campo-sirio/cb/source/d4skip.c
alex 5432d61de9 Modifiche A.G.A.
git-svn-id: svn://10.65.10.50/trunk@4681 c028cbd2-c16b-5b4b-a496-9718f37d4682
1997-06-16 13:10:44 +00:00

748 lines
20 KiB
C
Executable File

/* d4skip.c (c)Copyright Sequiter Software Inc., 1988-1996. All rights reserved. */
#include "d4all.h"
#ifndef S4UNIX
#ifdef __TURBOC__
#pragma hdrstop
#endif
#endif
#ifdef S4SERVER
/* -2 means eof, -3 means bof */
long d4skipRecno( DATA4 *data, long n )
{
#ifndef S4OFF_INDEX
TAG4 *tag ;
TAG4FILE *tagFile ;
#endif
long startRec, newRec ;
#ifndef S4OFF_INDEX
unsigned char *keyValue ;
int rc ;
long recno, nSkipped ;
#endif
CODE4 *c4 ;
#ifdef S4VBASIC
if ( c4parm_check( data, 2, E94801 ) )
return -1 ;
#endif
#ifdef E4PARM_LOW
if ( data == 0 )
return error4( 0, e4parm_null, E94801 ) ;
#endif
c4 = data->codeBase ;
if ( c4 == 0 )
return e4info ;
if ( error4code( c4 ) < 0 )
return error4code( c4 ) ;
if ( data->recNum < 1L )
{
#ifndef S4SERVER
if ( c4->errSkip )
return error4( c4, e4info, E84801 ) ;
#endif
return e4info ;
}
#ifndef S4OFF_INDEX
tag = data->tagSelected ; /* avoid function call */
if ( tag == 0 )
{
#endif
if ( n != 0L )
if ( d4recCountLessEq( data, 1L ) == 0 ) /* count == 0 */
return -4L ;
data->bofFlag = 0 ;
startRec = data->recNum ;
newRec = startRec + n ;
if ( newRec > 0L )
{
if ( d4recCountLessEq( data, newRec ) == 0 )
return -2L ;
return newRec ;
}
else
return -3L ;
#ifndef S4OFF_INDEX
}
else
{
tagFile = tag->tagFile ;
if ( data->eofFlag )
{
if ( n >= 0L )
return -2L ;
rc = d4bottom( data ) ;
if ( rc && rc != r4eof )
return rc ;
if ( rc == r4eof )
return -2L ;
n++ ;
data->recNum = tfile4recNo( tagFile ) ;
}
data->bofFlag = 0 ;
#ifndef S4OFF_WRITE
if ( data->recordChanged )
{
rc = d4updateRecord( data, 0 ) ; /* was 1 */
if ( rc < 0 )
return rc ;
}
#endif
t4versionCheck( tag, 1, 0 ) ;
if ( n == 0 )
return data->recNum ;
if ( tfile4recNo( tagFile ) != data->recNum )
{
if ( d4lockTest( data, data->recNum ) == 0 ) /* ensure latest from disk */
{
rc = d4go( data, data->recNum ) ;
if ( rc < 0 )
return rc ;
}
expr4context( tagFile->expr, data ) ;
tfile4exprKey( tagFile, &keyValue ) ;
rc = tfile4go( tagFile, keyValue, data->recNum, 0 ) ;
if ( rc < 0 )
return rc ;
if ( tfile4empty( tagFile ) )
return -4L ;
if ( tfile4eof( tagFile ) && n >= 0L )
return -2L ;
#ifdef S4HAS_DESCENDING
if ( tagFile->header.descending )
{
if ( (rc > 0) && (n < 0) )
n-- ;
}
else
if ( (rc > 0) && (n > 0) )
n-- ;
#else
if ( (rc > 0) && (n > 0) )
n-- ;
#endif
}
else
{
if ( tfile4eof( tagFile ) )
return -2L ;
}
nSkipped = tfile4dskip( tagFile, n ) ;
if ( n > 0 && nSkipped != n )
return -2L ;
if ( n < 0 && nSkipped != n )
return -3L ;
if ( tfile4eof( tagFile ) )
return -2L ;
recno = tfile4recNo( tagFile ) ;
if ( recno < 0 )
