96ece11cdd
Summary:
This change introduces a pure virtual initial implementation of the transaction
engine which is then implemented in two versions: single node and distributed.
The interface classes now have the following hierarchy:
```
Engine (pure interface)
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+----+---------- EngineDistributed (common logic)
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EngineSingleNode +-------+--------+
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EngineMaster EngineWorker
```
In addition to this layout the `EngineMaster` uses `EngineSingleNode` as its
underlying storage engine and only changes the necessary functions to make
them work with the `EngineWorker`.
After this change I recommend that you delete the following leftover files:
```
rm src/distributed/transactional_cache_cleaner_rpc_messages.*
rm src/transactions/common.*
rm src/transactions/engine_rpc_messages.*
```
Reviewers: teon.banek, msantl, buda
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1589
41 lines
1.1 KiB
C++
41 lines
1.1 KiB
C++
#pragma once
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#include "mvcc/record.hpp"
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#include "transactions/single_node/engine_single_node.hpp"
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/**
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* @brief - Empty class which inherits from mvcc:Record.
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*/
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class Prop : public mvcc::Record<Prop> {
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public:
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Prop *CloneData() { return new Prop; }
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};
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/**
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* @brief - Class which inherits from mvcc::Record and takes an atomic variable
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* to count number of destructor calls (to test if the record is actually
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* deleted).
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*/
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class DestrCountRec : public mvcc::Record<DestrCountRec> {
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public:
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explicit DestrCountRec(std::atomic<int> &count) : count_(count) {}
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DestrCountRec *CloneData() { return new DestrCountRec(count_); }
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~DestrCountRec() { ++count_; }
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private:
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std::atomic<int> &count_;
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};
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// helper function for creating a GC snapshot
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// if given a nullptr it makes a GC snapshot like there
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// are no active transactions
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auto GcSnapshot(tx::EngineSingleNode &engine, tx::Transaction *t) {
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if (t != nullptr) {
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tx::Snapshot gc_snap = t->snapshot();
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gc_snap.insert(t->id_);
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return gc_snap;
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} else {
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return engine.GlobalGcSnapshot();
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}
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}
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