1/* Implement Input/Output runtime actions for CHILL.
2   Copyright (C) 1992, 1993, 1998 Free Software Foundation, Inc.
3   Author: Wilfried Moser, et al
4
5This file is part of GNU CC.
6
7GNU CC is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2, or (at your option)
10any later version.
11
12GNU CC is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with GNU CC; see the file COPYING.  If not, write to
19the Free Software Foundation, 59 Temple Place - Suite 330,
20Boston, MA 02111-1307, USA.  */
21
22/* As a special exception, if you link this library with other files,
23   some of which are compiled with GCC, to produce an executable,
24   this library does not by itself cause the resulting executable
25   to be covered by the GNU General Public License.
26   This exception does not however invalidate any other reasons why
27   the executable file might be covered by the GNU General Public License.  */
28
29#include <setjmp.h>
30#include <stdlib.h>
31#include <errno.h>
32#include <sys/types.h>
33#include <unistd.h>
34
35#include "fileio.h"
36
37#ifdef EOF
38#undef EOF
39#endif
40#define EOF -1
41
42static
43Boolean
44doRead( Access_Mode* the_access, void* buf, size_t nbyte )
45{
46  size_t nread;
47
48  nread = read( the_access->association->handle, buf, nbyte );
49  if( nread == nbyte )
50  {
51    CLR_FLAG( the_access, IO_OUTOFFILE );
52    return True;
53  }
54  if( nread == 0 )
55  {
56    SET_FLAG( the_access, IO_OUTOFFILE );
57    return False;
58  }
59  the_access->association->syserrno = errno;
60  RWEXCEPTION( READFAIL, OS_IO_ERROR );
61  /* no return */
62}
63
64static
65int bgetc( int handle, readbuf_t* rbptr )
66{
67  if( rbptr->cur >= rbptr->len )
68    {
69      rbptr->len = read( handle, rbptr->buf, READBUFLEN );
70      if( rbptr->len == 0 )
71	return EOF;
72      rbptr->cur = 0;
73    }
74  return rbptr->buf[rbptr->cur++];
75}
76
77static
78void bungetc( readbuf_t* rbptr, int c )
79{
80  rbptr->buf[--rbptr->cur] = c;
81}
82
83void*
84__readrecord( Access_Mode*  the_access,
85              signed long   the_index,
86              char*         the_buf_addr,
87              char*         file,
88              int           line )
89{
90  unsigned long  info;
91  char*          actaddr;
92  unsigned short actlen;
93  off_t          filepos;
94  unsigned short reclen;
95  unsigned long  readlen;
96
97  if( !the_access )
98    CHILLEXCEPTION( file, line, EMPTY, NULL_ACCESS );
99
100  if( !the_access->association )
101    CHILLEXCEPTION( file, line, NOTCONNECTED, IS_NOT_CONNECTED );
102
103  /* Usage must not be WriteOnly */
104  if( the_access->association->usage == WriteOnly )
105    CHILLEXCEPTION( file, line, READFAIL, BAD_USAGE );
106
107  /* OUTOFFILE must not be True when connected for sequential read */
108  if( !TEST_FLAG( the_access, IO_INDEXED )
109      && TEST_FLAG( the_access, IO_OUTOFFILE ) )
110    CHILLEXCEPTION( file, line, READFAIL, OUT_OF_FILE );
111
112  /*
113   *  Positioning
114   */
115  if( TEST_FLAG( the_access, IO_INDEXED ) )
116  {
117    /* index expression must be within bounds of index mode */
118    if( the_index < the_access->lowindex
119        || the_access->highindex < the_index )
120      CHILLEXCEPTION( file, line, RANGEFAIL, BAD_INDEX );
121
122    filepos = the_access->base +
123              (the_index - the_access->lowindex) * the_access->reclength;
124
125    if( lseek( the_access->association->handle, filepos, SEEK_SET ) == -1L )
126      CHILLEXCEPTION( file, line, READFAIL, LSEEK_FAILS );
127  }
128
129  /* establish store loc */
130  if( !(actaddr = the_buf_addr ))
131  {
132    /* if not yet allocated, do it now */
133    if (!the_access->store_loc)
134      if( !(the_access->store_loc = (char*)malloc( the_access->reclength ) ) )
135	CHILLEXCEPTION( file, line, SPACEFAIL, STORE_LOC_ALLOC );
136    actaddr = the_access->store_loc;
137  }
138  actlen  = the_access->reclength;
139
140  if( (info = setjmp( __rw_exception )) )
141    CHILLEXCEPTION( file, line, info>>16, info & 0xffff );
142
143  if( TEST_FLAG( the_access, IO_TEXTIO ) )
144  {
145    readlen = actlen - 2;
146    if( TEST_FLAG( the_access, IO_INDEXED ) )
147    {
148      if( ! doRead( the_access, &reclen, sizeof(reclen) ) )
149        return NULL;
150      if( reclen > readlen )
151        CHILLEXCEPTION( file, line, RANGEFAIL, RECORD_TOO_LONG );
152      if( ! doRead( the_access, actaddr + 2, reclen ) )
153        CHILLEXCEPTION( file, line, READFAIL, RECORD_TOO_SHORT );
154    }
155    else
156    {
157      Association_Mode *assoc = the_access->association;
158      int              handle = assoc->handle;
159      readbuf_t*       rbuf   = assoc->bufptr;
160      char* cptr = actaddr+2;
161      int   curr;
162
163      reclen = 0;
164      while( readlen-- )
165      {
166        curr = bgetc( handle, rbuf );
167        if( curr == '\n' )
168          goto end_of_line;
169        if( curr == EOF )
170	{
171          if( !reclen )
172            SET_FLAG( the_access, IO_OUTOFFILE );
173          goto end_of_line;
174	}
175        *cptr++ = curr;
176        reclen++;
177      }
178      if( (curr = bgetc( handle, rbuf )) != '\n' )
179	{
180	  bungetc( rbuf, curr );
181	  CHILLEXCEPTION( file, line, RANGEFAIL, RECORD_TOO_LONG );
182	}
183end_of_line: ;
184    }
185    MOV2(actaddr,&reclen);
186  }
187  else
188  {
189    switch( the_access->rectype )
190    {
191    case Fixed:
192      if( ! doRead( the_access, actaddr, actlen ) )
193        return NULL;
194      break;
195    case VaryingChars:
196      if( TEST_FLAG( the_access->association, IO_VARIABLE ) )
197      {
198        if( ! doRead( the_access, &reclen, sizeof(reclen) ) )
199          return NULL;
200        if( reclen > actlen - 2 )
201          CHILLEXCEPTION( file, line, RANGEFAIL, RECORD_TOO_LONG );
202        readlen = TEST_FLAG( the_access, IO_INDEXED ) ? actlen - 2 : reclen;
203        if( ! doRead( the_access, actaddr + 2, readlen ) )
204          CHILLEXCEPTION( file, line, READFAIL, RECORD_TOO_SHORT );
205      }
206      else
207      {
208        if( ! doRead( the_access, actaddr + 2, reclen = actlen - 2 ) )
209          CHILLEXCEPTION( file, line, READFAIL, RECORD_TOO_SHORT );
210      }
211      MOV2(actaddr,&reclen);
212      break;
213    }
214  }
215
216  return actaddr;
217}
218