return recno ;
return recno ;
}
#endif
}
#endif /* S4SERVER */
/* flush the current record to disk, and update the data pointer to point
to a valid tag location (in case the current record has been filtered out */
/* direction is -1 if line up backwards, or 1 if line up forwards */
#ifdef P4ARGS_USED
#pragma argsused
#endif
int S4FUNCTION d4tagSync( DATA4 *data, TAG4 * const tag )
{
#ifdef S4OFF_INDEX
return 0 ;
#else
CODE4 *c4 ;
#ifdef S4CLIENT
int rc, saveRc ;
CONNECTION4 *connection ;
CONNECTION4TAG_SYNCH_INFO_IN info ;
CONNECTION4TAG_SYNCH_INFO_OUT *out ;
#ifndef S4OFF_MEMO
int i ;
#endif
#endif
#ifdef S4VBASIC
if ( c4parm_check( data, 2, E94803 ) )
return -1 ;
#endif
#ifdef E4PARM_HIGH
if ( data == 0 )
return error4( 0, e4parm_null, E94803 ) ;
#endif
if ( tag == 0 )
return 0 ;
c4 = data->codeBase ;
if ( error4code( c4 ) < 0 )
return error4code( c4 ) ;
#ifdef S4CLIENT
if ( data->recNum <= 0 || d4eof( data ) )
{
#ifndef S4OFF_MEMO
for ( i = 0; i < data->dataFile->nFieldsMemo; i++ )
f4memoReset( data->fieldsMemo[i].field ) ;
#endif
data->recordChanged = 0 ;
return 0 ;
}
if ( data->recordChanged == 0 )
return 0 ;
connection = data->dataFile->connection ;
if ( connection == 0 )
return error4stack( data->codeBase, e4connection, E94803 ) ;
connection4assign( connection, CON4TAG_SYNCH, data4clientId( data ), data4serverId( data ) ) ;
memcpy( info.tagName, tag->tagFile->alias, LEN4TAG_ALIAS ) ;
info.tagName[LEN4TAG_ALIAS] = 0 ;
info.recno = d4recNo( data ) ;
connection4addData( connection, &info, sizeof( CONNECTION4TAG_SYNCH_INFO_IN ), 0 ) ;
saveRc = connection4repeat( connection, -2, -1, -1, data ) ;
if ( saveRc == r4eof || saveRc == r4noRecords )
{
data->bofFlag = 0 ;
rc = d4goEof( data ) ;
if ( rc == 0 )
rc = r4eof ;
if ( saveRc == r4noRecords )
data->bofFlag = 1 ;
return rc ;
}
if ( saveRc == r4bof )
{
data->eofFlag = 0 ;
rc = d4goBof( data ) ;
data->bofFlag = 1 ;
if ( rc == 0 )
rc = r4bof ;
return rc ;
}
if ( saveRc != 0 )
{
if ( saveRc < 0 )
return connection4errorDescribe( connection, c4, saveRc, E94803, tag->tagFile->alias, 0, 0 ) ;
return saveRc ;
}
if ( connection4len( connection ) != sizeof( CONNECTION4TAG_SYNCH_INFO_OUT ) )
return error4( c4, e4packetLen, E94803 ) ;
out = (CONNECTION4TAG_SYNCH_INFO_OUT *)connection4data( connection ) ;
if ( out->recNo != 0 && out->recNo != d4recNo( data ) )
{
rc = d4go( data, out->recNo ) ;
if ( rc < 0 )
return rc ;
}
return saveRc ;
#else
return d4tagSyncDo( data, tag, 1 ) ;
#endif
#endif /* S4OFF_INDEX */
}
#ifndef S4OFF_INDEX
#ifndef S4CLIENT
int d4tagSyncDo( DATA4 *data, TAG4 * const tag, int direction )
{
int rc ;
CODE4 *c4 ;
unsigned char *keyValue ;
#ifndef S4OFF_MULTI
int done, verifyReccount ;
#ifndef S4OFF_TRAN
int nSkipped ;
#endif
#endif
TAG4 *oldSelected ;
