89 lines
1.7 KiB
C++
89 lines
1.7 KiB
C++
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#ifndef MEMGRAPH_TRANSACTION_TRANSACTIONENGINE_HPP
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#define MEMGRAPH_TRANSACTION_TRANSACTIONENGINE_HPP
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#include <cstdlib>
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#include <atomic>
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#include <mutex>
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#include <vector>
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#include <set>
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#include <list>
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#include "transaction.hpp"
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template <class id_t, class lock_t>
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class TransactionEngine
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{
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using trans_t = Transaction<id_t>;
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public:
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TransactionEngine(id_t n) : counter(n) {}
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Transaction<id_t> begin()
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{
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auto guard = acquire();
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auto id = ++counter;
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auto t = Transaction<id_t>(id, active);
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active.push_back(id);
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return t;
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}
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void commit(const Transaction<id_t>& t)
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{
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auto guard = acquire();
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finalize_transaction(t);
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}
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void rollback(const Transaction<id_t>& t)
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{
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auto guard = acquire();
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// what to do here?
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finalize_transaction(t);
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}
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// id of the last finished transaction
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id_t epochs_passed()
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{
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auto guard = acquire();
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return active.front() - 1;
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}
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// total number of transactions started from the beginning of time
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id_t count()
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{
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auto guard = acquire();
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return counter;
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}
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// the number of currently active transactions
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size_t size()
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{
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auto guard = acquire();
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return active.size();
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}
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private:
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void finalize_transaction(const Transaction<id_t>& t)
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{
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// remove transaction from the active transactions list
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auto last = std::remove(active.begin(), active.end(), t.id);
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active.erase(last, active.end());
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}
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std::unique_lock<lock_t> acquire()
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{
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return std::unique_lock<lock_t>(lock);
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}
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id_t counter;
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lock_t lock;
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std::vector<id_t> active;
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};
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#endif
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