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 *                 Eclipse Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *          http://www.eclipse.org/org/documents/epl-v10.html           *
11 *         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
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 #pragma prototyped
23 /*
24  * Glenn Fowler
25  * AT&T Bell Laboratories
26  *
27  * copy from rfd to wfd (with conditional mmap hacks)
28  */
29 
30 #include <ast.h>
31 #include <ast_mmap.h>
32 
33 #if _mmap_worthy > 1
34 
35 #include <ls.h>
36 
37 #define MAPSIZE		(1024*256)
38 
39 #endif
40 
41 #undef	BUFSIZ
42 #define BUFSIZ		4096
43 
44 /*
45  * copy n bytes from rfd to wfd
46  * actual byte count returned
47  * if n<=0 then ``good'' size is used
48  */
49 
50 off_t
astcopy(int rfd,int wfd,off_t n)51 astcopy(int rfd, int wfd, off_t n)
52 {
53 	register off_t	c;
54 #ifdef MAPSIZE
55 	off_t		pos;
56 	off_t		mapsize;
57 	char*		mapbuf;
58 	struct stat	st;
59 #endif
60 
61 	static int	bufsiz;
62 	static char*	buf;
63 
64 	if (n <= 0 || n >= BUFSIZ * 2)
65 	{
66 #if MAPSIZE
67 		if (!fstat(rfd, &st) && S_ISREG(st.st_mode) && (pos = lseek(rfd, (off_t)0, 1)) != ((off_t)-1))
68 		{
69 			if (pos >= st.st_size) return(0);
70 			mapsize = st.st_size - pos;
71 			if (mapsize > MAPSIZE) mapsize = (mapsize > n && n > 0) ? n : MAPSIZE;
72 			if (mapsize >= BUFSIZ * 2 && (mapbuf = (char*)mmap(NiL, mapsize, PROT_READ, MAP_SHARED, rfd, pos)) != ((caddr_t)-1))
73 			{
74 				if (write(wfd, mapbuf, mapsize) != mapsize || lseek(rfd, mapsize, 1) == ((off_t)-1)) return(-1);
75 				munmap((caddr_t)mapbuf, mapsize);
76 				return(mapsize);
77 			}
78 		}
79 #endif
80 		if (n <= 0) n = BUFSIZ;
81 	}
82 	if (n > bufsiz)
83 	{
84 		if (buf) free(buf);
85 		bufsiz = roundof(n, BUFSIZ);
86 		if (!(buf = newof(0, char, bufsiz, 0))) return(-1);
87 	}
88 	if ((c = read(rfd, buf, (size_t)n)) > 0 && write(wfd, buf, (size_t)c) != c) c = -1;
89 	return(c);
90 }
91