mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-07 23:13:34 +00:00
b01282e23e
This reduces the virtual memory usage of Emacs for me by 30%. We now have a simpler implementation that uses read(), rather mmap()ing the whole executable.
61 lines
3 KiB
C
61 lines
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/thread/tls.h"
|
|
#include "libc/zip.internal.h"
|
|
|
|
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->cdir + 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->data + 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) {
|
|
unassert(opt_offset >= 0 || opt_offset == -1);
|
|
return __zipos_read_impl(h, iov, iovlen, opt_offset);
|
|
}
|