
408d89b834fSdan   assert( (pParse->sNameToken.z==pName2->z && pName2->z!=0)
409d89b834fSdan        || (pParse->sNameToken.z==pName1->z && pName2->z==0)
410d89b834fSdan   );
411d89b834fSdan   pParse->sNameToken.n = (int)(
412d89b834fSdan       &pModuleName->z[pModuleName->n] - pParse->sNameToken.z
413d89b834fSdan   );
414f1a381e7Sdanielk1977 
415f1a381e7Sdanielk1977 #ifndef SQLITE_OMIT_AUTHORIZATION
416f1a381e7Sdanielk1977   /* Creating a virtual table invokes the authorization callback twice.
417f1a381e7Sdanielk1977   ** The first invocation, to obtain permission to INSERT a row into the
4181e32bed3Sdrh   ** sqlite_schema table, has already been made by sqlite3StartTable().
419f1a381e7Sdanielk1977   ** The second call, to obtain permission to create the table, is made now.
420f1a381e7Sdanielk1977   */
421f38524d2Sdrh   if( pTable->u.vtab.azArg ){
4227cc5595aSmistachkin     int iDb = sqlite3SchemaToIndex(db, pTable->pSchema);
4237cc5595aSmistachkin     assert( iDb>=0 ); /* The database the table is being created in */
424be718897Sdanielk1977     sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName,
425f38524d2Sdrh             pTable->u.vtab.azArg[0], pParse->db->aDb[iDb].zDbSName);
426f1a381e7Sdanielk1977   }
427f1a381e7Sdanielk1977 #endif
428b9bb7c18Sdrh }
429b9bb7c18Sdrh 
430b9bb7c18Sdrh /*
431b9bb7c18Sdrh ** This routine takes the module argument that has been accumulating
432b9bb7c18Sdrh ** in pParse->zArg[] and appends it to the list of arguments on the
433b9bb7c18Sdrh ** virtual table currently under construction in pParse->pTable.
434b9bb7c18Sdrh */
addArgumentToVtab(Parse * pParse)435b9bb7c18Sdrh static void addArgumentToVtab(Parse *pParse){
436b421b894Sdrh   if( pParse->sArg.z && pParse->pNewTable ){
4377c2d87cdSdrh     const char *z = (const char*)pParse->sArg.z;
43833b3933cSdanielk1977     int n = pParse->sArg.n;
43917435752Sdrh     sqlite3 *db = pParse->db;
4400aa3231fSdrh     addModuleArgument(pParse, pParse->pNewTable, sqlite3DbStrNDup(db, z, n));
441b9bb7c18Sdrh   }
442b9bb7c18Sdrh }
443b9bb7c18Sdrh 
444b9bb7c18Sdrh /*
445b9bb7c18Sdrh ** The parser calls this routine after the CREATE VIRTUAL TABLE statement
446b9bb7c18Sdrh ** has been completely parsed.
447b9bb7c18Sdrh */
sqlite3VtabFinishParse(Parse * pParse,Token * pEnd)448b9bb7c18Sdrh void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
449595a523aSdanielk1977   Table *pTab = pParse->pNewTable;  /* The table being constructed */
450595a523aSdanielk1977   sqlite3 *db = pParse->db;         /* The database connection */
451b9bb7c18Sdrh 
452595a523aSdanielk1977   if( pTab==0 ) return;
45378b2fa86Sdrh   assert( IsVirtual(pTab) );
454b9bb7c18Sdrh   addArgumentToVtab(pParse);
45533b3933cSdanielk1977   pParse->sArg.z = 0;
456f38524d2Sdrh   if( pTab->u.vtab.nArg<1 ) return;
457b9bb7c18Sdrh 
458b9bb7c18Sdrh   /* If the CREATE VIRTUAL TABLE statement is being entered for the
459b9bb7c18Sdrh   ** first time (in other words if the virtual table is actually being
4601e32bed3Sdrh   ** created now instead of just being read out of sqlite_schema) then
461b9bb7c18Sdrh   ** do additional initialization work and store the statement text
4621e32bed3Sdrh   ** in the sqlite_schema table.
463b9bb7c18Sdrh   */
464b9bb7c18Sdrh   if( !db->init.busy ){
465b9bb7c18Sdrh     char *zStmt;
46678efaba1Sdanielk1977     char *zWhere;
467b9bb7c18Sdrh     int iDb;
4687377945aSdan     int iReg;
469b9bb7c18Sdrh     Vdbe *v;
470b9bb7c18Sdrh 
4718e8c8896Sdrh     sqlite3MayAbort(pParse);
4728e8c8896Sdrh 
473b9bb7c18Sdrh     /* Compute the complete text of the CREATE VIRTUAL TABLE statement */
474b9bb7c18Sdrh     if( pEnd ){
475b27b7f5dSdrh       pParse->sNameToken.n = (int)(pEnd->z - pParse->sNameToken.z) + pEnd->n;
476b9bb7c18Sdrh     }
4771e536953Sdanielk1977     zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken);
478b9bb7c18Sdrh 
479b9bb7c18Sdrh     /* A slot for the record has already been allocated in the
480346a70caSdrh     ** schema table.  We just need to update that slot with all
48178efaba1Sdanielk1977     ** the information we've collected.
48278efaba1Sdanielk1977     **
483b7654111Sdrh     ** The VM register number pParse->regRowid holds the rowid of an
4841e32bed3Sdrh     ** entry in the sqlite_schema table tht was created for this vtab
485b7654111Sdrh     ** by sqlite3StartTable().
486b9bb7c18Sdrh     */
487b9bb7c18Sdrh     iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
488b9bb7c18Sdrh     sqlite3NestedParse(pParse,
489a4a871c2Sdrh       "UPDATE %Q." LEGACY_SCHEMA_TABLE " "
49078efaba1Sdanielk1977          "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
491b7654111Sdrh        "WHERE rowid=#%d",
492346a70caSdrh       db->aDb[iDb].zDbSName,
493b9bb7c18Sdrh       pTab->zName,
494b9bb7c18Sdrh       pTab->zName,
495b7654111Sdrh       zStmt,
496b7654111Sdrh       pParse->regRowid
497b9bb7c18Sdrh     );
498b9bb7c18Sdrh     v = sqlite3GetVdbe(pParse);
4999cbf3425Sdrh     sqlite3ChangeCookie(pParse, iDb);
50078efaba1Sdanielk1977 
50101c736dbSdrh     sqlite3VdbeAddOp0(v, OP_Expire);
502f4f31df0Sdrh     zWhere = sqlite3MPrintf(db, "name=%Q AND sql=%Q", pTab->zName, zStmt);
5036a5a13dfSdan     sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere, 0);
504f4f31df0Sdrh     sqlite3DbFree(db, zStmt);
5057377945aSdan 
5067377945aSdan     iReg = ++pParse->nMem;
507076e85f5Sdrh     sqlite3VdbeLoadString(v, iReg, pTab->zName);
5087377945aSdan     sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg);
509ddfec00dSdrh   }else{
5101e32bed3Sdrh     /* If we are rereading the sqlite_schema table create the in-memory
511ddfec00dSdrh     ** record of the table. */
51278efaba1Sdanielk1977     Table *pOld;
51378efaba1Sdanielk1977     Schema *pSchema = pTab->pSchema;
51478efaba1Sdanielk1977     const char *zName = pTab->zName;
515ddfec00dSdrh     assert( zName!=0 );
516ddfec00dSdrh     sqlite3MarkAllShadowTablesOf(db, pTab);
517acbcb7e0Sdrh     pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab);
51878efaba1Sdanielk1977     if( pOld ){
5194a642b60Sdrh       sqlite3OomFault(db);
52078efaba1Sdanielk1977       assert( pTab==pOld );  /* Malloc must have failed inside HashInsert() */
52178efaba1Sdanielk1977       return;
52278efaba1Sdanielk1977     }
5237e6ebfb2Sdanielk1977     pParse->pNewTable = 0;
524b9bb7c18Sdrh   }
525b9bb7c18Sdrh }
526b9bb7c18Sdrh 
527b9bb7c18Sdrh /*
528b9bb7c18Sdrh ** The parser calls this routine when it sees the first token
529b9bb7c18Sdrh ** of an argument to the module name in a CREATE VIRTUAL TABLE statement.
