/*
?*?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?
#include?
#include?
#include?
#include?


/*?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