SQLite

    __ptrMap.set(this, pDb);
    __stmtMap.set(this, Object.create(null));
    try{
      // Check for per-VFS post-open SQL/callback...
      const pVfs = capi.sqlite3_js_db_vfs(pDb);
      if(!pVfs) toss3("Internal error: cannot get VFS for new db handle.");
      const postInitSql = __vfsPostOpenSql[pVfs];
      if(postInitSql){
        if(capi.sqlite3_activate_see){
          /**
             In SEE-capable builds we have to avoid running any db
             code before the client has an opportunity to apply their
             decryption key. If we first run any db code, e.g. pragma
             journal_mode=..., then it will fail with SQLITE_NOTADB
             and the db handle will be left in an unusuable
             state. Note that at this point we do not actually know
             whether the db is encrypted, but if a client has gone out
             of their way to create an SEE build, it seems safe to
             assume that they are using the encryption.
          */
          sqlite3.config.warn(
            "Disabling execution of on-open() db code "+
            "because this is an SEE build. DB: "+fnJs
          );
        }else if(postInitSql instanceof Function){
          postInitSql(this, sqlite3);
        }else{
          checkSqlite3Rc(
            pDb, capi.sqlite3_exec(pDb, postInitSql, 0, 0, 0)
          );
        }
      }
    }catch(e){
      this.close();
      throw e;
    }
  };

     C-strings allocated via WASM. `flags` is required to be a JS
     string (because it's specific to this API, which is specific
     to JS).

     For purposes of passing a DB instance to C-style sqlite3
     functions, the DB object's read-only `pointer` property holds its
     `sqlite3*` pointer value. That property can also be used to check
     whether this DB instance is still open: it will evaluate to
     `undefined` after the DB object's close() method is called.

     In the main window thread, the filenames `":localStorage:"` and
     `":sessionStorage:"` are special: they cause the db to use either
     localStorage or sessionStorage for storing the database using
     the kvvfs. If one of these names are used, they trump
     any vfs name set in the arguments.
  */