530b9bb7c18Sdrh */
sqlite3VtabArgInit(Parse * pParse)531b9bb7c18Sdrh void sqlite3VtabArgInit(Parse *pParse){
532b9bb7c18Sdrh   addArgumentToVtab(pParse);
53333b3933cSdanielk1977   pParse->sArg.z = 0;
53433b3933cSdanielk1977   pParse->sArg.n = 0;
535b9bb7c18Sdrh }
536b9bb7c18Sdrh 
537b9bb7c18Sdrh /*
538b9bb7c18Sdrh ** The parser calls this routine for each token after the first token
539b9bb7c18Sdrh ** in an argument to the module name in a CREATE VIRTUAL TABLE statement.
540b9bb7c18Sdrh */
sqlite3VtabArgExtend(Parse * pParse,Token * p)541b9bb7c18Sdrh void sqlite3VtabArgExtend(Parse *pParse, Token *p){
54233b3933cSdanielk1977   Token *pArg = &pParse->sArg;
54333b3933cSdanielk1977   if( pArg->z==0 ){
54433b3933cSdanielk1977     pArg->z = p->z;
54533b3933cSdanielk1977     pArg->n = p->n;
54633b3933cSdanielk1977   }else{
547542a176dSdrh     assert(pArg->z <= p->z);
548b27b7f5dSdrh     pArg->n = (int)(&p->z[p->n] - pArg->z);
549b9bb7c18Sdrh   }
550b9bb7c18Sdrh }
551b9bb7c18Sdrh 
55278efaba1Sdanielk1977 /*
5539da9d471Sdanielk1977 ** Invoke a virtual table constructor (either xCreate or xConnect). The
5549da9d471Sdanielk1977 ** pointer to the function to invoke is passed as the fourth parameter
5559da9d471Sdanielk1977 ** to this procedure.
5569da9d471Sdanielk1977 */
vtabCallConstructor(sqlite3 * db,Table * pTab,Module * pMod,int (* xConstruct)(sqlite3 *,void *,int,const char * const *,sqlite3_vtab **,char **),char ** pzErr)5579da9d471Sdanielk1977 static int vtabCallConstructor(
5589da9d471Sdanielk1977   sqlite3 *db,
5599da9d471Sdanielk1977   Table *pTab,
560d1ab1ba5Sdanielk1977   Module *pMod,
561e4102960Sdrh   int (*xConstruct)(sqlite3*,void*,int,const char*const*,sqlite3_vtab**,char**),
5629da9d471Sdanielk1977   char **pzErr
5639da9d471Sdanielk1977 ){
56475395ccdSdan   VtabCtx sCtx;
565595a523aSdanielk1977   VTable *pVTable;
5669da9d471Sdanielk1977   int rc;
56778b2fa86Sdrh   const char *const*azArg;
568f38524d2Sdrh   int nArg = pTab->u.vtab.nArg;
5694ca8aac2Sdrh   char *zErr = 0;
57075395ccdSdan   char *zModuleName;
57141fb5cd1Sdan   int iDb;
57275395ccdSdan   VtabCtx *pCtx;
5739da9d471Sdanielk1977 
57478b2fa86Sdrh   assert( IsVirtual(pTab) );
57578b2fa86Sdrh   azArg = (const char *const*)pTab->u.vtab.azArg;
57678b2fa86Sdrh 
57775395ccdSdan   /* Check that the virtual-table is not already being initialized */
57875395ccdSdan   for(pCtx=db->pVtabCtx; pCtx; pCtx=pCtx->pPrior){
57975395ccdSdan     if( pCtx->pTab==pTab ){
58075395ccdSdan       *pzErr = sqlite3MPrintf(db,
58175395ccdSdan           "vtable constructor called recursively: %s", pTab->zName
58275395ccdSdan       );
58375395ccdSdan       return SQLITE_LOCKED;
58475395ccdSdan     }
58575395ccdSdan   }
58675395ccdSdan 
5873ee1416bSdrh   zModuleName = sqlite3DbStrDup(db, pTab->zName);
58801256832Sdanielk1977   if( !zModuleName ){
589fad3039cSmistachkin     return SQLITE_NOMEM_BKPT;
59001256832Sdanielk1977   }
59101256832Sdanielk1977 
5923ee1416bSdrh   pVTable = sqlite3MallocZero(sizeof(VTable));
593595a523aSdanielk1977   if( !pVTable ){
5943ee1416bSdrh     sqlite3OomFault(db);
595595a523aSdanielk1977     sqlite3DbFree(db, zModuleName);
596fad3039cSmistachkin     return SQLITE_NOMEM_BKPT;
597595a523aSdanielk1977   }
598595a523aSdanielk1977   pVTable->db = db;
599595a523aSdanielk1977   pVTable->pMod = pMod;
6002928a15bSdrh   pVTable->eVtabRisk = SQLITE_VTABRISK_Normal;
601595a523aSdanielk1977 
60241fb5cd1Sdan   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
603f38524d2Sdrh   pTab->u.vtab.azArg[1] = db->aDb[iDb].zDbSName;
60441fb5cd1Sdan 
605595a523aSdanielk1977   /* Invoke the virtual table constructor */
606b061d058Sdan   assert( &db->pVtabCtx );
607b061d058Sdan   assert( xConstruct );
608b061d058Sdan   sCtx.pTab = pTab;
609b061d058Sdan   sCtx.pVTable = pVTable;
61075395ccdSdan   sCtx.pPrior = db->pVtabCtx;
61175395ccdSdan   sCtx.bDeclared = 0;
612b061d058Sdan   db->pVtabCtx = &sCtx;
613595a523aSdanielk1977   rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr);
61475395ccdSdan   db->pVtabCtx = sCtx.pPrior;
6154a642b60Sdrh   if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
61675395ccdSdan   assert( sCtx.pTab==pTab );
6179da9d471Sdanielk1977 
6189da9d471Sdanielk1977   if( SQLITE_OK!=rc ){
6194ca8aac2Sdrh     if( zErr==0 ){
6201e536953Sdanielk1977       *pzErr = sqlite3MPrintf(db, "vtable constructor failed: %s", zModuleName);
621fe1368eeSdrh     }else {
6221e536953Sdanielk1977       *pzErr = sqlite3MPrintf(db, "%s", zErr);
623b975598eSdrh       sqlite3_free(zErr);
624fe1368eeSdrh     }
625595a523aSdanielk1977     sqlite3DbFree(db, pVTable);
626595a523aSdanielk1977   }else if( ALWAYS(pVTable->pVtab) ){
627595a523aSdanielk1977     /* Justification of ALWAYS():  A correct vtab constructor must allocate
628595a523aSdanielk1977     ** the sqlite3_vtab object if successful.  */
6295604cc0dSdrh     memset(pVTable->pVtab, 0, sizeof(pVTable->pVtab[0]));
630595a523aSdanielk1977     pVTable->pVtab->pModule = pMod->pModule;
631cc5979dbSdrh     pMod->nRefModule++;
632595a523aSdanielk1977     pVTable->nRef = 1;
63375395ccdSdan     if( sCtx.bDeclared==0 ){
6349da9d471Sdanielk1977       const char *zFormat = "vtable constructor did not declare schema: %s";
6351e536953Sdanielk1977       *pzErr = sqlite3MPrintf(db, zFormat, pTab->zName);
636595a523aSdanielk1977       sqlite3VtabUnlock(pVTable);
6379da9d471Sdanielk1977       rc = SQLITE_ERROR;
638595a523aSdanielk1977     }else{
639034ca14fSdanielk1977       int iCol;
640c1431144Sdrh       u16 oooHidden = 0;
641595a523aSdanielk1977       /* If everything went according to plan, link the new VTable structure
642f38524d2Sdrh       ** into the linked list headed by pTab->u.vtab.p. Then loop through the
643595a523aSdanielk1977       ** columns of the table to see if any of them contain the token "hidden".
