Trait libquery::ValueSrc [−] [src]

pub trait ValueSrc: InTimeInterval {
    fn value(&self, ident: &Ident) -> Option<Value>;

    fn stats(&self) -> &Stats;
}

A trait to extract values out of flow slices.

Required Methods

Extracts the given column.

Note that the caller must first check the container (with the PreFilter with the relevant query and must not ask for columns that are not accepted by the container (eg. if the container said MissingColumns. It is OK for the implementation to panic if it does.

If the implementation signaled MayUse and it is missing some values in some flows (because they are optional), it shall produce empty set inside the value.

Some implementation may produce multiple values if they have pre-aggregated input data. It must not happen to columns requested to aggregate by in the relevant PreFilter query.

Provides the statistics.

This provides the statistics (eg. sizes, speeds, etc) of the flow slice.

Implementors