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///////////////////////////////////////////////////////////////////////////////
//
/// \file block_encoder.c
/// \brief Encodes .lzma Blocks
//
// 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 "block_encoder.h"
#include "block_private.h"
#include "raw_encoder.h"
#include "check.h"
struct lzma_coder_s {
/// The filters in the chain; initialized with lzma_raw_decoder_init().
lzma_next_coder next;
/// Encoding options; we also write Total Size, Compressed Size, and
/// Uncompressed Size back to this structure when the encoding has
/// been finished.
lzma_options_block *options;
enum {
SEQ_CODE,
SEQ_PADDING,
SEQ_CHECK,
} sequence;
/// Compressed Size calculated while encoding
lzma_vli compressed_size;
/// Uncompressed Size calculated while encoding
lzma_vli uncompressed_size;
/// Position when writing out the Check field
size_t check_pos;
/// Check of the uncompressed data
lzma_check check;
};
static lzma_ret
block_encode(lzma_coder *coder, lzma_allocator *allocator,
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)
{
// Check that our amount of input stays in proper limits.
if (coder->options->uncompressed_size != LZMA_VLI_VALUE_UNKNOWN) {
if (action == LZMA_FINISH) {
if (coder->options->uncompressed_size
- coder->uncompressed_size
!= (lzma_vli)(in_size - *in_pos))
return LZMA_PROG_ERROR;
} else {
if (coder->options->uncompressed_size
- coder->uncompressed_size
< (lzma_vli)(in_size - *in_pos))
return LZMA_PROG_ERROR;
}
} else if (LZMA_VLI_VALUE_MAX - coder->uncompressed_size
< (lzma_vli)(in_size - *in_pos)) {
return LZMA_PROG_ERROR;
}
// Main loop
while (*out_pos < out_size
&& (*in_pos < in_size || action != LZMA_RUN))
switch (coder->sequence) {
case SEQ_CODE: {
const size_t in_start = *in_pos;
const size_t out_start = *out_pos;
const lzma_ret ret = coder->next.code(coder->next.coder,
allocator, in, in_pos, in_size,
out, out_pos, out_size, action);
const size_t in_used = *in_pos - in_start;
const size_t out_used = *out_pos - out_start;
// FIXME We must also check that Total Size doesn't get
// too big.
if (update_size(&coder->compressed_size, out_used,
coder->options->compressed_size))
return LZMA_DATA_ERROR;
// No need to check for overflow because we have already
// checked it at the beginning of this function.
coder->uncompressed_size += in_used;
lzma_check_update(&coder->check, coder->options->check,
in + in_start, in_used);
if (ret != LZMA_STREAM_END || action == LZMA_SYNC_FLUSH)
return ret;
assert(*in_pos == in_size);
coder->sequence = SEQ_PADDING;
break;
}
case SEQ_PADDING:
// Pad Compressed Data to a multiple of four bytes.
if (coder->compressed_size & 3) {
out[*out_pos] = 0x00;
++*out_pos;
if (update_size(&coder->compressed_size, 1,
coder->options->compressed_size))
return LZMA_DATA_ERROR;
break;
}
// Compressed and Uncompressed Sizes are now at their final
// values. Verify that they match the values given to us.
if (!is_size_valid(coder->compressed_size,
coder->options->compressed_size)
|| !is_size_valid(coder->uncompressed_size,
coder->options->uncompressed_size))
return LZMA_DATA_ERROR;
// Copy the values into coder->options. The caller
// may use this information to construct Index.
coder->options->compressed_size = coder->compressed_size;
coder->options->uncompressed_size = coder->uncompressed_size;
if (coder->options->check == LZMA_CHECK_NONE)
return LZMA_STREAM_END;
lzma_check_finish(&coder->check, coder->options->check);
coder->sequence = SEQ_CHECK;
// Fall through
case SEQ_CHECK:
out[*out_pos] = coder->check.buffer[coder->check_pos];
++*out_pos;
if (++coder->check_pos
== lzma_check_sizes[coder->options->check])
return LZMA_STREAM_END;
break;
default:
return LZMA_PROG_ERROR;
}
return LZMA_OK;
}
static void
block_encoder_end(lzma_coder *coder, lzma_allocator *allocator)
{
lzma_next_coder_end(&coder->next, allocator);
lzma_free(coder, allocator);
return;
}
static lzma_ret
block_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
lzma_options_block *options)
{
// While lzma_block_total_size_get() is meant to calculate the Total
// Size, it also validates the options excluding the filters.
if (lzma_block_total_size_get(options) == 0)
return LZMA_PROG_ERROR;
// Allocate and initialize *next->coder if needed.
if (next->coder == NULL) {
next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
if (next->coder == NULL)
return LZMA_MEM_ERROR;
next->code = &block_encode;
next->end = &block_encoder_end;
next->coder->next = LZMA_NEXT_CODER_INIT;
}
// Basic initializations
next->coder->sequence = SEQ_CODE;
next->coder->options = options;
next->coder->compressed_size = 0;
next->coder->uncompressed_size = 0;
// Initialize the check
next->coder->check_pos = 0;
return_if_error(lzma_check_init(&next->coder->check, options->check));
// Initialize the requested filters.
return lzma_raw_encoder_init(&next->coder->next, allocator,
options->filters);
}
extern lzma_ret
lzma_block_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
lzma_options_block *options)
{
lzma_next_coder_init(block_encoder_init, next, allocator, options);
}
extern LZMA_API lzma_ret
lzma_block_encoder(lzma_stream *strm, lzma_options_block *options)
{
lzma_next_strm_init(strm, block_encoder_init, options);
strm->internal->supported_actions[LZMA_RUN] = true;
strm->internal->supported_actions[LZMA_FINISH] = true;
return LZMA_OK;
}
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