644a371ace4Sdrh       ** If so, set the Column COLFLAG_HIDDEN flag and remove the token from
645595a523aSdanielk1977       ** the type string.  */
646f38524d2Sdrh       pVTable->pNext = pTab->u.vtab.p;
647f38524d2Sdrh       pTab->u.vtab.p = pVTable;
648595a523aSdanielk1977 
649034ca14fSdanielk1977       for(iCol=0; iCol<pTab->nCol; iCol++){
650d7564865Sdrh         char *zType = sqlite3ColumnType(&pTab->aCol[iCol], "");
651034ca14fSdanielk1977         int nType;
652034ca14fSdanielk1977         int i = 0;
653ea678832Sdrh         nType = sqlite3Strlen30(zType);
654034ca14fSdanielk1977         for(i=0; i<nType; i++){
655d7564865Sdrh           if( 0==sqlite3StrNICmp("hidden", &zType[i], 6)
656d7564865Sdrh            && (i==0 || zType[i-1]==' ')
657d7564865Sdrh            && (zType[i+6]=='\0' || zType[i+6]==' ')
658034ca14fSdanielk1977           ){
659034ca14fSdanielk1977             break;
660034ca14fSdanielk1977           }
661034ca14fSdanielk1977         }
662034ca14fSdanielk1977         if( i<nType ){
663034ca14fSdanielk1977           int j;
664034ca14fSdanielk1977           int nDel = 6 + (zType[i+6] ? 1 : 0);
665034ca14fSdanielk1977           for(j=i; (j+nDel)<=nType; j++){
666034ca14fSdanielk1977             zType[j] = zType[j+nDel];
667034ca14fSdanielk1977           }
668034ca14fSdanielk1977           if( zType[i]=='\0' && i>0 ){
669034ca14fSdanielk1977             assert(zType[i-1]==' ');
670034ca14fSdanielk1977             zType[i-1] = '\0';
671034ca14fSdanielk1977           }
672a371ace4Sdrh           pTab->aCol[iCol].colFlags |= COLFLAG_HIDDEN;
6736f6e60ddSdrh           pTab->tabFlags |= TF_HasHidden;
674a21f78b9Sdrh           oooHidden = TF_OOOHidden;
675a21f78b9Sdrh         }else{
676a21f78b9Sdrh           pTab->tabFlags |= oooHidden;
677034ca14fSdanielk1977         }
678034ca14fSdanielk1977       }
679034ca14fSdanielk1977     }
680595a523aSdanielk1977   }
681595a523aSdanielk1977 
682595a523aSdanielk1977   sqlite3DbFree(db, zModuleName);
6839da9d471Sdanielk1977   return rc;
6849da9d471Sdanielk1977 }
6859da9d471Sdanielk1977 
6869da9d471Sdanielk1977 /*
6877e6ebfb2Sdanielk1977 ** This function is invoked by the parser to call the xConnect() method
688fe3fcbe2Sdanielk1977 ** of the virtual table pTab. If an error occurs, an error code is returned
689fe3fcbe2Sdanielk1977 ** and an error left in pParse.
690fe3fcbe2Sdanielk1977 **
691fe3fcbe2Sdanielk1977 ** This call is a no-op if table pTab is not a virtual table.
6927e6ebfb2Sdanielk1977 */
sqlite3VtabCallConnect(Parse * pParse,Table * pTab)6937e6ebfb2Sdanielk1977 int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){
694595a523aSdanielk1977   sqlite3 *db = pParse->db;
695595a523aSdanielk1977   const char *zMod;
696d1ab1ba5Sdanielk1977   Module *pMod;
697595a523aSdanielk1977   int rc;
6987e6ebfb2Sdanielk1977 
699748ce211Sdrh   assert( pTab );
70006b7281cSdrh   assert( IsVirtual(pTab) );
70106b7281cSdrh   if( sqlite3GetVTable(db, pTab) ){
7027e6ebfb2Sdanielk1977     return SQLITE_OK;
7037e6ebfb2Sdanielk1977   }
7047e6ebfb2Sdanielk1977 
705595a523aSdanielk1977   /* Locate the required virtual table module */
706f38524d2Sdrh   zMod = pTab->u.vtab.azArg[0];
707acbcb7e0Sdrh   pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);
708595a523aSdanielk1977 
709d1ab1ba5Sdanielk1977   if( !pMod ){
710f38524d2Sdrh     const char *zModule = pTab->u.vtab.azArg[0];
711a4e76367Sdanielk1977     sqlite3ErrorMsg(pParse, "no such module: %s", zModule);
7127e6ebfb2Sdanielk1977     rc = SQLITE_ERROR;
7137e6ebfb2Sdanielk1977   }else{
7149da9d471Sdanielk1977     char *zErr = 0;
715d1ab1ba5Sdanielk1977     rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xConnect, &zErr);
7169da9d471Sdanielk1977     if( rc!=SQLITE_OK ){
7179da9d471Sdanielk1977       sqlite3ErrorMsg(pParse, "%s", zErr);
7187524b613Sdrh       pParse->rc = rc;
7197e6ebfb2Sdanielk1977     }
720633e6d57Sdrh     sqlite3DbFree(db, zErr);
7217e6ebfb2Sdanielk1977   }
7227e6ebfb2Sdanielk1977 
7237e6ebfb2Sdanielk1977   return rc;
7247e6ebfb2Sdanielk1977 }
7259da9d471Sdanielk1977 /*
7262cac2078Sdan ** Grow the db->aVTrans[] array so that there is room for at least one
7272cac2078Sdan ** more v-table. Return SQLITE_NOMEM if a malloc fails, or SQLITE_OK otherwise.
728e7ff403aSdanielk1977 */
growVTrans(sqlite3 * db)7292cac2078Sdan static int growVTrans(sqlite3 *db){
730e7ff403aSdanielk1977   const int ARRAY_INCR = 5;
731e7ff403aSdanielk1977 
732e7ff403aSdanielk1977   /* Grow the sqlite3.aVTrans array if required */
733e7ff403aSdanielk1977   if( (db->nVTrans%ARRAY_INCR)==0 ){
734595a523aSdanielk1977     VTable **aVTrans;
7350aa3231fSdrh     sqlite3_int64 nBytes = sizeof(sqlite3_vtab*)*
7360aa3231fSdrh                                  ((sqlite3_int64)db->nVTrans + ARRAY_INCR);
73726783a58Sdanielk1977     aVTrans = sqlite3DbRealloc(db, (void *)db->aVTrans, nBytes);
738e7ff403aSdanielk1977     if( !aVTrans ){
739fad3039cSmistachkin       return SQLITE_NOMEM_BKPT;
740e7ff403aSdanielk1977     }
741e7ff403aSdanielk1977     memset(&aVTrans[db->nVTrans], 0, sizeof(sqlite3_vtab *)*ARRAY_INCR);
742e7ff403aSdanielk1977     db->aVTrans = aVTrans;
743e7ff403aSdanielk1977   }
744e7ff403aSdanielk1977 
7452cac2078Sdan   return SQLITE_OK;
7462cac2078Sdan }
7472cac2078Sdan 
7482cac2078Sdan /*
7492cac2078Sdan ** Add the virtual table pVTab to the array sqlite3.aVTrans[]. Space should
7502cac2078Sdan ** have already been reserved using growVTrans().
7512cac2078Sdan */
addToVTrans(sqlite3 * db,VTable * pVTab)7522cac2078Sdan static void addToVTrans(sqlite3 *db, VTable *pVTab){
753e7ff403aSdanielk1977   /* Add pVtab to the end of sqlite3.aVTrans */
754595a523aSdanielk1977   db->aVTrans[db->nVTrans++] = pVTab;
755595a523aSdanielk1977   sqlite3VtabLock(pVTab);
756e7ff403aSdanielk1977 }
757e7ff403aSdanielk1977 
758e7ff403aSdanielk1977 /*
7599da9d471Sdanielk1977 ** This function is invoked by the vdbe to call the xCreate method
7609da9d471Sdanielk1977 ** of the virtual table named zTab in database iDb.
7619da9d471Sdanielk1977 **
7622e5c5052Sdrh ** If an error occurs, *pzErr is set to point to an English language
7639da9d471Sdanielk1977 ** description of the error and an SQLITE_XXX error code is returned.
