/* ** 2019-04-17 ** ** The author disclaims copyright to this source code. 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. ** ****************************************************************************** ** ** This file contains an implementation of two eponymous virtual tables, ** "sqlite_dbdata" and "sqlite_dbptr". Both modules require that the ** "sqlite_dbpage" eponymous virtual table be available. ** ** SQLITE_DBDATA: ** sqlite_dbdata is used to extract data directly from a database b-tree ** page and its associated overflow pages, bypassing the b-tree layer. ** The table schema is equivalent to: ** ** CREATE TABLE sqlite_dbdata( ** pgno INTEGER, ** cell INTEGER, ** field INTEGER, ** value ANY, ** schema TEXT HIDDEN ** ); ** ** IMPORTANT: THE VIRTUAL TABLE SCHEMA ABOVE IS SUBJECT TO CHANGE. IN THE ** FUTURE NEW NON-HIDDEN COLUMNS MAY BE ADDED BETWEEN "value" AND ** "schema". ** ** Each page of the database is inspected. If it cannot be interpreted as ** a b-tree page, or if it is a b-tree page containing 0 entries, the ** sqlite_dbdata table contains no rows for that page. Otherwise, the ** table contains one row for each field in the record associated with ** each cell on the page. For intkey b-trees, the key value is stored in ** field -1. ** ** For example, for the database: ** ** CREATE TABLE t1(a, b); -- root page is page 2 ** INSERT INTO t1(rowid, a, b) VALUES(5, 'v', 'five'); ** INSERT INTO t1(rowid, a, b) VALUES(10, 'x', 'ten'); ** ** the sqlite_dbdata table contains, as well as from entries related to ** page 1, content equivalent to: ** ** INSERT INTO sqlite_dbdata(pgno, cell, field, value) VALUES ** (2, 0, -1, 5 ), ** (2, 0, 0, 'v' ), ** (2, 0, 1, 'five'), ** (2, 1, -1, 10 ), ** (2, 1, 0, 'x' ), ** (2, 1, 1, 'ten' ); ** ** If database corruption is encountered, this module does not report an ** error. Instead, it attempts to extract as much data as possible and ** ignores the corruption. ** ** SQLITE_DBPTR: ** The sqlite_dbptr table has the following schema: ** ** CREATE TABLE sqlite_dbptr( ** pgno INTEGER, ** child INTEGER, ** schema TEXT HIDDEN ** ); ** ** It contains one entry for each b-tree pointer between a parent and ** child page in the database. */ #if !defined(SQLITEINT_H) #include "sqlite3ext.h" typedef unsigned char u8; #endif SQLITE_EXTENSION_INIT1 #include <string.h> #include <assert.h> #define DBDATA_PADDING_BYTES 100 typedef struct DbdataTable DbdataTable; typedef struct DbdataCursor DbdataCursor; /* Cursor object */ struct DbdataCursor { sqlite3_vtab_cursor base; /* Base class. Must be first */ sqlite3_stmt *pStmt; /* For fetching database pages */ int iPgno; /* Current page number */ u8 *aPage; /* Buffer containing page */ int nPage; /* Size of aPage[] in bytes */ int nCell; /* Number of cells on aPage[] */ int iCell; /* Current cell number */ int bOnePage; /* True to stop after one