1/*	$Id: dba_write.c,v 1.3 2016/08/05 23:15:08 schwarze Exp $ */
2/*
3 * Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 *
17 * Low-level functions for serializing allocation-based data to disk.
18 * The interface is defined in "dba_write.h".
19 */
20#include "config.h"
21
22#include <assert.h>
23#if HAVE_ENDIAN
24#include <endian.h>
25#elif HAVE_SYS_ENDIAN
26#include <sys/endian.h>
27#elif HAVE_NTOHL
28#include <arpa/inet.h>
29#endif
30#if HAVE_ERR
31#include <err.h>
32#endif
33#include <errno.h>
34#include <fcntl.h>
35#include <stdint.h>
36#include <stdio.h>
37
38#include "dba_write.h"
39
40static FILE	*ofp;
41
42
43int
44dba_open(const char *fname)
45{
46	ofp = fopen(fname, "w");
47	return ofp == NULL ? -1 : 0;
48}
49
50int
51dba_close(void)
52{
53	return fclose(ofp) == EOF ? -1 : 0;
54}
55
56int32_t
57dba_tell(void)
58{
59	long		 pos;
60
61	if ((pos = ftell(ofp)) == -1)
62		err(1, "ftell");
63	if (pos >= INT32_MAX) {
64		errno = EOVERFLOW;
65		err(1, "ftell = %ld", pos);
66	}
67	return pos;
68}
69
70void
71dba_seek(int32_t pos)
72{
73	if (fseek(ofp, pos, SEEK_SET) == -1)
74		err(1, "fseek(%d)", pos);
75}
76
77int32_t
78dba_align(void)
79{
80	int32_t		 pos;
81
82	pos = dba_tell();
83	while (pos & 3) {
84		dba_char_write('\0');
85		pos++;
86	}
87	return pos;
88}
89
90int32_t
91dba_skip(int32_t nmemb, int32_t sz)
92{
93	const int32_t	 out[5] = {0, 0, 0, 0, 0};
94	int32_t		 i, pos;
95
96	assert(sz >= 0);
97	assert(nmemb > 0);
98	assert(nmemb <= 5);
99	pos = dba_tell();
100	for (i = 0; i < sz; i++)
101		if (nmemb - fwrite(&out, sizeof(out[0]), nmemb, ofp))
102			err(1, "fwrite");
103	return pos;
104}
105
106void
107dba_char_write(int c)
108{
109	if (putc(c, ofp) == EOF)
110		err(1, "fputc");
111}
112
113void
114dba_str_write(const char *str)
115{
116	if (fputs(str, ofp) == EOF)
117		err(1, "fputs");
118	dba_char_write('\0');
119}
120
121void
122dba_int_write(int32_t i)
123{
124	i = htobe32(i);
125	if (fwrite(&i, sizeof(i), 1, ofp) != 1)
126		err(1, "fwrite");
127}
128