TAG4FILE *tagFile ;
long recno ;
c4 = data->codeBase ;
tagFile = tag->tagFile ;
expr4context( tagFile->expr, data ) ;
tfile4exprKey( tagFile, &keyValue ) ;
recno = tfile4recNo( tagFile ) ;
if ( recno != data->recNum )
{
rc = tfile4go( tagFile, keyValue, data->recNum, 0 ) ;
if ( rc )
return rc ;
}
oldSelected = data->tagSelected ;
d4tagSelect( data, tag ) ;
#ifndef S4OFF_WRITE
if ( data->recordChanged )
{
rc = d4updateRecord( data, 0 ) ;
if ( rc )
{
d4tagSelect( data, oldSelected ) ;
return rc ;
}
}
#endif
if ( data->eofFlag )
{
d4tagSelect( data, oldSelected ) ;
/* if forward skip not true, not eof, here is */
return d4goEof( data ) ;
}
else
{
t4versionCheck( tag, 1, 0 ) ;
if ( tfile4eof( tagFile ) )
return d4goEof( data ) ;
recno = tfile4recNo( tagFile ) ;
if ( recno != data->recNum )
rc = d4go( data, recno ) ;
else
rc = 0 ;
}
#ifndef S4OFF_MULTI
for( verifyReccount = 1, done = 0 ; done == 0 ; )
{
#ifndef S4OFF_TRAN
if ( code4transEnabled( c4 ) )
if ( t4unique( tag ) != 0 )
if ( code4tranStatus( c4 ) == r4active )
if ( d4lockTest( data, recno ) )
{
/* if within a transaction, and record is locked, it may mean
that the record contents have changed. If the current tag key
does not match, it must be an old entry (if a unique tag),
and thus skip over
*/
for ( ;; )
{
if ( recno > data->dataFile->minCount ) /* ensure correct sequencing for multi-user */
break ; /* just let the code below take care of this case */
verifyReccount = 1 ;
expr4context( tagFile->expr, data ) ;
if ( recno != d4recNo( data ) ) /* need to reposition data4 first */
d4go( data, recno ) ;
tfile4exprKey( tagFile, &keyValue ) ;
if ( memcmp( tfile4key( tagFile ), keyValue, tagFile->header.keyLen ) != 0 ) /* different, so skip */
nSkipped = (int)tfile4skip( tagFile, direction ) ;
else /* done */
break ;
if ( direction > 0 && nSkipped != 1 )
{
rc = d4goEof( data ) ;
done = 1 ;
break ;
}
if ( tfile4eof( tagFile ) )
{
data->bofFlag = 1 ;
rc = d4goEof( data ) ;
done = 1 ;
break ;
}
if ( tfile4recNo( tagFile ) != recno ) /* ok, may continue */
{
recno = tfile4recNo( tagFile ) ;
d4go( data, recno ) ;
break ;
}
}
}
#endif /* S4OFF_TRAN */
if ( done == 1 )
break ;
if ( verifyReccount == 1 )
{
verifyReccount = 0 ;
if ( recno > data->dataFile->minCount ) /* ensure correct sequencing for multi-user */
{
if ( d4recCountLessEq( data, recno ) == 0 )
{
rc = (int)tfile4skip( tagFile, direction ) ;
if ( rc < 0 )
done = 1 ;
else
{
if ( rc == 0 )
{
data->bofFlag = 1 ;
done = 1 ;
rc = d4goEof( data ) ;
}
else
{
recno = tfile4recNo( tagFile ) ;
if ( recno <= 0 || recno > data->dataFile->minCount )
{
done = 1 ;
rc = -1 ;
}
if ( tfile4recNo( tagFile ) != recno ) /* ok, may continue */
{
recno = tfile4recNo( tagFile ) ;
d4go( data, recno ) ;
break ;
}
}
}
}
}
else
