[eclipse-iceoryx#490] Add documentation

iceoryx2-ffi/ffi/src/api/port_factory_publisher_builder.rs

@@ -173,6 +173,17 @@ impl HandleToType for iox2_port_factory_publisher_builder_h_ref {
 
 // BEGIN C API
 
+/// Sets the max slice length for the publisher
+///
+/// # Arguments
+///
+/// * `port_factory_handle` - Must be a valid [`iox2_port_factory_publisher_builder_h_ref`]
+///   obtained by [`iox2_port_factory_pub_sub_publisher_builder`](crate::iox2_port_factory_pub_sub_publisher_builder).
+/// * `value` - The value to set max slice length to
+///
+/// # Safety
+///
+/// * `port_factory_handle` must be valid handles
 #[no_mangle]
 pub unsafe extern "C" fn iox2_port_factory_publisher_builder_set_max_slice_len(
     port_factory_handle: iox2_port_factory_publisher_builder_h_ref,

iceoryx2-ffi/ffi/src/api/publisher.rs

@@ -249,6 +249,18 @@ pub unsafe extern "C" fn iox2_publisher_unable_to_deliver_strategy(
     }
 }
 
+/// Returns the maximum `[u8]` length that can be loaned in one sample, i.e. the max number of
+/// elements in the `[u8]` payload type used by the C binding.
+///
+/// # Arguments
+///
+/// * `publisher_handle` obtained by [`iox2_port_factory_publisher_builder_create`](crate::iox2_port_factory_publisher_builder_create)
+///
+/// Returns the maximum number of elements as a [`c_int`].
+///
+/// # Safety
+///
+/// * `publisher_handle` is valid and non-null
 #[no_mangle]
 pub unsafe extern "C" fn iox2_publisher_max_slice_len(
     publisher_handle: iox2_publisher_h_ref,

iceoryx2-ffi/ffi/src/api/service_builder_pub_sub.rs

@@ -480,6 +480,17 @@ pub unsafe extern "C" fn iox2_service_builder_pub_sub_set_max_subscribers(
     }
 }
 
+/// Sets the payload alignment for the builder
+///
+/// # Arguments
+///
+/// * `service_builder_handle` - Must be a valid [`iox2_service_builder_pub_sub_h_ref`]
+///   obtained by [`iox2_service_builder_pub_sub`](crate::iox2_service_builder_pub_sub).
+/// * `value` - The value to set the payload alignment to
+///
+/// # Safety
+///
+/// * `service_builder_handle` must be valid handles
 #[no_mangle]
 pub unsafe extern "C" fn iox2_service_builder_pub_sub_set_payload_alignment(
     service_builder_handle: iox2_service_builder_pub_sub_h_ref,