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Overview
Comment: | Add a prototype for an extension that sits in between the SQLite native code virtual table interface and a CLR IDisposable object. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | disposable-vtable |
Files: | files | file ages | folders |
SHA1: |
10bba8d0821159a45c6a0d6c3cef897c |
User & Date: | drh 2013-06-13 00:32:29.814 |
Context
2013-06-20
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00:20 | Integration adjustments for the vtshim module. (check-in: bf2e28ddb2 user: mistachkin tags: disposable-vtable) | |
2013-06-13
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00:32 | Add a prototype for an extension that sits in between the SQLite native code virtual table interface and a CLR IDisposable object. (check-in: 10bba8d082 user: drh tags: disposable-vtable) | |
2013-06-12
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20:18 | Activate the one-pass optimization. Update comments, especially the descriptions of the various objects. (check-in: e120c558a5 user: drh tags: nextgen-query-plan-exp) | |
Changes
Added ext/misc/vtshim.c.
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In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** ** A shim that sits between the SQLite virtual table interface and ** managed memory of .NET */ #include "sqlite3ext.h" SQLITE_EXTENSION_INIT1 #include <assert.h> #include <string.h> #ifndef SQLITE_OMIT_VIRTUALTABLE /* Forward references */ typedef struct vtshim_aux vtshim_aux; typedef struct vtshim_vtab vtshim_vtab; typedef struct vtshim_cursor vtshim_cursor; /* The vtshim_aux argument is the auxiliary parameter that is passed ** into sqlite3_create_module_v2(). */ struct vtshim_aux { void *pChildAux; /* pAux for child virtual tables */ void (*xChildDestroy)(void*); /* Destructor for pChildAux */ const sqlite3_module *pMod; /* Methods for child virtual tables */ sqlite3 *db; /* The database to which we are attached */ const char *zName; /* Name of the module */ int bDisposed; /* True if disposed */ vtshim_vtab *pAllVtab; /* List of all vtshim_vtab objects */ sqlite3_module sSelf; /* Methods used by this shim */ }; /* A vtshim virtual table object */ struct vtshim_vtab { sqlite3_vtab base; /* Base class - must be first */ sqlite3_vtab *pChild; /* Child virtual table */ vtshim_aux *pAux; /* Pointer to vtshim_aux object */ vtshim_cursor *pAllCur; /* List of all cursors */ vtshim_vtab **ppPrev; /* Previous on list */ vtshim_vtab *pNext; /* Next on list */ }; /* A vtshim cursor object */ struct vtshim_cursor { sqlite3_vtab_cursor base; /* Base class - must be first */ sqlite3_vtab_cursor *pChild; /* Cursor generated by the managed subclass */ vtshim_cursor **ppPrev; /* Previous on list of all cursors */ vtshim_cursor *pNext; /* Next on list of all cursors */ }; /* Methods for the vtshim module */ static int vtshimCreate( sqlite3 *db, void *pPAux, int argc, const char *const*argv, sqlite3_vtab **ppVtab, char **pzErr ){ vtshim_aux *pAux = (vtshim_aux*)pPAux; vtshim_vtab *pNew; int rc; assert( db==pAux->db ); pNew = sqlite3_malloc( sizeof(*pNew) ); *ppVtab = (sqlite3_vtab*)pNew; if( pNew==0 ) return SQLITE_NOMEM; memset(pNew, 0, sizeof(*pNew)); rc = pAux->pMod->xCreate(db, pAux->pChildAux, argc, argv, &pNew->pChild, pzErr); if( rc ){ sqlite3_free(pNew); *ppVtab = 0; } pNew->ppPrev = &pAux->pAllVtab; pNew->pNext = pAux->pAllVtab; if( pAux->pAllVtab ) pAux->pAllVtab->ppPrev = &pNew->pNext; pAux->pAllVtab = pNew; return rc; } static int vtshimConnect( sqlite3 *db, void *pPAux, int argc, const char *const*argv, sqlite3_vtab **ppVtab, char **pzErr ){ vtshim_aux *pAux = (vtshim_aux*)pPAux; vtshim_vtab *pNew; int rc; assert( db==pAux->db ); pNew = sqlite3_malloc( sizeof(*pNew) ); *ppVtab = (sqlite3_vtab*)pNew; if( pNew==0 ) return SQLITE_NOMEM; memset(pNew, 0, sizeof(*pNew)); rc = pAux->pMod->xConnect(db, pAux->pChildAux, argc, argv, &pNew->pChild, pzErr); if( rc ){ sqlite3_free(pNew); *ppVtab = 0; } pNew->ppPrev = &pAux->pAllVtab; pNew->pNext = pAux->pAllVtab; if( pAux->pAllVtab ) pAux->pAllVtab->ppPrev = &pNew->pNext; pAux->pAllVtab = pNew; return rc; } static int vtshimBestIndex( sqlite3_vtab *pBase, sqlite3_index_info *pIdxInfo ){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xBestIndex(pVtab->pChild, pIdxInfo); } static int vtshimDisconnect(sqlite3_vtab *pBase){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; int rc = SQLITE_OK; if( !pAux->bDisposed ){ rc = pAux->pMod->xDisconnect(pVtab->pChild); } if( pVtab->pNext ) pVtab->pNext->ppPrev = pVtab->ppPrev; *pVtab->ppPrev = pVtab->pNext; sqlite3_free(pVtab); return rc; } static int vtshimDestroy(sqlite3_vtab *pBase){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; int rc = SQLITE_OK; if( !pAux->bDisposed ){ rc = pAux->pMod->xDestroy(pVtab->pChild); } if( pVtab->pNext ) pVtab->pNext->ppPrev = pVtab->ppPrev; *pVtab->ppPrev = pVtab->pNext; sqlite3_free(pVtab); return rc; } static int vtshimOpen(sqlite3_vtab *pBase, sqlite3_vtab_cursor **ppCursor){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; vtshim_cursor *pCur; int rc; *ppCursor = 0; if( pAux->bDisposed ) return SQLITE_ERROR; pCur = sqlite3_malloc( sizeof(*pCur) ); if( pCur==0 ) return SQLITE_NOMEM; memset(pCur, 0, sizeof(*pCur)); rc = pAux->pMod->xOpen(pVtab->pChild, &pCur->pChild); if( rc ){ sqlite3_free(pCur); return rc; } pCur->pChild->pVtab = pVtab->pChild; *ppCursor = &pCur->base; pCur->ppPrev = &pVtab->pAllCur; if( pVtab->pAllCur ) pVtab->pAllCur->ppPrev = &pCur->pNext; pCur->pNext = pVtab->pAllCur; pVtab->pAllCur = pCur; return SQLITE_OK; } static int vtshimClose(sqlite3_vtab_cursor *pX){ vtshim_cursor *pCur = (vtshim_cursor*)pX; vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab; vtshim_aux *pAux = pVtab->pAux; int rc = SQLITE_OK; if( !pAux->bDisposed ){ rc = pAux->pMod->xClose(pCur->pChild); } if( pCur->pNext ) pCur->pNext->ppPrev = pCur->ppPrev; *pCur->ppPrev = pCur->pNext; sqlite3_free(pCur); return rc; } static int vtshimFilter( sqlite3_vtab_cursor *pX, int idxNum, const char *idxStr, int argc, sqlite3_value **argv ){ vtshim_cursor *pCur = (vtshim_cursor*)pX; vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xFilter(pCur->pChild, idxNum, idxStr, argc, argv); } static int vtshimNext(sqlite3_vtab_cursor *pX){ vtshim_cursor *pCur = (vtshim_cursor*)pX; vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xNext(pCur->pChild); } static int vtshimEof(sqlite3_vtab_cursor *pX){ vtshim_cursor *pCur = (vtshim_cursor*)pX; vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xEof(pCur->pChild); } static int vtshimColumn(sqlite3_vtab_cursor *pX, sqlite3_context *ctx, int i){ vtshim_cursor *pCur = (vtshim_cursor*)pX; vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xColumn(pCur->pChild, ctx, i); } static int vtshimRowid(sqlite3_vtab_cursor *pX, sqlite3_int64 *pRowid){ vtshim_cursor *pCur = (vtshim_cursor*)pX; vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xRowid(pCur->pChild, pRowid); } static int vtshimUpdate( sqlite3_vtab *pBase, int argc, sqlite3_value **argv, sqlite3_int64 *pRowid ){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xUpdate(pVtab->pChild, argc, argv, pRowid); } static int vtshimBegin(sqlite3_vtab *pBase){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xBegin(pVtab->pChild); } static int vtshimSync(sqlite3_vtab *pBase){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xSync(pVtab->pChild); } static int vtshimCommit(sqlite3_vtab *pBase){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xCommit(pVtab->pChild); } static int vtshimRollback(sqlite3_vtab *pBase){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xRollback(pVtab->pChild); } static int vtshimFindFunction( sqlite3_vtab *pBase, int nArg, const char *zName, void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), void **ppArg ){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xFindFunction(pVtab->pChild, nArg, zName, pxFunc, ppArg); } static int vtshimRename(sqlite3_vtab *pBase, const char *zNewName){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xRename(pVtab->pChild, zNewName); } static int vtshimSavepoint(sqlite3_vtab *pBase, int n){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xSavepoint(pVtab->pChild, n); } static int vtshimRelease(sqlite3_vtab *pBase, int n){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xRelease(pVtab->pChild, n); } static int vtshimRollbackTo(sqlite3_vtab *pBase, int n){ vtshim_vtab *pVtab = (vtshim_vtab*)pBase; vtshim_aux *pAux = pVtab->pAux; if( pAux->bDisposed ) return SQLITE_ERROR; return pAux->pMod->xRollbackTo(pVtab->pChild, n); } /* The destructor function for a disposible module */ static void vtshimAuxDestructor(void *pXAux){ vtshim_aux *pAux = (vtshim_aux*)pXAux; assert( pAux->pAllVtab==0 ); if( !pAux->bDisposed && pAux->xChildDestroy ){ pAux->xChildDestroy(pAux->pChildAux); } sqlite3_free(pAux); } #ifdef _WIN32 __declspec(dllexport) #endif void *sqlite3_create_disposable_module( sqlite3 *db, /* SQLite connection to register module with */ const char *zName, /* Name of the module */ const sqlite3_module *p, /* Methods for the module */ void *pClientData, /* Client data for xCreate/xConnect */ void(*xDestroy)(void*) /* Module destructor function */ ){ vtshim_aux *pAux; int rc; pAux = sqlite3_malloc( sizeof(*pAux) ); if( pAux==0 ){ if( xDestroy ) xDestroy(pClientData); return 0; } pAux->pChildAux = pClientData; pAux->xChildDestroy = xDestroy; pAux->pMod = p; pAux->db = db; pAux->zName = zName; pAux->bDisposed = 0; pAux->pAllVtab = 0; pAux->sSelf.iVersion = p->iVersion<=1 ? p->iVersion : 1; pAux->sSelf.xCreate = p->xCreate ? vtshimCreate : 0; pAux->sSelf.xConnect = p->xConnect ? vtshimConnect : 0; pAux->sSelf.xBestIndex = p->xBestIndex ? vtshimBestIndex : 0; pAux->sSelf.xDisconnect = p->xDisconnect ? vtshimDisconnect : 0; pAux->sSelf.xDestroy = p->xDestroy ? vtshimDestroy : 0; pAux->sSelf.xOpen = p->xOpen ? vtshimOpen : 0; pAux->sSelf.xClose = p->xClose ? vtshimClose : 0; pAux->sSelf.xFilter = p->xFilter ? vtshimFilter : 0; pAux->sSelf.xNext = p->xNext ? vtshimNext : 0; pAux->sSelf.xEof = p->xEof ? vtshimEof : 0; pAux->sSelf.xColumn = p->xColumn ? vtshimColumn : 0; pAux->sSelf.xRowid = p->xRowid ? vtshimRowid : 0; pAux->sSelf.xUpdate = p->xUpdate ? vtshimUpdate : 0; pAux->sSelf.xBegin = p->xBegin ? vtshimBegin : 0; pAux->sSelf.xSync = p->xSync ? vtshimSync : 0; pAux->sSelf.xCommit = p->xCommit ? vtshimCommit : 0; pAux->sSelf.xRollback = p->xRollback ? vtshimRollback : 0; pAux->sSelf.xFindFunction = p->xFindFunction ? vtshimFindFunction : 0; pAux->sSelf.xRename = p->xRename ? vtshimRename : 0; if( p->iVersion>=1 ){ pAux->sSelf.xSavepoint = p->xSavepoint ? vtshimSavepoint : 0; pAux->sSelf.xRelease = p->xRelease ? vtshimRelease : 0; pAux->sSelf.xRollbackTo = p->xRollbackTo ? vtshimRollbackTo : 0; }else{ pAux->sSelf.xSavepoint = 0; pAux->sSelf.xRelease = 0; pAux->sSelf.xRollbackTo = 0; } rc = sqlite3_create_module_v2(db, zName, &pAux->sSelf, pAux, vtshimAuxDestructor); return rc==SQLITE_OK ? (void*)pAux : 0; } #ifdef _WIN32 __declspec(dllexport) #endif void sqlite3_dispose_module(void *pX){ vtshim_aux *pAux = (vtshim_aux*)pX; if( !pAux->bDisposed ){ vtshim_vtab *pVtab; vtshim_cursor *pCur; for(pVtab=pAux->pAllVtab; pVtab; pVtab=pVtab->pNext){ for(pCur=pVtab->pAllCur; pCur; pCur=pCur->pNext){ pAux->pMod->xClose(pCur->pChild); } pAux->pMod->xDisconnect(pVtab->pChild); } pAux->bDisposed = 1; if( pAux->xChildDestroy ) pAux->xChildDestroy(pAux->pChildAux); } } #endif /* SQLITE_OMIT_VIRTUALTABLE */ #ifdef _WIN32 __declspec(dllexport) #endif int sqlite3_vtshim_init( sqlite3 *db, char **pzErrMsg, const sqlite3_api_routines *pApi ){ SQLITE_EXTENSION_INIT2(pApi); return SQLITE_OK; } |