[BACK]Return to dba_write.c CVS log [TXT][DIR] Up to [cvsweb.bsd.lv] / mandoc

File: [cvsweb.bsd.lv] / mandoc / dba_write.c (download)

Revision 1.3, Fri Aug 5 23:15:08 2016 UTC (4 years, 9 months ago) by schwarze
Branch: MAIN
CVS Tags: VERSION_1_14_5, VERSION_1_14_4, VERSION_1_14_3, VERSION_1_14_2, VERSION_1_14_1, HEAD
Changes since 1.2: +7 -1 lines

The concept of endianness seems to be somewhat newfangled, so the
respective conversion functions are not yet properly standardized.
Rumour has it that POSIX is working on it, though.
For now, sprinkle some configuration glue.

/*	$Id: dba_write.c,v 1.3 2016/08/05 23:15:08 schwarze Exp $ */
/*
 * Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Low-level functions for serializing allocation-based data to disk.
 * The interface is defined in "dba_write.h".
 */
#include "config.h"

#include <assert.h>
#if HAVE_ENDIAN
#include <endian.h>
#elif HAVE_SYS_ENDIAN
#include <sys/endian.h>
#elif HAVE_NTOHL
#include <arpa/inet.h>
#endif
#if HAVE_ERR
#include <err.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>

#include "dba_write.h"

static FILE	*ofp;


int
dba_open(const char *fname)
{
	ofp = fopen(fname, "w");
	return ofp == NULL ? -1 : 0;
}

int
dba_close(void)
{
	return fclose(ofp) == EOF ? -1 : 0;
}

int32_t
dba_tell(void)
{
	long		 pos;

	if ((pos = ftell(ofp)) == -1)
		err(1, "ftell");
	if (pos >= INT32_MAX) {
		errno = EOVERFLOW;
		err(1, "ftell = %ld", pos);
	}
	return pos;
}

void
dba_seek(int32_t pos)
{
	if (fseek(ofp, pos, SEEK_SET) == -1)
		err(1, "fseek(%d)", pos);
}

int32_t
dba_align(void)
{
	int32_t		 pos;

	pos = dba_tell();
	while (pos & 3) {
		dba_char_write('\0');
		pos++;
	}
	return pos;
}

int32_t
dba_skip(int32_t nmemb, int32_t sz)
{
	const int32_t	 out[5] = {0, 0, 0, 0, 0};
	int32_t		 i, pos;

	assert(sz >= 0);
	assert(nmemb > 0);
	assert(nmemb <= 5);
	pos = dba_tell();
	for (i = 0; i < sz; i++)
		if (nmemb - fwrite(&out, sizeof(out[0]), nmemb, ofp))
			err(1, "fwrite");
	return pos;
}

void
dba_char_write(int c)
{
	if (putc(c, ofp) == EOF)
		err(1, "fputc");
}

void
dba_str_write(const char *str)
{
	if (fputs(str, ofp) == EOF)
		err(1, "fputs");
	dba_char_write('\0');
}

void
dba_int_write(int32_t i)
{
	i = htobe32(i);
	if (fwrite(&i, sizeof(i), 1, ofp) != 1)
		err(1, "fwrite");
}