Optimistic locking option

src/main/kotlin/nl/astraeus/persistence/TransactionLog.kt

@@ -0,0 +1,33 @@
+package nl.astraeus.nl.astraeus.persistence
+
+import java.io.File
+import java.io.ObjectInputStream
+
+class TransactionLog(
+  val directory: File,
+) {
+  val fileManager = FileManager(directory)
+
+  fun showTransactions() {
+    fileManager.findLastSnapshot().let { (after, snapshot) ->
+      println("Last snapshot: $snapshot")
+
+      val transactions = fileManager.findTransactionsAfter(after ?: 0L)
+
+      println("Transactions:")
+      transactions?.forEach { transaction ->
+        transaction.inputStream().use { input ->
+          ObjectInputStream(input).use { ois ->
+            val versionNumber = ois.readInt()
+            check(versionNumber == 1) { "Unsupported version number: $versionNumber" }
+            val transactionNumber = ois.readLong()
+            val actions = ois.readObject() as Set<Action>
+            println("[$versionNumber]  $transactionNumber - ${actions.joinToString(",")}")
+          }
+        }
+      }
+    }
+
+  }
+
+}