1 /** @file
2     Small standard I/O/seek/close functions.
3     These maintain the `known seek offset' for seek optimisation.
4 
5     Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR>
6     This program and the accompanying materials are licensed and made available
7     under the terms and conditions of the BSD License that accompanies this
8     distribution.  The full text of the license may be found at
9     http://opensource.org/licenses/bsd-license.
10 
11     THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
12     WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
13 
14     Copyright (c) 1990, 1993
15     The Regents of the University of California.  All rights reserved.
16 
17     This code is derived from software contributed to Berkeley by
18     Chris Torek.
19 
20     Redistribution and use in source and binary forms, with or without
21     modification, are permitted provided that the following conditions
22     are met:
23       - Redistributions of source code must retain the above copyright
24         notice, this list of conditions and the following disclaimer.
25       - Redistributions in binary form must reproduce the above copyright
26         notice, this list of conditions and the following disclaimer in the
27         documentation and/or other materials provided with the distribution.
28       - Neither the name of the University nor the names of its contributors
29         may be used to endorse or promote products derived from this software
30         without specific prior written permission.
31 
32     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
33     AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34     IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35     ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
36     LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
37     CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
38     SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
39     INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
40     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
41     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42     POSSIBILITY OF SUCH DAMAGE.
43 
44     NetBSD: stdio.c,v 1.13 2003/08/07 16:43:33 agc Exp
45     stdio.c 8.1 (Berkeley) 6/4/93
46 **/
47 #include  <LibConfig.h>
48 
49 #include  "namespace.h"
50 
51 #include  <assert.h>
52 #include  <errno.h>
53 #include  <fcntl.h>
54 #include  <stdio.h>
55 #include  <unistd.h>
56 
57 #include  "reentrant.h"
58 #include  "local.h"
59 
60 int
__sread(void * cookie,char * buf,int n)61 __sread(void *cookie, char *buf, int n)
62 {
63   FILE *fp = cookie;
64   int ret;
65 
66   _DIAGASSERT(fp != NULL);
67   _DIAGASSERT(buf != NULL);
68   if(fp == NULL) {
69     errno = EINVAL;
70     return (EOF);
71   }
72 
73   ret = (int)read(fp->_file, buf, (size_t)n);
74   /* if the read succeeded, update the current offset */
75   if (ret >= 0)
76     fp->_offset += ret;
77   else
78     fp->_flags &= ~__SOFF;  /* paranoia */
79   return (ret);
80 }
81 
82 int
__swrite(void * cookie,char const * buf,int n)83 __swrite(void *cookie, char const *buf, int n)
84 {
85   FILE *fp = cookie;
86 
87   _DIAGASSERT(cookie != NULL);
88   _DIAGASSERT(buf != NULL);
89   if(fp == NULL) {
90     errno = EINVAL;
91     return (EOF);
92   }
93 
94   if (fp->_flags & __SAPP)
95     (void) lseek(fp->_file, (off_t)0, SEEK_END);
96   fp->_flags &= ~__SOFF;  /* in case FAPPEND mode is set */
97   return (int)(write(fp->_file, (char *)buf, (size_t)n));
98 }
99 
100 fpos_t
__sseek(void * cookie,fpos_t offset,int whence)101 __sseek(void *cookie, fpos_t offset, int whence)
102 {
103   FILE *fp = cookie;
104   off_t ret;
105 
106   _DIAGASSERT(fp != NULL);
107   if(fp == NULL) {
108     errno = EINVAL;
109     return (EOF);
110   }
111 
112   ret = lseek(fp->_file, (off_t)offset, whence);
113   if (ret == -1L)
114     fp->_flags &= ~__SOFF;
115   else {
116     fp->_flags |= __SOFF;
117     fp->_offset = ret;
118   }
119   return (ret);
120 }
121 
122 int
__sclose(void * cookie)123 __sclose(void *cookie)
124 {
125 
126   _DIAGASSERT(cookie != NULL);
127   if(cookie == NULL) {
128     errno = EINVAL;
129     return (EOF);
130   }
131 
132   return (close(((FILE *)cookie)->_file));
133 }
134