libcryfs/implementations/caching/NewBlock.cpp

70 lines
1.7 KiB
C++

#include "NewBlock.h"
#include "CachingBlockStore.h"
#include <messmer/cpp-utils/assert/assert.h>
using cpputils::Data;
using boost::none;
namespace blockstore {
namespace caching {
NewBlock::NewBlock(const Key &key, Data data, CachingBlockStore *blockStore)
:Block(key),
_blockStore(blockStore),
_data(std::move(data)),
_baseBlock(none),
_dataChanged(true) {
}
NewBlock::~NewBlock() {
writeToBaseBlockIfChanged();
}
const void *NewBlock::data() const {
return _data.data();
}
void NewBlock::write(const void *source, uint64_t offset, uint64_t size) {
ASSERT(offset <= _data.size() && offset + size <= _data.size(), "Write outside of valid area");
std::memcpy((uint8_t*)_data.data()+offset, source, size);
_dataChanged = true;
}
void NewBlock::writeToBaseBlockIfChanged() {
if (_dataChanged) {
if (_baseBlock == none) {
//TODO _data.copy() necessary?
auto newBase = _blockStore->tryCreateInBaseStore(key(), _data.copy());
ASSERT(newBase != boost::none, "Couldn't create base block"); //TODO What if tryCreate fails due to a duplicate key? We should ensure we don't use duplicate keys.
_baseBlock = std::move(*newBase);
} else {
(*_baseBlock)->write(_data.data(), 0, _data.size());
}
_dataChanged = false;
}
}
void NewBlock::remove() {
if (_baseBlock != none) {
_blockStore->removeFromBaseStore(std::move(*_baseBlock));
}
_dataChanged = false;
}
void NewBlock::flush() {
writeToBaseBlockIfChanged();
ASSERT(_baseBlock != none, "At this point, the base block should already have been created but wasn't");
(*_baseBlock)->flush();
}
size_t NewBlock::size() const {
return _data.size();
}
bool NewBlock::alreadyExistsInBaseStore() const {
return _baseBlock != none;
}
}
}