764633e6d57Sdrh ** In this case the caller must call sqlite3DbFree(db, ) on *pzErr.
7659da9d471Sdanielk1977 */
sqlite3VtabCallCreate(sqlite3 * db,int iDb,const char * zTab,char ** pzErr)7669da9d471Sdanielk1977 int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){
7679da9d471Sdanielk1977   int rc = SQLITE_OK;
7689da9d471Sdanielk1977   Table *pTab;
769d1ab1ba5Sdanielk1977   Module *pMod;
770595a523aSdanielk1977   const char *zMod;
7719da9d471Sdanielk1977 
77269c33826Sdrh   pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName);
773f38524d2Sdrh   assert( pTab && IsVirtual(pTab) && !pTab->u.vtab.p );
774595a523aSdanielk1977 
775595a523aSdanielk1977   /* Locate the required virtual table module */
776f38524d2Sdrh   zMod = pTab->u.vtab.azArg[0];
777acbcb7e0Sdrh   pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);
7789da9d471Sdanielk1977 
7799da9d471Sdanielk1977   /* If the module has been registered and includes a Create method,
7809da9d471Sdanielk1977   ** invoke it now. If the module has not been registered, return an
7819da9d471Sdanielk1977   ** error. Otherwise, do nothing.
7829da9d471Sdanielk1977   */
783d8b1bfc6Sdrh   if( pMod==0 || pMod->pModule->xCreate==0 || pMod->pModule->xDestroy==0 ){
784595a523aSdanielk1977     *pzErr = sqlite3MPrintf(db, "no such module: %s", zMod);
7859da9d471Sdanielk1977     rc = SQLITE_ERROR;
7869da9d471Sdanielk1977   }else{
787d1ab1ba5Sdanielk1977     rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xCreate, pzErr);
7889da9d471Sdanielk1977   }
7899da9d471Sdanielk1977 
790748ce211Sdrh   /* Justification of ALWAYS():  The xConstructor method is required to
791748ce211Sdrh   ** create a valid sqlite3_vtab if it returns SQLITE_OK. */
792595a523aSdanielk1977   if( rc==SQLITE_OK && ALWAYS(sqlite3GetVTable(db, pTab)) ){
7932cac2078Sdan     rc = growVTrans(db);
7942cac2078Sdan     if( rc==SQLITE_OK ){
7952cac2078Sdan       addToVTrans(db, sqlite3GetVTable(db, pTab));
7962cac2078Sdan     }
797e7ff403aSdanielk1977   }
798e7ff403aSdanielk1977 
7999da9d471Sdanielk1977   return rc;
8009da9d471Sdanielk1977 }
801be8a7835Sdanielk1977 
802be8a7835Sdanielk1977 /*
803fe3fcbe2Sdanielk1977 ** This function is used to set the schema of a virtual table.  It is only
804fe3fcbe2Sdanielk1977 ** valid to call this function from within the xCreate() or xConnect() of a
805fe3fcbe2Sdanielk1977 ** virtual table module.
806fe3fcbe2Sdanielk1977 */
sqlite3_declare_vtab(sqlite3 * db,const char * zCreateTable)8077e6ebfb2Sdanielk1977 int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
8084e23536eSdan   VtabCtx *pCtx;
8097e6ebfb2Sdanielk1977   int rc = SQLITE_OK;
81027641703Sdrh   Table *pTab;
8116903bf6dSdrh   Parse sParse;
812ebd1ff62Sdrh   int initBusy;
8137e6ebfb2Sdanielk1977 
8149ca95730Sdrh #ifdef SQLITE_ENABLE_API_ARMOR
81596c707a3Sdrh   if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){
81696c707a3Sdrh     return SQLITE_MISUSE_BKPT;
81796c707a3Sdrh   }
8189ca95730Sdrh #endif
81927641703Sdrh   sqlite3_mutex_enter(db->mutex);
8204e23536eSdan   pCtx = db->pVtabCtx;
82175395ccdSdan   if( !pCtx || pCtx->bDeclared ){
82213f40da3Sdrh     sqlite3Error(db, SQLITE_MISUSE);
82327641703Sdrh     sqlite3_mutex_leave(db->mutex);
824413c3d36Sdrh     return SQLITE_MISUSE_BKPT;
8257e6ebfb2Sdanielk1977   }
82675395ccdSdan   pTab = pCtx->pTab;
82744266ec6Sdrh   assert( IsVirtual(pTab) );
8287e6ebfb2Sdanielk1977 
829c692df27Sdrh   sqlite3ParseObjectInit(&sParse, db);
830cf8f2895Sdan   sParse.eParseMode = PARSE_MODE_DECLARE_VTAB;
8311a25be1aSdrh   sParse.disableTriggers = 1;
832ebd1ff62Sdrh   /* We should never be able to reach this point while loading the
833ebd1ff62Sdrh   ** schema.  Nevertheless, defend against that (turn off db->init.busy)
834ebd1ff62Sdrh   ** in case a bug arises. */
835ebd1ff62Sdrh   assert( db->init.busy==0 );
836ebd1ff62Sdrh   initBusy = db->init.busy;
837ebd1ff62Sdrh   db->init.busy = 0;
8386903bf6dSdrh   sParse.nQueryLoop = 1;
83954bc6381Sdrh   if( SQLITE_OK==sqlite3RunParser(&sParse, zCreateTable)
84016118265Sdrh    && ALWAYS(sParse.pNewTable!=0)
84116118265Sdrh    && ALWAYS(!db->mallocFailed)
842f38524d2Sdrh    && IsOrdinaryTable(sParse.pNewTable)
8437e6ebfb2Sdanielk1977   ){
84454bc6381Sdrh     assert( sParse.zErrMsg==0 );
845595a523aSdanielk1977     if( !pTab->aCol ){
8466903bf6dSdrh       Table *pNew = sParse.pNewTable;
847273bfe9fSdrh       Index *pIdx;
84862340f84Sdrh       pTab->aCol = pNew->aCol;
849f38524d2Sdrh       sqlite3ExprListDelete(db, pNew->u.tab.pDfltList);
8507dec804dSdrh       pTab->nNVCol = pTab->nCol = pNew->nCol;
8517edcf627Sdrh       pTab->tabFlags |= pNew->tabFlags & (TF_WithoutRowid|TF_NoVisibleRowid);
85262340f84Sdrh       pNew->nCol = 0;
85362340f84Sdrh       pNew->aCol = 0;
854273bfe9fSdrh       assert( pTab->pIndex==0 );
855e3740f27Sdrh       assert( HasRowid(pNew) || sqlite3PrimaryKeyIndex(pNew)!=0 );
856e3740f27Sdrh       if( !HasRowid(pNew)
857e3740f27Sdrh        && pCtx->pVTable->pMod->pModule->xUpdate!=0
858e3740f27Sdrh        && sqlite3PrimaryKeyIndex(pNew)->nKeyCol!=1
859e3740f27Sdrh       ){
860e3740f27Sdrh         /* WITHOUT ROWID virtual tables must either be read-only (xUpdate==0)
861e3740f27Sdrh         ** or else must have a single-column PRIMARY KEY */
862ac9c3d2cSdrh         rc = SQLITE_ERROR;
863ac9c3d2cSdrh       }
864273bfe9fSdrh       pIdx = pNew->pIndex;
865273bfe9fSdrh       if( pIdx ){
866273bfe9fSdrh         assert( pIdx->pNext==0 );
867273bfe9fSdrh         pTab->pIndex = pIdx;
86862340f84Sdrh         pNew->pIndex = 0;
869273bfe9fSdrh         pIdx->pTable = pTab;
870273bfe9fSdrh       }
871595a523aSdanielk1977     }
87275395ccdSdan     pCtx->bDeclared = 1;
8737e6ebfb2Sdanielk1977   }else{
87454bc6381Sdrh     sqlite3ErrorWithMsg(db, SQLITE_ERROR,
87554bc6381Sdrh           (sParse.zErrMsg ? "%s" : 0), sParse.zErrMsg);
87654bc6381Sdrh     sqlite3DbFree(db, sParse.zErrMsg);
8777e6ebfb2Sdanielk1977     rc = SQLITE_ERROR;
8787e6ebfb2Sdanielk1977   }
879cf8f2895Sdan   sParse.eParseMode = PARSE_MODE_NORMAL;
8807e6ebfb2Sdanielk1977 
8816903bf6dSdrh   if( sParse.pVdbe ){
8826903bf6dSdrh     sqlite3VdbeFinalize(sParse.pVdbe);
883238746a6Sdanielk1977   }
8846903bf6dSdrh   sqlite3DeleteTable(db, sParse.pNewTable);
885c692df27Sdrh   sqlite3ParseObjectReset(&sParse);
886ebd1ff62Sdrh   db->init.busy = initBusy;
8877e6ebfb2Sdanielk1977 
8884ac285a1Sdrh   assert( (rc&0xff)==rc );
88927641703Sdrh   rc = sqlite3ApiExit(db, rc);
89027641703Sdrh   sqlite3_mutex_leave(db->mutex);
89127641703Sdrh   return rc;
8927e6ebfb2Sdanielk1977 }
8937e6ebfb2Sdanielk1977 
8947e6ebfb2Sdanielk1977 /*
8959e39ce87Sdanielk1977 ** This function is invoked by the vdbe to call the xDestroy method
8969e39ce87Sdanielk1977 ** of the virtual table named zTab in database iDb. This occurs
8979e39ce87Sdanielk1977 ** when a DROP TABLE is mentioned.
