[Feature]: Expand IO interface

[BinaryRyan]

Description of new feature

Can you open an interface for users to implement read and write on their own, so that I can package TLS inside

Scenarios for new feature

Gnet does not support tls

[panjf2000]

How do you plan on doing TLS with the customized Read() and Write() methods?

[BinaryRyan]

@panjf2000
Maybe I could maintain a state machine to implement TLS, but that would be quite troublesome. Actually, I'm wondering if gnet can provide an asynchronous engine. I hope to pass the socket fd into it. What I want gnet to do is event notification without actively reading data, because that would involve a series of protocol encryption/decryption and serialization, which gnet can't handle at present. For example:

engine := gnet_async_engine_new(interface, xxxx)
gnet_io_init(engine, server_recv_cb, fd, E_READ)

This way, I can call the read method to read data in the server_recv_cb method.

[BinaryRyan]

I think the current framework of gnet can indeed implement the aforementioned approach. This would allow users to handle their own serialization and TLS implementations independently. By providing a mechanism for pure event notifications without automatic data reading, gnet can remain lightweight while offering greater flexibility, enabling users to integrate custom protocols, encryption/decryption logic, and serialization methods according to their specific needs. Such a design would strike a better balance between the framework's built-in capabilities and user-defined extensions.

[panjf2000]

Currently, gnet performs the system call read(2) when receiving a read event from the kernel. Are you suggesting not to do it so that the users can read the data themself?