/*
* Copyright (c) 2020 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* $Id: //eng/vdo-releases/aluminum/src/c++/vdo/base/compressedBlock.c#3 $
*/
#include "compressedBlock.h"
#include "memoryAlloc.h"
#include "numeric.h"
static const VersionNumber COMPRESSED_BLOCK_1_0 = {
.majorVersion = 1,
.minorVersion = 0,
};
/**********************************************************************/
void resetCompressedBlockHeader(CompressedBlockHeader *header)
{
STATIC_ASSERT(sizeof(header->fields) == sizeof(header->raw));
header->fields.version = packVersionNumber(COMPRESSED_BLOCK_1_0);
memset(header->fields.sizes, 0, sizeof(header->fields.sizes));
}
/**********************************************************************/
static uint16_t
getCompressedFragmentSize(const CompressedBlockHeader *header, byte slot)
{
return getUInt16LE(header->fields.sizes[slot]);
}
/**********************************************************************/
int getCompressedBlockFragment(BlockMappingState mappingState,
char *buffer,
BlockSize blockSize,
uint16_t *fragmentOffset,
uint16_t *fragmentSize)
{
if (!isCompressed(mappingState)) {
return VDO_INVALID_FRAGMENT;
}
CompressedBlockHeader *header = (CompressedBlockHeader *) buffer;
VersionNumber version = unpackVersionNumber(header->fields.version);
if (!areSameVersion(version, COMPRESSED_BLOCK_1_0)) {
return VDO_INVALID_FRAGMENT;
}
byte slot = getSlotFromState(mappingState);
if (slot >= MAX_COMPRESSION_SLOTS) {
return VDO_INVALID_FRAGMENT;
}
uint16_t compressedSize = getCompressedFragmentSize(header, slot);
uint16_t offset = sizeof(CompressedBlockHeader);
for (unsigned int i = 0; i < slot; i++) {
offset += getCompressedFragmentSize(header, i);
if (offset >= blockSize) {
return VDO_INVALID_FRAGMENT;
}
}
if ((offset + compressedSize) > blockSize) {
return VDO_INVALID_FRAGMENT;
}
*fragmentOffset = offset;
*fragmentSize = compressedSize;
return VDO_SUCCESS;
}
/**********************************************************************/
void putCompressedBlockFragment(CompressedBlock *block,
unsigned int fragment,
uint16_t offset,
const char *data,
uint16_t size)
{
storeUInt16LE(block->header.fields.sizes[fragment], size);
memcpy(&block->data[offset], data, size);
}