SQLite

  i64 iOffset;                    /* Value of 'pgOffset' column */
  int szPage;                     /* Value of 'pgSize' column */
};

struct StatTable {
  sqlite3_vtab base;
  sqlite3 *db;
  int iDb;                        /* Index of database to analyze */
};

#ifndef get2byte
# define get2byte(x)   ((x)[0]<<8 | (x)[1])
#endif

/*
** Connect to or create a statvfs virtual table.
*/
static int statConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  StatTable *pTab = 0;
  int rc = SQLITE_OK;
  int iDb;

  if( argc>=4 ){
    iDb = sqlite3FindDbName(db, argv[3]);
    if( iDb<0 ){
      *pzErr = sqlite3_mprintf("no such database: %s", argv[3]);
      return SQLITE_ERROR;
    }
  }else{
    iDb = 0;
  }
  rc = sqlite3_declare_vtab(db, VTAB_SCHEMA);
  if( rc==SQLITE_OK ){
    pTab = (StatTable *)sqlite3_malloc64(sizeof(StatTable));
    if( pTab==0 ) rc = SQLITE_NOMEM;
  }

  assert( rc==SQLITE_OK || pTab==0 );
  if( rc==SQLITE_OK ){
    memset(pTab, 0, sizeof(StatTable));
    pTab->db = db;
    pTab->iDb = iDb;
  }

  *ppVtab = (sqlite3_vtab*)pTab;
  return rc;
}

/*

  StatCursor *pCsr;
  int rc;

  pCsr = (StatCursor *)sqlite3_malloc64(sizeof(StatCursor));
  if( pCsr==0 ){
    rc = SQLITE_NOMEM;
  }else{
    char *zSql;
    memset(pCsr, 0, sizeof(StatCursor));
    pCsr->base.pVtab = pVTab;

    zSql = sqlite3_mprintf(
        "SELECT 'sqlite_master' AS name, 1 AS rootpage, 'table' AS type"
        "  UNION ALL  "
        "SELECT name, rootpage, type"
        "  FROM \"%w\".sqlite_master WHERE rootpage!=0"
        "  ORDER BY name", pTab->db->aDb[pTab->iDb].zName);
    if( zSql==0 ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
      sqlite3_free(zSql);
    }
    if( rc!=SQLITE_OK ){
      sqlite3_free(pCsr);
      pCsr = 0;
    }
  }

  *ppCursor = (sqlite3_vtab_cursor *)pCsr;

/*
** Populate the pCsr->iOffset and pCsr->szPage member variables. Based on
** the current value of pCsr->iPageno.
*/
static void statSizeAndOffset(StatCursor *pCsr){
  StatTable *pTab = (StatTable *)((sqlite3_vtab_cursor *)pCsr)->pVtab;
  Btree *pBt = pTab->db->aDb[pTab->iDb].pBt;
  Pager *pPager = sqlite3BtreePager(pBt);
  sqlite3_file *fd;
  sqlite3_int64 x[2];

  /* The default page size and offset */
  pCsr->szPage = sqlite3BtreeGetPageSize(pBt);
  pCsr->iOffset = (i64)pCsr->szPage * (pCsr->iPageno - 1);

  /* If connected to a ZIPVFS backend, override the page size and
  ** offset with actual values obtained from ZIPVFS.
  */
  fd = sqlite3PagerFile(pPager);
  x[0] = pCsr->iPageno;
  if( fd->pMethods!=0 && sqlite3OsFileControl(fd, 230440, &x)==SQLITE_OK ){
    pCsr->iOffset = x[0];
    pCsr->szPage = (int)x[1];
  }
}

/*
** Move a statvfs cursor to the next entry in the file.
*/
static int statNext(sqlite3_vtab_cursor *pCursor){
  int rc;
  int nPayload;
  StatCursor *pCsr = (StatCursor *)pCursor;
  StatTable *pTab = (StatTable *)pCursor->pVtab;
  Btree *pBt = pTab->db->aDb[pTab->iDb].pBt;
  Pager *pPager = sqlite3BtreePager(pBt);

  sqlite3_free(pCsr->zPath);
  pCsr->zPath = 0;

statNextRestart:
  if( pCsr->aPage[0].pPg==0 ){

db close
forcedelete test.db
sqlite3 db test.db
register_dbstat_vtab db
do_execsql_test stat-5.1 {
  PRAGMA auto_vacuum = OFF;
  CREATE TABLE tx(y);
  ATTACH ':memory:' AS aux1;
  CREATE VIRTUAL TABLE temp.stat USING dbstat(aux1);
  CREATE TABLE aux1.t1(x);
  INSERT INTO t1 VALUES(zeroblob(1513));
  INSERT INTO t1 VALUES(zeroblob(1514));
  SELECT name, path, pageno, pagetype, ncell, payload, unused, mx_payload
    FROM stat WHERE name = 't1';
} [list \
  t1 / 2 leaf 2 993 5 1517                \
  t1 /000+000000 3 overflow 0 1020 0 0    \
  t1 /001+000000 4 overflow 0 1020 0 0    \
]

do_catchsql_test stat-6.1 {
  CREATE VIRTUAL TABLE temp.s2 USING dbstat(mainx);
} {1 {no such database: mainx}}

finish_test