xz/src/liblzma/common/alone_encoder.c

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2007-12-08 22:42:33 +00:00
///////////////////////////////////////////////////////////////////////////////
//
/// \file alone_decoder.c
/// \brief Decoder for LZMA_Alone files
//
// 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 "common.h"
#include "lzma_encoder.h"
struct lzma_coder_s {
lzma_next_coder next;
enum {
SEQ_PROPERTIES,
SEQ_DICTIONARY_SIZE,
SEQ_UNCOMPRESSED_SIZE,
SEQ_CODE,
} sequence;
size_t pos;
lzma_options_alone options;
};
static lzma_ret
alone_encode(lzma_coder *coder,
lzma_allocator *allocator lzma_attribute((unused)),
const uint8_t *restrict in, size_t *restrict in_pos,
size_t in_size, uint8_t *restrict out,
size_t *restrict out_pos, size_t out_size,
lzma_action action)
{
while (*out_pos < out_size)
switch (coder->sequence) {
case SEQ_PROPERTIES:
if (lzma_lzma_encode_properties(
&coder->options.lzma, out + *out_pos)) {
return LZMA_PROG_ERROR;
}
coder->sequence = SEQ_DICTIONARY_SIZE;
++*out_pos;
break;
case SEQ_DICTIONARY_SIZE:
out[*out_pos] = coder->options.lzma.dictionary_size
>> (coder->pos * 8);
if (++coder->pos == 4) {
coder->pos = 0;
coder->sequence = SEQ_UNCOMPRESSED_SIZE;
}
++*out_pos;
break;
case SEQ_UNCOMPRESSED_SIZE:
out[*out_pos] = coder->options.uncompressed_size
>> (coder->pos * 8);
if (++coder->pos == 8) {
coder->pos = 0;
coder->sequence = SEQ_CODE;
}
++*out_pos;
break;
case SEQ_CODE: {
return coder->next.code(coder->next.coder,
allocator, in, in_pos, in_size,
out, out_pos, out_size, action);
}
default:
return LZMA_PROG_ERROR;
}
return LZMA_OK;
}
static void
alone_encoder_end(lzma_coder *coder, lzma_allocator *allocator)
{
lzma_next_coder_end(&coder->next, allocator);
lzma_free(coder, allocator);
return;
}
// At least for now, this is not used by any internal function.
static lzma_ret
alone_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
const lzma_options_alone *options)
{
if (next->coder == NULL) {
next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
if (next->coder == NULL)
return LZMA_MEM_ERROR;
next->code = &alone_encode;
next->end = &alone_encoder_end;
next->coder->next = LZMA_NEXT_CODER_INIT;
}
// Initialize the LZMA_Alone coder variables.
next->coder->sequence = SEQ_PROPERTIES;
next->coder->pos = 0;
next->coder->options = *options;
// Verify uncompressed_size since the other functions assume that
// it is valid.
if (!lzma_vli_is_valid(next->coder->options.uncompressed_size))
return LZMA_PROG_ERROR;
// Initialize the LZMA encoder.
const lzma_filter_info filters[2] = {
{
.init = &lzma_lzma_encoder_init,
.options = &next->coder->options.lzma,
.uncompressed_size = next->coder->options
.uncompressed_size,
}, {
.init = NULL,
}
};
return lzma_next_filter_init(&next->coder->next, allocator, filters);
}
/*
extern lzma_ret
lzma_alone_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
const lzma_options_alone *options)
{
lzma_next_coder_init(alone_encoder_init, next, allocator, options);
}
*/
extern LZMA_API lzma_ret
lzma_alone_encoder(lzma_stream *strm, const lzma_options_alone *options)
{
lzma_next_strm_init(strm, alone_encoder_init, options);
strm->internal->supported_actions[LZMA_RUN] = true;
strm->internal->supported_actions[LZMA_FINISH] = true;
return LZMA_OK;
}