page */ int szDb; sqlite3_int64 iRowid; /* Only for the sqlite_dbdata table */ u8 *pRec; /* Buffer containing current record */ int nRec; /* Size of pRec[] in bytes */ int nHdr; /* Size of header in bytes */ int iField; /* Current field number */ u8 *pHdrPtr; u8 *pPtr; sqlite3_int64 iIntkey; /* Integer key value */ }; /* Table object */ struct DbdataTable { sqlite3_vtab base; /* Base class. Must be first */ sqlite3 *db; /* The database connection */ sqlite3_stmt *pStmt; /* For fetching database pages */ int bPtr; /* True for sqlite3_dbptr table */ }; /* Column and schema definitions for sqlite_dbdata */ #define DBDATA_COLUMN_PGNO 0 #define DBDATA_COLUMN_CELL 1 #define DBDATA_COLUMN_FIELD 2 #define DBDATA_COLUMN_VALUE 3 #define DBDATA_COLUMN_SCHEMA 4 #define DBDATA_SCHEMA \ "CREATE TABLE x(" \ " pgno INTEGER," \ " cell INTEGER," \ " field INTEGER," \ " value ANY," \ " schema TEXT HIDDEN" \ ")" /* Column and schema definitions for sqlite_dbptr */ #define DBPTR_COLUMN_PGNO 0 #define DBPTR_COLUMN_CHILD 1 #define DBPTR_COLUMN_SCHEMA 2 #define DBPTR_SCHEMA \ "CREATE TABLE x(" \ " pgno INTEGER," \ " child INTEGER," \ " schema TEXT HIDDEN" \ ")" /* ** Connect to an sqlite_dbdata (pAux==0) or sqlite_dbptr (pAux!=0) virtual ** table. */ static int dbdataConnect( sqlite3 *db, void *pAux, int argc, const char *const*argv, sqlite3_vtab **ppVtab, char **pzErr ){ DbdataTable *pTab = 0; int rc = sqlite3_declare_vtab(db, pAux ? DBPTR_SCHEMA : DBDATA_SCHEMA); if( rc==SQLITE_OK ){ pTab = (DbdataTable*)sqlite3_malloc64(sizeof(DbdataTable)); if( pTab==0 ){ rc = SQLITE_NOMEM; }else{ memset(pTab, 0, sizeof(DbdataTable)); pTab->db = db; pTab->bPtr = (pAux!=0); } } *ppVtab = (sqlite3_vtab*)pTab; return rc; } /* ** Disconnect from or destroy a sqlite_dbdata or sqlite_dbptr virtual table. */ static int dbdataDisconnect(sqlite3_vtab *pVtab){ DbdataTable *pTab = (DbdataTable*)pVtab; if( pTab ){ sqlite3_finalize(pTab->pStmt); sqlite3_free(pVtab); } return SQLITE_OK; } /* ** This function interprets two types of constraints: ** ** schema=? ** pgno=? ** ** If neither are present, idxNum is set to 0. If schema=? is present, ** the 0x01 bit in idxNum is set. If pgno=? is present, the 0x02 bit ** in idxNum is set. ** ** If both parameters are present, schema is in position 0 and pgno in ** position 1. */ static int dbdataBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdx){ DbdataTable *pTab = (DbdataTable*)tab; int i; int iSchema = -1; int iPgno = -1; int colSchema = (pTab->bPtr ? DBPTR_COLUMN_SCHEMA : DBDATA_COLUMN_SCHEMA); for(i=0; i<pIdx->nConstraint; i++){ struct sqlite3_index_constraint *p = &pIdx->aConstraint[i]; if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ){ if( p->iColumn==colSchema ){ if( p->usable==0 ) return SQLITE_CONSTRAINT; iSchema = i; } if( p->iColumn==DBDATA_COLUMN_PGNO && p->usable ){ iPgno = i; } } } if( iSchema>=0 ){ pIdx->aConstraintUsage[iSchema].argvIndex = 1; pIdx->aConstraintUsage[iSchema].omit = 1; } if( iPgno>=0 ){ pIdx->aConstraintUsage[iPgno].argvIndex = 1 + (iSchema>=0); pIdx->aConstraintUsage[iPgno].omit = 1; pIdx->estimatedCost = 100; pIdx->estimatedRows = 50; if( pTab->bPtr==0 && pIdx->nOrderBy && pIdx->aOrderBy[0].desc==0 ){ int iCol = pIdx->aOrderBy[0].iColumn; if( pIdx->nOrderBy==1 ){ pIdx->orderByConsumed = (iCol==0 || iCol==1); }else if( pIdx->nOrderBy==2 && pIdx->aOrderBy[1].desc==0 && iCol==0 ){ pIdx->orderByConsumed = (pIdx->aOrderBy[1].iColumn==1); } } }else{ pIdx->estimatedCost = 100000000; pIdx->estimatedRows = 1000000000; } pIdx->idxNum = (iSchema>=0 ? 0x01 : 0x00) | (iPgno>=0 ? 0x02 : 0x00); return SQLITE_OK; } /* ** Open a new sqlite_dbdata or sqlite_dbptr cursor. */ static int dbdataOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){ DbdataCursor *pCsr; pCsr = (DbdataCursor*)sqlite3_malloc64(sizeof(DbdataCursor)); if( pCsr==0 ){ return SQLITE_NOMEM; }else{ memset(pCsr, 0, sizeof(DbdataCursor)); pCsr->base.pVtab = pVTab; } *ppCursor = (sqlite3_vtab_cursor *)pCsr; return SQLITE_OK; } /* ** Restore a cursor object to the state it was in when first allocated ** by dbdataOpen(). */ static void dbdataResetCursor(DbdataCursor *pCsr){ DbdataTable *pTab = (DbdataTable*)(pCsr->base.pVtab); if( pTab->pStmt==0 ){ pTab->pStmt = pCsr->pStmt; }else{ sqlite3_finalize(pCsr->pStmt); } pCsr->pStmt = 0; pCsr->iPgno = 1; pCsr->iCell = 0; pCsr->iField = 0; pCsr->bOnePage = 0; sqlite3_free(pCsr->aPage); sqlite3_free(pCsr->pRec); pCsr->pRec = 0; pCsr->aPage = 0; } /* ** Close an sqlite_dbdata or sqlite_dbptr cursor. */ static int dbdataClose(sqlite3_vtab_cursor *pCursor){ DbdataCursor *pCsr = (DbdataCursor*)pCursor; dbdataResetCursor(pCsr); sqlite3_free(pCsr); return SQLITE_OK; } /* ** Utility methods to decode 16 and 32-bit big-endian unsigned integers. */ static unsigned int get_uint16(unsigned char *a){ return (a[0]<<8)|a[1]; } static unsigned int get_uint32(unsigned char *a){ return ((unsigned int)a[0]<<24) | ((unsigned int)a[1]<<16) | ((unsigned int)a[2]<<8) | ((unsigned int)a[3]); } /* ** Load page pgno from the database via the sqlite_dbpage virtual table. ** If successful, set (*ppPage) to point to a buffer containing the page ** data, (*pnPage) to the size of that buffer in bytes and return ** SQLITE_OK. In this case it is the responsibility of the caller to ** eventually free the buffer using sqlite3_free(). ** ** Or, if an error occurs, set both (*ppPage) and (*pnPage) to 0 and ** return an SQLite error code. */ static int dbdataLoadPage( DbdataCursor *pCsr, /* Cursor object */ unsigned int pgno, /* Page number of page to load */ u8 **ppPage, /* OUT: pointer to page buffer */ int *pnPage /* OUT: Size of (*ppPage) in bytes */ ){ int rc2; int rc = SQLITE_OK; sqlite3_stmt *pStmt = pCsr->pStmt; *ppPage = 0; *pnPage = 