| Index: doc/examples/xz_pipe_comp.c
|
| ===================================================================
|
| --- doc/examples/xz_pipe_comp.c (revision 0)
|
| +++ doc/examples/xz_pipe_comp.c (revision 0)
|
| @@ -0,0 +1,127 @@
|
| +/*
|
| + * 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;
|
| +}
|
| +
|
|
|
| Property changes on: doc/examples/xz_pipe_comp.c
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
|
|
|
|
|