Make Document Serializable or other was to preserve a Document

[PhantomYdn]

ArcadeDB Version: 2.10.2

JDK Version: 11

OS: 11

Use Case: There is a web-form where users enter some information which expected to be serialized later into a Document. It will be very nice if ArcadeDB will allow using exactly the same form (Document) which later will be used for persistence. In OrientDB ODocument is serializable, so you can use it during pre-creation phase among several request-responses (so different sessions of working with a DB). The same behavior is useful for modification as well because it's useful to keep an intermediate state before actual persisting.

[lvca]

You could do that by using

Binary buffer = database.getSerializer().serialize(database, record);

A Binary is just a wrapper of byte[]. You can transfer wherever you want and the deserialize it:

database.newDocument("Employee").fromMap(
  database.getSerializer().deserializeProperties(database, buffer, null )
);

The serialized document in ArcadeDB doesn't contain the type name (this saves a lot of space on disk) because it's inferred from the bucket id. For this reason, it's not possible to create an API that given a document recreate it back, but you need to create it from the database instance passing its type first.

I think the best thing would be storing the RID and then the record binary form, so you can always recreate it. Example:

Serialize a document with:

Binary buffer = new Binary();
database.getSerializer().serializeValue(database, buffer, BinaryTypes.TYPE_RID, document.getIdentity());
buffer.append( database.getSerializer().serialize(database, record) );

And then deserialize it back:

RID rid = database.getSerializer().deserializeValue( database, buffer, BinaryTypes.TYPE_RID, null );
DocumentType type = schema.getTypeByBucketId(rid.getBucketId());
record = recordFactory.newImmutableRecord(database, type, rid, buffer, null);

[lvca]

I'd like to keep this issue open so we could create a new class PortableRecord where we do all of this for the user. Example of an API for the end-user:

// SERIALIZE A DOCUMENT/VERTEX/EDGE
Binary buffer = new PortableRecord( document ).toBinary();

...

// DESERIALIZE A DOCUMENT/VERTEX/EDGE
Record record = new PortableRecord( buffer ).toRecord();

@PhantomYdn WDYT?

[PhantomYdn]

@lvca, looks good for me - but is it possible to make it serializable? I understand that in this case in some ThreadLocal an object Database should be stored... Btw, what's the difference will be in this case between PortableRecord and DetachedDocument?

[lvca]

DetachedDocument is more for working offline and/or attaching the document to another database. But it has a Map<> under the hood, pretty basic. Portable would be to import/export the document.

I think implementing Java serializable is probably the best idea, to be compatible with the entire Java universe. Also, ArcadeDB binary serialization is very compressed, but it lacks the name of the properties (because they are saved in a dictionary).

[PhantomYdn]

@lvca , thank you for the implementation! But I have found one interesting trick which you used and which is quite nasty...
You are pre-creating a Document of a required type before deserialization. I understand that you are doing that to have an association with Database. But as a result you have to have some top level Object to manage actual true deserialization. Under "true deserialization" I mean case when, you have just ObjectInputStream and by invoking readObject you are reading "from scratch" actual object: so no "partial pre-creation".