0; sqlite3_bind_int64(pStmt, 2, pgno); if( SQLITE_ROW==sqlite3_step(pStmt) ){ int nCopy = sqlite3_column_bytes(pStmt, 0); if( nCopy>0 ){ u8 *pPage; pPage = (u8*)sqlite3_malloc64(nCopy + DBDATA_PADDING_BYTES); if( pPage==0 ){ rc = SQLITE_NOMEM; }else{ const u8 *pCopy = sqlite3_column_blob(pStmt, 0); memcpy(pPage, pCopy, nCopy); memset(&pPage[nCopy], 0, DBDATA_PADDING_BYTES); } *ppPage = pPage; *pnPage = nCopy; } } rc2 = sqlite3_reset(pStmt); if( rc==SQLITE_OK ) rc = rc2; return rc; } /* ** Read a varint. Put the value in *pVal and return the number of bytes. */ static int dbdataGetVarint(const u8 *z, sqlite3_int64 *pVal){ sqlite3_uint64 u = 0; int i; for(i=0; i<8; i++){ u = (u<<7) + (z[i]&0x7f); if( (z[i]&0x80)==0 ){ *pVal = (sqlite3_int64)u; return i+1; } } u = (u<<8) + (z[i]&0xff); *pVal = (sqlite3_int64)u; return 9; } /* ** Like dbdataGetVarint(), but set the output to 0 if it is less than 0 ** or greater than 0xFFFFFFFF. This can be used for all varints in an ** SQLite database except for key values in intkey tables. */ static int dbdataGetVarintU32(const u8 *z, sqlite3_int64 *pVal){ sqlite3_int64 val; int nRet = dbdataGetVarint(z, &val); if( val<0 || val>0xFFFFFFFF ) val = 0; *pVal = val; return nRet; } /* ** Return the number of bytes of space used by an SQLite value of type ** eType. */ static int dbdataValueBytes(int eType){ switch( eType ){ case 0: case 8: case 9: case 10: case 11: return 0; case 1: return 1; case 2: return 2; case 3: return 3; case 4: return 4; case 5: return 6; case 6: case 7: return 8; default: if( eType>0 ){ return ((eType-12) / 2); } return 0; } } /* ** Load a value of type eType from buffer pData and use it to set the ** result of context object pCtx. */ static void dbdataValue( sqlite3_context *pCtx, int eType, u8 *pData, int nData ){ if( eType>=0 && dbdataValueBytes(eType)<=nData ){ switch( eType ){ case 0: case 10: case 11: sqlite3_result_null(pCtx); break; case 8: sqlite3_result_int(pCtx, 0); break; case 9: sqlite3_result_int(pCtx, 1); break; case 1: case 2: case 3: case 4: case 5: case 6: case 7: { sqlite3_uint64 v = (signed char)pData[0]; pData++; switch( eType ){ case 7: case 6: v = (v<<16) + (pData[0]<<8) + pData[1]; pData += 2; case 5: v = (v<<16) + (pData[0]<<8) + pData[1]; pData += 2; case 4: v = (v<<8) + pData[0]; pData++; case 3: v = (v<<8) + pData[0]; pData++; case 2: v = (v<<8) + pData[0]; pData++; } if( eType==7 ){ double r; memcpy(&r, &v, sizeof(r)); sqlite3_result_double(pCtx, r); }else{ sqlite3_result_int64(pCtx, (sqlite3_int64)v); } break; } default: { int n = ((eType-12) / 2); if( eType % 2 ){ sqlite3_result_text(pCtx, (const char*)pData, n, SQLITE_TRANSIENT); }else{ sqlite3_result_blob(pCtx, pData, n, SQLITE_TRANSIENT); } } } } } /* ** Move an sqlite_dbdata or sqlite_dbptr cursor to the next entry. */ static int dbdataNext(sqlite3_vtab_cursor *pCursor){ DbdataCursor *pCsr = (DbdataCursor*)pCursor; DbdataTable *pTab = (DbdataTable*)pCursor->pVtab; pCsr->iRowid++; while( 1 ){ int rc; int iOff = (pCsr->iPgno==1 ? 