cosmopolitan/libc/runtime/zipos-read.c
Justine Tunney 110559ce6a
Make ZipOS and Qemu work better
This change improves the dirstream library in a lot of respects,
especially for /zip/... files. Also turn off MAP_STACK on Aarch64
because Qemu seems to implement it differently than Linux and it's
probably responsible for a lot of mysterious crashes.
2023-08-15 18:32:50 -07:00

70 lines
3.3 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 │
│ │
│ 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/calls/struct/iovec.h"
#include "libc/runtime/zipos.internal.h"
#include "libc/sysv/consts/s.h"
#include "libc/sysv/errfuns.h"
#include "libc/zip.internal.h"
static size_t GetIovSize(const struct iovec *iov, size_t iovlen) {
size_t i, r;
for (r = i = 0; i < iovlen; ++i) r += iov[i].iov_len;
return r;
}
static ssize_t __zipos_read_impl(struct ZiposHandle *h, const struct iovec *iov,
size_t iovlen, ssize_t opt_offset) {
int i;
int64_t b, x, y;
if (h->cfile == ZIPOS_SYNTHETIC_DIRECTORY ||
S_ISDIR(GetZipCfileMode(h->zipos->map + h->cfile))) {
return eisdir();
}
if (opt_offset == -1) {
x = y = h->pos;
} else {
x = y = opt_offset;
}
for (i = 0; i < iovlen && y < h->size; ++i, y += b) {
b = MIN(iov[i].iov_len, h->size - y);
if (b) memcpy(iov[i].iov_base, h->mem + y, b);
}
if (opt_offset == -1) {
h->pos = y;
}
return y - x;
}
/**
* Reads data from zip store object.
*
* @return [1..size] bytes on success, 0 on EOF, or -1 w/ errno; with
* exception of size==0, in which case return zero means no error
* @asyncsignalsafe
*/
ssize_t __zipos_read(struct ZiposHandle *h, const struct iovec *iov,
size_t iovlen, ssize_t opt_offset) {
ssize_t rc;
unassert(opt_offset >= 0 || opt_offset == -1);
pthread_mutex_lock(&h->lock);
rc = __zipos_read_impl(h, iov, iovlen, opt_offset);
pthread_mutex_unlock(&h->lock);
return rc;
}