** 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
**
** This module requires that the "sqlite_dbpage" eponymous virtual table be
** available.
+**
+**
+** CREATE TABLE sqlite_dbptr(
+** pgno INTEGER,
+** child INTEGER,
+** schema TEXT HIDDEN
+** );
*/
#if !defined(SQLITEINT_H)
#include "sqlite3ext.h"
typedef struct DbdataTable DbdataTable;
typedef struct DbdataCursor DbdataCursor;
+
/* A cursor for the sqlite_dbdata table */
struct DbdataCursor {
sqlite3_vtab_cursor base; /* Base class. Must be first */
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 */
+ sqlite3_int64 iRowid;
+
+ /* Only for the sqlite_dbdata table */
u8 *pRec; /* Buffer containing current record */
int nRec; /* Size of pRec[] in bytes */
int nField; /* Number of fields in pRec */
int iField; /* Current field number */
sqlite3_int64 iIntkey; /* Integer key value */
-
- sqlite3_int64 iRowid;
};
/* The sqlite_dbdata table */
struct DbdataTable {
sqlite3_vtab base; /* Base class. Must be first */
sqlite3 *db; /* The database connection */
+ int bPtr; /* True for sqlite3_dbptr table */
};
#define DBDATA_COLUMN_PGNO 0
#define DBDATA_COLUMN_VALUE 3
#define DBDATA_COLUMN_SCHEMA 4
+#define DBPTR_COLUMN_PGNO 0
+#define DBPTR_COLUMN_CHILD 1
+#define DBPTR_COLUMN_SCHEMA 2
+
#define DBDATA_SCHEMA \
"CREATE TABLE x(" \
" pgno INTEGER," \
" schema TEXT HIDDEN" \
")"
+#define DBPTR_SCHEMA \
+ "CREATE TABLE x(" \
+ " pgno INTEGER," \
+ " child INTEGER," \
+ " schema TEXT HIDDEN" \
+ ")"
+
/*
** Connect to the sqlite_dbdata virtual table.
*/
char **pzErr
){
DbdataTable *pTab = 0;
- int rc = sqlite3_declare_vtab(db, DBDATA_SCHEMA);
+ int rc = sqlite3_declare_vtab(db, pAux ? DBPTR_SCHEMA : DBDATA_SCHEMA);
if( rc==SQLITE_OK ){
pTab = (DbdataTable*)sqlite3_malloc64(sizeof(DbdataTable));
}else{
memset(pTab, 0, sizeof(DbdataTable));
pTab->db = db;
+ pTab->bPtr = (pAux!=0);
}
}
** position 1.
*/
static int dbdataBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+ 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<pIdxInfo->nConstraint; i++){
struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[i];
if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
- if( p->iColumn==DBDATA_COLUMN_SCHEMA ){
+ if( p->iColumn==colSchema ){
if( p->usable==0 ) return SQLITE_CONSTRAINT;
iSchema = i;
}
pCsr->iPgno = 1;
pCsr->iCell = 0;
pCsr->iField = 0;
+ pCsr->bOnePage = 0;
}
/*
** Move a dbdata cursor to the next entry in the file.
*/
static int dbdataNext(sqlite3_vtab_cursor *pCursor){
- DbdataCursor *pCsr = (DbdataCursor *)pCursor;
+ DbdataCursor *pCsr = (DbdataCursor*)pCursor;
+ DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;
pCsr->iRowid++;
while( 1 ){
int rc;
+ int iOff = (pCsr->iPgno==1 ? 100 : 0);
if( pCsr->aPage==0 ){
rc = dbdataLoadPage(pCsr, pCsr->iPgno, &pCsr->aPage, &pCsr->nPage);
- if( rc!=SQLITE_OK ) return rc;
- pCsr->iCell = 0;
- pCsr->nCell = get_uint16(&pCsr->aPage[pCsr->iPgno==1 ? 103 : 3]);
+ if( rc!=SQLITE_OK || pCsr->aPage==0 ) return rc;
+ pCsr->iCell = pTab->bPtr ? -2 : 0;
+ pCsr->nCell = get_uint16(&pCsr->aPage[iOff+3]);
}
- /* If there is no record loaded, load it now. */
- if( pCsr->pRec==0 ){
- int iOff = (pCsr->iPgno==1 ? 100 : 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:
- pCsr->iCell = pCsr->nCell;
- break;
+ 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;
+ }
- iOff += 8 + nPointer + pCsr->iCell*2;
- 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 */
- iOff += dbdataGetVarint(&pCsr->aPage[iOff], &nPayload);
-
- /* If this is a leaf intkey cell, load the rowid */
- if( bHasRowid ){
- iOff += dbdataGetVarint(&pCsr->aPage[iOff], &pCsr->iIntkey);
- }
-
- /* Allocate space for payload */
- pCsr->pRec = (u8*)sqlite3_malloc64(nPayload);
