diff options
Diffstat (limited to 'usr.bin/mandoc/dba_write.c')
-rw-r--r-- | usr.bin/mandoc/dba_write.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/usr.bin/mandoc/dba_write.c b/usr.bin/mandoc/dba_write.c new file mode 100644 index 0000000..ef15dbe --- /dev/null +++ b/usr.bin/mandoc/dba_write.c @@ -0,0 +1,117 @@ +/* $OpenBSD: dba_write.c,v 1.1 2016/08/01 10:32:39 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 <assert.h> +#include <endian.h> +#include <err.h> +#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"); +} |