freebsd-src/usr.bin/gzip/unzstd.c
Dag-Erling Smørgrav f9349d4274 gzip: Add support for decompressing zstd files.
Sponsored by:	Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D37236
2022-11-04 13:42:09 +01:00

90 lines
2.5 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2022 Klara, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* This file is #included by gzip.c */
static off_t
unzstd(int in, int out, char *pre, size_t prelen, off_t *bytes_in)
{
static char *ibuf, *obuf;
ZSTD_inBuffer zib;
ZSTD_outBuffer zob;
ZSTD_DCtx *zds;
ssize_t res;
size_t zres;
size_t bytes_out = 0;
int eof = 0;
if (ibuf == NULL)
ibuf = malloc(BUFLEN);
if (obuf == NULL)
obuf = malloc(BUFLEN);
if (ibuf == NULL || obuf == NULL)
maybe_err("malloc");
zds = ZSTD_createDStream();
ZSTD_initDStream(zds);
zib.src = pre;
zib.size = prelen;
zib.pos = 0;
if (bytes_in != NULL)
*bytes_in = prelen;
zob.dst = obuf;
zob.size = BUFLEN;
zob.pos = 0;
while (!eof) {
if (zib.pos >= zib.size) {
res = read(in, ibuf, BUFLEN);
if (res < 0)
maybe_err("read");
if (res == 0)
eof = 1;
infile_newdata(res);
zib.src = ibuf;
zib.size = res;
zib.pos = 0;
if (bytes_in != NULL)
*bytes_in += res;
}
zres = ZSTD_decompressStream(zds, &zob, &zib);
if (ZSTD_isError(zres)) {
maybe_errx("%s", ZSTD_getErrorName(zres));
}
if (zob.pos > 0) {
res = write(out, obuf, zob.pos);
if (res < 0)
maybe_err("write");
zob.pos = 0;
bytes_out += res;
}
}
ZSTD_freeDStream(zds);
return (bytes_out);
}