blob: a2bc9eee1fa9ba68ed120fe40acf170cada82d55 [file] [log] [blame]
///////////////////////////////////////////////////////////////////////////////
//
/// \file alone_decoder.c
/// \brief Decoder for LZMA_Alone files
//
// Author: Lasse Collin
//
// This file has been put into the public domain.
// You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////
#include "common.h"
#include "lzma_encoder.h"
#define ALONE_HEADER_SIZE (1 + 4 + 8)
struct lzma_coder_s {
lzma_next_coder next;
enum {
SEQ_HEADER,
SEQ_CODE,
} sequence;
size_t header_pos;
uint8_t header[ALONE_HEADER_SIZE];
};
static lzma_ret
alone_encode(lzma_coder *coder,
const 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_HEADER:
lzma_bufcpy(coder->header, &coder->header_pos,
ALONE_HEADER_SIZE,
out, out_pos, out_size);
if (coder->header_pos < ALONE_HEADER_SIZE)
return LZMA_OK;
coder->sequence = SEQ_CODE;
break;
case SEQ_CODE:
return coder->next.code(coder->next.coder,
allocator, in, in_pos, in_size,
out, out_pos, out_size, action);
default:
assert(0);
return LZMA_PROG_ERROR;
}
return LZMA_OK;
}
static void
alone_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
{
lzma_next_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, const lzma_allocator *allocator,
const lzma_options_lzma *options)
{
lzma_next_coder_init(&alone_encoder_init, next, allocator);
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;
}
// Basic initializations
next->coder->sequence = SEQ_HEADER;
next->coder->header_pos = 0;
// Encode the header:
// - Properties (1 byte)
if (lzma_lzma_lclppb_encode(options, next->coder->header))
return LZMA_OPTIONS_ERROR;
// - Dictionary size (4 bytes)
if (options->dict_size < LZMA_DICT_SIZE_MIN)
return LZMA_OPTIONS_ERROR;
// Round up to the next 2^n or 2^n + 2^(n - 1) depending on which
// one is the next unless it is UINT32_MAX. While the header would
// allow any 32-bit integer, we do this to keep the decoder of liblzma
// accepting the resulting files.
uint32_t d = options->dict_size - 1;
d |= d >> 2;
d |= d >> 3;
d |= d >> 4;
d |= d >> 8;
d |= d >> 16;
if (d != UINT32_MAX)
++d;
unaligned_write32le(next->coder->header + 1, d);
// - Uncompressed size (always unknown and using EOPM)
memset(next->coder->header + 1 + 4, 0xFF, 8);
// Initialize the LZMA encoder.
const lzma_filter_info filters[2] = {
{
.init = &lzma_lzma_encoder_init,
.options = (void *)(options),
}, {
.init = NULL,
}
};
return lzma_next_filter_init(&next->coder->next, allocator, filters);
}
/*
extern lzma_ret
lzma_alone_encoder_init(lzma_next_coder *next, const 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_lzma *options)
{
lzma_next_strm_init(alone_encoder_init, strm, options);
strm->internal->supported_actions[LZMA_RUN] = true;
strm->internal->supported_actions[LZMA_FINISH] = true;
return LZMA_OK;
}