8989e39ce87Sdanielk1977 **
8999e39ce87Sdanielk1977 ** This call is a no-op if zTab is not a virtual table.
9009e39ce87Sdanielk1977 */
sqlite3VtabCallDestroy(sqlite3 * db,int iDb,const char * zTab)901748ce211Sdrh int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab){
9029e39ce87Sdanielk1977   int rc = SQLITE_OK;
9039e39ce87Sdanielk1977   Table *pTab;
9049e39ce87Sdanielk1977 
90569c33826Sdrh   pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName);
9067b108e4cSdrh   if( ALWAYS(pTab!=0)
9077b108e4cSdrh    && ALWAYS(IsVirtual(pTab))
9087b108e4cSdrh    && ALWAYS(pTab->u.vtab.p!=0)
9097b108e4cSdrh   ){
910a68d6282Sdrh     VTable *p;
911197d59ffSmistachkin     int (*xDestroy)(sqlite3_vtab *);
912f38524d2Sdrh     for(p=pTab->u.vtab.p; p; p=p->pNext){
913a68d6282Sdrh       assert( p->pVtab );
914a68d6282Sdrh       if( p->pVtab->nRef>0 ){
915a68d6282Sdrh         return SQLITE_LOCKED;
916a68d6282Sdrh       }
917a68d6282Sdrh     }
918a68d6282Sdrh     p = vtabDisconnectAll(db, pTab);
919197d59ffSmistachkin     xDestroy = p->pMod->pModule->xDestroy;
920a1ca00edSdrh     if( xDestroy==0 ) xDestroy = p->pMod->pModule->xDisconnect;
921a1ca00edSdrh     assert( xDestroy!=0 );
922c589acbcSdan     pTab->nTabRef++;
923a1ca00edSdrh     rc = xDestroy(p->pVtab);
924595a523aSdanielk1977     /* Remove the sqlite3_vtab* from the aVTrans[] array, if applicable */
9259e39ce87Sdanielk1977     if( rc==SQLITE_OK ){
926f38524d2Sdrh       assert( pTab->u.vtab.p==p && p->pNext==0 );
927595a523aSdanielk1977       p->pVtab = 0;
928f38524d2Sdrh       pTab->u.vtab.p = 0;
929595a523aSdanielk1977       sqlite3VtabUnlock(p);
9309e39ce87Sdanielk1977     }
931c589acbcSdan     sqlite3DeleteTable(db, pTab);
9329e39ce87Sdanielk1977   }
9339e39ce87Sdanielk1977 
9349e39ce87Sdanielk1977   return rc;
9359e39ce87Sdanielk1977 }
9369e39ce87Sdanielk1977 
937f9e7dda7Sdanielk1977 /*
938e7ff403aSdanielk1977 ** This function invokes either the xRollback or xCommit method
939e7ff403aSdanielk1977 ** of each of the virtual tables in the sqlite3.aVTrans array. The method
940e7ff403aSdanielk1977 ** called is identified by the second argument, "offset", which is
941e7ff403aSdanielk1977 ** the offset of the method to call in the sqlite3_module structure.
942e7ff403aSdanielk1977 **
943e7ff403aSdanielk1977 ** The array is cleared after invoking the callbacks.
944e7ff403aSdanielk1977 */
callFinaliser(sqlite3 * db,int offset)9457209c697Sdrh static void callFinaliser(sqlite3 *db, int offset){
946e7ff403aSdanielk1977   int i;
9470b83fa82Sdanielk1977   if( db->aVTrans ){
948e4bec379Sdan     VTable **aVTrans = db->aVTrans;
949e4bec379Sdan     db->aVTrans = 0;
950748ce211Sdrh     for(i=0; i<db->nVTrans; i++){
951e4bec379Sdan       VTable *pVTab = aVTrans[i];
952595a523aSdanielk1977       sqlite3_vtab *p = pVTab->pVtab;
953595a523aSdanielk1977       if( p ){
954e7ff403aSdanielk1977         int (*x)(sqlite3_vtab *);
955595a523aSdanielk1977         x = *(int (**)(sqlite3_vtab *))((char *)p->pModule + offset);
956595a523aSdanielk1977         if( x ) x(p);
957595a523aSdanielk1977       }
958346506f9Sdrh       pVTab->iSavepoint = 0;
959595a523aSdanielk1977       sqlite3VtabUnlock(pVTab);
960e7ff403aSdanielk1977     }
961e4bec379Sdan     sqlite3DbFree(db, aVTrans);
962e7ff403aSdanielk1977     db->nVTrans = 0;
963e7ff403aSdanielk1977   }
9640b83fa82Sdanielk1977 }
965e7ff403aSdanielk1977 
966e7ff403aSdanielk1977 /*
9673e3a84d3Sdanielk1977 ** Invoke the xSync method of all virtual tables in the sqlite3.aVTrans
9683e3a84d3Sdanielk1977 ** array. Return the error code for the first error that occurs, or
9693e3a84d3Sdanielk1977 ** SQLITE_OK if all xSync operations are successful.
9703e3a84d3Sdanielk1977 **
971016f7811Sdan ** If an error message is available, leave it in p->zErrMsg.
972f9e7dda7Sdanielk1977 */
sqlite3VtabSync(sqlite3 * db,Vdbe * p)973016f7811Sdan int sqlite3VtabSync(sqlite3 *db, Vdbe *p){
974e7ff403aSdanielk1977   int i;
975e7ff403aSdanielk1977   int rc = SQLITE_OK;
976595a523aSdanielk1977   VTable **aVTrans = db->aVTrans;
97720b1eaffSdanielk1977 
97820b1eaffSdanielk1977   db->aVTrans = 0;
979748ce211Sdrh   for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){
980e7ff403aSdanielk1977     int (*x)(sqlite3_vtab *);
981595a523aSdanielk1977     sqlite3_vtab *pVtab = aVTrans[i]->pVtab;
982595a523aSdanielk1977     if( pVtab && (x = pVtab->pModule->xSync)!=0 ){
983e7ff403aSdanielk1977       rc = x(pVtab);
984016f7811Sdan       sqlite3VtabImportErrmsg(p, pVtab);
985e7ff403aSdanielk1977     }
986e7ff403aSdanielk1977   }
98720b1eaffSdanielk1977   db->aVTrans = aVTrans;
988e7ff403aSdanielk1977   return rc;
989f9e7dda7Sdanielk1977 }
990f9e7dda7Sdanielk1977 
991f9e7dda7Sdanielk1977 /*
992f9e7dda7Sdanielk1977 ** Invoke the xRollback method of all virtual tables in the
993f9e7dda7Sdanielk1977 ** sqlite3.aVTrans array. Then clear the array itself.