100 : 0); int bNextPage = 0; if( pCsr->aPage==0 ){ while( 1 ){ if( pCsr->bOnePage==0 && pCsr->iPgno>pCsr->szDb ) return SQLITE_OK; rc = dbdataLoadPage(pCsr, pCsr->iPgno, &pCsr->aPage, &pCsr->nPage); if( rc!=SQLITE_OK ) return rc; if( pCsr->aPage ) break; pCsr->iPgno++; } pCsr->iCell = pTab->bPtr ? -2 : 0; pCsr->nCell = get_uint16(&pCsr->aPage[iOff+3]); } if( pTab->bPtr ){ if( pCsr->aPage[iOff]!=0x02 && pCsr->aPage[iOff]!=0x05 ){ pCsr->iCell = pCsr->nCell; } pCsr->iCell++; if( pCsr->iCell>=pCsr->nCell ){ sqlite3_free(pCsr->aPage); pCsr->aPage = 0; if( pCsr->bOnePage ) return SQLITE_OK; pCsr->iPgno++; }else{ return SQLITE_OK; } }else{ /* If there is no record loaded, load it now. */ if( pCsr->pRec==0 ){ int bHasRowid = 0; int nPointer = 0; sqlite3_int64 nPayload = 0; sqlite3_int64 nHdr = 0; int iHdr; int U, X; int nLocal; switch( pCsr->aPage[iOff] ){ case 0x02: nPointer = 4; break; case 0x0a: break; case 0x0d: bHasRowid = 1; break; default: /* This is not a b-tree page with records on it. Continue. */ pCsr->iCell = pCsr->nCell; break; } if( pCsr->iCell>=pCsr->nCell ){ bNextPage = 1; }else{ iOff += 8 + nPointer + pCsr->iCell*2; if( iOff>pCsr->nPage ){ bNextPage = 1; }else{ iOff = get_uint16(&pCsr->aPage[iOff]); } /* For an interior node cell, skip past the child-page number */ iOff += nPointer; /* Load the "byte of payload including overflow" field */ if( bNextPage || iOff>pCsr->nPage ){ bNextPage = 1; }else{ iOff += dbdataGetVarintU32(&pCsr->aPage[iOff], &nPayload); } /* If this is a leaf intkey cell, load the rowid */ if( bHasRowid && !bNextPage && iOff<pCsr->nPage ){ iOff += dbdataGetVarint(&pCsr->aPage[iOff], &pCsr->iIntkey); } /* Figure out how much data to read from the local page */ U = pCsr->nPage; if( bHasRowid ){ X = U-35; }else{ X = ((U-12)*64/255)-23; } if( nPayload<=X ){ nLocal = nPayload; }else{ int M, K; M = ((U-12)*32/255)-23; K = M+((nPayload-M)%(U-4)); if( K<=X ){ nLocal = K; }else{ nLocal = M; } } if( bNextPage || nLocal+iOff>pCsr->nPage ){ bNextPage = 1; }else{ /* Allocate space for payload. And a bit more to catch small buffer ** overruns caused by attempting to read a varint or similar from ** near the end of a corrupt record. */ pCsr->pRec = (u8*)sqlite3_malloc64(nPayload+DBDATA_PADDING_BYTES); if( pCsr->pRec==0 ) return SQLITE_NOMEM; memset(pCsr->pRec, 0, nPayload+DBDATA_PADDING_BYTES); pCsr->nRec = nPayload; /* Load the nLocal bytes of payload */ memcpy(pCsr->pRec, &pCsr->aPage[iOff], nLocal); iOff += nLocal; /* Load content from overflow pages */ if( nPayload>nLocal ){ sqlite3_int64 nRem = nPayload - nLocal; unsigned int pgnoOvfl = get_uint32(&pCsr->aPage[iOff]); while( nRem>0 ){ u8 *aOvfl = 0; int nOvfl = 0; int nCopy; rc = dbdataLoadPage(pCsr, pgnoOvfl, &aOvfl, &nOvfl); assert( rc!