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xz-archive/src/liblzma/common/index.h
Lasse Collin 1a7ec87c8e Revised the Index handling code.
This breaks API and ABI but most apps are not affected
since most apps don't use this part of the API. You will
get a compile error if you are using anything that got
broken.

Summary of changes:

  - Ability to store Stream Flags, which are needed
    for random-access reading in multi-Stream files.

  - Separate function to set size of Stream Padding.

  - Iterator structure makes it possible to read the same
    lzma_index from multiple threads at the same time.

  - A lot faster code to locate Blocks.

  - Removed lzma_index_equal() without adding anything
    to replace it. I don't know what it should do exactly
    with the new features and what actually needs this
    function in the first place other than test_index.c,
    which now has its own code to compare lzma_indexes.
2009-12-31 22:45:53 +02:00

73 lines
1.9 KiB
C

///////////////////////////////////////////////////////////////////////////////
//
/// \file index.h
/// \brief Handling of Index
//
// Author: Lasse Collin
//
// This file has been put into the public domain.
// You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////
#ifndef LZMA_INDEX_H
#define LZMA_INDEX_H
#include "common.h"
/// Minimum Unpadded Size
#define UNPADDED_SIZE_MIN LZMA_VLI_C(5)
/// Maximum Unpadded Size
#define UNPADDED_SIZE_MAX (LZMA_VLI_MAX & ~LZMA_VLI_C(3))
/// 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);
/// Set for how many Records to allocate memory the next time
/// lzma_index_append() needs to allocate space for a new Record.
/// This is used only by the Index decoder.
extern void lzma_index_prealloc(lzma_index *i, lzma_vli records);
/// Round the variable-length integer to the next multiple of four.
static inline lzma_vli
vli_ceil4(lzma_vli vli)
{
assert(vli <= LZMA_VLI_MAX);
return (vli + 3) & ~LZMA_VLI_C(3);
}
/// Calculate the size of the Index field excluding Index Padding
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;
}
/// Calculate the size of the Index field including Index Padding
static inline lzma_vli
index_size(lzma_vli count, lzma_vli index_list_size)
{
return vli_ceil4(index_size_unpadded(count, index_list_size));
}
/// Calculate the total size of the Stream
static inline lzma_vli
index_stream_size(lzma_vli blocks_size,
lzma_vli count, lzma_vli index_list_size)
{
return LZMA_STREAM_HEADER_SIZE + blocks_size
+ index_size(count, index_list_size)
+ LZMA_STREAM_HEADER_SIZE;
}
#endif