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Cleaned up Block encoder and moved the no longer shared 

code from block_private.h to block_decoder.c. Now the Block
encoder doesn't need compressed_size and uncompressed_size
from lzma_block structure to be initialized.
This commit is contained in:
Lasse Collin 2008-09-10 00:27:02 +03:00
parent 07efcb5a6b
commit 2ba01bfa75
5 changed files with 66 additions and 100 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
src/liblzma/api/lzma/block.h
View File

@ -38,7 +38,6 @@ typedef struct {
* Read by:
* - lzma_block_header_encode()
* - lzma_block_header_decode()
* - lzma_block_encoder()
* - lzma_block_decoder()
*
* Written by:
@ -74,7 +73,6 @@ typedef struct {
* Read by:
* - lzma_block_header_size()
* - lzma_block_header_encode()
* - lzma_block_encoder()
* - lzma_block_decoder()
*
* Written by:
@ -103,7 +101,6 @@ typedef struct {
* Read by:
* - lzma_block_header_size()
* - lzma_block_header_encode()
* - lzma_block_encoder()
* - lzma_block_decoder()
*
* Written by:

1
src/liblzma/common/Makefile.am
View File

@ -28,7 +28,6 @@ libcommon_la_SOURCES = \
common.h \
bsr.h \
block_util.c \
block_private.h \
filter_common.c \
filter_common.h \
index.c \

23
src/liblzma/common/block_decoder.c
View File

@ -18,7 +18,6 @@
///////////////////////////////////////////////////////////////////////////////
#include "block_decoder.h"
#include "block_private.h"
#include "filter_decoder.h"
#include "check.h"
@ -56,6 +55,28 @@ struct lzma_coder_s {
};
static inline bool
update_size(lzma_vli *size, lzma_vli add, lzma_vli limit)
{
if (limit > LZMA_VLI_VALUE_MAX)
limit = LZMA_VLI_VALUE_MAX;
if (limit < *size || limit - *size < add)
return true;
*size += add;
return false;
}
static inline bool
is_size_valid(lzma_vli size, lzma_vli reference)
{
return reference == LZMA_VLI_VALUE_UNKNOWN || reference == size;
}
static lzma_ret
block_decode(lzma_coder *coder, lzma_allocator *allocator,
const uint8_t *restrict in, size_t *restrict in_pos,

92
src/liblzma/common/block_encoder.c
View File

@ -18,11 +18,25 @@
///////////////////////////////////////////////////////////////////////////////
#include "block_encoder.h"
#include "block_private.h"
#include "filter_encoder.h"
#include "check.h"
/// The maximum size of a single Block is limited by the maximum size of
/// a Stream, which is 2^63 - 1 bytes (i.e. LZMA_VLI_VALUE_MAX). We could
/// take into account the headers etc. to determine the exact maximum size
/// of the Compressed Data field, but the complexity would give us nothing
/// useful. Instead, limit the size of Compressed Data so that even with
/// biggest possible Block Header and Check fields the total size of the
/// Block stays as valid VLI. This way we don't produce incorrect output
/// if someone will really try creating a Block of 8 EiB.
///
/// ~LZMA_VLI_C(3) is to guarantee that if we need padding at the end of
/// the Compressed Data field, it will still stay in the proper limit.
#define COMPRESSED_SIZE_MAX ((LZMA_VLI_VALUE_MAX - LZMA_BLOCK_HEADER_SIZE_MAX \
- LZMA_CHECK_SIZE_MAX) & ~LZMA_VLI_C(3))
struct lzma_coder_s {
/// The filters in the chain; initialized with lzma_raw_decoder_init().
lzma_next_coder next;
@ -59,26 +73,9 @@ block_encode(lzma_coder *coder, lzma_allocator *allocator,
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)) {
if (LZMA_VLI_VALUE_MAX - coder->uncompressed_size < 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;
@ -91,12 +88,11 @@ block_encode(lzma_coder *coder, lzma_allocator *allocator,
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))
if (COMPRESSED_SIZE_MAX - coder->compressed_size < out_used)
return LZMA_DATA_ERROR;
coder->compressed_size += out_used;
// No need to check for overflow because we have already
// checked it at the beginning of this function.
coder->uncompressed_size += in_used;
@ -108,31 +104,28 @@ block_encode(lzma_coder *coder, lzma_allocator *allocator,
return ret;
assert(*in_pos == in_size);
assert(action == LZMA_FINISH);
coder->sequence = SEQ_PADDING;
break;
}
// Fall through
case SEQ_PADDING:
// Pad Compressed Data to a multiple of four bytes.
if (coder->compressed_size & 3) {
while (coder->compressed_size & 3) {
if (*out_pos >= out_size)
return LZMA_OK;
out[*out_pos] = 0x00;
++*out_pos;
if (update_size(&coder->compressed_size, 1,
coder->options->compressed_size))
return LZMA_DATA_ERROR;
break;
// No need to use check for overflow here since we
// have already checked in SEQ_CODE that Compressed
// Size will stay in proper limits.
++coder->compressed_size;
}
// 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;
@ -146,21 +139,24 @@ block_encode(lzma_coder *coder, lzma_allocator *allocator,
// Fall through
case SEQ_CHECK:
out[*out_pos] = coder->check.buffer.u8[coder->check_pos];
++*out_pos;
case SEQ_CHECK: {
const uint32_t check_size
= lzma_check_size(coder->options->check);
if (++coder->check_pos
== lzma_check_size(coder->options->check))
return LZMA_STREAM_END;
while (*out_pos < out_size) {
out[*out_pos] = coder->check.buffer.u8[
coder->check_pos];
++*out_pos;
break;
if (++coder->check_pos == check_size)
return LZMA_STREAM_END;
}
default:
return LZMA_PROG_ERROR;
return LZMA_OK;
}
}
return LZMA_OK;
return LZMA_PROG_ERROR;
}

47
src/liblzma/common/block_private.h
View File

@ -1,47 +0,0 @@
///////////////////////////////////////////////////////////////////////////////
//
/// \file block_private.h
/// \brief Common stuff for Block encoder and decoder
//
// 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.
//
///////////////////////////////////////////////////////////////////////////////
#ifndef LZMA_BLOCK_COMMON_H
#define LZMA_BLOCK_COMMON_H
#include "common.h"
static inline bool
update_size(lzma_vli *size, lzma_vli add, lzma_vli limit)
{
if (limit > LZMA_VLI_VALUE_MAX)
limit = LZMA_VLI_VALUE_MAX;
if (limit < *size || limit - *size < add)
return true;
*size += add;
return false;
}
static inline bool
is_size_valid(lzma_vli size, lzma_vli reference)
{
return reference == LZMA_VLI_VALUE_UNKNOWN || reference == size;
}
#endif