2 * Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies).
4 * This component and the accompanying materials are made available
5 * under the terms of "Eclipse Public License v1.0"
6 * which accompanies this distribution, and is available
7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".
9 * Initial Contributors:
10 * Nokia Corporation - initial contribution.
20 #ifndef _SYS_STDIO_T_H_
21 #define _SYS_STDIO_T_H_
34 unsigned char * _base;
39 We need fpos_t for the following, but it doesn't have a leading "_",
40 so we use _fpos_t instead.
45 typedef long _fpos_t; /* XXX must match off_t in <sys/types.h> */
46 /* (and must be `long' for now) */
49 Stdio state variables.
51 The following always hold:
53 if (_flags&(__SLBF|__SWR)) == (__SLBF|__SWR),
54 _lbfsize is -_bf._size, else _lbfsize is 0
55 if _flags&__SRD, _w is 0
56 if _flags&__SWR, _r is 0
58 This ensures that the getc and putc macros (or inline functions) never
59 try to write or read from a file that is in `read' or `write' mode.
60 (Moreover, they can, and do, automatically switch from read mode to
61 write mode, and back, on "r+" and "w+" files.)
63 _lbfsize is used only to make the inline line-buffered output stream
64 code as compact as possible.
66 _ub, _up, and _ur are used when ungetc() pushes back more characters
67 than fit in the current _bf, or when ungetc() pushes back a character
68 that does not match the previous one in _bf. When this happens,
69 _ub._base becomes non-nil (i.e., a stream has ungetc() data iff
70 _ub._base!=NULL) and _up and _ur save the current values of _p and _r.
75 unsigned char *_p; /* current position in (some) buffer */
76 int _r; /* read space left for getc() */
77 int _w; /* write space left for putc() */
78 short _flags; /* flags, below; this FILE is free if 0 */
79 short _file; /* fileno, if Unix descriptor, else -1 */
80 struct __sbuf _bf; /* the buffer (at least 1 byte, if !NULL) */
81 int _lbfsize; /* 0 or -_bf._size, for inline putc */
84 void * _cookie; /* cookie passed to io functions */
86 int (*_read) (void * _cookie, char *_buf, int _n);
87 int (*_write)(void * _cookie, const char *_buf, int _n);
88 _fpos_t (*_seek) (void * _cookie, _fpos_t _offset, int _whence);
89 int (*_close)(void * _cookie);
91 /* separate buffer for long sequences of ungetc() */
92 struct __sbuf _ub; /* ungetc buffer */
93 unsigned char * _up; /* saved _p when _p is doing ungetc data */
94 int _ur; /* saved _r when _r is counting ungetc data */
96 /* tricks to meet minimum requirements even when malloc() fails */
97 unsigned char _ubuf[3]; /* guarantee an ungetc() buffer */
98 unsigned char _nbuf[1]; /* guarantee a getc() buffer */
100 /* separate buffer for fgetline() when line crosses buffer boundary */
101 struct __sbuf _lb; /* buffer for fgetline() */
103 /* Unix stdio files get aligned to block boundaries on fseek() */
104 int _blksize; /* stat.st_blksize (may be != _bf._size) */
105 int _offset; /* current lseek offset */
107 struct _reent * _data; /* pointer back to re-entrancy context block */
114 #endif /* _SYS_STDIO_T_H_ */