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Diffstat (limited to 'private/crt32/stdio/setvbuf.c')
| -rw-r--r-- | private/crt32/stdio/setvbuf.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/private/crt32/stdio/setvbuf.c b/private/crt32/stdio/setvbuf.c new file mode 100644 index 000000000..665cee028 --- /dev/null +++ b/private/crt32/stdio/setvbuf.c @@ -0,0 +1,180 @@ +/*** +*setvbuf.c - set buffer size for a stream +* +* Copyright (c) 1985-1993, Microsoft Corporation. All rights reserved. +* +*Purpose: +* defines setvbuf() - set the buffering mode and size for a stream. +* +*Revision History: +* 09-19-83 RN initial version +* 06-26-85 TC modified to allow user defined buffers of various sizes +* 06-24-86 DFW kludged to fix incompatability with Xenix values of +* _IOFBF, _IOLBF +* 02-09-87 JCR added "buffer=&(_iob2[fileno(stream)]._charbuf);" +* to handle _IONBF case +* 02-25-87 JCR added support for default buffer and IBMC20-condition +* code +* 04-13-87 JCR changed type of szie from int to size_t (unsigned int) +* and changed a related comparison +* 06-29-87 JCR Took out the _OLD_IOFBF/_OLD_IOLBF kludge for MSC. +* Should be taken out for IBM too... +* 09-28-87 JCR Corrected _iob2 indexing (now uses _iob_index() macro). +* 11-02-87 JCR Multi-thread support +* 12-11-87 JCR Added "_LOAD_DS" to declaration +* 05-27-88 PHG Merged DLL and normal versions +* 06-06-88 JCR Optimized _iob2 references +* 06-14-88 JCR Use near pointer to reference _iob[] entries +* 08-09-88 JCR Buffer size can't be greater than INT_MAX +* 08-25-88 GJF Don't use FP_OFF() macro for the 386 +* 08-18-89 GJF Clean up, now specific to OS/2 2.0 (i.e., 386 flat +* model). Also fixed copyright and indents. +* 02-15-90 GJF _iob[], _iob2[] merge. Also, cleanup, a little tuning +* and fixed copyright. +* 03-19-90 GJF Made calling type _CALLTYPE1, added #include +* <cruntime.h> and removed #include <register.h>. +* 05-29-90 SBM Use _flush, not [_]fflush[_lk] +* 07-23-90 SBM Replaced <assertm.h> by <assert.h> +* 10-03-90 GJF New-style function declarator. +* 04-27-93 CFW Change _IONBF size to 2 bytes to hold wide char. +* +*******************************************************************************/ + +#include <cruntime.h> +#include <stdio.h> +#include <file2.h> +#include <assert.h> +#include <malloc.h> +#include <internal.h> +#include <os2dll.h> +#include <limits.h> + +/*** +*int setvbuf(stream, buffer, type, size) - set buffering for a file +* +*Purpose: +* Controls buffering and buffer size for the specified stream. The +* array pointed to by buf is used as a buffer, unless NULL, in which +* case we'll allocate a buffer automatically. type specifies the type +* of buffering: _IONBF = no buffer, _IOFBF = buffered, _IOLBF = same +* as _IOFBF. +* +*Entry: +* FILE *stream - stream to control buffer on +* char *buffer - pointer to buffer to use (NULL means auto allocate) +* int type - type of buffering (_IONBF, _IOFBF or _IOLBF) +* size_t size - size of buffer +* +*Exit: +* return 0 if successful +* returns non-zero if fails +* +*Exceptions: +* +*******************************************************************************/ + +int _CRTAPI1 setvbuf ( + FILE *str, + char *buffer, + int type, + size_t size + ) +{ + REG1 FILE *stream; +#ifdef MTHREAD + int index; +#endif + int retval=0; /* assume good return */ + + assert(str != NULL); + + /* + * (1) Make sure type is one of the three legal values. + * (2) If we are buffering, make sure size is greater than 0. + */ + if ( (type != _IONBF) && ((size == 0) || (size > INT_MAX) || + ((type != _IOFBF) && (type != _IOLBF))) ) + return(-1); + + /* force size to be even */ + size &= (size_t)~1; + + /* + * Init stream pointers + */ + stream = str; + +#ifdef MTHREAD + index = _iob_index(stream); +#endif + /* + * Lock the file + */ + _lock_str(index); + + /* + * Flush the current buffer and free it, if it is ours. + */ + _flush(stream); + _freebuf(stream); + + /* + * Clear a bunch of bits in stream->_flag (all bits related to + * buffering and those which used to be in stream2->_flag2). Most + * of these should never be set when setvbuf() is called, but it + * doesn't cost anything to be safe. + */ + stream->_flag &= ~(_IOMYBUF | _IOYOURBUF | _IONBF | _IOFEOF | + _IOFLRTN | _IOCTRLZ); + + /* + * CASE 1: No Buffering. + */ + if (type & _IONBF) { + stream->_flag |= _IONBF; + buffer = (char *)&(stream->_charbuf); + size = 2; + } + + /* + * NOTE: Cases 2 and 3 (below) cover type == _IOFBF or type == _IOLBF + * Line buffering is treated as the same as full buffering, so the + * _IOLBF bit in stream->_flag is never set. Finally, since _IOFBF is + * defined to be 0, full buffering is simply assumed whenever _IONBF + * is not set. + */ + + /* + * CASE 2: Default Buffering -- Allocate a buffer for the user. + */ + else if ( buffer == NULL ) { + if ( (buffer = malloc(size)) == NULL ) { + /* + * force library pre-termination procedure (placed here + * because the code path should almost never be hit) + */ + _cflush++; + + retval = -1; + goto done; + } + stream->_flag |= _IOMYBUF; + } + + /* + * CASE 3: User Buffering -- Use the buffer supplied by the user. + */ + else { + stream->_flag |= _IOYOURBUF; + } + + /* + * Common return for all cases. + */ + stream->_bufsiz = size; + stream->_ptr = stream->_base = buffer; + stream->_cnt = 0; +done: + _unlock_str(index); + return(retval); +} |