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///////////////////////////////////////////////////////////////////////////////
//
/// \file lzma_literal.c
/// \brief Literal Coder
//
// Copyright (C) 1999-2006 Igor Pavlov
// Copyright (C) 2007 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.
//
///////////////////////////////////////////////////////////////////////////////
#include "lzma_literal.h"
extern lzma_ret
lzma_literal_init(lzma_literal_coder **coder, lzma_allocator *allocator,
uint32_t literal_context_bits, uint32_t literal_pos_bits)
{
// Verify that arguments are sane.
if (literal_context_bits > LZMA_LITERAL_CONTEXT_BITS_MAX
|| literal_pos_bits > LZMA_LITERAL_POS_BITS_MAX)
return LZMA_HEADER_ERROR;
// Calculate the number of states the literal coder must store.
const uint32_t states = literal_states(
literal_pos_bits, literal_context_bits);
// Allocate a new literal coder, if needed.
if (*coder == NULL || (**coder).literal_context_bits
!= literal_context_bits
|| (**coder).literal_pos_bits != literal_pos_bits) {
// Free the old coder, if any.
lzma_free(*coder, allocator);
// Allocate a new one.
*coder = lzma_alloc(sizeof(lzma_literal_coder)
+ states * LIT_SIZE * sizeof(probability),
allocator);
if (*coder == NULL)
return LZMA_MEM_ERROR;
// Store the new settings.
(**coder).literal_context_bits = literal_context_bits;
(**coder).literal_pos_bits = literal_pos_bits;
// Calculate also the literal_pos_mask. It's not changed
// anywhere else than here.
(**coder).literal_pos_mask = (1 << literal_pos_bits) - 1;
}
// Reset the literal coder.
for (uint32_t i = 0; i < states; ++i)
for (uint32_t j = 0; j < LIT_SIZE; ++j)
bit_reset((**coder).coders[i][j]);
return LZMA_OK;
}
extern void
lzma_literal_end(lzma_literal_coder **coder, lzma_allocator *allocator)
{
lzma_free(*coder, allocator);
*coder = NULL;
}
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