aboutsummaryrefslogtreecommitdiff
path: root/db2/os/os_rw.c
blob: e0a8163d82b1c5fca327cb3de5e92eefdba4a54c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1997, 1998
 *	Sleepycat Software.  All rights reserved.
 */

#include "config.h"

#ifndef lint
static const char sccsid[] = "@(#)os_rw.c	10.11 (Sleepycat) 10/12/98";
#endif /* not lint */

#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>

#include <errno.h>
#include <unistd.h>
#endif

#include "db_int.h"
#include "os_jump.h"

/*
 * __os_io --
 *	Do an I/O.
 *
 * PUBLIC: int __os_io __P((DB_IO *, int, ssize_t *));
 */
int
__os_io(db_iop, op, niop)
	DB_IO *db_iop;
	int op;
	ssize_t *niop;
{
	int ret;

#ifdef HAVE_PREAD
	switch (op) {
	case DB_IO_READ:
		if (__db_jump.j_read != NULL)
			goto slow;
		*niop = pread(db_iop->fd_io, db_iop->buf,
		    db_iop->bytes, (off_t)db_iop->pgno * db_iop->pagesize);
		break;
	case DB_IO_WRITE:
		if (__db_jump.j_write != NULL)
			goto slow;
		*niop = pwrite(db_iop->fd_io, db_iop->buf,
		    db_iop->bytes, (off_t)db_iop->pgno * db_iop->pagesize);
		break;
	}
	if (*niop == db_iop->bytes)
		return (0);
slow:
#endif
	if (db_iop->mutexp != NULL)
		(void)__db_mutex_lock(db_iop->mutexp, db_iop->fd_lock);

	if ((ret = __os_seek(db_iop->fd_io,
	    db_iop->pagesize, db_iop->pgno, 0, 0, SEEK_SET)) != 0)
		goto err;
	switch (op) {
	case DB_IO_READ:
		ret =
		    __os_read(db_iop->fd_io, db_iop->buf, db_iop->bytes, niop);
		break;
	case DB_IO_WRITE:
		ret =
		    __os_write(db_iop->fd_io, db_iop->buf, db_iop->bytes, niop);
		break;
	}

err:	if (db_iop->mutexp != NULL)
		(void)__db_mutex_unlock(db_iop->mutexp, db_iop->fd_lock);

	return (ret);

}

/*
 * __os_read --
 *	Read from a file handle.
 *
 * PUBLIC: int __os_read __P((int, void *, size_t, ssize_t *));
 */
int
__os_read(fd, addr, len, nrp)
	int fd;
	void *addr;
	size_t len;
	ssize_t *nrp;
{
	size_t offset;
	ssize_t nr;
	u_int8_t *taddr;

	for (taddr = addr,
	    offset = 0; offset < len; taddr += nr, offset += nr) {
		if ((nr = __db_jump.j_read != NULL ?
		    __db_jump.j_read(fd, taddr, len - offset) :
		    read(fd, taddr, len - offset)) < 0)
			return (errno);
		if (nr == 0)
			break;
	}
	*nrp = taddr - (u_int8_t *)addr;
	return (0);
}

/*
 * __os_write --
 *	Write to a file handle.
 *
 * PUBLIC: int __os_write __P((int, void *, size_t, ssize_t *));
 */
int
__os_write(fd, addr, len, nwp)
	int fd;
	const void *addr;
	size_t len;
	ssize_t *nwp;
{
	size_t offset;
	ssize_t nw;
	const u_int8_t *taddr;

	for (taddr = addr,
	    offset = 0; offset < len; taddr += nw, offset += nw)
		if ((nw = __db_jump.j_write != NULL ?
		    __db_jump.j_write(fd, taddr, len - offset) :
		    write(fd, taddr, len - offset)) < 0)
			return (errno);
	*nwp = len;
	return (0);
}