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- /*
- JAMLIB - A JAM subroutine library
- Copyright (C) 1999 Björn Stenberg
- This library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
- This library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public
- License along with this library; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- Changes made by Johan Billing 2000-04-16:
-
- - Changed source to use feof() instead of errno == EPASTEOF
- - Changed source to use structrw to read and write structures
- */
- /***********************************************************************
- **
- ** LASTREAD.C -- Lastread pointer handling
- **
- ** Author: Bj”rn Stenberg ([email protected])
- **
- ***********************************************************************/
- #include <stdio.h>
- #include <errno.h>
- #include "jam.h"
- #include "structrw.h"
- /***********************************************************************
- **
- ** File global variables
- **
- ***********************************************************************/
- /***********************************************************************
- **
- ** JAM_ReadLastRead - Read LastRead record
- **
- ***********************************************************************/
- int JAM_ReadLastRead( s_JamBase* Base_PS,
- uint32_t User_I,
- s_JamLastRead* Record_PS )
- {
- s_JamLastRead Record_S;
- int Pos_I;
- if (!Record_PS)
- return JAM_BAD_PARAM;
- if ( fseek( Base_PS->LrdFile_PS, 0, SEEK_SET ) ) {
- Base_PS->Errno_I = errno;
- return JAM_IO_ERROR;
- }
- for ( Pos_I = 0; ; Pos_I++ ) {
- if ( 1 > freadjamlastread(Base_PS->LrdFile_PS,&Record_S) ) {
- if ( feof(Base_PS->LrdFile_PS) )
- return JAM_NO_USER;
- Base_PS->Errno_I = errno;
- return JAM_IO_ERROR;
- }
- if ( Record_S.UserID == User_I ) {
- Base_PS->LastUserPos_I = Pos_I;
- Base_PS->LastUserId_I = User_I;
- *Record_PS = Record_S;
- return 0;
- }
- }
- return 0;
- }
- /***********************************************************************
- **
- ** JAM_WriteLastRead - Write LastRead record
- **
- ***********************************************************************/
- int JAM_WriteLastRead( s_JamBase* Base_PS,
- uint32_t User_I,
- s_JamLastRead* Record_PS )
- {
- s_JamLastRead Record_S;
- int Pos_I;
- if (!Record_PS)
- return JAM_BAD_PARAM;
- /* if the last read is stored */
- if ( User_I == Base_PS->LastUserId_I ) {
- Pos_I = Base_PS->LastUserPos_I * sizeof( s_JamLastRead );
- if ( fseek( Base_PS->LrdFile_PS, Pos_I, SEEK_SET ) ) {
- Base_PS->Errno_I = errno;
- return JAM_IO_ERROR;
- }
- /* be safe, check it */
- if ( 1 > freadjamlastread(Base_PS->LrdFile_PS,&Record_S) ) {
- Base_PS->Errno_I = errno;
- return JAM_IO_ERROR;
- }
- /* is it where we expected it to be? */
- if ( User_I == Record_S.UserID ) {
-
- if ( fseek( Base_PS->LrdFile_PS, Pos_I, SEEK_SET ) ) {
- Base_PS->Errno_I = errno;
- return JAM_IO_ERROR;
- }
- if ( 1 > fwritejamlastread(Base_PS->LrdFile_PS,Record_PS) ) {
- Base_PS->Errno_I = errno;
- return JAM_IO_ERROR;
- }
- fflush(Base_PS -> LrdFile_PS);
- return 0;
- }
- }
- /* no last position, or position incorrect */
- if ( fseek( Base_PS->LrdFile_PS, 0, SEEK_SET ) ) {
- Base_PS->Errno_I = errno;
- return JAM_IO_ERROR;
- }
- for ( Pos_I = 0; ; Pos_I++ ) {
- if ( 1 > freadjamlastread(Base_PS->LrdFile_PS,&Record_S) ) {
- if ( feof(Base_PS->LrdFile_PS) ) {
- /* user not in file, append a new record */
- if ( fseek( Base_PS->LrdFile_PS, 0, SEEK_END ) ) {
- Base_PS->Errno_I = errno;
- return JAM_IO_ERROR;
- }
- break;
- }
- Base_PS->Errno_I = errno;
- return JAM_IO_ERROR;
- }
- /* found the user? */
- if ( Record_S.UserID == User_I ) {
- if ( fseek( Base_PS->LrdFile_PS, Pos_I * sizeof(s_JamLastRead),
- SEEK_SET ) ) {
- Base_PS->Errno_I = errno;
- return JAM_IO_ERROR;
- }
- break;
- }
- }
- if ( 1 > fwritejamlastread(Base_PS->LrdFile_PS,Record_PS) ) {
- Base_PS->Errno_I = errno;
- return JAM_IO_ERROR;
- }
- fflush( Base_PS->LrdFile_PS );
- return 0;
- }
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