done = 1 ;
}
else
done = 1 ;
}
#endif /* S4OFF_MULTI */
d4tagSelect( data, oldSelected ) ;
return rc ;
}
#endif /* S4CLIENT */
#endif /* S4OFF_INDEX */
int S4FUNCTION d4skip( DATA4 *data, const long nSkip )
{
int rc ;
CODE4 *c4 ;
#ifdef S4CLIENT
int saveRc ;
CONNECTION4 *connection ;
CONNECTION4GO_INFO_OUT *out ;
CONNECTION4SKIP_INFO_IN info ;
#else
#ifndef S4OFF_INDEX
unsigned char *keyValue ;
long nSkipped, recno ;
TAG4FILE *tagFile ;
#endif
long n ;
#ifndef S4SERVER
int saveFlag ;
#endif
long startRec, newRec ;
int oldEofFlag, c1 ;
#endif
#ifndef S4OFF_INDEX
TAG4 *tag ;
#endif
#ifdef S4VBASIC
if ( c4parm_check( data, 2, E94802 ) )
return -1 ;
#endif
#ifdef E4PARM_HIGH
if ( data == 0 )
return error4( 0, e4parm_null, E94802 ) ;
#endif
c4 = data->codeBase ;
if ( error4code( c4 ) < 0 )
return error4code( c4 ) ;
if ( data->recNum < 1L )
{
#ifndef S4SERVER
if ( c4->errSkip )
error4( c4, e4info, E84801 ) ;
#endif
return e4info ;
}
#ifdef S4CLIENT
rc = d4updateRecord( data, 0 ) ; /* returns -1 if error4code( codeBase ) < 0 */
if ( rc )
return rc ;
connection = data->dataFile->connection ;
if ( connection == 0 )
return error4stack( data->codeBase, e4connection, E94802 ) ;
connection4assign( connection, CON4SKIP, data4clientId( data ), data4serverId( data ) ) ;
info.startPos = data->recNum ;
info.numSkip = nSkip ;
#ifdef S4OFF_INDEX
info.usesTag = 0 ;
#else
tag = data->tagSelected ;
if ( tag == 0 )
info.usesTag = 0 ;
else
{
info.usesTag = 1 ;
memcpy( info.tagName, tag->tagFile->alias, LEN4TAG_ALIAS ) ;
info.tagName[LEN4TAG_ALIAS] = 0 ;
}
#endif
connection4addData( connection, &info, sizeof( CONNECTION4SKIP_INFO_IN ), 0 ) ;
rc = connection4repeat( connection, -2, -1, -1, data ) ;
if ( rc == r4locked )
return r4locked ;
if ( (long)connection4len( connection ) < (long)sizeof( CONNECTION4GO_INFO_OUT ) )
return error4( c4, e4packetLen, E94802 ) ;
out = (CONNECTION4GO_INFO_OUT *)connection4data( connection ) ;
saveRc = out->skipRc ;
if ( saveRc < 0 )
{
if ( tag == 0 )
return connection4error( connection, c4, saveRc, E94802 ) ;
else
return connection4errorDescribe( connection, c4, saveRc, E94802, tag->tagFile->alias, 0, 0 ) ;
}
if ( saveRc == r4eof || saveRc == r4noRecords )
{
data->bofFlag = 0 ;
rc = d4goEof( data ) ;
if ( rc == 0 )
rc = r4eof ;
if ( saveRc == r4noRecords )
data->bofFlag = 1 ;
return rc ;
}
if ( saveRc == r4bof )
{
data->eofFlag = 0 ;
rc = d4goBof( data ) ;
data->bofFlag = 1 ;
if ( rc == 0 )
rc = r4bof ;
return rc ;
}
if ( saveRc != 0 )
{
if ( saveRc < 0 )
return error4( c4, saveRc, E94802 ) ;
return saveRc ;
}
rc = connection4status( connection ) ;
if ( out->recNo != 0 )
{
if ( (long)connection4len( connection ) != (long)sizeof( CONNECTION4GO_INFO_OUT ) + (long)dfile4recWidth( data->dataFile ) )
