mirror of https://git.tukaani.org/xz.git
128 lines
3.0 KiB
C
128 lines
3.0 KiB
C
/*
|
|
* xz_pipe_comp.c
|
|
* A simple example of pipe-only xz compressor implementation.
|
|
* version: 2010-07-12 - by Daniel Mealha Cabrita
|
|
* Not copyrighted -- provided to the public domain.
|
|
*
|
|
* Compiling:
|
|
* Link with liblzma. GCC example:
|
|
* $ gcc -llzma xz_pipe_comp.c -o xz_pipe_comp
|
|
*
|
|
* Usage example:
|
|
* $ cat some_file | ./xz_pipe_comp > some_file.xz
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdint.h>
|
|
#include <inttypes.h>
|
|
#include <stdbool.h>
|
|
#include <lzma.h>
|
|
|
|
|
|
/* COMPRESSION SETTINGS */
|
|
|
|
/* analogous to xz CLI options: -0 to -9 */
|
|
#define COMPRESSION_LEVEL 6
|
|
|
|
/* boolean setting, analogous to xz CLI option: -e */
|
|
#define COMPRESSION_EXTREME true
|
|
|
|
/* see: /usr/include/lzma/check.h LZMA_CHECK_* */
|
|
#define INTEGRITY_CHECK LZMA_CHECK_CRC64
|
|
|
|
|
|
/* read/write buffer sizes */
|
|
#define IN_BUF_MAX 4096
|
|
#define OUT_BUF_MAX 4096
|
|
|
|
/* error codes */
|
|
#define RET_OK 0
|
|
#define RET_ERROR_INIT 1
|
|
#define RET_ERROR_INPUT 2
|
|
#define RET_ERROR_OUTPUT 3
|
|
#define RET_ERROR_COMPRESSION 4
|
|
|
|
|
|
/* note: in_file and out_file must be open already */
|
|
int xz_compress (FILE *in_file, FILE *out_file)
|
|
{
|
|
uint32_t preset = COMPRESSION_LEVEL | (COMPRESSION_EXTREME ? LZMA_PRESET_EXTREME : 0);
|
|
lzma_check check = INTEGRITY_CHECK;
|
|
lzma_stream strm = LZMA_STREAM_INIT; /* alloc and init lzma_stream struct */
|
|
uint8_t in_buf [IN_BUF_MAX];
|
|
uint8_t out_buf [OUT_BUF_MAX];
|
|
size_t in_len; /* length of useful data in in_buf */
|
|
size_t out_len; /* length of useful data in out_buf */
|
|
bool in_finished = false;
|
|
bool out_finished = false;
|
|
lzma_action action;
|
|
lzma_ret ret_xz;
|
|
int ret;
|
|
|
|
ret = RET_OK;
|
|
|
|
/* initialize xz encoder */
|
|
ret_xz = lzma_easy_encoder (&strm, preset, check);
|
|
if (ret_xz != LZMA_OK) {
|
|
fprintf (stderr, "lzma_easy_encoder error: %d\n", (int) ret_xz);
|
|
return RET_ERROR_INIT;
|
|
}
|
|
|
|
while ((! in_finished) && (! out_finished)) {
|
|
/* read incoming data */
|
|
in_len = fread (in_buf, 1, IN_BUF_MAX, in_file);
|
|
|
|
if (feof (in_file)) {
|
|
in_finished = true;
|
|
}
|
|
if (ferror (in_file)) {
|
|
in_finished = true;
|
|
ret = RET_ERROR_INPUT;
|
|
}
|
|
|
|
strm.next_in = in_buf;
|
|
strm.avail_in = in_len;
|
|
|
|
/* if no more data from in_buf, flushes the
|
|
internal xz buffers and closes the xz data
|
|
with LZMA_FINISH */
|
|
action = in_finished ? LZMA_FINISH : LZMA_RUN;
|
|
|
|
/* loop until there's no pending compressed output */
|
|
do {
|
|
/* out_buf is clean at this point */
|
|
strm.next_out = out_buf;
|
|
strm.avail_out = OUT_BUF_MAX;
|
|
|
|
/* compress data */
|
|
ret_xz = lzma_code (&strm, action);
|
|
|
|
if ((ret_xz != LZMA_OK) && (ret_xz != LZMA_STREAM_END)) {
|
|
fprintf (stderr, "lzma_code error: %d\n", (int) ret_xz);
|
|
out_finished = true;
|
|
ret = RET_ERROR_COMPRESSION;
|
|
} else {
|
|
/* write compressed data */
|
|
out_len = OUT_BUF_MAX - strm.avail_out;
|
|
fwrite (out_buf, 1, out_len, out_file);
|
|
if (ferror (out_file)) {
|
|
out_finished = true;
|
|
ret = RET_ERROR_OUTPUT;
|
|
}
|
|
}
|
|
} while (strm.avail_out == 0);
|
|
}
|
|
|
|
lzma_end (&strm);
|
|
return ret;
|
|
}
|
|
|
|
int main ()
|
|
{
|
|
int ret;
|
|
|
|
ret = xz_compress (stdin, stdout);
|
|
return ret;
|
|
}
|
|
|