=SQLITE_OK || aOvfl==0 || nOvfl==pCsr->nPage ); if( rc!=SQLITE_OK ) return rc; if( aOvfl==0 ) break; nCopy = U-4; if( nCopy>nRem ) nCopy = nRem; memcpy(&pCsr->pRec[nPayload-nRem], &aOvfl[4], nCopy); nRem -= nCopy; pgnoOvfl = get_uint32(aOvfl); sqlite3_free(aOvfl); } } iHdr = dbdataGetVarintU32(pCsr->pRec, &nHdr); pCsr->nHdr = nHdr; pCsr->pHdrPtr = &pCsr->pRec[iHdr]; pCsr->pPtr = &pCsr->pRec[pCsr->nHdr]; pCsr->iField = (bHasRowid ? -1 : 0); } } }else{ pCsr->iField++; if( pCsr->iField>0 ){ sqlite3_int64 iType; if( pCsr->pHdrPtr>&pCsr->pRec[pCsr->nRec] ){ bNextPage = 1; }else{ pCsr->pHdrPtr += dbdataGetVarintU32(pCsr->pHdrPtr, &iType); pCsr->pPtr += dbdataValueBytes(iType); } } } if( bNextPage ){ sqlite3_free(pCsr->aPage); sqlite3_free(pCsr->pRec); pCsr->aPage = 0; pCsr->pRec = 0; if( pCsr->bOnePage ) return SQLITE_OK; pCsr->iPgno++; }else{ if( pCsr->iField<0 || pCsr->pHdrPtr<&pCsr->pRec[pCsr->nHdr] ){ return SQLITE_OK; } /* Advance to the next cell. The next iteration of the loop will load ** the record and so on. */ sqlite3_free(pCsr->pRec); pCsr->pRec = 0; pCsr->iCell++; } } } assert( !"can't get here" ); return SQLITE_OK; } /* ** Return true if the cursor is at EOF. */ static int dbdataEof(sqlite3_vtab_cursor *pCursor){ DbdataCursor *pCsr = (DbdataCursor*)pCursor; return pCsr->aPage==0; } /* ** Determine the size in pages of database zSchema (where zSchema is ** "main", "temp" or the name of an attached database) and set ** pCsr->szDb accordingly. If successful, return SQLITE_OK. Otherwise, ** an SQLite error code. */ static int dbdataDbsize(DbdataCursor *pCsr, const char *zSchema){ DbdataTable *pTab = (DbdataTable*)pCsr->base.pVtab; char *zSql = 0; int rc, rc2; sqlite3_stmt *pStmt = 0; zSql = sqlite3_mprintf("PRAGMA %Q.page_count", zSchema); if( zSql==0 ) return SQLITE_NOMEM; rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pStmt, 0); sqlite3_free(zSql); if( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){ pCsr->szDb = sqlite3_column_int(pStmt, 0); } rc2 = sqlite3_finalize(pStmt); if( rc==SQLITE_OK ) rc = rc2; return rc; } /* ** xFilter method for sqlite_dbdata and sqlite_dbptr. */ static int dbdataFilter( sqlite3_vtab_cursor *pCursor, int idxNum, const char *idxStr, int argc, sqlite3_value **argv ){ DbdataCursor *pCsr = (DbdataCursor*)pCursor; DbdataTable *pTab = (DbdataTable*)pCursor->pVtab; int rc = SQLITE_OK; const char *zSchema = "main"; dbdataResetCursor(pCsr); assert( pCsr->iPgno==1 ); if( idxNum & 0x01 ){ zSchema = (const char*)sqlite3_value_text(argv[0]); } if( idxNum & 0x02 ){ pCsr->iPgno = sqlite3_value_int(argv[(idxNum & 0x01)]); pCsr->bOnePage = 1; }else{ pCsr->nPage = dbdataDbsize(pCsr, zSchema); rc = dbdataDbsize(pCsr, zSchema); } if( rc==SQLITE_OK ){ if( pTab->pStmt ){ pCsr->pStmt = pTab->pStmt; pTab->pStmt = 0; }else{ rc = sqlite3_prepare_v2(pTab->db, "SELECT data FROM sqlite_dbpage(?) WHERE