Attribute Macro handler

#[handler]

A helper attribute for #[sdk_derive(...)]. It doesn’t do anyting on its own; it only marks functions that represent a paratime method handler. The permitted forms are:

• #[handler(call = "my_module.MyCall")]: Marks a function that handles the “my_module.MyCall” call and can be passed to oasis_runtime_sdk::module::dispatch_call.

• #[handler(prefetch = "my_module.MyCall")]: Marks a function that handles the request to prefetch any data ahead of the “my_module.MyCall” call. Its signature should be Fn( add_prefix: &mut dyn FnMut(Prefix) -> (), body: cbor::Value, auth_info: &AuthInfo, ) -> Result<(), oasis_runtime_sdk::error::RuntimeError>

• #[handler(query = "my_module.MyQuery")]: Marks a function that handles the “my_module.MyQuery” query and can be passed to oasis_runtime_sdk::module::dispatch_query.

• #[handler(message_result = "my_module.MyMR")]: Marks a function that handles the “my_module.MyMR” message result and can be passed to oasis_runtime_sdk::module::dispatch_message_result.

Query handler can also contain the expensive tag. Example: #[handler(query = "my_module.MyQuery", expensive)]. Queries tagged expensive can be enabled/disabled are disabled by default to avoid excessive costs to the node operator. This can be overridden in the node config.

NOTE: This attribute is parsed by the #[sdk_derive(...)] macro, which cannot interpret the attribute name semantically. Use #[handler], not #[oasis_runtime_sdk_macros::handler] or other paths/aliases.