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Change FcbReadWrite to handle multiple records at once; this allows

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for the optimization of FcbRandomBlockIO.


git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@718 6ac86273-5f31-0410-b378-82cca8765d1b
This commit is contained in:
Bart Oldeman 2003-10-16 15:03:16 +00:00
parent dd9df1f3a6
commit 492fef1f72
3 changed files with 39 additions and 32 deletions
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58
kernel/fcbfns.c
View File

@ -244,39 +244,50 @@ UBYTE FcbReadWrite(xfcb FAR * lpXfcb, UCOUNT recno, int mode)
{
ULONG lPosit;
long nTransfer;
BYTE FAR * FcbIoPtr = dta;
fcb FAR *lpFcb;
FcbIoPtr += recno * lpFcb->fcb_recsiz;
if ((ULONG)recno * lpFcb->fcb_recsiz >= 0x10000ul ||
FP_OFF(FcbIoPtr) < FP_OFF(dta))
return FCB_ERR_SEGMENT_WRAP;
unsigned size;
unsigned long bigsize;
unsigned recsiz;
/* Convert to fcb if necessary */
lpFcb = ExtFcbToFcb(lpXfcb);
recsiz = lpFcb->fcb_recsiz;
bigsize = (ULONG)recsiz * recno;
if (bigsize > 0xffff)
return FCB_ERR_SEGMENT_WRAP;
size = (unsigned)bigsize;
if (FP_OFF(dta) + size < FP_OFF(dta))
return FCB_ERR_SEGMENT_WRAP;
/* Now update the fcb and compute where we need to position */
/* to. */
lPosit = FcbRec(lpFcb) * lpFcb->fcb_recsiz;
lPosit = FcbRec(lpFcb) * recsiz;
if ((CritErrCode = -SftSeek(lpFcb->fcb_sftno, lPosit, 0)) != SUCCESS)
return FCB_ERR_NODATA;
/* Do the read */
nTransfer = DosRWSft(lpFcb->fcb_sftno, lpFcb->fcb_recsiz, FcbIoPtr, mode);
nTransfer = DosRWSft(lpFcb->fcb_sftno, size, dta, mode & ~XFR_FCB_RANDOM);
if (nTransfer < 0)
CritErrCode = -(int)nTransfer;
/* Now find out how we will return and do it. */
if (nTransfer == lpFcb->fcb_recsiz)
if (mode & XFR_WRITE)
lpFcb->fcb_fsize = SftGetFsize(lpFcb->fcb_sftno);
/* if end-of-file, then partial read should count last record */
if (mode & XFR_FCB_RANDOM && recsiz > 0)
lpFcb->fcb_rndm += ((unsigned)nTransfer + recsiz - 1) / recsiz;
size -= (unsigned)nTransfer;
if (size == 0)
{
if (mode == XFR_WRITE) lpFcb->fcb_fsize = SftGetFsize(lpFcb->fcb_sftno);
FcbNextRecord(lpFcb);
return FCB_SUCCESS;
}
if (mode == XFR_READ && nTransfer > 0)
size %= lpFcb->fcb_recsiz;
if (mode & XFR_READ && size > 0)
{
fmemset(FcbIoPtr + (unsigned)nTransfer, 0, lpFcb->fcb_recsiz - (unsigned)nTransfer);
fmemset((char FAR *)dta + (unsigned)nTransfer, 0, size);
FcbNextRecord(lpFcb);
return FCB_ERR_EOF;
}
@ -340,28 +351,21 @@ void FcbCalcRec(xfcb FAR * lpXfcb)
UBYTE FcbRandomBlockIO(xfcb FAR * lpXfcb, UWORD *nRecords, int mode)
{
unsigned recno;
UBYTE nErrorCode = FCB_SUCCESS;
UBYTE nErrorCode;
fcb FAR *lpFcb;
unsigned long old;
FcbCalcRec(lpXfcb);
/* Convert to fcb if necessary */
lpFcb = ExtFcbToFcb(lpXfcb);
for (recno = 0; recno < *nRecords; recno++)
{
nErrorCode = FcbReadWrite(lpXfcb, recno, mode);
/* end-of-file, partial read should count last record */
if (nErrorCode == FCB_ERR_EOF)
recno++;
if (nErrorCode != FCB_SUCCESS)
break;
}
*nRecords = recno;
old = lpFcb->fcb_rndm;
nErrorCode = FcbReadWrite(lpXfcb, *nRecords, mode);
*nRecords = lpFcb->fcb_rndm - old;
/* Now update the fcb */
lpFcb->fcb_rndm = FcbRec(lpFcb);
FcbCalcRec(lpXfcb);
return nErrorCode;
}
@ -381,7 +385,7 @@ UBYTE FcbRandomIO(xfcb FAR * lpXfcb, int mode)
uwCurrentBlock = lpFcb->fcb_cublock;
ucCurrentRecord = lpFcb->fcb_curec;
nErrorCode = FcbReadWrite(lpXfcb, 0, mode);
nErrorCode = FcbReadWrite(lpXfcb, 1, mode);
lpFcb->fcb_cublock = uwCurrentBlock;
lpFcb->fcb_curec = ucCurrentRecord;

2
kernel/globals.h
View File

@ -111,6 +111,8 @@ FAR * ASM DPBp; /* First drive Parameter Block */
#define XFR_READ 1
#define XFR_WRITE 2
#define XFR_FORCE_WRITE 3
/* flag to update fcb_rndm field */
#define XFR_FCB_RANDOM 4
#define RDONLY 0
#define WRONLY 1

11
kernel/inthndlr.c
View File

@ -556,12 +556,12 @@ dispatch:
case 0x14:
/* FCB read */
lr.AL = FcbReadWrite(FP_DS_DX, 0, XFR_READ);
lr.AL = FcbReadWrite(FP_DS_DX, 1, XFR_READ);
break;
case 0x15:
/* FCB write */
lr.AL = FcbReadWrite(FP_DS_DX, 0, XFR_WRITE);
lr.AL = FcbReadWrite(FP_DS_DX, 1, XFR_WRITE);
break;
case 0x16:
@ -622,7 +622,8 @@ dispatch:
/* Get default DPB */
/* case 0x1f: see case 0x32 */
/* Random read using FCB */
/* Random read using FCB: fields not updated
(XFR_RANDOM should not be used here) */
case 0x21:
lr.AL = FcbRandomIO(FP_DS_DX, XFR_READ);
break;
@ -658,12 +659,12 @@ dispatch:
/* Read random record(s) using FCB */
case 0x27:
lr.AL = FcbRandomBlockIO(FP_DS_DX, &lr.CX, XFR_READ);
lr.AL = FcbRandomBlockIO(FP_DS_DX, &lr.CX, XFR_READ | XFR_FCB_RANDOM);
break;
/* Write random record(s) using FCB */
case 0x28:
lr.AL = FcbRandomBlockIO(FP_DS_DX, &lr.CX, XFR_WRITE);
lr.AL = FcbRandomBlockIO(FP_DS_DX, &lr.CX, XFR_WRITE | XFR_FCB_RANDOMXS);
break;
/* Parse File Name */