#include <stdio.h>
#include <stdlib.h>
+#include <limits.h>
#ifndef REGTEST
-int setvbuf( FILE * _PDCLIB_restrict stream, char * _PDCLIB_restrict buf, int mode, size_t size )
+int setvbuf( struct _PDCLIB_file_t * _PDCLIB_restrict stream, char * _PDCLIB_restrict buf, int mode, size_t size )
{
- /* TODO: Only allowed on a "virgin" stream; add check. */
- if ( ( stream->status & ( _IOFBF | _IOLBF | _IONBF ) ) /* Only allowed on "virgin" stream */
- || ( ( mode != _IOFBF ) && ( mode != _IOLBF ) && ( mode != _IONBF ) ) /* invalid mode */
- || ( ( buf == NULL ) && ( ( buf = malloc( size ) ) == NULL ) ) /* no memory available */
- )
+ switch ( mode )
{
- return -1;
+ case _IONBF:
+ /* When unbuffered I/O is requested, we keep the buffer anyway, as
+ we don't want to e.g. flush the stream for every character of a
+ stream being printed.
+ */
+ break;
+ case _IOFBF:
+ case _IOLBF:
+ if ( size > INT_MAX || size == 0 )
+ {
+ /* PDCLib only supports buffers up to INT_MAX in size. A size
+ of zero doesn't make sense.
+ */
+ return -1;
+ }
+ if ( buf == NULL )
+ {
+ /* User requested buffer size, but leaves it to library to
+ allocate the buffer.
+ */
+ /* If current buffer is big enough for requested size, but not
+ over twice as big (and wasting memory space), we use the
+ current buffer (i.e., do nothing), to save the malloc() /
+ free() overhead.
+ */
+ if ( ( stream->bufsize < size ) || ( stream->bufsize > ( size << 1 ) ) )
+ {
+ /* Buffer too small, or much too large - allocate. */
+ if ( ( buf = (char *) malloc( size ) ) == NULL )
+ {
+ /* Out of memory error. */
+ return -1;
+ }
+ /* This buffer must be free()d on fclose() */
+ stream->status |= _PDCLIB_FREEBUFFER;
+ }
+ }
+ stream->buffer = buf;
+ stream->bufsize = size;
+ break;
+ default:
+ /* If mode is something else than _IOFBF, _IOLBF or _IONBF -> exit */
+ return -1;
}
+ /* Deleting current buffer mode */
+ stream->status &= ~( _IOFBF | _IOLBF | _IONBF );
+ /* Set user-defined mode */
stream->status |= mode;
- stream->buffer = buf;
- stream->bufsize = size;
return 0;
}
#ifdef TEST
#include <_PDCLIB_test.h>
+#include <errno.h>
+
+#define BUFFERSIZE 500
+
int main( void )
{
- TESTCASE( NO_TESTDRIVER );
+#ifndef REGTEST
+ char buffer[ BUFFERSIZE ];
+ FILE * fh;
+ /* full buffered, user-supplied buffer */
+ TESTCASE( ( fh = tmpfile() ) != NULL );
+ TESTCASE( setvbuf( fh, buffer, _IOFBF, BUFFERSIZE ) == 0 );
+ TESTCASE( fh->buffer == buffer );
+ TESTCASE( fh->bufsize == BUFFERSIZE );
+ TESTCASE( ( fh->status & ( _IOFBF | _IONBF | _IOLBF ) ) == _IOFBF );
+ TESTCASE( fclose( fh ) == 0 );
+ /* line buffered, lib-supplied buffer */
+ TESTCASE( ( fh = tmpfile() ) != NULL );
+ TESTCASE( setvbuf( fh, NULL, _IOLBF, BUFFERSIZE ) == 0 );
+ TESTCASE( fh->buffer != NULL );
+ TESTCASE( fh->bufsize == BUFFERSIZE );
+ TESTCASE( ( fh->status & ( _IOFBF | _IONBF | _IOLBF ) ) == _IOLBF );
+ TESTCASE( fclose( fh ) == 0 );
+ /* not buffered, user-supplied buffer */
+ TESTCASE( ( fh = tmpfile() ) != NULL );
+ TESTCASE( setvbuf( fh, buffer, _IONBF, BUFFERSIZE ) == 0 );
+ TESTCASE( ( fh->status & ( _IOFBF | _IONBF | _IOLBF ) ) == _IONBF );
+ TESTCASE( fclose( fh ) == 0 );
+#else
+ puts( " NOTEST setvbuf() test driver is PDCLib-specific." );
+#endif
return TEST_RESULTS;
}
#endif
+