NullPointerException in HTreeMap.get

[franck102]

Hi,

I am getting an NPE in HTreeMap.get, the stack trace is below.

The map is created using this code:

_mapdb = DBMaker.fileDB(filePath.toFile()).
            allocateStartSize(ALLOCATE_START_SIZE).
            allocateIncrement(ALLOCATE_INCREMENT).
            closeOnJvmShutdown().
            transactionEnable().
            fileMmapEnableIfSupported().
            make();
        _metricsMap = _mapdb.
            hashMap("metrics", Serializer.STRING, new JacksonSerializer<>(MetricDefinition.class)).
            createOrOpen();

The key supplied to get() is non null, and it doesn't exist in the map. This is during load tests and there are many concurrent calls to

map.get(String key)
map.put(key, value);
map.values().stream()...
map.size()```

The stack trace:

java.lang.NullPointerException: null at org.mapdb.volume.ByteBufferVol.getSlice(ByteBufferVol.java:43) at org.mapdb.volume.ByteBufferVol.getLong(ByteBufferVol.java:122) at org.mapdb.volume.ReadOnlyVolume.getLong(ReadOnlyVolume.java:62) at org.mapdb.StoreWAL.getIndexVal(StoreWAL.kt:167) at org.mapdb.StoreWAL.get(StoreWAL.kt:499) at org.mapdb.IndexTreeListJava.treeGetNonBinary(IndexTreeListJava.java:254) at org.mapdb.IndexTreeListJava.treeGet(IndexTreeListJava.java:189) at org.mapdb.IndexTreeLongLongMap.get(IndexTreeLongLongMap.kt:82) at org.mapdb.HTreeMap.getprotected(HTreeMap.kt:629) at org.mapdb.HTreeMap.get(HTreeMap.kt:603)```