Struct MetadataSnapshot 

pub struct MetadataSnapshot {
    pub segments: Vec<SegmentEntry>,
    pub vector_indexes: Vec<VectorIndexEntry>,
    pub total_blocks: u64,
    pub free_list: Vec<Extent>,
    pub user_metadata: Vec<u8>,
}

Point-in-time snapshot of all index metadata, stored in the metadata root block referenced by a root pointer.

Contains the segment directory, vector-index directory, allocator state, and free list — everything needed to reconstruct the index state after a crash.

See [[architecture-storage-format#Root Metadata]].

Fields

segments: Vec<SegmentEntry>

Live segments and their block locations.

vector_indexes: Vec<VectorIndexEntry>

Live per-field vector indexes (HNSW today; algorithm-agnostic). Index-wide artifact, decoupled from segments per [[global-vector-indices]].

total_blocks: u64

Total number of data blocks the file spans.

free_list: Vec<Extent>

Free block extents available for reuse.

user_metadata: Vec<u8>

Opaque application metadata (e.g., serialized field mappings, deletion bitmaps). The storage layer does not interpret this — it just persists and returns the bytes.

Implementations

impl MetadataSnapshot

pub fn empty() -> Self

Create an empty snapshot for a fresh index.

pub fn serialized_size(&self) -> usize

Serialized size in bytes.

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

Serialize to bytes for storage in a metadata block.

The output is checksummed by the caller (via xxh3_checksum) and stored in a block referenced by a root pointer.

pub fn from_bytes(data: &[u8]) -> Result<Self>

Deserialize from bytes read from a metadata block.

Errors

Returns LuciError::IndexCorrupted if the data is truncated or contains invalid values.

pub fn fits_in_single_block(&self) -> bool

Check that the serialized metadata fits within a single block.

Returns false if overflow chaining would be needed (not yet implemented).

Trait Implementations

impl Clone for MetadataSnapshot

fn clone(&self) -> MetadataSnapshot

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MetadataSnapshot

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

Formats the value using the given formatter.

impl Eq for MetadataSnapshot

impl PartialEq for MetadataSnapshot

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for MetadataSnapshot