Low Level Functions >

Purpose

Set the current fysical position of an open file

Prototype

FUNCTION _BtGetDirect ( hFile AS PTR, dwPosition AS DWORD, ptrData AS PTR, nRecLen REF WORD, ptrKey AS PTR, nKeyNum AS BYTE, nLockBias AS WORD ) AS LOGIC PASCAL

Argument(s)

<hFile>

File handle that was returned by _BtOpen

Physical position that you want to set

Pointer to the databuffer that you want to fill

Length of the data structure. This value must be at least as long as the fixed-length portion of the record.

Pointer to the Key buffer. Allocate BSIMAX_KEY_SIZE for this buffer

<nKey>

Key Number, first key is numbered 0. Specify a value of 0xFF if you want no logical currency established.

Lock bias to apply to the record. this can be one of the following:

0 No Lock

BIAS_NOWAIT_LOCK (200) Single Lock

BIAS_M_NOWAIT_LOCK (400) Multilpe Lock

Return

LOGIC Was the positioning successful

Description

The Get Direct/Record operation retrieves a record using its physical location in the file instead of using one of the defined index paths.

If the Get Direct/Record operation is unsuccessful and the MicroKernel cannot return the requested record, the MicroKernel may return one of the following status codes:

22	Data Buffer Length

43	Invalid Data Record Address

44	Specified Key Path Invalid

82	Application Lost Positioning

84	Record/Page Locked

85	File Locked

When you request a no-wait lock on a record that is currently not available (either the record is locked by another client or the whole file is locked by an exclusive transaction), the MicroKernel returns either Status Code 84 (Record/Page Locked) or Status Code 85 (File Locked).