An open MVMap causes a conflict with TransactionMap

[mikko]

An open MVMap causes a conflict with TransactionMap in the below simple example:

import org.h2.mvstore.MVMap;

import org.h2.mvstore.MVStore;

import org.h2.mvstore.db.TransactionStore;

import org.h2.mvstore.db.TransactionStore.Transaction;

import org.h2.mvstore.db.TransactionStore.TransactionMap;

import org.h2.mvstore.MVMap;

import org.h2.mvstore.MVStore;

import org.h2.mvstore.db.TransactionStore;

import org.h2.mvstore.db.TransactionStore.Transaction;

import org.h2.mvstore.db.TransactionStore.TransactionMap;

public class H2TestMain5 {

public static void main(String[] args) {

String fileName = "MVStoreFile.dat";

MVStore s = MVStore.open(fileName);

MVMap<Integer, String> auxMap;

        auxMap = s.openMap("testMap");

        

TransactionStore ts = new TransactionStore(s);

        ts.init();

        Transaction tx = ts.begin();

TransactionMap<Integer, String> testMap = tx.openMap("testMap");

testMap.put(new Integer(0), "Hi");

testMap.put(new Integer(1), "Hello");

testMap.put(new Integer(2), "Hello world");

        tx.commit();

        ts.close();

        //auxMap = s.openMap("testMap");

        for (int i = 0; i < 3; i++) {

        System.out.println(auxMap.get(i));

}

        s.close();

}

}

After line:

testMap.put(new Integer(0), "Hi");

the testMap is incorrectly closed and due to this the following line:

testMap.put(new Integer(1), "Hello");

gives in debugger the following errors:

Exception in thread "main" java.lang.IllegalStateException: This map is closed [1.4.191/4]

at org.h2.mvstore.DataUtils.newIllegalStateException(DataUtils.java:773)

at org.h2.mvstore.MVMap.beforeWrite(MVMap.java:1039)

at org.h2.mvstore.MVMap.put(MVMap.java:117)

at org.h2.mvstore.db.TransactionStore.log(TransactionStore.java:282)

at org.h2.mvstore.db.TransactionStore$Transaction.log(TransactionStore.java:706)

at org.h2.mvstore.db.TransactionStore$TransactionMap.trySet(TransactionStore.java:1104)

at org.h2.mvstore.db.TransactionStore$TransactionMap.set(TransactionStore.java:1027)

at org.h2.mvstore.db.TransactionStore$TransactionMap.put(TransactionStore.java:1005)

at t2test2.H2TestMain5.main(H2TestMain5.java:24)

However, when run without debugger the erros are:

Exception in thread "main" java.lang.IllegalArgumentException: Could not serialize Hi [1.4.191/0]

at org.h2.mvstore.DataUtils.newIllegalArgumentException(DataUtils.java:736)

at org.h2.mvstore.type.ObjectDataType.serialize(ObjectDataType.java:355)

at org.h2.mvstore.type.ObjectDataType$SerializedObjectType.write(ObjectDataType.java:1531)

at org.h2.mvstore.type.ObjectDataType.write(ObjectDataType.java:128)

at org.h2.mvstore.type.ObjectDataType.write(ObjectDataType.java:122)

at org.h2.mvstore.Page.write(Page.java:744)

at org.h2.mvstore.Page.writeUnsavedRecursive(Page.java:825)

at org.h2.mvstore.Page.writeUnsavedRecursive(Page.java:831)

at org.h2.mvstore.MVStore.storeNowTry(MVStore.java:1141)

at org.h2.mvstore.MVStore.storeNow(MVStore.java:1046)

at org.h2.mvstore.MVStore.commitAndSave(MVStore.java:1035)

at org.h2.mvstore.MVStore.commit(MVStore.java:996)

at org.h2.mvstore.db.TransactionStore.close(TransactionStore.java:217)

at t2test2.H2TestMain5.main(H2TestMain5.java:28)

Caused by: java.io.NotSerializableException: org.h2.mvstore.db.TransactionStore$VersionedValue

at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)

at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)

at org.h2.mvstore.type.ObjectDataType.serialize(ObjectDataType.java:352)

... 12 more

  If the opening of the auxMap is moved to the commented line:

  //auxMap = s.openMap("testMap");

  then the program works correctly.

  

  In addition, it seems that after line:

  ts.close();

  the TransactionMap testMap is still open.

  Shouldn't it be closed because the TransactionStore used to open it is now closed?

  

[Noel Grandin]

You should either access your maps via MVStore or via TransactionStore. But not both.​ That is not supported (and does not make any sense).