return error4( c4, e4packetLen, E94802 ) ;
return d4goVirtual( data, out->recNo, rc, out, connection ) ; /* maybe r4locked, or whatever */
}
return rc ;
#else
n = nSkip ;
#ifndef S4OFF_INDEX
tag = data->tagSelected ;
if ( tag == 0 )
{
#endif
data->bofFlag = 0 ;
startRec = data->recNum ;
newRec = startRec + n ;
if ( newRec > 0L )
{
#ifndef S4SERVER
saveFlag = c4->errGo ;
c4->errGo = 0 ;
#endif
#ifndef S4OFF_OPTIMIZE
data->dataFile->hiPrio = -1 ; /* indicate d4skip - data level */
#endif
rc = d4go( data, newRec ) ;
#ifndef S4OFF_OPTIMIZE
data->dataFile->hiPrio = 0 ;
#endif
#ifndef S4SERVER
c4->errGo = saveFlag ;
#endif
if ( rc >= 0 && rc != r4entry )
return rc ;
}
c1 = d4recCountLessEq( data, 1L ) ;
if ( c1 < 0 )
return c1 ;
if ( ( c1 == 0 ) || ( d4recCountLessEq( data, newRec ) == 0 ) )
{
if ( c1 == 0L )
{
rc = d4goEof( data ) ;
if ( rc != r4eof )
return rc ;
data->bofFlag = 1 ;
}
if ( n < 0 )
{
data->bofFlag = 1 ;
return r4bof ;
}
else
return d4goEof( data ) ;
}
if ( newRec < 1L )
{
oldEofFlag = data->eofFlag ;
rc = d4go( data, 1L ) ;
if ( rc )
return rc ;
data->bofFlag = 1 ;
data->eofFlag = oldEofFlag ;
return r4bof ;
}
return d4go( data, newRec ) ;
#ifndef S4OFF_INDEX
}
else
{
tagFile = tag->tagFile ;
if ( data->eofFlag )
{
if ( n >= 0 )
return d4goEof( data ) ;
rc = d4bottom( data ) ;
if ( rc && rc != r4eof )
return rc ;
if ( rc == r4eof )
{
rc = d4goEof( data ) ;
if ( rc != r4eof )
return rc ;
return r4bof ;
}
n++ ;
data->recNum = tfile4recNo( tagFile ) ;
}
data->bofFlag = 0 ;
#ifndef S4OFF_WRITE
if ( data->recordChanged )
{
rc = d4updateRecord( data, 0 ) ; /* was 1 */
if ( rc < 0 )
return rc ;
}
#endif
t4versionCheck( tag, 1, 0 ) ;
if ( n == 0 )
return 0 ;
if ( tfile4recNo( tagFile ) != data->recNum )
{
rc = d4go( data, data->recNum ) ;
if ( rc )
return rc ;
expr4context( tagFile->expr, data ) ;
tfile4exprKey( tagFile, &keyValue ) ;
rc = tfile4go( tagFile, keyValue, data->recNum, 0 ) ;
if ( rc < 0 )
return rc ;
#ifdef S4HAS_DESCENDING
if ( tagFile->header.descending )
{
if ( (rc > 0) && (n < 0) )
n-- ;
}
else
if ( (rc > 0) && (n > 0) )
n-- ;
#else
if ( (rc > 0) && (n > 0) )
n-- ;
#endif
}
nSkipped = tfile4dskip( tagFile, n ) ;
if ( n > 0 && nSkipped != n )
return d4goEof( data ) ;
if ( tfile4eof( tagFile ) )
{
data->bofFlag = 1 ;
return d4goEof( data ) ;
}
recno = tfile4recNo( tagFile ) ;
if ( recno < 0 )
return (int)recno ;
rc = d4go( data, recno ) ;
if ( rc )
return rc ;
#ifndef S4OFF_MULTI
rc = d4tagSyncDo( data, tag, n > 0 ? 1 : -1 ) ;
if ( rc != 0 )
return rc ;
#endif
if ( n == nSkipped )
return 0 ;
#ifdef S4HAS_DESCENDING
if ( ( n < 0 && !tagFile->header.descending ) || ( n < 0 && tagFile->header.descending ) )
#else
if ( n < 0 )
#endif
{
data->bofFlag = 1 ;
return r4bof ;
}
}
return 0 ;
#endif
#endif
}