Struct StringInterner 

pub struct StringInterner { /* private fields */ }

A string interner that deduplicates strings to reduce memory usage

This is particularly useful for RDF parsing where:

• Common predicates (rdf:type, rdfs:label, etc.) appear many times
• Namespace URIs are repeated frequently
• Language tags and datatypes are reused

Example

use oxirs_ttl::toolkit::StringInterner;
use std::sync::Arc;

let mut interner = StringInterner::new();

// These will all point to the same underlying string
let s1 = interner.intern("http://www.w3.org/1999/02/22-rdf-syntax-ns#type");
let s2 = interner.intern("http://www.w3.org/1999/02/22-rdf-syntax-ns#type");

// The Arc pointers should be the same (cheap to clone)
assert!(Arc::ptr_eq(&s1, &s2));

Implementations

impl StringInterner

pub fn new() -> Self

Create a new string interner

pub fn with_capacity(capacity: usize) -> Self

Create a new string interner with pre-allocated capacity

pub fn with_common_namespaces() -> Self

Create a new interner pre-populated with common RDF namespaces

pub fn intern(&mut self, s: &str) -> Arc<String>

Intern a string, returning an Arc to the deduplicated version

If the string has been seen before, returns the existing Arc. Otherwise, allocates a new String and stores it.

pub fn intern_if_beneficial<'a>( &mut self, s: &'a str, min_length: usize, ) -> Cow<'a, str>

Intern a string only if it’s likely to be repeated

Uses heuristics to decide whether to intern:

• Always intern if it contains common namespace patterns
• Always intern if it’s a common language tag
• Otherwise, intern if length > threshold

pub fn len(&self) -> usize

Get the number of unique strings stored

pub fn is_empty(&self) -> bool

Check if the interner is empty

pub fn stats(&self) -> &InternerStats

Get interning statistics

pub fn hit_rate(&self) -> f64

Get the cache hit rate (0.0 to 1.0)

pub fn clear(&mut self)

Clear all interned strings and reset statistics

pub fn memory_usage(&self) -> usize

Estimate memory usage in bytes

pub fn shrink_to_fit(&mut self)

Shrink the hash map to fit the current number of entries

Trait Implementations

impl Clone for StringInterner

fn clone(&self) -> StringInterner

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StringInterner

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

Formats the value using the given formatter.

impl Default for StringInterner

fn default() -> Self

Returns the “default value” for a type.