xref: /titanic_44/usr/src/lib/libast/common/sfio/sfresize.c (revision 3e14f97f673e8a630f076077de35afdd43dc1587)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 #include	"sfhdr.h"
23 
24 /*	Resize a stream.
25 	Written by Kiem-Phong Vo.
26 */
27 
28 #if __STD_C
sfresize(Sfio_t * f,Sfoff_t size)29 int sfresize(Sfio_t* f, Sfoff_t size)
30 #else
31 int sfresize(f, size)
32 Sfio_t*		f;
33 Sfoff_t		size;
34 #endif
35 {
36 	SFMTXDECL(f);
37 
38 	SFMTXENTER(f, -1);
39 
40 	if(size < 0 || f->extent < 0 ||
41 	   (f->mode != SF_WRITE && _sfmode(f,SF_WRITE,0) < 0) )
42 		SFMTXRETURN(f, -1);
43 
44 	SFLOCK(f,0);
45 
46 	if(f->flags&SF_STRING)
47 	{	SFSTRSIZE(f);
48 
49 		if(f->extent >= size)
50 		{	if((f->flags&SF_MALLOC) && (f->next - f->data) <= size)
51 			{	size_t	s = (((size_t)size + 1023)/1024)*1024;
52 				Void_t*	d;
53 				if(s < f->size && (d = realloc(f->data, s)) )
54 				{	f->data = d;
55 					f->size = s;
56 					f->extent = s;
57 				}
58 			}
59 			memclear((char*)(f->data+size), (int)(f->extent-size));
60 		}
61 		else
62 		{	if(SFSK(f, size, SEEK_SET, f->disc) != size)
63 				SFMTXRETURN(f, -1);
64 			memclear((char*)(f->data+f->extent), (int)(size-f->extent));
65 		}
66 	}
67 	else
68 	{	if(f->next > f->data)
69 			SFSYNC(f);
70 #if _lib_ftruncate
71 		if(ftruncate(f->file, (sfoff_t)size) < 0)
72 			SFMTXRETURN(f, -1);
73 #else
74 		SFMTXRETURN(f, -1);
75 #endif
76 	}
77 
78 	f->extent = size;
79 
80 	SFOPEN(f, 0);
81 
82 	SFMTXRETURN(f, 0);
83 }
84