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