implemented a simple commit log

transaction/commit_log.hpp

@@ -0,0 +1,44 @@
+#ifndef MEMGRAPH_TRANSACTION_COMMIT_LOG_HPP
+#define MEMGRAPH_TRANSACTION_COMMIT_LOG_HPP
+
+#include <cstdint>
+
+#include <boost/dynamic_bitset/dynamic_bitset.hpp>
+
+#include "sync/spinlock.hpp"
+#include "sync/lockable.hpp"
+
+// optimize allocation performance by preallocating chunks in like 2MB or so
+// optimize memory by purging old transactions after vacuuming or something
+// this is not sustainable in the long run
+
+class CommitLog : Lockable<SpinLock>
+{
+    void begin()
+    {
+        auto guard = this->acquire();
+        log.push_back(0);
+    }
+
+    void mark_aborted(uint64_t)
+    {
+        // this would be useful in a different implementation
+    }
+
+    void mark_committed(uint64_t id)
+    {
+        auto guard = this->acquire();
+        log.set(id, true);
+    }
+
+    bool is_committed(uint64_t id)
+    {
+        auto guard = this->acquire();
+        return log[id];
+    }
+
+private:
+    boost::dynamic_bitset<uint64_t> log;
+};
+
+#endif