1*ff2dbb0fSschwarze /* $OpenBSD: dba_write.c,v 1.1 2016/08/01 10:32:39 schwarze Exp $ */
2*ff2dbb0fSschwarze /*
3*ff2dbb0fSschwarze * Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
4*ff2dbb0fSschwarze *
5*ff2dbb0fSschwarze * Permission to use, copy, modify, and distribute this software for any
6*ff2dbb0fSschwarze * purpose with or without fee is hereby granted, provided that the above
7*ff2dbb0fSschwarze * copyright notice and this permission notice appear in all copies.
8*ff2dbb0fSschwarze *
9*ff2dbb0fSschwarze * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10*ff2dbb0fSschwarze * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11*ff2dbb0fSschwarze * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12*ff2dbb0fSschwarze * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13*ff2dbb0fSschwarze * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14*ff2dbb0fSschwarze * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15*ff2dbb0fSschwarze * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16*ff2dbb0fSschwarze *
17*ff2dbb0fSschwarze * Low-level functions for serializing allocation-based data to disk.
18*ff2dbb0fSschwarze * The interface is defined in "dba_write.h".
19*ff2dbb0fSschwarze */
20*ff2dbb0fSschwarze #include <assert.h>
21*ff2dbb0fSschwarze #include <endian.h>
22*ff2dbb0fSschwarze #include <err.h>
23*ff2dbb0fSschwarze #include <errno.h>
24*ff2dbb0fSschwarze #include <fcntl.h>
25*ff2dbb0fSschwarze #include <stdint.h>
26*ff2dbb0fSschwarze #include <stdio.h>
27*ff2dbb0fSschwarze
28*ff2dbb0fSschwarze #include "dba_write.h"
29*ff2dbb0fSschwarze
30*ff2dbb0fSschwarze static FILE *ofp;
31*ff2dbb0fSschwarze
32*ff2dbb0fSschwarze
33*ff2dbb0fSschwarze int
dba_open(const char * fname)34*ff2dbb0fSschwarze dba_open(const char *fname)
35*ff2dbb0fSschwarze {
36*ff2dbb0fSschwarze ofp = fopen(fname, "w");
37*ff2dbb0fSschwarze return ofp == NULL ? -1 : 0;
38*ff2dbb0fSschwarze }
39*ff2dbb0fSschwarze
40*ff2dbb0fSschwarze int
dba_close(void)41*ff2dbb0fSschwarze dba_close(void)
42*ff2dbb0fSschwarze {
43*ff2dbb0fSschwarze return fclose(ofp) == EOF ? -1 : 0;
44*ff2dbb0fSschwarze }
45*ff2dbb0fSschwarze
46*ff2dbb0fSschwarze int32_t
dba_tell(void)47*ff2dbb0fSschwarze dba_tell(void)
48*ff2dbb0fSschwarze {
49*ff2dbb0fSschwarze long pos;
50*ff2dbb0fSschwarze
51*ff2dbb0fSschwarze if ((pos = ftell(ofp)) == -1)
52*ff2dbb0fSschwarze err(1, "ftell");
53*ff2dbb0fSschwarze if (pos >= INT32_MAX) {
54*ff2dbb0fSschwarze errno = EOVERFLOW;
55*ff2dbb0fSschwarze err(1, "ftell = %ld", pos);
56*ff2dbb0fSschwarze }
57*ff2dbb0fSschwarze return pos;
58*ff2dbb0fSschwarze }
59*ff2dbb0fSschwarze
60*ff2dbb0fSschwarze void
dba_seek(int32_t pos)61*ff2dbb0fSschwarze dba_seek(int32_t pos)
62*ff2dbb0fSschwarze {
63*ff2dbb0fSschwarze if (fseek(ofp, pos, SEEK_SET) == -1)
64*ff2dbb0fSschwarze err(1, "fseek(%d)", pos);
65*ff2dbb0fSschwarze }
66*ff2dbb0fSschwarze
67*ff2dbb0fSschwarze int32_t
dba_align(void)68*ff2dbb0fSschwarze dba_align(void)
69*ff2dbb0fSschwarze {
70*ff2dbb0fSschwarze int32_t pos;
71*ff2dbb0fSschwarze
72*ff2dbb0fSschwarze pos = dba_tell();
73*ff2dbb0fSschwarze while (pos & 3) {
74*ff2dbb0fSschwarze dba_char_write('\0');
75*ff2dbb0fSschwarze pos++;
76*ff2dbb0fSschwarze }
77*ff2dbb0fSschwarze return pos;
78*ff2dbb0fSschwarze }
79*ff2dbb0fSschwarze
80*ff2dbb0fSschwarze int32_t
dba_skip(int32_t nmemb,int32_t sz)81*ff2dbb0fSschwarze dba_skip(int32_t nmemb, int32_t sz)
82*ff2dbb0fSschwarze {
83*ff2dbb0fSschwarze const int32_t out[5] = {0, 0, 0, 0, 0};
84*ff2dbb0fSschwarze int32_t i, pos;
85*ff2dbb0fSschwarze
86*ff2dbb0fSschwarze assert(sz >= 0);
87*ff2dbb0fSschwarze assert(nmemb > 0);
88*ff2dbb0fSschwarze assert(nmemb <= 5);
89*ff2dbb0fSschwarze pos = dba_tell();
90*ff2dbb0fSschwarze for (i = 0; i < sz; i++)
91*ff2dbb0fSschwarze if (nmemb - fwrite(&out, sizeof(out[0]), nmemb, ofp))
92*ff2dbb0fSschwarze err(1, "fwrite");
93*ff2dbb0fSschwarze return pos;
94*ff2dbb0fSschwarze }
95*ff2dbb0fSschwarze
96*ff2dbb0fSschwarze void
dba_char_write(int c)97*ff2dbb0fSschwarze dba_char_write(int c)
98*ff2dbb0fSschwarze {
99*ff2dbb0fSschwarze if (putc(c, ofp) == EOF)
100*ff2dbb0fSschwarze err(1, "fputc");
101*ff2dbb0fSschwarze }
102*ff2dbb0fSschwarze
103*ff2dbb0fSschwarze void
dba_str_write(const char * str)104*ff2dbb0fSschwarze dba_str_write(const char *str)
105*ff2dbb0fSschwarze {
106*ff2dbb0fSschwarze if (fputs(str, ofp) == EOF)
107*ff2dbb0fSschwarze err(1, "fputs");
108*ff2dbb0fSschwarze dba_char_write('\0');
109*ff2dbb0fSschwarze }
110*ff2dbb0fSschwarze
111*ff2dbb0fSschwarze void
dba_int_write(int32_t i)112*ff2dbb0fSschwarze dba_int_write(int32_t i)
113*ff2dbb0fSschwarze {
114*ff2dbb0fSschwarze i = htobe32(i);
115*ff2dbb0fSschwarze if (fwrite(&i, sizeof(i), 1, ofp) != 1)
116*ff2dbb0fSschwarze err(1, "fwrite");
117*ff2dbb0fSschwarze }
118