findrec.c

T-kernel 的extension源代码

/*
 *----------------------------------------------------------------------
 *    T-Kernel / Standard Extension
 *
 *    Copyright (C) 2006 by Ken Sakamura. All rights reserved.
 *    T-Kernel / Standard Extension is distributed 
 *      under the T-License for T-Kernel / Standard Extension.
 *----------------------------------------------------------------------
 *
 *    Version:   1.00.00
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2006/8/11.
 *
 *----------------------------------------------------------------------
 */

/*
 *	findrec.c (file)
 *
 *	File management
 *	Record retrieval
 */

#include "fileio.h"
#include "diskio.h"


LOCAL ER getFileName( FileName fname, LINK *lnk, FsInfo *fsinfo );
LOCAL ER seekRecord( RCB **rcb, W offset, OFCB *ofcb );
LOCAL ER findRecord( RCB **rcb, W fwd, UW typemask, UH subtype, OFCB *ofcb );
LOCAL WER matchLinkRecord( RCB *rcb, W mode, LINK *lnk, RIdx *ri, SFN *sfn, FsInfo *fsinfo );
LOCAL ER findLinkRecord( RCB **rcb, W fwd, W mode, LINK *lnk, UH subtype, OFCB *ofcb );
LOCAL WER startRecord( RCB **rcb, W mode, OFCB *ofcb );
LOCAL ER setRecnum( W *recnum, RCB *rcb, OFCB *ofcb );
LOCAL ER searchLinkRecord_O( RIdx *ri, W fid, FileName fname, W n, RCB **rcb, OFCB *ofcb );
LOCAL ER searchLinkRecord_C( RIdx *ri, W fid, FileName fname, W n, OFCB *ofcb );

#define TSD_MLR_POS_0		0
#define TSD_MLR_POS_1		1
#define TSD_MLR_POS_2		2
#define TSD_MLR_POS_3		3
#define TSD_MLR_POS_4		4
#define TSD_FRE_PTN_0X00000001	0x00000001U
#define TSD_FIS_VAL_M1		(-1)
#define TSD_FLR_MSK_0X7F00	0x7f00U
#define TSD_FFR_MSK_0XF		0xfU
#define TSD_SLR_VAL_0X80	(UB)0x80

/*
 * Obtain the file name of lnk.
 */
LOCAL ER getFileName( FileName fname, LINK *lnk, FsInfo *fsinfo )
{
	ER	err;

	if ( isSameFS(lnk->fs_name, fsinfo) != 0 ) {

		/* lnk is the current file system. */
		err = fmpGetFileName(lnk->f_id, fname, fsinfo);
		if ( err < E_OK ) {
			goto err_ret;
		}
	} else {

		/* lnk is a different file system. */
		err = fmIGetFileInfo(lnk, fname, NULL, NULL);
		if ( err < E_OK ) {
			goto err_ret;
		}
	}

	return E_OK;

err_ret:
	DEBUG_PRINT(("getFileName err = %d\n", err));
	return err;
}

/*
 * Move the record.
 *	Return the record that has moved from *rcb by offset to *rcb.
 */
LOCAL ER seekRecord( RCB **rcb, W offset, OFCB *ofcb )
{
	RCB	*p = *rcb;

	if ( offset >= 0 ) {

		/* Move in the direction of higher record number. */
		while ( --offset >= 0 ) {
			if ( isEndRCB(p, ofcb) ) {
				return E_REC;
			}
			p = nextRCB(p);
		}
	} else {

		/* Move in the direction of lower record number. */
		while ( ++offset <= 0 ) {
			p = prevRCB(p);
			if ( isEndRCB(p, ofcb) ) {
				return E_REC;
			}
		}
	}

	*rcb = p;
	return E_OK;
}

/*
 * Record retrieval
 *	Search from *rcb to fwd, and return the record that matches in typemask/subtype
 *	to *rcb.
 */
LOCAL ER findRecord( RCB **rcb, W fwd, UW typemask, UH subtype, OFCB *ofcb )
{
	RCB	*p = *rcb;
	ER	err;

	while ( !isEndRCB(p, ofcb) ) {

		/* Make valid the contents of RCB. */
		err = fmpSetRCB(p, ofcb);
		if ( err < E_OK ) {
			return err;
		}

		/* Record type */
		if ( (INT)((TSD_FRE_PTN_0X00000001  <<  p->rtype) & typemask) != 0 )  {

