Open64: osprey/libf/fio/unitseek.c Source File

00001 /*
00002  * Copyright 2004, 2005, 2006 PathScale, Inc.  All Rights Reserved.
00003  */
00004 
00005 /*
00006 
00007   Copyright (C) 2000, 2001, Silicon Graphics, Inc.  All Rights Reserved.
00008 
00009   This program is free software; you can redistribute it and/or modify it
00010   under the terms of version 2.1 of the GNU Lesser General Public License 
00011   as published by the Free Software Foundation.
00012 
00013   This program is distributed in the hope that it would be useful, but
00014   WITHOUT ANY WARRANTY; without even the implied warranty of
00015   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
00016 
00017   Further, this software is distributed without any warranty that it is
00018   free of the rightful claim of any third person regarding infringement 
00019   or the like.  Any license provided herein, whether implied or 
00020   otherwise, applies only to this software file.  Patent licenses, if
00021   any, provided herein do not apply to combinations of this program with 
00022   other software, or any other product whatsoever.  
00023 
00024   You should have received a copy of the GNU Lesser General Public 
00025   License along with this program; if not, write the Free Software 
00026   Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, 
00027   USA.
00028 
00029   Contact information:  Silicon Graphics, Inc., 1600 Amphitheatre Pky,
00030   Mountain View, CA 94043, or:
00031 
00032   http://www.sgi.com
00033 
00034   For further information regarding this notice, see:
00035 
00036   http://oss.sgi.com/projects/GenInfo/NoticeExplan
00037 
00038 */
00039 
00040 
00041 
00042 #pragma ident "@(#) libf/fio/unitseek.c 92.1  06/18/99 18:38:26"
00043 
00044 #include <errno.h>
00045 #include <foreign.h>
00046 #include <liberrno.h>
00047 #include <stdio.h>
00048 #include <string.h>
00049 #include "fio.h"
00050 #if defined(__mips) || (defined(_LITTLE_ENDIAN) && defined(__sv2))
00051 #define LIBFSEEK fseek64
00052 #else
00053 #ifdef KEY /* Bug 1678 */
00054 /* Need 64 bit position to support large files */
00055 #define LIBFSEEK fseeko
00056 #else /* KEY Bug 1678 */
00057 #define LIBFSEEK fseek
00058 #endif /* KEY Bug 1678 */
00059 #endif
00060 /*
00061  *  _unit_seek 
00062  *    Fortran seek.  This routine exists as a support
00063  *    routine for direct access I/O.  It handles the
00064  *    logical or physical seek to the specified record.
00065  *
00066  *  input:
00067  *    cup unit pointer
00068  *    recn  record number (1 is the first record)
00069  *    iost  statement state information
00070  *
00071  *  returns:
00072  *     0  for success (cup->udalast is also updated)
00073  *    >0  for error, value is error number
00074  */
00075 
00076 int
00077 _unit_seek(
00078   unit  *cup, /* Unit pointer */
00079   recn_t  recn, /* Record number */
00080   int iost) /* Statement type */
00081 {
00082   register int  errn;   /* Error number   */
00083   register int  isfmt;    /* 1 if formatted else 0*/
00084   register long recl;   /* Record length  */
00085   register off_t  pos;    /* File position  */
00086   struct ffsw fst;    /* FFIO status block  */
00087 
00088   errn  = 0;
00089   recl  = cup->urecl;   /* Get record length */
00090   isfmt = cup->ufmt ? 1 : 0;  /* Formatted? */
00091 
00092   if (recn <= 0)
00093     return(FEIVRECN); /* Invalid record number */
00094 
00095   if ((iost & TF_READ) && (recn > cup->udamax))
00096     return(FENORECN); /* Reading a nonexistent record */
00097 
00098   switch (cup->ufs) {
00099 
00100     case FS_TEXT:
00101     case STD:
00102 
00103       /*
00104        * Seek to the requested record number.  If formatted
00105        * I/O, then adjust the record length to account for
00106        * the newline delimiters.
00107        */
00108 
00109       assert ( strlen("\n") == 1 );
00110 
00111       recl  = recl + isfmt;
00112       pos = (off_t) (recn - 1) * recl;
00113       if (LIBFSEEK(cup->ufp.std, pos, SEEK_SET) != 0)
00114         errn  = errno;
00115 
00116       break;
00117 
00118     case FS_FDC:
00119 
00120       /*
00121        * Seek to the requested record number and let
00122        * the FFIO layer make whatever adjustments are
00123        * necessary for record delimiters.
00124        */
00125 
00126       pos = (off_t)(recn - 1) * recl;
00127       if( XRCALL(cup->ufp.fdc, seekrtn)
00128           cup->ufp.fdc, pos, 0, &fst) < 0)
00129         errn  = fst.sw_error;
00130 #if PURE_ENABLED
00131       else
00132         if (cup->ufmt == 0) /* If unformatted */
00133           cup->ufbitpos = offset << 3;
00134 #endif  /* PURE_ENABLED */
00135 
00136       break;
00137 
00138     case FS_TAPE:
00139     case FS_BIN:
00140     default:
00141       errn  = FEINTUNK; /* Deep weeds */
00142       break;
00143   } /* switch */
00144 
00145   /*
00146    * If successful seek, update last record processed.  Note that
00147    * for formatted I/O, the last record processed will be incremented
00148    * in endrec() processing.
00149    */
00150 
00151   if (errn == 0)
00152     cup->udalast  = recn - isfmt;
00153 
00154   return(errn);
00155 }