51 lines
1.3 KiB
C
51 lines
1.3 KiB
C
|
#pragma once
|
||
|
|
#ifndef BLOCKSTORE_IMPLEMENTATIONS_CACHING_NEWBLOCK_H_
|
||
|
|
#define BLOCKSTORE_IMPLEMENTATIONS_CACHING_NEWBLOCK_H_
|
||
|
|
|
||
|
|
#include "../../interface/BlockStore.h"
|
||
|
|
#include "../../utils/Data.h"
|
||
|
|
|
||
|
|
#include "messmer/cpp-utils/macros.h"
|
||
|
|
#include <memory>
|
||
|
|
|
||
|
|
namespace blockstore {
|
||
|
|
namespace caching {
|
||
|
|
class CachingBlockStore;
|
||
|
|
|
||
|
|
//TODO Does it make sense to write a general DataBackedBlock that just stores a Data object and maps the block operations to it?
|
||
|
|
// Can we reuse that object somewhere else?
|
||
|
|
// Maybe a second abstract class for BlockRefBackedBlock?
|
||
|
|
|
||
|
|
// This is a block that was created in CachingBlockStore, but doesn't exist in the base block store yet.
|
||
|
|
// It only exists in the cache and it is created in the base block store when destructed.
|
||
|
|
class NewBlock: public Block {
|
||
|
|
public:
|
||
|
|
NewBlock(const Key &key, Data data, CachingBlockStore *blockStore);
|
||
|
|
virtual ~NewBlock();
|
||
|
|
|
||
|
|
const void *data() const override;
|
||
|
|
void write(const void *source, uint64_t offset, uint64_t size) override;
|
||
|
|
void flush() override;
|
||
|
|
|
||
|
|
size_t size() const override;
|
||
|
|
|
||
|
|
void remove();
|
||
|
|
|
||
|
|
bool alreadyExistsInBaseStore() const;
|
||
|
|
|
||
|
|
private:
|
||
|
|
CachingBlockStore *_blockStore;
|
||
|
|
Data _data;
|
||
|
|
std::unique_ptr<Block> _baseBlock;
|
||
|
|
bool _dataChanged;
|
||
|
|
|
||
|
|
void writeToBaseBlockIfChanged();
|
||
|
|
|
||
|
|
DISALLOW_COPY_AND_ASSIGN(NewBlock);
|
||
|
|
};
|
||
|
|
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif
|