Struct IndexMetadata 

pub struct IndexMetadata {
    pub version: u32,
    pub schema: Schema,
    pub segment_metas: HashMap<String, SegmentMetaInfo>,
    pub vector_fields: HashMap<u32, FieldVectorMeta>,
    pub total_vectors: usize,
}

Unified index metadata - single source of truth for index state

Fields

version: u32

Version for compatibility

schema: Schema

Index schema

segment_metas: HashMap<String, SegmentMetaInfo>

Segment metadata: segment_id -> info (doc count, etc.) Using HashMap allows O(1) lookup and stores doc counts for merge decisions

vector_fields: HashMap<u32, FieldVectorMeta>

Per-field vector index metadata

total_vectors: usize

Total vectors across all segments (updated on commit)

Implementations

impl IndexMetadata

pub fn new(schema: Schema) -> Self

Create new metadata with schema

pub fn segment_ids(&self) -> Vec<String>

Get segment IDs as a sorted Vec (deterministic ordering for doc_id_offset assignment)

pub fn add_segment(&mut self, segment_id: String, num_docs: u32)

Add or update a segment with its doc count

pub fn remove_segment(&mut self, segment_id: &str)

Remove a segment

pub fn has_segment(&self, segment_id: &str) -> bool

Check if segment exists

pub fn segment_doc_count(&self, segment_id: &str) -> Option<u32>

Get segment doc count

pub fn is_field_built(&self, field_id: u32) -> bool

Check if a field has been built

pub fn get_field_meta(&self, field_id: u32) -> Option<&FieldVectorMeta>

Get field metadata

pub fn init_field(&mut self, field_id: u32, index_type: VectorIndexType)

Initialize field metadata (called when field is first seen)

pub fn mark_field_built( &mut self, field_id: u32, vector_count: usize, num_clusters: usize, centroids_file: String, codebook_file: Option<String>, )

Mark field as built with trained structures

pub fn should_build_field(&self, field_id: u32, threshold: usize) -> bool

Check if field should be built based on threshold

pub async fn load<D: Directory>(dir: &D) -> Result<Self>

Load from directory

If metadata.json is missing but metadata.json.tmp exists (crash between write and rename), recovers from the temp file.

pub async fn save<D: DirectoryWriter>(&self, dir: &D) -> Result<()>

Save to directory (atomic: write temp file, then rename)

Uses write-then-rename so a crash mid-write won’t corrupt the existing metadata file. On POSIX, rename is atomic.

pub async fn load_trained_structures<D: Directory>( &self, dir: &D, ) -> Option<TrainedVectorStructures>

Load trained structures from index-level files for fields in Built state.

Returns Some(TrainedVectorStructures) if at least one field has trained centroids, None otherwise.

Trait Implementations

impl Clone for IndexMetadata

fn clone(&self) -> IndexMetadata

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for IndexMetadata

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for IndexMetadata

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for IndexMetadata

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

where __S: Serializer,

Serialize this value into the given Serde serializer.