1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565
use fst::{IntoStreamer, Streamer, Map}; use fst::automaton::{Automaton, Str, Subsequence}; pub use levenshtein_automata::{LevenshteinAutomatonBuilder, Distance as LevenshteinDistance}; use maybe_owned::MaybeOwned; use serde::{Serialize, Deserialize}; use std::collections::HashMap; pub use self::collectors::TopScoreCollector; mod collectors; mod serialization; mod streams; /// Score type, used for keeping a per-item score in `SearchStream`. pub type Score = u64; type BoxedStream<'f> = Box<dyn for<'a> Streamer<'a, Item = (&'a [u8], u64, Score)> + 'f>; /// FST stream on which various operations can be chained. pub struct SearchStream<'s>(BoxedStream<'s>); impl<'s> SearchStream<'s> { /// Scores a stream, using the given closure. /// /// # Examples /// /// Basic usage: /// /// ``` /// use fst::Streamer; /// use porigon::Searchable; /// /// let searchable = Searchable::build_from_iter(vec!( /// ("foo".as_bytes(), 0), /// ("foobar".as_bytes(), 1)) /// ).unwrap(); /// let mut strm = searchable /// .starts_with("foo") /// .rescore(|key, _, _| key.len() as porigon::Score) /// ; /// assert_eq!(strm.next(), Some(("foo".as_bytes(), 0, 3))); /// assert_eq!(strm.next(), Some(("foobar".as_bytes(), 1, 6))); /// assert_eq!(strm.next(), None); /// ``` /// /// You can also use this to build upon a previously set score: /// /// ``` /// use fst::Streamer; /// use porigon::Searchable; /// /// let searchable = Searchable::build_from_iter(vec!( /// ("foo".as_bytes(), 0), /// ("foobar".as_bytes(), 1)) /// ).unwrap(); /// let mut strm = searchable /// .starts_with("foo") /// .rescore(|key, _, _| key.len() as porigon::Score) /// .rescore(|_, index, old_score| (old_score << 16) | index) /// ; /// assert_eq!(strm.next(), Some(("foo".as_bytes(), 0, 3 << 16))); /// assert_eq!(strm.next(), Some(("foobar".as_bytes(), 1, (6 << 16) | 1))); /// assert_eq!(strm.next(), None); /// ``` pub fn rescore<F: 's + Fn(&[u8], u64, crate::Score) -> crate::Score>(self, func: F) -> Self { self.map(move |key, index, score| (key, index, func(key, index, score))) } /// Filters a stream, using the given closure. /// /// # Example /// /// ``` /// use fst::Streamer; /// use porigon::Searchable; /// /// let searchable = Searchable::build_from_iter(vec!( /// ("foo".as_bytes(), 0), /// ("foobar".as_bytes(), 1)) /// ).unwrap(); /// let mut strm = searchable /// .starts_with("foo") /// .filter(|key, _, _| key != "foobar".as_bytes()) /// ; /// assert_eq!(strm.next(), Some(("foo".as_bytes(), 0, 0))); /// assert_eq!(strm.next(), None); /// ``` pub fn filter<F: 's + Fn(&[u8], u64, crate::Score) -> bool>(self, func: F) -> Self { SearchStream(Box::new(streams::FilteredStream::new(self, func))) } /// Maps over a stream, using the given closure. /// /// This more of an advanced method, used for changing the stream's key or index. Most probably /// you want to use [rescore()](#method.rescore) instead. /// /// # Example /// /// ``` /// use fst::Streamer; /// use porigon::Searchable; /// /// let mut items = vec!( /// ("this is a bar".as_bytes(), 15), /// ("is a bar".as_bytes(), (1 << 32) | 15), /// ("a bar".as_bytes(), (1 << 32) | 15), /// ("bar".as_bytes(), (1 << 32) | 15), /// ("barfoo".as_bytes(), 16) /// ); /// items.sort_by_key(|(key, _)| *key); /// let searchable = Searchable::build_from_iter(items).unwrap(); /// let mut strm = searchable /// .starts_with("bar") /// .map(|key, index, score| (key, index & !(1 << 32), score)) /// ; /// assert_eq!(strm.next(), Some(("bar".as_bytes(), 15, 0))); /// assert_eq!