mirror of https://github.com/facebook/rocksdb.git
31 lines
1.0 KiB
C++
31 lines
1.0 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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#pragma once
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#include "rocksdb/types.h"
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namespace rocksdb {
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class ReadCallback {
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public:
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virtual ~ReadCallback() {}
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// Will be called to see if the seq number visible; if not it moves on to
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// the next seq number.
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virtual bool IsVisible(SequenceNumber seq) = 0;
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// This is called to determine the maximum visible sequence number for the
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// current transaction for read-your-own-write semantics. This is so that
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// for write unprepared, we will not skip keys that are written by the
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// current transaction with the seek to snapshot optimization.
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//
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// For other uses, this returns zero, meaning that the current snapshot
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// sequence number is the maximum visible sequence number.
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inline virtual SequenceNumber MaxUnpreparedSequenceNumber() { return 0; };
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};
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} // namespace rocksdb
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