Crate dyntext 

Trigram + bloom-filter text index.

dyntext is the algorithmic core of the dynomite text-search surface. It ports the inverted-index pipeline from pg_tre – a PostgreSQL access method for approximate-regex matching – into pure Rust, so the same trigram + bloom funnel can sit behind dynomite’s Redis FT.* command surface.

Phase 1 scope

This crate currently implements:

• Three-byte n-gram extraction with padding so the input’s boundary bytes get full coverage (see trigram).
• A roaring-bitmap-backed inverted index keyed by trigram hash (see postings::Postings).
• A standard bloom filter with configurable bit count and hash count (see bloom::BloomFilter).
• A combined index::TextIndex that ties the three together and serves exact-substring queries through the four-tier filter funnel from the design doc.

Phase 2 + 3 scope

Phase 2 adds regex-driven search on top of the existing exact-substring path:

• A small internal regex AST built from regex_syntax’s HIR (see regex_ast).
• A required-trigram extractor that walks the AST and computes the trigrams every matching string must contain (see prefix_extract).
• index::TextIndex::search_regex, which uses the extractor to prune the postings lists before running the actual matcher (currently regex::bytes::Regex).

Phase 3 adds the approximate-regex recheck:

• Safe FFI wrapper around the TRE C library for approximate-regex matching with up to k typos (see tre). The wrapper is the optional recheck step; the trigram + bloom funnel is reused unchanged.
• Phase 4: Redis FT.SEARCH / FT.REGEX command parser integration on top of the dynvec fold.

Optional features

• noxu – enables the [persist] module that serialises a TextIndex to an embedded Noxu DB environment so the trigram postings, per-doc bloom filters, and raw text survive a process restart. The feature pulls in noxu-db and bincode as workspace path dependencies.

Quick start

use dyntext::index::TextIndex;

let mut idx = TextIndex::new();
let id_a = idx.insert(b"the quick brown fox".to_vec());
let id_b = idx.insert(b"jumped over a lazy dog".to_vec());
let id_c = idx.insert(b"another brown fox here".to_vec());

let hits = idx.search_substring(b"brown fox");
assert!(hits.contains(&id_a));
assert!(hits.contains(&id_c));
assert!(!hits.contains(&id_b));

Re-exports

pub use bloom::BloomFilter;

pub use index::IndexedDoc;

pub use index::TextIndex;

pub use index::MIN_TRIGRAM_QUERY_LEN;

pub use postings::Postings;

pub use prefix_extract::required_trigram_hashes;

pub use prefix_extract::required_trigrams;

pub use regex_ast::parse as parse_regex;

pub use regex_ast::Ast as RegexAst;

pub use regex_ast::RegexError;

pub use tre::TreCompiledPattern;

pub use tre::TreError;

pub use tre::TreMatch;

pub use tre::TreMatchOpts;

pub use trigram::extract_query_trigram_set;

pub use trigram::extract_query_trigrams;

pub use trigram::extract_trigram_set;

pub use trigram::extract_trigrams;

pub use trigram::hash_trigram;

Modules

bloom

Standard bloom filter with configurable bit count and hash count.

index

Top-level TextIndex type combining trigram extraction, the inverted postings index, and the per-document bloom filter into a single insert-and-search facility.

postings

Inverted-index data structure mapping trigram hash to the set of document ids whose text contains the trigram.

prefix_extract

Required-trigram extraction from a regex AST.

regex_ast

Internal regex AST used by the Phase 2 prefix extractor.

tre

Safe Rust wrapper around tre-sys.

trigram

Three-byte n-gram extraction.