fdf882ded2
Summary: When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433 Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag. Differential Revision: D19977691 fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
54 lines
1.8 KiB
C++
54 lines
1.8 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_NAMESPACE {
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class ReadCallback {
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public:
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ReadCallback(SequenceNumber last_visible_seq)
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: max_visible_seq_(last_visible_seq) {}
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ReadCallback(SequenceNumber last_visible_seq, SequenceNumber min_uncommitted)
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: max_visible_seq_(last_visible_seq), min_uncommitted_(min_uncommitted) {}
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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 IsVisibleFullCheck(SequenceNumber seq) = 0;
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inline bool IsVisible(SequenceNumber seq) {
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assert(min_uncommitted_ > 0);
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assert(min_uncommitted_ >= kMinUnCommittedSeq);
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if (seq < min_uncommitted_) { // handles seq == 0 as well
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assert(seq <= max_visible_seq_);
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return true;
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} else if (max_visible_seq_ < seq) {
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assert(seq != 0);
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return false;
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} else {
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assert(seq != 0); // already handled in the first if-then clause
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return IsVisibleFullCheck(seq);
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}
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}
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inline SequenceNumber max_visible_seq() { return max_visible_seq_; }
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// Refresh to a more recent visible seq
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virtual void Refresh(SequenceNumber seq) { max_visible_seq_ = seq; }
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protected:
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// The max visible seq, it is usually the snapshot but could be larger if
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// transaction has its own writes written to db.
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SequenceNumber max_visible_seq_ = kMaxSequenceNumber;
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// Any seq less than min_uncommitted_ is committed.
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const SequenceNumber min_uncommitted_ = kMinUnCommittedSeq;
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};
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} // namespace ROCKSDB_NAMESPACE
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