Struct LabelIndexSignal 

pub struct LabelIndexSignal {
    pub present: bool,
    pub bytes: u64,
    pub entries: Option<u64>,
}

The file’s label-prefix-search affordance: does it carry a LABEL_INDEX section (kind 8), how many labels, and how large is it?

Measured at read time, never stored, for the reasons TextIndexSignal gives: presence and size come free with the header, and entries is the u64 at bytes 20..28 of the section’s fixed preamble — one 32-byte range read, never the index. A file without the section may still answer a prefix search from the legacy label block of its pyramid-meta (at most 8,192 labels); that block is not measured here, because reading it means fetching the whole pyramid-meta.

Fields

present: bool

True iff the file has a kind-8 section. Always written, including as false.

bytes: u64

Byte length of the whole LABEL_INDEX section.

entries: Option<u64>

Number of (subject, label) entries; None when there is no index or its preamble was unreadable.

Implementations

impl LabelIndexSignal

pub fn probe<R>(reader: &R, header: &Header) -> LabelIndexSignal

where R: RangeReader + ?Sized,

Measure the signal from a file’s header, through the reader the card was read with: nothing beyond the header when there is no index, one 32-byte range read when there is.

pub fn describe(&self) -> String

One line for the human catalog view.

Trait Implementations

impl Clone for LabelIndexSignal

fn clone(&self) -> LabelIndexSignal

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for LabelIndexSignal

impl Debug for LabelIndexSignal

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

Formats the value using the given formatter.

impl Default for LabelIndexSignal

fn default() -> LabelIndexSignal

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for LabelIndexSignal

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for LabelIndexSignal

impl PartialEq for LabelIndexSignal

fn eq(&self, other: &LabelIndexSignal) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for LabelIndexSignal

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.

impl StructuralPartialEq for LabelIndexSignal