xz/src/liblzma/common/index.h

///////////////////////////////////////////////////////////////////////////////
//
/// \file       index.h
/// \brief      Handling of Index
//
//  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_INDEX_H
#define LZMA_INDEX_H

#include "common.h"


/// Maximum encoded value of Total Size.
#define TOTAL_SIZE_ENCODED_MAX (LZMA_VLI_MAX / 4 - 1)

/// Convert the real Total Size value to a value that is stored to the Index.
#define total_size_encode(size) ((size) / 4 - 1)

/// Convert the encoded Total Size value from Index to the real Total Size.
#define total_size_decode(size) (((size) + 1) * 4)


/// Get the size of the Index Padding field. This is needed by Index encoder
/// and decoder, but applications should have no use for this.
extern uint32_t lzma_index_padding_size(const lzma_index *i);


static inline lzma_vli
index_size_unpadded(lzma_vli count, lzma_vli index_list_size)
{
	// Index Indicator + Number of Records + List of Records + CRC32
	return 1 + lzma_vli_size(count) + index_list_size + 4;
}


static inline lzma_vli
index_size(lzma_vli count, lzma_vli index_list_size)
{
	// Round up to a mulitiple of four.
	return (index_size_unpadded(count, index_list_size) + 3)
			& ~LZMA_VLI_C(3);
}


static inline lzma_vli
index_stream_size(
		lzma_vli total_size, lzma_vli count, lzma_vli index_list_size)
{
	return LZMA_STREAM_HEADER_SIZE + total_size
			+ index_size(count, index_list_size)
			+ LZMA_STREAM_HEADER_SIZE;
}

#endif