pgno=?", -1, &pCsr->pStmt, 0 ); } } if( rc==SQLITE_OK ){ rc = sqlite3_bind_text(pCsr->pStmt, 1, zSchema, -1, SQLITE_TRANSIENT); }else{ pTab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db)); } if( rc==SQLITE_OK ){ rc = dbdataNext(pCursor); } return rc; } /* ** Return a column for the sqlite_dbdata or sqlite_dbptr table. */ static int dbdataColumn( sqlite3_vtab_cursor *pCursor, sqlite3_context *ctx, int i ){ DbdataCursor *pCsr = (DbdataCursor*)pCursor; DbdataTable *pTab = (DbdataTable*)pCursor->pVtab; if( pTab->bPtr ){ switch( i ){ case DBPTR_COLUMN_PGNO: sqlite3_result_int64(ctx, pCsr->iPgno); break; case DBPTR_COLUMN_CHILD: { int iOff = pCsr->iPgno==1 ? 100 : 0; if( pCsr->iCell<0 ){ iOff += 8; }else{ iOff += 12 + pCsr->iCell*2; if( iOff>pCsr->nPage ) return SQLITE_OK; iOff = get_uint16(&pCsr->aPage[iOff]); } if( iOff<=pCsr->nPage ){ sqlite3_result_int64(ctx, get_uint32(&pCsr->aPage[iOff])); } break; } } }else{ switch( i ){ case DBDATA_COLUMN_PGNO: sqlite3_result_int64(ctx, pCsr->iPgno); break; case DBDATA_COLUMN_CELL: sqlite3_result_int(ctx, pCsr->iCell); break; case DBDATA_COLUMN_FIELD: sqlite3_result_int(ctx, pCsr->iField); break; case DBDATA_COLUMN_VALUE: { if( pCsr->iField<0 ){ sqlite3_result_int64(ctx, pCsr->iIntkey); }else{ sqlite3_int64 iType; dbdataGetVarintU32(pCsr->pHdrPtr, &iType); dbdataValue( ctx, iType, pCsr->pPtr, &pCsr->pRec[pCsr->nRec] - pCsr->pPtr ); } break; } } } return SQLITE_OK; } /* ** Return the rowid for an sqlite_dbdata or sqlite_dptr table. */ static int dbdataRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){ DbdataCursor *pCsr = (DbdataCursor*)pCursor; *pRowid = pCsr->iRowid; return SQLITE_OK; } /* ** Invoke this routine to register the "sqlite_dbdata" virtual table module */ static int sqlite3DbdataRegister(sqlite3 *db){ static sqlite3_module dbdata_module = { 0, /* iVersion */ 0, /* xCreate */ dbdataConnect, /* xConnect */ dbdataBestIndex, /* xBestIndex */ dbdataDisconnect, /* xDisconnect */ 0, /* xDestroy */ dbdataOpen, /* xOpen - open a cursor */ dbdataClose, /* xClose - close a cursor */ dbdataFilter, /* xFilter - configure scan constraints */ dbdataNext, /* xNext - advance a cursor */ dbdataEof, /* xEof - check for end of scan */ dbdataColumn, /* xColumn - read data */ dbdataRowid, /* xRowid - read data */ 0, /* xUpdate */ 0, /* xBegin */ 0, /* xSync */ 0, /* xCommit */ 0, /* xRollback */ 0, /* xFindMethod */ 0, /* xRename */ 0, /* xSavepoint */ 0, /* xRelease */ 0, /* xRollbackTo */ 0 /* xShadowName */ }; int rc = sqlite3_create_module(db, "sqlite_dbdata", &dbdata_module, 0); if( rc==SQLITE_OK ){ rc = sqlite3_create_module(db, "sqlite_dbptr", &dbdata_module, (void*)1); } return rc; } #ifdef _WIN32 __declspec(dllexport) #endif int sqlite3_dbdata_init( sqlite3 *db, char **pzErrMsg, const sqlite3_api_routines *pApi ){ SQLITE_EXTENSION_INIT2(pApi); return sqlite3DbdataRegister(db); }