API generification

This issue is rather an open discussion about how the client will handle multiple back-ends, the concerns we want to address are:

• naming the project and the package
• how to handle specific backend operations (PG has notifications/notices, MY has ping, etc…)

Current WIP for MySQL support https://github.com/reactiverse/reactive-pg-client/tree/mysql_support

Naming

• The Reactive SQL Client
  • io.reactiverse.sqlclient
• The Reactive DB Client
  • io.reactiverse.dbclient
  • io.reactiverse.rdbc
  • io.reactiverse.dbc

Specific operations

Proposal 1

• Provide a generic API in the project package that does not provide specific operations
• Each database has its own package and extends the generic API providing specific operations

Examples

public interface DbConnection {
}

public interface PgConnection extends DbConnection {
  // Specific stuff here
}

Issues : we cannot really do this unless with use self bound generics ,i.e

public interface DbClient<C extends DbConnection> {
  void connect(Handler<AsyncResult<C>> handler);
}

public interface PgClient extends DbClient<PgConnection> {
}

unless we don’t abstract PgClient ?

Proposal 2

Flat interface style, provide an API that exposes everything. It is simple but not ideal and certainly won’t help the user.

[vietj]

I’ve pushed another commit that move more interfaces to the sqlclient package and now it looks ok to me.

• the io.reactiverse.sqlclient does not leak into io.reactiverse.pgclient for the main types
• the user will need to cast SqlConnection to PgConnection to access specific API, etc…

I believe the PG specific datatypes will be removed from Row / Tuple and can be used using type tokens:

<T> T get(int index, Class<T> type);

which can used this way:

Numeric numeric = row.get(0, Numeric.class);

[vietj]

I pushed the specific data type decoupling with PG in the branch https://github.com/reactiverse/reactive-pg-client/tree/api-test-1

I think this branch could be merged in the mysql-support branch as I think the result is satisfying for the moment