NetBSD/usr.bin/gzip/unxz.c
2011-08-17 14:07:45 +00:00

122 lines
2.6 KiB
C

#include <stdarg.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <lzma.h>
static off_t
unxz(int i, int o, char *pre, size_t prelen, off_t *bytes_in)
{
lzma_stream strm = LZMA_STREAM_INIT;
static const int flags = LZMA_TELL_UNSUPPORTED_CHECK|LZMA_CONCATENATED;
lzma_ret ret;
lzma_action action = LZMA_RUN;
off_t bytes_out, bp;
uint8_t ibuf[BUFSIZ];
uint8_t obuf[BUFSIZ];
if (bytes_in == NULL)
bytes_in = &bp;
strm.next_in = ibuf;
memcpy(ibuf, pre, prelen);
strm.avail_in = read(i, ibuf + prelen, sizeof(ibuf) - prelen);
if (strm.avail_in == (size_t)-1)
maybe_err("read failed");
strm.avail_in += prelen;
*bytes_in = strm.avail_in;
if ((ret = lzma_stream_decoder(&strm, UINT64_MAX, flags)) != LZMA_OK)
maybe_errx("Can't initialize decoder (%d)", ret);
strm.next_out = NULL;
strm.avail_out = 0;
if ((ret = lzma_code(&strm, LZMA_RUN)) != LZMA_OK)
maybe_errx("Can't read headers (%d)", ret);
bytes_out = 0;
strm.next_out = obuf;
strm.avail_out = sizeof(obuf);
for (;;) {
if (strm.avail_in == 0) {
strm.next_in = ibuf;
strm.avail_in = read(i, ibuf, sizeof(ibuf));
switch (strm.avail_in) {
case (size_t)-1:
maybe_err("read failed");
/*NOTREACHED*/
case 0:
action = LZMA_FINISH;
break;
default:
*bytes_in += strm.avail_in;
break;
}
}
ret = lzma_code(&strm, action);
// Write and check write error before checking decoder error.
// This way as much data as possible gets written to output
// even if decoder detected an error.
if (strm.avail_out == 0 || ret != LZMA_OK) {
const size_t write_size = sizeof(obuf) - strm.avail_out;
if (write(o, obuf, write_size) != (ssize_t)write_size)
maybe_err("write failed");
strm.next_out = obuf;
strm.avail_out = sizeof(obuf);
bytes_out += write_size;
}
if (ret != LZMA_OK) {
if (ret == LZMA_STREAM_END) {
// Check that there's no trailing garbage.
if (strm.avail_in != 0 || read(i, ibuf, 1))
ret = LZMA_DATA_ERROR;
else {
lzma_end(&strm);
return bytes_out;
}
}
const char *msg;
switch (ret) {
case LZMA_MEM_ERROR:
msg = strerror(ENOMEM);
break;
case LZMA_FORMAT_ERROR:
msg = "File format not recognized";
break;
case LZMA_OPTIONS_ERROR:
// FIXME: Better message?
msg = "Unsupported compression options";
break;
case LZMA_DATA_ERROR:
msg = "File is corrupt";
break;
case LZMA_BUF_ERROR:
msg = "Unexpected end of input";
break;
case LZMA_MEMLIMIT_ERROR:
msg = "Reached memory limit";
break;
default:
maybe_errx("Unknown error (%d)", ret);
break;
}
maybe_errx("%s", msg);
}
}
}