994f9e7dda7Sdanielk1977 */
sqlite3VtabRollback(sqlite3 * db)995f9e7dda7Sdanielk1977 int sqlite3VtabRollback(sqlite3 *db){
9967209c697Sdrh   callFinaliser(db, offsetof(sqlite3_module,xRollback));
997e7ff403aSdanielk1977   return SQLITE_OK;
998f9e7dda7Sdanielk1977 }
999f9e7dda7Sdanielk1977 
1000f9e7dda7Sdanielk1977 /*
1001f9e7dda7Sdanielk1977 ** Invoke the xCommit method of all virtual tables in the
1002f9e7dda7Sdanielk1977 ** sqlite3.aVTrans array. Then clear the array itself.
1003f9e7dda7Sdanielk1977 */
sqlite3VtabCommit(sqlite3 * db)1004f9e7dda7Sdanielk1977 int sqlite3VtabCommit(sqlite3 *db){
10057209c697Sdrh   callFinaliser(db, offsetof(sqlite3_module,xCommit));
1006e7ff403aSdanielk1977   return SQLITE_OK;
1007f9e7dda7Sdanielk1977 }
1008f9e7dda7Sdanielk1977 
1009f9e7dda7Sdanielk1977 /*
1010f9e7dda7Sdanielk1977 ** If the virtual table pVtab supports the transaction interface
1011f9e7dda7Sdanielk1977 ** (xBegin/xRollback/xCommit and optionally xSync) and a transaction is
1012f9e7dda7Sdanielk1977 ** not currently open, invoke the xBegin method now.
1013f9e7dda7Sdanielk1977 **
1014f9e7dda7Sdanielk1977 ** If the xBegin call is successful, place the sqlite3_vtab pointer
1015f9e7dda7Sdanielk1977 ** in the sqlite3.aVTrans array.
1016f9e7dda7Sdanielk1977 */
sqlite3VtabBegin(sqlite3 * db,VTable * pVTab)1017595a523aSdanielk1977 int sqlite3VtabBegin(sqlite3 *db, VTable *pVTab){
1018f9e7dda7Sdanielk1977   int rc = SQLITE_OK;
101920b1eaffSdanielk1977   const sqlite3_module *pModule;
102020b1eaffSdanielk1977 
102120b1eaffSdanielk1977   /* Special case: If db->aVTrans is NULL and db->nVTrans is greater
102220b1eaffSdanielk1977   ** than zero, then this function is being called from within a
102320b1eaffSdanielk1977   ** virtual module xSync() callback. It is illegal to write to
1024748ce211Sdrh   ** virtual module tables in this case, so return SQLITE_LOCKED.
102520b1eaffSdanielk1977   */
1026093e0f6fSdanielk1977   if( sqlite3VtabInSync(db) ){
102720b1eaffSdanielk1977     return SQLITE_LOCKED;
102820b1eaffSdanielk1977   }
1029595a523aSdanielk1977   if( !pVTab ){
103020b1eaffSdanielk1977     return SQLITE_OK;
103120b1eaffSdanielk1977   }
1032595a523aSdanielk1977   pModule = pVTab->pVtab->pModule;
103320b1eaffSdanielk1977 
1034f9e7dda7Sdanielk1977   if( pModule->xBegin ){
1035f9e7dda7Sdanielk1977     int i;
1036f9e7dda7Sdanielk1977 
1037f9e7dda7Sdanielk1977     /* If pVtab is already in the aVTrans array, return early */
1038748ce211Sdrh     for(i=0; i<db->nVTrans; i++){
1039595a523aSdanielk1977       if( db->aVTrans[i]==pVTab ){
1040f9e7dda7Sdanielk1977         return SQLITE_OK;
1041f9e7dda7Sdanielk1977       }
1042f9e7dda7Sdanielk1977     }
1043f9e7dda7Sdanielk1977 
10442cac2078Sdan     /* Invoke the xBegin method. If successful, add the vtab to the
10452cac2078Sdan     ** sqlite3.aVTrans[] array. */
10462cac2078Sdan     rc = growVTrans(db);
10472cac2078Sdan     if( rc==SQLITE_OK ){
1048595a523aSdanielk1977       rc = pModule->xBegin(pVTab->pVtab);
10493e3a84d3Sdanielk1977       if( rc==SQLITE_OK ){
105065c4f591Sdan         int iSvpt = db->nStatement + db->nSavepoint;
10512cac2078Sdan         addToVTrans(db, pVTab);
1052914b7e42Sdan         if( iSvpt && pModule->xSavepoint ){
1053914b7e42Sdan           pVTab->iSavepoint = iSvpt;
1054914b7e42Sdan           rc = pModule->xSavepoint(pVTab->pVtab, iSvpt-1);
1055914b7e42Sdan         }
10562cac2078Sdan       }
1057f9e7dda7Sdanielk1977     }
10583e3a84d3Sdanielk1977   }
1059f9e7dda7Sdanielk1977   return rc;
1060f9e7dda7Sdanielk1977 }
1061f9e7dda7Sdanielk1977 
1062d9495cd0Sdan /*
1063d9495cd0Sdan ** Invoke either the xSavepoint, xRollbackTo or xRelease method of all
1064d9495cd0Sdan ** virtual tables that currently have an open transaction. Pass iSavepoint
1065d9495cd0Sdan ** as the second argument to the virtual table method invoked.
1066d9495cd0Sdan **
1067d9495cd0Sdan ** If op is SAVEPOINT_BEGIN, the xSavepoint method is invoked. If it is
1068d9495cd0Sdan ** SAVEPOINT_ROLLBACK, the xRollbackTo method. Otherwise, if op is
1069d9495cd0Sdan ** SAVEPOINT_RELEASE, then the xRelease method of each virtual table with
1070d9495cd0Sdan ** an open transaction is invoked.
1071d9495cd0Sdan **
1072d9495cd0Sdan ** If any virtual table method returns an error code other than SQLITE_OK,
1073d9495cd0Sdan ** processing is abandoned and the error returned to the caller of this
1074d9495cd0Sdan ** function immediately. If all calls to virtual table methods are successful,
1075d9495cd0Sdan ** SQLITE_OK is returned.
1076d9495cd0Sdan */
sqlite3VtabSavepoint(sqlite3 * db,int op,int iSavepoint)1077a311b803Sdan int sqlite3VtabSavepoint(sqlite3 *db, int op, int iSavepoint){
1078a311b803Sdan   int rc = SQLITE_OK;
1079a311b803Sdan 
1080a311b803Sdan   assert( op==SAVEPOINT_RELEASE||op==SAVEPOINT_ROLLBACK||op==SAVEPOINT_BEGIN );
1081ea8562edSdan   assert( iSavepoint>=-1 );
1082d9495cd0Sdan   if( db->aVTrans ){
1083d9495cd0Sdan     int i;
1084a311b803Sdan     for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){
1085e4855224Sdrh       VTable *pVTab = db->aVTrans[i];
1086e4855224Sdrh       const sqlite3_module *pMod = pVTab->pMod->pModule;
1087341cadeeSdan       if( pVTab->pVtab && pMod->iVersion>=2 ){
1088d9495cd0Sdan         int (*xMethod)(sqlite3_vtab *, int);
108983a635a2Sdan         sqlite3VtabLock(pVTab);
1090a311b803Sdan         switch( op ){
1091a311b803Sdan           case SAVEPOINT_BEGIN:
1092d9495cd0Sdan             xMethod = pMod->xSavepoint;
1093346506f9Sdrh             pVTab->iSavepoint = iSavepoint+1;
1094a311b803Sdan             break;
1095a311b803Sdan           case SAVEPOINT_ROLLBACK:
1096d9495cd0Sdan             xMethod = pMod->xRollbackTo;
1097a311b803Sdan             break;
1098a311b803Sdan           default:
1099d9495cd0Sdan             xMethod = pMod->xRelease;
1100a311b803Sdan             break;
1101a311b803Sdan         }
1102346506f9Sdrh         if( xMethod && pVTab->iSavepoint>iSavepoint ){
1103341cadeeSdan           rc = xMethod(pVTab->pVtab, iSavepoint);
1104346506f9Sdrh         }
110583a635a2Sdan         sqlite3VtabUnlock(pVTab);
1106d9495cd0Sdan       }
1107a311b803Sdan     }
1108a311b803Sdan   }
1109a311b803Sdan   return rc;
1110a311b803Sdan }
1111a311b803Sdan 
1112b7f6f68fSdrh /*
1113b7f6f68fSdrh ** The first parameter (pDef) is a function implementation.  The
1114b7f6f68fSdrh ** second parameter (pExpr) is the first argument to this function.
