Struct TopicSampleResult

• Defined in File data_types.hpp

Struct Documentation

struct TopicSampleResult

Result of a single-topic sample operation.

has_data is true if a message was actually received within the timeout; otherwise the result is metadata-only. Metadata fields (topic_name, message_type, publisher_count, subscriber_count, publishers, subscribers) are populated on a best-effort basis even when no data arrived.

error_code is populated when the per-topic sample failed with a recoverable provider error (cold-wait cap exhausted, subscribe failed, etc) inside a batch call (sample_parallel). Single-topic sample() surfaces these via tl::expected<..., ErrorInfo> instead. When error_code is set, has_data is always false and metadata may be partial.

Public Members

std::string topic_name

std::string message_type

std::optional<nlohmann::json> data

Message data as JSON (nullopt when unavailable)

bool has_data = {false}

Whether actual data was received.

std::size_t publisher_count = {0}

std::size_t subscriber_count = {0}

std::int64_t timestamp_ns = {0}

Sample timestamp in ns since epoch.

std::vector<TopicEndpoint> publishers

Publisher endpoints with QoS.

std::vector<TopicEndpoint> subscribers

Subscriber endpoints with QoS.

std::optional<std::string> error_code

Per-topic SOVD error code (set on partial-batch failure)

std::optional<std::string> error_message

Per-topic error message paired with error_code.

int error_http_status = {0}

Per-topic HTTP status (0 when error_code is empty)