cosmopolitan/tool/decode/lib/bitabuilder.c

77 lines
3.0 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/bits/bits.h"
#include "libc/log/check.h"
#include "libc/macros.h"
#include "libc/mem/mem.h"
#include "libc/runtime/runtime.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "tool/decode/lib/bitabuilder.h"
/**
* @fileoverview Sparse bit array builder.
*/
struct BitaBuilder {
size_t i, n;
unsigned *p;
};
struct BitaBuilder *bitabuilder_new(void) {
return calloc(1, sizeof(struct BitaBuilder));
}
void bitabuilder_free(struct BitaBuilder **bbpp) {
if (*bbpp) {
free_s(&(*bbpp)->p);
free_s(bbpp);
}
}
/**
* Sets bit.
*
* @return false if out of memory
*/
bool bitabuilder_setbit(struct BitaBuilder *bb, size_t bit) {
void *p2;
size_t i, n;
i = MAX(bb->i, ROUNDUP(bit / CHAR_BIT + 1, __BIGGEST_ALIGNMENT__));
if (i > bb->n) {
n = i + (i >> 2);
if ((p2 = realloc(bb->p, n))) {
memset((char *)p2 + bb->n, 0, n - bb->n);
bb->n = n;
bb->p = p2;
} else {
return false;
}
}
bb->i = i;
bts(bb->p, bit);
return true;
}
bool bitabuilder_fwrite(const struct BitaBuilder *bb, FILE *f) {
return fwrite(bb->p, bb->i, 1, f);
}