1115b7f6f68fSdrh ** If pExpr is a column in a virtual table, then let the virtual
1116b7f6f68fSdrh ** table implementation have an opportunity to overload the function.
1117b7f6f68fSdrh **
1118b7f6f68fSdrh ** This routine is used to allow virtual table implementations to
1119b7f6f68fSdrh ** overload MATCH, LIKE, GLOB, and REGEXP operators.
1120b7f6f68fSdrh **
1121b7f6f68fSdrh ** Return either the pDef argument (indicating no change) or a
1122b7f6f68fSdrh ** new FuncDef structure that is marked as ephemeral using the
1123b7f6f68fSdrh ** SQLITE_FUNC_EPHEM flag.
1124b7f6f68fSdrh */
sqlite3VtabOverloadFunction(sqlite3 * db,FuncDef * pDef,int nArg,Expr * pExpr)1125b7f6f68fSdrh FuncDef *sqlite3VtabOverloadFunction(
112617435752Sdrh   sqlite3 *db,    /* Database connection for reporting malloc problems */
1127b7f6f68fSdrh   FuncDef *pDef,  /* Function to possibly overload */
1128b7f6f68fSdrh   int nArg,       /* Number of arguments to the function */
1129b7f6f68fSdrh   Expr *pExpr     /* First argument to the function */
1130b7f6f68fSdrh ){
1131b7f6f68fSdrh   Table *pTab;
1132b7f6f68fSdrh   sqlite3_vtab *pVtab;
1133b7f6f68fSdrh   sqlite3_module *pMod;
11342d80151fSdrh   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**) = 0;
1135dc5ea5c7Sdrh   void *pArg = 0;
1136b7f6f68fSdrh   FuncDef *pNew;
1137777b17afSdrh   int rc = 0;
1138b7f6f68fSdrh 
1139b7f6f68fSdrh   /* Check to see the left operand is a column in a virtual table */
1140748ce211Sdrh   if( NEVER(pExpr==0) ) return pDef;
1141b7f6f68fSdrh   if( pExpr->op!=TK_COLUMN ) return pDef;
1142477572b9Sdrh   assert( ExprUseYTab(pExpr) );
1143eda079cdSdrh   pTab = pExpr->y.pTab;
1144*63b3a64cSdrh   if( NEVER(pTab==0) ) return pDef;
114544266ec6Sdrh   if( !IsVirtual(pTab) ) return pDef;
1146595a523aSdanielk1977   pVtab = sqlite3GetVTable(db, pTab)->pVtab;
1147b7f6f68fSdrh   assert( pVtab!=0 );
1148b7f6f68fSdrh   assert( pVtab->pModule!=0 );
11495bd270b2Sdanielk1977   pMod = (sqlite3_module *)pVtab->pModule;
1150b7f6f68fSdrh   if( pMod->xFindFunction==0 ) return pDef;
1151b7f6f68fSdrh 
1152b72e88d7Srse   /* Call the xFindFunction method on the virtual table implementation
115392011847Sdrh   ** to see if the implementation wants to overload this function.
115492011847Sdrh   **
115592011847Sdrh   ** Though undocumented, we have historically always invoked xFindFunction
115692011847Sdrh   ** with an all lower-case function name.  Continue in this tradition to
115792011847Sdrh   ** avoid any chance of an incompatibility.
1158a70034deSdrh   */
115992011847Sdrh #ifdef SQLITE_DEBUG
116092011847Sdrh   {
116192011847Sdrh     int i;
116292011847Sdrh     for(i=0; pDef->zName[i]; i++){
116392011847Sdrh       unsigned char x = (unsigned char)pDef->zName[i];
116492011847Sdrh       assert( x==sqlite3UpperToLower[x] );
1165a70034deSdrh     }
116617435752Sdrh   }
116792011847Sdrh #endif
116892011847Sdrh   rc = pMod->xFindFunction(pVtab, nArg, pDef->zName, &xSFunc, &pArg);
1169a70034deSdrh   if( rc==0 ){
1170b7f6f68fSdrh     return pDef;
1171b7f6f68fSdrh   }
1172b7f6f68fSdrh 
1173b7f6f68fSdrh   /* Create a new ephemeral function definition for the overloaded
1174b7f6f68fSdrh   ** function */
1175ea678832Sdrh   pNew = sqlite3DbMallocZero(db, sizeof(*pNew)
1176e25a50b6Sdanielk1977                              + sqlite3Strlen30(pDef->zName) + 1);
1177b7f6f68fSdrh   if( pNew==0 ){
1178b7f6f68fSdrh     return pDef;
1179b7f6f68fSdrh   }
1180b7f6f68fSdrh   *pNew = *pDef;
11816ad224e9Sdrh   pNew->zName = (const char*)&pNew[1];
11826ad224e9Sdrh   memcpy((char*)&pNew[1], pDef->zName, sqlite3Strlen30(pDef->zName)+1);
11832d80151fSdrh   pNew->xSFunc = xSFunc;
1184b7f6f68fSdrh   pNew->pUserData = pArg;
1185d36e1041Sdrh   pNew->funcFlags |= SQLITE_FUNC_EPHEM;
1186b7f6f68fSdrh   return pNew;
1187b7f6f68fSdrh }
1188b7f6f68fSdrh 
11894f3dd150Sdrh /*
11904f3dd150Sdrh ** Make sure virtual table pTab is contained in the pParse->apVirtualLock[]
11914f3dd150Sdrh ** array so that an OP_VBegin will get generated for it.  Add pTab to the
11924f3dd150Sdrh ** array if it is missing.  If pTab is already in the array, this routine
11934f3dd150Sdrh ** is a no-op.
11944f3dd150Sdrh */
sqlite3VtabMakeWritable(Parse * pParse,Table * pTab)11954f3dd150Sdrh void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){
119665a7cd16Sdan   Parse *pToplevel = sqlite3ParseToplevel(pParse);
11974f3dd150Sdrh   int i, n;
1198748ce211Sdrh   Table **apVtabLock;
1199748ce211Sdrh 
12004f3dd150Sdrh   assert( IsVirtual(pTab) );
120165a7cd16Sdan   for(i=0; i<pToplevel->nVtabLock; i++){
120265a7cd16Sdan     if( pTab==pToplevel->apVtabLock[i] ) return;
12034f3dd150Sdrh   }
120465a7cd16Sdan   n = (pToplevel->nVtabLock+1)*sizeof(pToplevel->apVtabLock[0]);
1205d924e7bcSdrh   apVtabLock = sqlite3Realloc(pToplevel->apVtabLock, n);
1206748ce211Sdrh   if( apVtabLock ){
120765a7cd16Sdan     pToplevel->apVtabLock = apVtabLock;
120865a7cd16Sdan     pToplevel->apVtabLock[pToplevel->nVtabLock++] = pTab;
1209344c38e3Sdrh   }else{
12104a642b60Sdrh     sqlite3OomFault(pToplevel->db);
12114f3dd150Sdrh   }
12124f3dd150Sdrh }
12134f3dd150Sdrh 
1214ef45bb75Sdrh /*
12150b2c140aSdrh ** Check to see if virtual table module pMod can be have an eponymous
121651be3873Sdrh ** virtual table instance.  If it can, create one if one does not already
1217bd24e8faSdan ** exist. Return non-zero if either the eponymous virtual table instance
1218bd24e8faSdan ** exists when this routine returns or if an attempt to create it failed
1219bd24e8faSdan ** and an error message was left in pParse.
122051be3873Sdrh **
122151be3873Sdrh ** An eponymous virtual table instance is one that is named after its
122251be3873Sdrh ** module, and more importantly, does not require a CREATE VIRTUAL TABLE
122351be3873Sdrh ** statement in order to come into existance.  Eponymous virtual table
122451be3873Sdrh ** instances always exist.  They cannot be DROP-ed.