			/* Record subtype */
			if ( (subtype == 0) || (p->stype == subtype) ) {

				/* Found */
				*rcb = p;
				return E_OK;
			}
		}

		p = ( fwd == 0 )? prevRCB(p): nextRCB(p);
	}

	return E_REC; /* Not found */
}

/*
 * Judge the link record search condition.
 *	Perform matching between the record of *rcb and *lnk according to mode.
 *	When matched, return 1. When not matched, return 0.
 */
LOCAL WER matchLinkRecord( RCB *rcb, W mode, LINK *lnk,
					RIdx *ri, SFN *sfn, FsInfo *fsinfo )
{
	BOOL		match = TRUE;
	DfRecordIndex	*ridx;
	BOOL		bigEndian = fsinfo->bigEndian;
	ER		err;

	/* Read the record index. */
	err = fmpSeekRIdx(ri, &rcb->idxadr);
	if ( err < E_OK ) {
		goto err_ret1;
	}

	ridx = fmpGetRIdx(ri);
	if ( ridx == NULL ) {
		goto err_ret2;
	}

	if ( match && ((W)((UW)mode & (UW)F_SFILE) != 0) ) {	/* Same file */
		FID fid = fmConvEndianH(ridx->l.fid, bigEndian);
		match = (fid == lnk->f_id);
	}

	if ( match && ((W)((UW)mode & (UW)F_SNAME) != 0) ) {	/* Same file name */
		FID fid = fmConvEndianH(ridx->l.fid, bigEndian);
		err = fmpMatchSFN(sfn, fid, NULL);
		if ( err < E_OK ) {
			goto err_ret1;
		}
		match = (BOOL)err;
	}

	if ( match && ((W)((UW)mode & (UW)F_SATR1) != 0) ) {	/* Same attribute data 1 */
		UH atr = fmConvEndianH(ridx->l.atr[TSD_MLR_POS_0], bigEndian);
		match = (atr == lnk->atr1);
	}
	if ( match && ((W)((UW)mode & (UW)F_SATR2) != 0) ) {	/* Same attribute data 2 */
		UH atr = fmConvEndianH(ridx->l.atr[TSD_MLR_POS_1], bigEndian);
		match = (atr == lnk->atr2);
	}
	if ( match && ((W)((UW)mode & (UW)F_SATR3) != 0) ) {	/* Same attribute data 3 */
		UH atr = fmConvEndianH(ridx->l.atr[TSD_MLR_POS_2], bigEndian);
		match = (atr == lnk->atr3);
	}
	if ( match && ((W)((UW)mode & (UW)F_SATR4) != 0) ) {	/* Same attribute data 4 */
		UH atr = fmConvEndianH(ridx->l.atr[TSD_MLR_POS_3], bigEndian);
		match = (atr == lnk->atr4);
	}
	if ( match && ((W)((UW)mode & (UW)F_SATR5) != 0) ) {	/* Same attribute data 5 */
		UH atr = fmConvEndianH(ridx->l.atr[TSD_MLR_POS_4], bigEndian);
		match = (atr == lnk->atr5);
	}

	return match;

err_ret2:
	err = fmpGetRIdxError(ri);
err_ret1:
	DEBUG_PRINT(("matchLinkRecord err = %d\n", err));
	return err;
}

/*
 * Link record retrieval
 *	Search from *rcb to fwd according to mode,
 *	and return the record that matches in lnk/subtype to *rcb.
 */
LOCAL ER findLinkRecord( RCB **rcb, W fwd, W mode,
				LINK *lnk, UH subtype, OFCB *ofcb )
{
	FsInfo		*fsinfo = ofcb->fsinfo;
	BOOL		match = FALSE;
	RCB		*p = *rcb;
	RIdx		ri;
	SFN		sfn;
	FileName	fname;
	ER		err;

	if ( ((UW)mode & ~TSD_FLR_MSK_0X7F00) != 0U ) {
		err = E_PAR;
		goto err_ret1;
	}

	/* Prepare to read the record index. */
	err = fmpOpenRIdx(&ri, FIRST_RIdx, ofcb);
	if ( err < E_OK ) {
		goto err_ret1;
	}

	if ( ((UW)mode & (UW)F_SFILE) != 0U ) {
		if ( !isSameFS(lnk->fs_name, fsinfo) ) {
			err = E_REC;
			goto err_ret2;
		}
	}

	if ( ((UW)mode & (UW)F_SNAME) != 0U ) {

		/* Obtain the file name of lnk. */
		err = getFileName(fname, lnk, fsinfo);
		if ( err < E_OK ) {
			goto err_ret2;
		}

