Struct MetadataStore 

pub struct MetadataStore { /* private fields */ }

The name-keyed metadata store: object name → { attribute → value }, string values, deterministic iteration (a BTreeMap so the persisted JSON is stable). Empty records are never retained (removing the last attribute drops the whole record).

Implementations

impl MetadataStore

pub fn new() -> Self

pub fn is_empty(&self) -> bool

Whether the store holds no records at all.

pub fn set_attribute(&mut self, name: &str, key: &str, value: &str)

Set (or overwrite) one attribute of name’s record. An empty object name or key is ignored (no phantom records).

pub fn remove_attribute(&mut self, name: &str, key: &str) -> bool

Remove one attribute of name’s record, dropping the record if it becomes empty. Returns whether the attribute existed.

pub fn attribute(&self, name: &str, key: &str) -> Option<&str>

One attribute’s value (None if the object or key is unknown).

pub fn record(&self, name: &str) -> BTreeMap<String, String>

One object’s whole record (empty map if the object has no metadata).

pub fn all(&self) -> &BTreeMap<String, BTreeMap<String, String>>

The whole store (all records), read-only.

pub fn density(&self, name: &str) -> f64

The resolved density (mass per mm³) for name: its density attribute parsed as a positive finite number, else DEFAULT_DENSITY.

pub fn clear(&mut self)

Drop every record (a part load replaces the store wholesale).

pub fn record_json(&self, name: &str) -> String

One object’s record as a JSON object { key: value, ... } ({} when the object has no metadata).

pub fn to_json(&self) -> Value

The whole store as a JSON value { name: { key: value, ... }, ... } — the persisted shape and the whole-store getter.

pub fn to_json_string(&self) -> String

The whole store as a JSON string (the whole-store getter’s string form).

pub fn load_json(&mut self, value: Option<&Value>)

Replace the whole store from a persisted metadata value (or None, which clears it — loading a part with no metadata). Non-string leaf values are coerced to their JSON text so a legacy document never fails the load.

Trait Implementations

impl Clone for MetadataStore

fn clone(&self) -> MetadataStore

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MetadataStore

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

Formats the value using the given formatter.

impl Default for MetadataStore

fn default() -> MetadataStore

Returns the “default value” for a type.