- if( pCsr->pRec==0 ) return SQLITE_NOMEM;
- pCsr->nRec = nPayload;
-
- 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;
+ if( pCsr->iCell>=pCsr->nCell ){
+ sqlite3_free(pCsr->aPage);
+ pCsr->aPage = 0;
+ if( pCsr->bOnePage ) return SQLITE_OK;
+ pCsr->iPgno++;
+ continue;
+ }
+
+ iOff += 8 + nPointer + pCsr->iCell*2;
+ 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 */
+ iOff += dbdataGetVarint(&pCsr->aPage[iOff], &nPayload);
+
+ /* If this is a leaf intkey cell, load the rowid */
+ if( bHasRowid ){
+ iOff += dbdataGetVarint(&pCsr->aPage[iOff], &pCsr->iIntkey);
+ }
+
+ /* Allocate space for payload */
+ pCsr->pRec = (u8*)sqlite3_malloc64(nPayload);
+ if( pCsr->pRec==0 ) return SQLITE_NOMEM;
+ pCsr->nRec = nPayload;
+
+ U = pCsr->nPage;
+ if( bHasRowid ){
+ X = U-35;
}else{
- nLocal = M;
+ X = ((U-12)*64/255)-23;
}
- }
-
- /* 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;
- u32 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 || nOvfl==pCsr->nPage );
- if( rc!=SQLITE_OK ) return rc;
-
- nCopy = U-4;
- if( nCopy>nRem ) nCopy = nRem;
- memcpy(&pCsr->pRec[nPayload-nRem], &aOvfl[4], nCopy);
- nRem -= nCopy;
-
- sqlite3_free(aOvfl);
+ 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;
+ }
}
+
+ /* 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;
+ u32 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 || nOvfl==pCsr->nPage );
+ if( rc!=SQLITE_OK ) return rc;
+
+ nCopy = U-4;
+ if( nCopy>nRem ) nCopy = nRem;
+ memcpy(&pCsr->pRec[nPayload-nRem], &aOvfl[4], nCopy);
+ nRem -= nCopy;
+
+ sqlite3_free(aOvfl);
+ }
+ }
+
+ /* Figure out how many fields in the record */
+ pCsr->nField = 0;
+ iHdr = dbdataGetVarint(pCsr->pRec, &nHdr);
+ while( iHdr<nHdr ){
+ sqlite3_int64 iDummy;
+ iHdr += dbdataGetVarint(&pCsr->pRec[iHdr], &iDummy);
+ pCsr->nField++;
+ }
+
+ pCsr->iField = (bHasRowid ? -2 : -1);
}
-
- /* Figure out how many fields in the record */
- pCsr->nField = 0;
- iHdr = dbdataGetVarint(pCsr->pRec, &nHdr);
- while( iHdr<nHdr ){
- sqlite3_int64 iDummy;
- iHdr += dbdataGetVarint(&pCsr->pRec[iHdr], &iDummy);
- pCsr->nField++;
- }
-
- pCsr->iField = (bHasRowid ? -2 : -1);
+
+ pCsr->iField++;
+ if( pCsr->iField<pCsr->nField ) 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++;
}
-
- pCsr->iField++;
- if( pCsr->iField<pCsr->nField ) 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" );
}
if( idxNum & 0x02 ){
pCsr->iPgno = sqlite3_value_int(argv[(idxNum & 0x01)]);
+ pCsr->bOnePage = 1;
}
rc = sqlite3_prepare_v2(pTab->db,
int i
){
DbdataCursor *pCsr = (DbdataCursor*)pCursor;
- 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{
- int iHdr;
- sqlite3_int64 iType;
- sqlite3_int64 iOff;
- int i;
- iHdr = dbdataGetVarint(pCsr->pRec, &iOff);
- for(i=0; i<pCsr->iField; i++){
- iHdr += dbdataGetVarint(&pCsr->pRec[iHdr], &iType);
- iOff += dbdataValueBytes(iType);
+ 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;
+ iOff = get_uint16(&pCsr->aPage[iOff]);
}
- dbdataGetVarint(&pCsr->pRec[iHdr], &iType);
-
- dbdataValue(ctx, iType, &pCsr->pRec[iOff]);
+ 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{
+ int iHdr;
+ sqlite3_int64 iType;
+ sqlite3_int64 iOff;
+ int i;
+ iHdr = dbdataGetVarint(pCsr->pRec, &iOff);
+ for(i=0; i<pCsr->iField; i++){
+ iHdr += dbdataGetVarint(&pCsr->pRec[iHdr], &iType);
+ iOff += dbdataValueBytes(iType);
+ }
+ dbdataGetVarint(&pCsr->pRec[iHdr], &iType);
+
+ dbdataValue(ctx, iType, &pCsr->pRec[iOff]);
+ }
+ break;
}
- break;
}
}
return SQLITE_OK;
0, /* xRollbackTo */
0 /* xShadowName */
};
- return sqlite3_create_module(db, "sqlite_dbdata", &dbdata_module, 0);
+
+ 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
projects / thirdparty / sqlite.git / commitdiff
