1/***********************************************************************
2*                                                                      *
3*               This software is part of the ast package               *
4*          Copyright (c) 1985-2011 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/*	Fundamental function to create a new stream.
25**	The argument flags defines the type of stream and the scheme
26**	of buffering.
27**
28**	Written by Kiem-Phong Vo.
29*/
30
31#if __STD_C
32Sfio_t* sfnew(Sfio_t* oldf, Void_t* buf, size_t size, int file, int flags)
33#else
34Sfio_t* sfnew(oldf,buf,size,file,flags)
35Sfio_t* oldf;	/* old stream to be reused */
36Void_t*	buf;	/* a buffer to read/write, if NULL, will be allocated */
37size_t	size;	/* buffer size if buf is given or desired buffer size */
38int	file;	/* file descriptor to read/write from */
39int	flags;	/* type of file stream */
40#endif
41{
42	reg Sfio_t*	f;
43	reg int		sflags;
44
45	SFONCE();	/* initialize mutexes */
46
47	if(!(flags&SF_RDWR))
48		return NIL(Sfio_t*);
49
50	sflags = 0;
51	if((f = oldf) )
52	{	if(flags&SF_EOF)
53		{	if(f != sfstdin && f != sfstdout && f != sfstderr)
54				f->mutex = NIL(Vtmutex_t*);
55			SFCLEAR(f, f->mutex);
56			oldf = NIL(Sfio_t*);
57		}
58		else if(f->mode&SF_AVAIL)
59		{	/* only allow SF_STATIC to be already closed */
60			if(!(f->flags&SF_STATIC) )
61				return NIL(Sfio_t*);
62			sflags = f->flags;
63			oldf = NIL(Sfio_t*);
64		}
65		else
66		{	/* reopening an open stream, close it first */
67			sflags = f->flags;
68
69			if(((f->mode&SF_RDWR) != f->mode && _sfmode(f,0,0) < 0) ||
70			   SFCLOSE(f) < 0 )
71				return NIL(Sfio_t*);
72
73			if(f->data && ((flags&SF_STRING) || size != (size_t)SF_UNBOUND) )
74			{	if(sflags&SF_MALLOC)
75					free((Void_t*)f->data);
76				f->data = NIL(uchar*);
77			}
78			if(!f->data)
79				sflags &= ~SF_MALLOC;
80		}
81	}
82
83	if(!f)
84	{	/* reuse a standard stream structure if possible */
85		if(!(flags&SF_STRING) && file >= 0 && file <= 2)
86		{	f = file == 0 ? sfstdin : file == 1 ? sfstdout : sfstderr;
87			if(f)
88			{	if(f->mode&SF_AVAIL)
89				{	sflags = f->flags;
90					SFCLEAR(f, f->mutex);
91				}
92				else	f = NIL(Sfio_t*);
93			}
94		}
95
96		if(!f)
97		{	if(!(f = (Sfio_t*)malloc(sizeof(Sfio_t))) )
98				return NIL(Sfio_t*);
99			SFCLEAR(f, NIL(Vtmutex_t*));
100		}
101	}
102
103	/* create a mutex */
104	if(!f->mutex)
105		f->mutex = vtmtxopen(NIL(Vtmutex_t*), VT_INIT);
106
107	/* stream type */
108	f->mode = (flags&SF_READ) ? SF_READ : SF_WRITE;
109	f->flags = (flags&SF_FLAGS) | (sflags&(SF_MALLOC|SF_STATIC));
110	f->bits = (flags&SF_RDWR) == SF_RDWR ? SF_BOTH : 0;
111	f->file = file;
112	f->here = f->extent = 0;
113	f->getr = f->tiny[0] = 0;
114
115	f->mode |= SF_INIT;
116	if(size != (size_t)SF_UNBOUND)
117	{	f->size = size;
118		f->data = size <= 0 ? NIL(uchar*) : (uchar*)buf;
119	}
120	f->endb = f->endr = f->endw = f->next = f->data;
121
122	if(_Sfnotify)
123		(*_Sfnotify)(f, SF_NEW, (void*)((long)f->file));
124
125	if(f->flags&SF_STRING)
126		(void)_sfmode(f,f->mode&SF_RDWR,0);
127
128	return f;
129}
130