		/* Prepare to retrieve the file name. */
		err = fmpOpenSFN(&sfn, fname, fsinfo);
		if ( err < E_OK ) {
			goto err_ret2;
		}
	}

	while ( !isEndRCB(p, ofcb) ) {

		/* Make valid the contents of RCB. */
		err = fmpSetRCB(p, ofcb);
		if ( err < E_OK ) {
			goto err_ret3;
		}

		/* Whether the record type and record subtype match or not. */
		if ( isLinkRecord(p->rtype)
		  && ((subtype == 0 )||( p->stype == subtype))) {

			/* Judge the search condition. */
			err = matchLinkRecord(p, mode, lnk, &ri, &sfn, fsinfo);
			if ( err < E_OK ) {
				goto err_ret3;
			}

			match = (BOOL)err;
			if ( match != FALSE ) {
				/* Found */
				*rcb = p;
				break;
			}
		}

		p = ( fwd == 0 )? prevRCB(p): nextRCB(p);
	}

	if ( ((UW)mode & (UW)F_SNAME) != 0U ) {
		err = fmpCloseSFN(&sfn);
		if ( err < E_OK ) {
			goto err_ret2;
		}
	}

	err = fmpCloseRIdx(&ri);
	if ( err < E_OK ) {
		goto err_ret1;
	}

	return ( match != 0 )? E_OK: E_REC;

err_ret3:
	if ( ((UW)mode & (UW)F_SNAME) != 0U ) {
		(void)fmpCloseSFN(&sfn);
	}
err_ret2:
	(void)fmpCloseRIdx(&ri);
err_ret1:
	DEBUG_PRINT(("findLinkRecord err = %d\n", err));
	return err;
}

/*
 * Select a record to start searching from according to the mode specification.
 *	Set *rcb to the current record and call it.
 *	Select a record to start searching from according to mode, and return it to *rcb.
 *	Return the search direction (Forward 1/Backward 0) to the return value.
 */
LOCAL WER startRecord( RCB **rcb, W mode, OFCB *ofcb )
{
	RCB	*p = *rcb;
	W	fwd;

	switch ( mode ) {
	  case F_FWD:		/* Forward search */
		fwd = 1;
		break;

	  case F_BWD:		/* Backward search */
		fwd = 0;
		break;

	  case F_NFWD:		/* Forward search (from the next) */
		if ( isEndRCB(p, ofcb) != 0 ) {
			return E_REC;
		}
		p = nextRCB(p);
		fwd = 1;
		break;

	  case F_NBWD:		/* Backward search (from the previous)  */
		p = prevRCB(p);
		if ( isEndRCB(p, ofcb) != 0 ) {
			return E_REC;
		}
		fwd = 0;
		break;

	  case F_TOPEND:	/* From the start to end */
		p = FirstRCB(ofcb);
		fwd = 1;
		break;

	  case F_ENDTOP:	/* From the end to start */
		p = prevRCB(EndRCB(ofcb));
		fwd = 0;
		break;

	  default:
		return E_PAR;
	}

	*rcb = p;
	return fwd;
}

/*
 * Return the record number to recnum.
 */
LOCAL ER setRecnum( W *recnum, RCB *rcb, OFCB *ofcb )
{
	ER	err;

	if ( recnum != NULL ) {
		err = CheckSpaceRW(recnum, sizeof(W));
		if ( err < E_OK ) {
			return err;
		}

		if ( isEndRCB(rcb, ofcb) != 0 ) {
			*recnum = ofcb->nrec;
		} else {
			err = fmpSetRCB(rcb, ofcb);
			if ( err < E_OK ) {
				return err;
			}
			*recnum = rcb->recnum;
		}
	}
	return E_OK;
}

/*
 * Move the record position.
 */
EXPORT void fmpSeekRecord( FmCmdPkt *pkt )
{
	FM_SEE_REC_PARA	*cmdPara = (FM_SEE_REC_PARA*)pkt->cmd.para;
	FD		*fd;
	OFCB		*ofcb;
	RCB		*rcb;
	ER		err;

	/* Obtain FD and OFCB. */
	fd = getFDp(cmdPara->fd);
	ofcb = fd->ofcb;

	/* Start record */
	if ( cmdPara->mode == 0 ) {