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API referenceModule APIClasses

hololink::module::DataChannelInterfaceV1

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Handle to a single data path on an HSB device.

DataChannel represents the path that sensor or actuator data travels between the host system (usually via RDMA) and the device itself.

  • A single HSB device can support any number of DataChannel instances.
  • Data producers or consumers use this object to find enumeration metadata provided by the application at construction time. This data is configured by the application per application requirements (e.g. using a specific sensor number or configuration)– enumeration metadata found just by listening to BOOTP messages may not have this application-specific setup.
  • Channel specific objects are invalidated when device_lost is called here, so later calls to get_service will reinitialize these– supporting device reconnection.
#include <hololink/module/data_channel.hpp>

Example

auto& adapter = hololink::module::Adapter::get_adapter();
auto metadata = adapter.wait_for_channel(hololink_ip, discovery_timeout);
auto channel = hololink::module::DataChannelInterfaceV1::get_service(metadata);
// Reach the device this channel runs on.
channel->hololink()->start();

Inherits from: hololink::module::ConfigurableService< DataChannelInterfaceV1 > (public)

Methods

enumeration_metadata

virtual const EnumerationMetadata & hololink::module::DataChannelInterfaceV1::enumeration_metadata() const

The enumeration metadata this channel was configured with.

Every service on this channel is configured from this snapshot.

Returns: The metadata describing this channel.

virtual std::shared_ptr<HololinkInterfaceV1> hololink::module::DataChannelInterfaceV1::hololink() const

The device this channel runs on.

The same device an application gets by fetching HololinkInterfaceV1 with this channel’s enumeration metadata.

Returns: The device.

device_lost

virtual hololink_module_status_t hololink::module::DataChannelInterfaceV1::device_lost()

Invalidate the services cached for the device this channel runs on, following loss of contact with it.

Does what HololinkInterfaceV1::device_lost() does, for applications that hold a channel and not the device it runs on.

Returns: HOLOLINK_MODULE_OK or an error status.

configure

virtual void hololink::module::ConfigurableService<DataChannelInterfaceV1>::configure(
    const EnumerationMetadata &
)

Use metadata contents to initialize this instance.

This routine is guaranteed to be called the first time a call to get_service(metadata) is called on a specific service instance.

module

std::shared_ptr<Module> hololink::module::ServiceBase::module() const

The Module that this service was published from.

The service holds no strong reference to its Module, so this does not extend the Module’s lifetime.

Returns: The owning Module, or an empty pointer if the service has not been published or its Module no longer exists.

Static methods

get_service

static std::shared_ptr<DataChannelInterfaceV1> hololink::module::ConfigurableService<DataChannelInterfaceV1>::get_service(
    const EnumerationMetadata &metadata,
    bool allow_null = false
)

Fetch a service, configured by EnumerationMetadata.

Module usually caches service objects; so when a specific service instance isn’t found, it will be constructed with the current values in EnumerationMetadata. Later calls to get_service are likely to return that cached instance, ignoring changes to any enumeration metadata that aren’t specifically related to service addressing.

Returns: A shared pointer to the requested service (<Derived>).

Throws: std::runtime_error when allow_null==false and the service lookup (or construction) fails.

Parameters

metadata
const EnumerationMetadata &

Addressing and configuration for the service.

allow_null
boolDefaults to false

Use true to return nullptr when the service cannot be resolved; the default false value raises a std::runtime_error.

for_each_type_id

static bool hololink::module::Service<DataChannelInterfaceV1>::for_each_type_id(
    Callback &&cb
)

Iterate over every type_id supported by this instance.

The callback signature is bool(const char*) — returning false halts the walk; true continues. Iteration is depth-first, so you’ll see the most specific implementation types first.