cosmopolitan/libc/x/xloadzd.c
Justine Tunney 10fd8bdb70 Unbloat the build
This change resurrects ae5d06dc53
2022-08-11 00:15:29 -07:00

72 lines
3.1 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 2021 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or 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. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/fmt/leb128.h"
#include "libc/intrin/lockcmpxchg.h"
#include "libc/mem/mem.h"
#include "libc/nexgen32e/crc32.h"
#include "libc/runtime/internal.h"
#include "libc/runtime/runtime.h"
#include "libc/x/x.h"
#include "third_party/zlib/zlib.h"
/**
* Loads δzd encoded data once atomically.
*
* @param o points to your static init guard
* @param t points to your static pointer holder
* @param p is read-only data compressed using raw deflate
* @param n is byte length of deflated data
* @param m is byte length of inflated data
* @param c is number of items in array
* @param z is byte length of items
* @param s is crc32 checksum
* @return pointer to decoded data
* @threadsafe
*/
void *xloadzd(bool *o, void **t, const void *p, size_t n, size_t m, size_t c,
size_t z, uint32_t s) {
void *r;
size_t i;
z_stream zs;
char *q, *b;
int64_t x, y;
assert(z == 2 || z == 4);
b = q = malloc(m);
__inflate(q, m, p, n);
r = memalign(z, c * z);
for (x = i = 0; i < c; ++i) {
b += unzleb64(b, 10, &y);
x += y;
if (z == 2) {
((uint16_t *)r)[i] = x;
} else {
((uint32_t *)r)[i] = x;
}
}
free(q);
assert(crc32_z(0, r, c * z) == s);
if (_lockcmpxchg(t, 0, r)) {
__cxa_atexit(free, r, 0);
} else {
free(q);
}
*o = true;
return *t;
}