1/*-
2 * See the file LICENSE for redistribution information.
3 *
4 * Copyright (c) 1997, 1998
5 *	Sleepycat Software.  All rights reserved.
6 */
7
8#include "config.h"
9
10#ifndef lint
11static const char sccsid[] = "@(#)os_rw.c	10.11 (Sleepycat) 10/12/98";
12#endif /* not lint */
13
14#ifndef NO_SYSTEM_INCLUDES
15#include <sys/types.h>
16
17#include <errno.h>
18#include <unistd.h>
19#endif
20
21#include "db_int.h"
22#include "os_jump.h"
23
24/*
25 * __os_io --
26 *	Do an I/O.
27 *
28 * PUBLIC: int __os_io __P((DB_IO *, int, ssize_t *));
29 */
30int
31__os_io(db_iop, op, niop)
32	DB_IO *db_iop;
33	int op;
34	ssize_t *niop;
35{
36	int ret;
37
38#ifdef HAVE_PREAD
39	switch (op) {
40	case DB_IO_READ:
41		if (__db_jump.j_read != NULL)
42			goto slow;
43		*niop = pread(db_iop->fd_io, db_iop->buf,
44		    db_iop->bytes, (off_t)db_iop->pgno * db_iop->pagesize);
45		break;
46	case DB_IO_WRITE:
47		if (__db_jump.j_write != NULL)
48			goto slow;
49		*niop = pwrite(db_iop->fd_io, db_iop->buf,
50		    db_iop->bytes, (off_t)db_iop->pgno * db_iop->pagesize);
51		break;
52	}
53	if (*niop == db_iop->bytes)
54		return (0);
55slow:
56#endif
57	if (db_iop->mutexp != NULL)
58		(void)__db_mutex_lock(db_iop->mutexp, db_iop->fd_lock);
59
60	if ((ret = __os_seek(db_iop->fd_io,
61	    db_iop->pagesize, db_iop->pgno, 0, 0, SEEK_SET)) != 0)
62		goto err;
63	switch (op) {
64	case DB_IO_READ:
65		ret =
66		    __os_read(db_iop->fd_io, db_iop->buf, db_iop->bytes, niop);
67		break;
68	case DB_IO_WRITE:
69		ret =
70		    __os_write(db_iop->fd_io, db_iop->buf, db_iop->bytes, niop);
71		break;
72	}
73
74err:	if (db_iop->mutexp != NULL)
75		(void)__db_mutex_unlock(db_iop->mutexp, db_iop->fd_lock);
76
77	return (ret);
78
79}
80
81/*
82 * __os_read --
83 *	Read from a file handle.
84 *
85 * PUBLIC: int __os_read __P((int, void *, size_t, ssize_t *));
86 */
87int
88__os_read(fd, addr, len, nrp)
89	int fd;
90	void *addr;
91	size_t len;
92	ssize_t *nrp;
93{
94	size_t offset;
95	ssize_t nr;
96	u_int8_t *taddr;
97
98	for (taddr = addr,
99	    offset = 0; offset < len; taddr += nr, offset += nr) {
100		if ((nr = __db_jump.j_read != NULL ?
101		    __db_jump.j_read(fd, taddr, len - offset) :
102		    read(fd, taddr, len - offset)) < 0)
103			return (errno);
104		if (nr == 0)
105			break;
106	}
107	*nrp = taddr - (u_int8_t *)addr;
108	return (0);
109}
110
111/*
112 * __os_write --
113 *	Write to a file handle.
114 *
115 * PUBLIC: int __os_write __P((int, void *, size_t, ssize_t *));
116 */
117int
118__os_write(fd, addr, len, nwp)
119	int fd;
120	void *addr;
121	size_t len;
122	ssize_t *nwp;
123{
124	size_t offset;
125	ssize_t nw;
126	u_int8_t *taddr;
127
128	for (taddr = addr,
129	    offset = 0; offset < len; taddr += nw, offset += nw)
130		if ((nw = __db_jump.j_write != NULL ?
131		    __db_jump.j_write(fd, taddr, len - offset) :
132		    write(fd, taddr, len - offset)) < 0)
133			return (errno);
134	*nwp = len;
135	return (0);
136}
137