cosmopolitan/libc/runtime/zipos-get.c
Jōshin 6e6fc38935
Apply clang-format update to repo (#1154)
Commit bc6c183 introduced a bunch of discrepancies between what files
look like in the repo and what clang-format says they should look like.
However, there were already a few discrepancies prior to that. Most of
these discrepancies seemed to be unintentional, but a few of them were
load-bearing (e.g., a #include that violated header ordering needing
something to have been #defined by a 'later' #include.)

I opted to take what I hope is a relatively smooth-brained approach: I
reverted the .clang-format change, ran clang-format on the whole repo,
reapplied the .clang-format change, reran clang-format again, and then
reverted the commit that contained the first run. Thus the full effect
of this PR should only be to apply the changed formatting rules to the
repo, and from skimming the results, this seems to be the case.

My work can be checked by applying the short, manual commits, and then
rerunning the command listed in the autogenerated commits (those whose
messages I have prefixed auto:) and seeing if your results agree.

It might be that the other diffs should be fixed at some point but I'm
leaving that aside for now.

fd '\.c(c|pp)?$' --print0| xargs -0 clang-format -i
2024-04-25 10:38:00 -07:00

170 lines
6.3 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 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/atomic.h"
#include "libc/calls/calls.h"
#include "libc/calls/metalfile.internal.h"
#include "libc/calls/struct/stat.h"
#include "libc/cosmo.h"
#include "libc/fmt/conv.h"
#include "libc/intrin/cmpxchg.h"
#include "libc/intrin/promises.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/macros.internal.h"
#include "libc/mem/alg.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/zipos.internal.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/auxv.h"
#include "libc/sysv/consts/f.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/posix.h"
#include "libc/sysv/consts/prot.h"
#include "libc/thread/thread.h"
#include "libc/zip.internal.h"
#ifdef __x86_64__
__static_yoink(APE_COM_NAME);
#endif
static struct Zipos __zipos;
static atomic_uint __zipos_once;
static void __zipos_dismiss(uint8_t *map, const uint8_t *cdir, long pg) {
uint64_t i, n, c, ef, lf, mo, lo, hi;
// determine the byte range of zip file content (excluding central dir)
c = GetZipCdirOffset(cdir);
n = GetZipCdirRecords(cdir);
for (lo = c, hi = i = 0; i < n; ++i, c += ZIP_CFILE_HDRSIZE(map + c)) {
lf = GetZipCfileOffset(map + c);
if (lf < lo)
lo = lf;
ef = lf + ZIP_LFILE_HDRSIZE(map + lf) + GetZipLfileCompressedSize(map + lf);
if (ef > hi)
hi = ef;
}
// unmap the executable portion beneath the local files
mo = ROUNDDOWN(lo, FRAMESIZE);
if (mo)
munmap(map, mo);
// this is supposed to reduce our rss usage but does it really?
lo = ROUNDDOWN(lo, pg);
hi = MIN(ROUNDUP(hi, pg), ROUNDDOWN(c, pg));
if (hi > lo) {
posix_madvise(map + lo, hi - lo, POSIX_MADV_DONTNEED);
}
}
static int __zipos_compare_names(const void *a, const void *b, void *c) {
const size_t *x = (const size_t *)a;
const size_t *y = (const size_t *)b;
struct Zipos *z = (struct Zipos *)c;
int xn = ZIP_CFILE_NAMESIZE(z->map + *x);
int yn = ZIP_CFILE_NAMESIZE(z->map + *y);
int n = MIN(xn, yn);
if (n) {
int res =
memcmp(ZIP_CFILE_NAME(z->map + *x), ZIP_CFILE_NAME(z->map + *y), n);
if (res)
return res;
}
return xn - yn; // xn and yn are 16-bit
}
// creates binary searchable array of file offsets to cdir records
static void __zipos_generate_index(struct Zipos *zipos) {
size_t c, i;
zipos->records = GetZipCdirRecords(zipos->cdir);
zipos->index = _mapanon(zipos->records * sizeof(size_t));
for (i = 0, c = GetZipCdirOffset(zipos->cdir); i < zipos->records;
++i, c += ZIP_CFILE_HDRSIZE(zipos->map + c)) {
zipos->index[i] = c;
}
// smoothsort() isn't the fastest algorithm, but it guarantees
// o(nlogn) won't smash the stack and doesn't depend on malloc
smoothsort_r(zipos->index, zipos->records, sizeof(size_t),
__zipos_compare_names, zipos);
}
static void __zipos_init(void) {
char *endptr;
const char *s;
struct stat st;
int x, fd, err, msg;
uint8_t *map, *cdir;
const char *progpath;
if (!(s = getenv("COSMOPOLITAN_DISABLE_ZIPOS"))) {
// this environment variable may be a filename or file descriptor
if ((progpath = getenv("COSMOPOLITAN_INIT_ZIPOS")) &&
(x = strtol(progpath, &endptr, 10)) >= 0 && !*endptr) {
fd = x;
} else {
fd = -1;
}
if (fd != -1 || PLEDGED(RPATH)) {
if (fd == -1) {
if (!progpath) {
progpath = GetProgramExecutableName();
}
fd = open(progpath, O_RDONLY);
}
if (fd != -1) {
if (!fstat(fd, &st) && (map = mmap(0, st.st_size, PROT_READ, MAP_SHARED,
fd, 0)) != MAP_FAILED) {
if ((cdir = GetZipEocd(map, st.st_size, &err))) {
long pagesz = getauxval(AT_PAGESZ);
__zipos_dismiss(map, cdir, pagesz);
__zipos.map = map;
__zipos.cdir = cdir;
__zipos.dev = st.st_ino;
__zipos.pagesz = pagesz;
__zipos_generate_index(&__zipos);
msg = kZipOk;
} else {
munmap(map, st.st_size);
msg = !cdir ? err : kZipErrorRaceCondition;
}
} else {
msg = kZipErrorMapFailed;
}
close(fd);
} else {
msg = kZipErrorOpenFailed;
}
} else {
msg = -666;
}
} else {
progpath = 0;
msg = -777;
}
STRACE("__zipos_get(%#s) → %d% m", progpath, msg);
}
/**
* Returns pointer to zip central directory of current executable.
* @asyncsignalsafe
*/
struct Zipos *__zipos_get(void) {
cosmo_once(&__zipos_once, __zipos_init);
return __zipos.cdir ? &__zipos : 0;
}