Struct VecMeta 

pub struct VecMeta {
    pub dim: u64,
    pub seed: u64,
    pub bits: u64,
    pub max: u64,
    pub medoid: u64,
    pub watermark: u64,
}

Everything one vector field needs to be read back correctly, in one row (keys::catalog_field(CAT_VEC, field)). Nothing here is derivable from the vectors:

• dim is the field’s width; a row of another width is corruption at birth, refused rather than discovered as a garbage distance later.
• seed and bits ARE the fingerprint recipe – (dim, seed, bits) is the whole of it, so any process, at any later date, re-derives the encoder that wrote the codes rather than the one the code’s defaults happen to produce that day.
• max is the highest id that ever carried a vector for this field. nearest_par partitions [1, max]; next_id is wrong for it when vectors are set on caller-managed ids with no nodes (caught by the parallel-vs-serial equality test: partitions covered almost nothing and the test diverged).
• medoid and watermark are the nav tier’s start point and fast resume point. 0 means “no graph yet”, which is a usable sentinel because the id allocator reserves 0 and hands out nothing below 1. The watermark rides each fold insert; ids written behind it are recorded separately in CAT_NAV_PENDING, so a crash resumes from facts rather than ordering.

Fields

dim: u64

seed: u64

bits: u64

max: u64

medoid: u64

watermark: u64

Implementations

impl VecMeta

pub const LEN: usize = 48

Six big-endian words. Fixed width: a short row is a row this build cannot read, and reading it half-way would hand out a recipe that decodes every code in the field wrongly.

pub fn encode(&self) -> Vec<u8>

pub fn decode(b: &[u8]) -> Option<VecMeta>

Trait Implementations

impl Clone for VecMeta

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for VecMeta

impl Debug for VecMeta

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

Formats the value using the given formatter.

impl Default for VecMeta

fn default() -> Self

Returns the “default value” for a type.

impl Eq for VecMeta

impl PartialEq for VecMeta

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for VecMeta