Enum MetadataPerSource 

pub enum MetadataPerSource {
    Unresolved,
    Partial(Arc<PartialMetadata>),
    Full(Arc<[Arc<FileMetadata>]>),
}

Available on crate features lazy and parquet only.

Footer metadata retained per scan source.

Source indices refer to the scan’s source list; a source not covered by the variant is unknown. Canonical format: Partial is used iff the subset is neither empty nor full.

Variants

Unresolved

No per-source metadata retained.

Partial(Arc<PartialMetadata>)

Footers of a strict subset of the sources.

Full(Arc<[Arc<FileMetadata>]>)

Every source’s footer: entry i is the footer of source i.

Implementations

impl MetadataPerSource

pub fn first_metadata(&self) -> Option<&Arc<FileMetadata>>

Footer of the scan’s current source 0, when resolved.

Every resolve that reads source 0’s footer retains it, so this is Some for any non-Unresolved value produced by resolve.

pub fn gather_first(&self) -> MetadataPerSource

Gather the first entry in the set.

Trait Implementations

impl Clone for MetadataPerSource

fn clone(&self) -> MetadataPerSource

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MetadataPerSource

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

Formats the value using the given formatter.

impl Default for MetadataPerSource

fn default() -> MetadataPerSource

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for MetadataPerSource

fn deserialize<__D>( __deserializer: __D, ) -> Result<MetadataPerSource, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for MetadataPerSource

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.