MVStore table engine (improved performance)

h2/src/main/org/h2/mvstore/db/TransactionStore.java

@@ -63,6 +63,8 @@ public class TransactionStore {
 
     private long lastTransactionId;
     
+    private long firstOpenTransaction = -1;
+
     /**
      * Create a new transaction store.
      *
@@ -108,6 +110,10 @@ public class TransactionStore {
         if (lastKey != null && lastKey.longValue() > lastTransactionId) {
             throw DataUtils.newIllegalStateException("Last transaction not stored");
         }
+        if (undoLog.size() > 0) {
+            long[] key = undoLog.firstKey();
+            firstOpenTransaction = key[0];
+        }
     }
 
     /**
@@ -199,6 +205,9 @@ public class TransactionStore {
         long[] undoKey = { t.getId(), logId };
         Object[] log = new Object[] { opType, mapId, key, oldValue };
         undoLog.put(undoKey, log);
+        if (firstOpenTransaction == -1 || t.getId() < firstOpenTransaction) {
+            firstOpenTransaction = t.getId();
+        }
     }
 
     /**
@@ -249,10 +258,19 @@ public class TransactionStore {
     }
     
     boolean isTransactionOpen(long transactionId) {
-        int todoSlow;
 //        if (transactionId < firstOpenTransaction) {
 //            return false;
 //        }
+        if (firstOpenTransaction == -1) {
+            if (undoLog.size() == 0) {
+                return false;
+            }
+            long[] key = undoLog.firstKey();
+            firstOpenTransaction = key[0];
+        }
+        if (firstOpenTransaction == transactionId) {
+            return true;
+        }
         long[] key = { transactionId, -1 };
         key = undoLog.higherKey(key);
         return key != null && key[0] == transactionId;
@@ -263,6 +281,9 @@ public class TransactionStore {
             preparedTransactions.remove(t.getId());
         }
         t.setStatus(Transaction.STATUS_CLOSED);
+        if (t.getId() == firstOpenTransaction) {
+            firstOpenTransaction = -1;
+        }
     }
 
     /**

h2/src/test/org/h2/test/store/TestMVTableEngine.java

@@ -95,10 +95,10 @@ int tes;
         // fast size
         
         // 10 / 800000
-        // 1265 mvstore;LOCK_MODE=0 before
-        // 1434 mvstore;LOCK_MODE=0 after
-        // 1126 mvstore;DEFAULT_TABLE_ENGINE=org.h2.mvstore.db.MVTableEngine;LOCK_MODE=0;LOG=0 before
-        // 1136 mvstore;DEFAULT_TABLE_ENGINE=org.h2.mvstore.db.MVTableEngine;LOCK_MODE=0;LOG=0 after
+        // 1272 mvstore;LOCK_MODE=0 before
+        // 1449 mvstore;LOCK_MODE=0 after
+        // 1076 mvstore;DEFAULT_TABLE_ENGINE=org.h2.mvstore.db.MVTableEngine;LOCK_MODE=0;LOG=0 before
+        // 1086 mvstore;DEFAULT_TABLE_ENGINE=org.h2.mvstore.db.MVTableEngine;LOCK_MODE=0;LOG=0 after
 
         // 100 / 800000
         // 2010 mvstore;LOCK_MODE=0 before