/**
* \file lzma/easy.h
* \brief Easy to use encoder initialization
*
* \author Copyright (C) 1999-2006 Igor Pavlov
* \author Copyright (C) 2008 Lasse Collin
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
#ifndef LZMA_H_INTERNAL
# error Never include this file directly. Use <lzma.h> instead.
#endif
/**
* \brief Compression level names for lzma_easy_* functions
*
* At the moment, all the compression levels support LZMA_SYNC_FLUSH.
* In future there may be levels that don't support LZMA_SYNC_FLUSH.
* However, the LZMA_SYNC_FLUSH support won't be removed from the
* existing compression levels.
*
* \note If liblzma is built without encoder support, or with some
* filters disabled, some of the compression levels may be
* unsupported. In that case, the initialization functions
* will return LZMA_HEADER_ERROR.
*/
typedef enum {
LZMA_EASY_COPY,
/**<
* No compression; the data is just wrapped into .lzma
* container.
*/
LZMA_EASY_LZMA_1,
/**<
* LZMA filter with fast compression (fast in terms of LZMA).
* If you are interested in the exact options used, see
* lzma_preset_lzma[0]. Note that the exact options may
* change between liblzma versions.
*
* At the moment, the command line tool uses these settings
* when `lzma -1' is used. In future, the command line tool
* may default to some more complex way to determine the
* settings used e.g. the type of files being compressed.
*
* LZMA_EASY_LZMA_2 is equivalent to lzma_preset_lzma[1]
* and so on.
*/
LZMA_EASY_LZMA_2,
LZMA_EASY_LZMA_3,
LZMA_EASY_LZMA_4,
LZMA_EASY_LZMA_5,
LZMA_EASY_LZMA_6,
LZMA_EASY_LZMA_7,
LZMA_EASY_LZMA_8,
LZMA_EASY_LZMA_9,
} lzma_easy_level;
/**
* \brief Default compression level for Data Blocks
*
* Data Blocks contain the actual compressed data. It's not straightforward
* to recommend a default level, because in some cases keeping the resource
* usage relatively low is more important that getting the maximum
* compression ratio.
*/
#define LZMA_EASY_DEFAULT LZMA_EASY_LZMA_7
/**
* \brief Default compression level for Metadata Blocks
*
* Metadata Blocks are present only in Multi-Block Streams. Metadata Blocks
* contain the Extra Records (if any) and some book-keeping data that is
* used by decoders.
*/
#define LZMA_EASY_METADATA_DEFAULT LZMA_EASY_LZMA_3
/**
* \brief Calculates rough memory requirements of a compression level
*
* This function is a wrapper for lzma_memory_usage(), which is declared
* in lzma/filter.h.
*
* \return Approximate memory usage of the encoder with the given
* compression level in mebibytes (value * 1024 * 1024 bytes).
* On error (e.g. compression level is not supported),
* UINT32_MAX is returned.
*/
extern uint32_t lzma_easy_memory_usage(lzma_easy_level level);
/**
* \brief Initializes Single-Block .lzma Stream encoder
*
* This function is intended for those who just want to use the basic LZMA
* features (that is, most developers out there). Lots of assumptions are
* made, which are correct for most situations or at least good enough.
*
* \param strm Pointer to lzma_stream that is at least initialized
* with LZMA_STREAM_INIT.
* \param level Compression level to use. This selects a set of
* compression settings from a list of compression
* presets.
*
* \return - LZMA_OK: Initialization succeeded. Use lzma_code() to
* encode your data.
* - LZMA_MEM_ERROR: Memory allocation failed. All memory
* previously allocated for *strm is now freed.
* - LZMA_HEADER_ERROR: The given compression level is not
* supported by this build of liblzma.
*
* If initialization succeeds, use lzma_code() to do the actual encoding.
* Valid values for `action' (the second argument of lzma_code()) are
* LZMA_RUN, LZMA_SYNC_FLUSH, and LZMA_FINISH. In future, there may be
* compression levels that don't support LZMA_SYNC_FLUSH.
*/
extern lzma_ret lzma_easy_encoder_single(
lzma_stream *strm, lzma_easy_level level);
/**
* \brief Initializes Multi-Block .lzma Stream encoder
*
* If you want to be able to store Extra Records or want to be able to use
* LZMA_FULL_FLUSH, you need to create a Multi-Block Stream.
*
* \param strm Pointer to lzma_stream that is at least initialized
* with LZMA_STREAM_INIT.
* \param level Compression level to use for the data being encoded.
* \param metadata_level
* Compression level to use for Metadata Blocks.
* Metadata Blocks contain the Extra Records (if any)
* and some book-keeping data that is used by decoders.
* \param header Pointer to a list of Extra Records to be stored to
* the Header Metadata Block. Set this to NULL to omit
* Header Metadata Block completely. The list must be
* kept available until the encoding has finished.
* \param footer Pointer to a list of Extra Records to be stored to
* the Footer Metadata Block. Set this to NULL if you
* don't want to store any Extra Records (the Footer
* Metadata Block will still be written for other
* reasons.) The list must be kept available until
* the encoding has finished.
*
* \return - LZMA_OK: Initialization succeeded. Use lzma_code() to
* encode your data.
* - LZMA_MEM_ERROR: Memory allocation failed. All memory
* previously allocated for *strm is now freed.
* - LZMA_HEADER_ERROR: The given compression level is not
* supported by this build of liblzma.
*
* If initialization succeeds, use lzma_code() to do the actual encoding.
* Valid values for `action' (the second argument of lzma_code()) are
* LZMA_RUN, LZMA_SYNC_FLUSH, LZMA_FULL_FLUSH, and LZMA_FINISH. In future,
* there may be compression levels that don't support LZMA_SYNC_FLUSH.
* LZMA_FULL_FLUSH will always work with all compression levels.
*/
extern lzma_ret lzma_easy_encoder_multi(lzma_stream *strm,
lzma_easy_level level, lzma_easy_level metadata_level,
const lzma_extra *header, const lzma_extra *footer);
