Real "read-only" mode with optimized memory consumption

[michael-schnell]

Eclipse Store seems to add a lot of additional objects in memory.

Is there an option to load a real "read-only" model without that overhead? The "Read-Only" mode seems only to prevent writing, but does not seem to reduce the memory usage.

An alternative might be to purely use the Eclipse Serializer, but it lacks the "PersistenceTypeDictionary" of Eclipse Store. Would it be possible to use the "PersistenceTypeDictionary" standalone along with the Eclipse Serializer?

Here is a real world example with lots of objects that show a huge increase of memory consumption:

WITHOUT eclipse-store (root not persisted yet)

Total Bytes: 1’539’901’142
Total Classes: 8’556
Total Instances: 36’786’586

AFTER READING FROM eclipse-store

Total Bytes: 3’639’238’206
Total Classes: 9’730
Total Instances: 57’754’666

[michael-schnell]

For anyone arriving at this issue:

The solution is to use the TypedSerializer instead of Serializer. This includes all type information in the byte array:

try (final Serializer<byte[]> serializer = TypedSerializer.Bytes()) {
    final byte[] data = serializer.serialize(root);
    ...
} catch (final Exception ex) {
    throw new IllegalStateException("Failed to serialize data", ex);
}

For more information take a look at this discussion: "How to extract the type information from the serializer":
eclipse-serializer/serializer#84 (comment)

Unfortunately there is almost no documentation the Eclipse Serializer, which is pretty bad.