Struct ContentFilteredTopic 

pub struct ContentFilteredTopic<T: DdsType> { /* private fields */ }

ContentFilteredTopic<T> — a sub-topic of a Topic<T> with a filter expression. Spec reference: OMG DDS 1.4 §2.2.2.3.3.

“ContentFilteredTopic is a specialization of TopicDescription that allows for content-based subscriptions. The selection of the content is done using a filter_expression with parameters (filter_parameters).”

The filter expression is a SQL subset (DDS-DCPS Annex B, BNF): field op literal-or-param, AND/OR/NOT composition, parens, LIKE. The concrete parser lives in zerodds-sql-filter.

Lifecycle: the CFT holds a clone of the related topic (shared Arc<TopicInner>) and is itself cloneable. Filter parameters are mutable at runtime (spec §2.2.2.3.3.7).

Implementations

impl<T: DdsType> ContentFilteredTopic<T>

pub fn get_filter_expression(&self) -> &str

Spec §2.2.2.3.3.4 get_filter_expression.

pub fn get_filter_parameters(&self) -> Vec<String>

Spec §2.2.2.3.3.5 get_filter_parameters.

pub fn set_filter_parameters(&self, params: Vec<String>) -> Result<()>

Spec §2.2.2.3.3.6 set_filter_parameters. Swaps the parameters (equal count is not enforced — the spec says “should match the number of %n tokens” as a recommendation; we verify it strictly).

Errors

BadParameter if a %N index is outside the new vec.

pub fn get_related_topic(&self) -> &Topic<T>

Spec §2.2.2.3.3.3 get_related_topic.

pub fn evaluate<R: RowAccess>(&self, row: &R) -> Result<bool>

Evaluates the filter against a decoded sample. Returns Ok(true) if the sample should pass, Ok(false) if it is filtered out, Err if the expression does not fit the row schema (caller’s decision: filter denies or error).

Errors

• PreconditionNotMet if the filter-parameter lock is poisoned.
• BadParameter if a field in the expression does not exist in the row or a type mismatch occurs.

Trait Implementations

impl<T: DdsType> Clone for ContentFilteredTopic<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug + DdsType> Debug for ContentFilteredTopic<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: DdsType> TopicDescription for ContentFilteredTopic<T>

fn get_type_name(&self) -> &str

The type name comes from the related topic — a CFT shares the schema with the underlying topic.

fn get_name(&self) -> &str

Topic name (e.g. "ChatterTopic"). Spec §2.2.2.3.1 get_name.

fn get_participant(&self) -> &DomainParticipant

Owning participant. Spec §2.2.2.3.1 get_participant.