122551be3873Sdrh **
122651be3873Sdrh ** Any virtual table module for which xConnect and xCreate are the same
122751be3873Sdrh ** method can have an eponymous virtual table instance.
122851be3873Sdrh */
sqlite3VtabEponymousTableInit(Parse * pParse,Module * pMod)122951be3873Sdrh int sqlite3VtabEponymousTableInit(Parse *pParse, Module *pMod){
123051be3873Sdrh   const sqlite3_module *pModule = pMod->pModule;
123151be3873Sdrh   Table *pTab;
123251be3873Sdrh   char *zErr = 0;
123351be3873Sdrh   int rc;
123451be3873Sdrh   sqlite3 *db = pParse->db;
123551be3873Sdrh   if( pMod->pEpoTab ) return 1;
1236398f872dSdrh   if( pModule->xCreate!=0 && pModule->xCreate!=pModule->xConnect ) return 0;
12370b2c140aSdrh   pTab = sqlite3DbMallocZero(db, sizeof(Table));
123851be3873Sdrh   if( pTab==0 ) return 0;
12390b2c140aSdrh   pTab->zName = sqlite3DbStrDup(db, pMod->zName);
12400b2c140aSdrh   if( pTab->zName==0 ){
12410b2c140aSdrh     sqlite3DbFree(db, pTab);
12420b2c140aSdrh     return 0;
12430b2c140aSdrh   }
124451be3873Sdrh   pMod->pEpoTab = pTab;
124579df7782Sdrh   pTab->nTabRef = 1;
1246f38524d2Sdrh   pTab->eTabType = TABTYP_VTAB;
124751be3873Sdrh   pTab->pSchema = db->aDb[0].pSchema;
1248f38524d2Sdrh   assert( pTab->u.vtab.nArg==0 );
1249509c3fc0Sdrh   pTab->iPKey = -1;
12503d8c92d0Sdrh   pTab->tabFlags |= TF_Eponymous;
12510aa3231fSdrh   addModuleArgument(pParse, pTab, sqlite3DbStrDup(db, pTab->zName));
12520aa3231fSdrh   addModuleArgument(pParse, pTab, 0);
12530aa3231fSdrh   addModuleArgument(pParse, pTab, sqlite3DbStrDup(db, pTab->zName));
125451be3873Sdrh   rc = vtabCallConstructor(db, pTab, pMod, pModule->xConnect, &zErr);
125551be3873Sdrh   if( rc ){
125651be3873Sdrh     sqlite3ErrorMsg(pParse, "%s", zErr);
125751be3873Sdrh     sqlite3DbFree(db, zErr);
125851be3873Sdrh     sqlite3VtabEponymousTableClear(db, pMod);
125951be3873Sdrh   }
126051be3873Sdrh   return 1;
126151be3873Sdrh }
126251be3873Sdrh 
126351be3873Sdrh /*
126451be3873Sdrh ** Erase the eponymous virtual table instance associated with
126551be3873Sdrh ** virtual table module pMod, if it exists.
126651be3873Sdrh */
sqlite3VtabEponymousTableClear(sqlite3 * db,Module * pMod)126751be3873Sdrh void sqlite3VtabEponymousTableClear(sqlite3 *db, Module *pMod){
126851be3873Sdrh   Table *pTab = pMod->pEpoTab;
1269d7fd6aa4Sdrh   if( pTab!=0 ){
12700b2c140aSdrh     /* Mark the table as Ephemeral prior to deleting it, so that the
12710b2c140aSdrh     ** sqlite3DeleteTable() routine will know that it is not stored in
12720b2c140aSdrh     ** the schema. */
12730b2c140aSdrh     pTab->tabFlags |= TF_Ephemeral;
12740b2c140aSdrh     sqlite3DeleteTable(db, pTab);
127551be3873Sdrh     pMod->pEpoTab = 0;
127651be3873Sdrh   }
127751be3873Sdrh }
127851be3873Sdrh 
127951be3873Sdrh /*
1280ef45bb75Sdrh ** Return the ON CONFLICT resolution mode in effect for the virtual
1281ef45bb75Sdrh ** table update operation currently in progress.
1282ef45bb75Sdrh **
1283ef45bb75Sdrh ** The results of this routine are undefined unless it is called from
1284ef45bb75Sdrh ** within an xUpdate method.
1285ef45bb75Sdrh */
sqlite3_vtab_on_conflict(sqlite3 * db)1286b061d058Sdan int sqlite3_vtab_on_conflict(sqlite3 *db){
1287ef45bb75Sdrh   static const unsigned char aMap[] = {
128887f67bf1Sdrh     SQLITE_ROLLBACK, SQLITE_ABORT, SQLITE_FAIL, SQLITE_IGNORE, SQLITE_REPLACE
1289b061d058Sdan   };
12909ca95730Sdrh #ifdef SQLITE_ENABLE_API_ARMOR
12919ca95730Sdrh   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
12929ca95730Sdrh #endif
1293b061d058Sdan   assert( OE_Rollback==1 && OE_Abort==2 && OE_Fail==3 );
1294b061d058Sdan   assert( OE_Ignore==4 && OE_Replace==5 );
1295b061d058Sdan   assert( db->vtabOnConflict>=1 && db->vtabOnConflict<=5 );
1296ef45bb75Sdrh   return (int)aMap[db->vtabOnConflict-1];
1297b061d058Sdan }
1298b061d058Sdan 
1299ef45bb75Sdrh /*
1300ef45bb75Sdrh ** Call from within the xCreate() or xConnect() methods to provide
1301ef45bb75Sdrh ** the SQLite core with additional information about the behavior
1302ef45bb75Sdrh ** of the virtual table being implemented.
1303ef45bb75Sdrh */
sqlite3_vtab_config(sqlite3 * db,int op,...)1304b061d058Sdan int sqlite3_vtab_config(sqlite3 *db, int op, ...){
1305b061d058Sdan   va_list ap;
1306b061d058Sdan   int rc = SQLITE_OK;
13072928a15bSdrh   VtabCtx *p;
1308b061d058Sdan 
13099ca95730Sdrh #ifdef SQLITE_ENABLE_API_ARMOR
13109ca95730Sdrh   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
13119ca95730Sdrh #endif
1312b061d058Sdan   sqlite3_mutex_enter(db->mutex);
13132928a15bSdrh   p = db->pVtabCtx;
1314b061d058Sdan   if( !p ){
1315b061d058Sdan     rc = SQLITE_MISUSE_BKPT;
1316b061d058Sdan   }else{
131744266ec6Sdrh     assert( p->pTab==0 || IsVirtual(p->pTab) );
13182928a15bSdrh     va_start(ap, op);
13192928a15bSdrh     switch( op ){
13202928a15bSdrh       case SQLITE_VTAB_CONSTRAINT_SUPPORT: {
1321b061d058Sdan         p->pVTable->bConstraint = (u8)va_arg(ap, int);
1322b061d058Sdan         break;
1323b061d058Sdan       }
13242928a15bSdrh       case SQLITE_VTAB_INNOCUOUS: {
13252928a15bSdrh         p->pVTable->eVtabRisk = SQLITE_VTABRISK_Low;
13262928a15bSdrh         break;
13272928a15bSdrh       }
13282928a15bSdrh       case SQLITE_VTAB_DIRECTONLY: {
13292928a15bSdrh         p->pVTable->eVtabRisk = SQLITE_VTABRISK_High;
13302928a15bSdrh         break;
13312928a15bSdrh       }
13322928a15bSdrh       default: {
1333b061d058Sdan         rc = SQLITE_MISUSE_BKPT;
1334b061d058Sdan         break;
1335b061d058Sdan       }
13362928a15bSdrh     }
1337b061d058Sdan     va_end(ap);
13382928a15bSdrh   }
1339b061d058Sdan 
134013f40da3Sdrh   if( rc!=SQLITE_OK ) sqlite3Error(db, rc);
1341b061d058Sdan   sqlite3_mutex_leave(db->mutex);
1342b061d058Sdan   return rc;
1343b061d058Sdan }
1344b061d058Sdan 
1345b9bb7c18Sdrh #endif /* SQLITE_OMIT_VIRTUALTABLE */
1346