(strm.next(), Some(("barfoo".as_bytes(), 16, 0))); /// assert_eq!(strm.next(), None); /// ``` pub fn map<F: 's + Fn(&[u8], u64, crate::Score) -> (&[u8], u64, crate::Score)>(self, func: F) -> Self { SearchStream(Box::new(streams::MappedStream::new(self, func))) } } impl<'a, 's> Streamer<'a> for SearchStream<'s> { type Item = (&'a [u8], u64, Score); fn next(&'a mut self) -> Option<Self::Item> { self.0.next() } } /// Main entry point to building and querying FSTs. /// /// This is a thin wrapper around `fst::Map`, providing easy access to querying it in /// various ways (exact_match, starts_with, levenshtein, ...). /// /// NOTE: this struct is serializable #[derive(Serialize, Deserialize)] pub struct Searchable { map: serialization::SerializableMap, duplicates: HashMap<u64, Vec<u64>>, } impl Searchable { fn create_stream<'a, A: 'a>(&'a self, automaton: A) -> SearchStream<'a> where A: Automaton { struct Adapter<'m, A>(fst::map::Stream<'m, A>) where A: Automaton; impl<'a, 'm, A> Streamer<'a> for Adapter<'m, A> where A: Automaton { type Item = (&'a [u8], u64, Score); fn next(&'a mut self) -> Option<Self::Item> { self.0.next().map(|(key, index)| (key, index, 0)) } } let stream = self.map.as_ref().search(automaton).into_stream(); let deduped_stream = streams::DeduplicatedStream::new(Adapter(stream), &self.duplicates); SearchStream(Box::new(deduped_stream)) } /// Creates a `SearchStream` from a `StartsWith` matcher for the given `query`. /// /// # Example /// ``` /// use fst::Streamer; /// use porigon::Searchable; /// /// let items = vec!( /// ("bar".as_bytes(), 1), /// ("foo".as_bytes(), 2), /// ("foo_bar".as_bytes(), 3) /// ); /// let searchable = Searchable::build_from_iter(items).unwrap(); /// /// let mut strm = searchable.starts_with("foo"); /// assert_eq!(strm.next(), Some(("foo".as_bytes(), 2, 0))); /// assert_eq!(strm.next(), Some(("foo_bar".as_bytes(), 3, 0))); /// assert_eq!(strm.next(), None); /// ``` /// pub fn starts_with<'a>(&'a self, query: &'a str) -> SearchStream<'a> { let automaton = Str::new(query).starts_with(); self.create_stream(automaton) } /// Creates a `SearchStream` from an `ExactMatch` matcher for the given `query`. /// /// # Example /// ``` /// use fst::Streamer; /// use porigon::Searchable; /// /// let items = vec!( /// ("bar".as_bytes(), 1), /// ("foo".as_bytes(), 2), /// ("foo_bar".as_bytes(), 3) /// ); /// let searchable = Searchable::build_from_iter(items).unwrap(); /// /// let mut strm = searchable.exact_match("foo"); /// assert_eq!(strm.next(), Some(("foo".as_bytes(), 2, 0))); /// assert_eq!(strm.next(), None); /// ``` /// pub fn exact_match<'a>(&'a self, query: &'a str) -> SearchStream<'a> { let automaton = Str::new(query); self.create_stream(automaton) } /// Creates a `SearchStream` from a `levenshtein_automata::DFA` matcher. /// /// This method supports both moving the DFA or passing a reference to it. /// /// # Example /// ``` /// use fst::Streamer; /// use porigon::{LevenshteinAutomatonBuilder, Searchable}; /// /// let items = vec!( /// ("bar".as_bytes(), 1), /// ("fob".as_bytes(), 2), /// ("foo".as_bytes(), 3), /// ("foo_bar".as_bytes(), 4) /// ); /// let searchable = Searchable::build_from_iter(items).unwrap(); /// let levenshtein_builder = LevenshteinAutomatonBuilder::new(1, false); /// /// let dfa = levenshtein_builder.build_dfa("foo"); /// let mut strm = searchable.levenshtein(&dfa); /// assert_eq!(strm.next(), Some(("fob".as_bytes(), 2, 0))); /// assert_eq!(strm.next(), Some(("foo".as_bytes(), 3, 0))); /// assert_eq!(strm.next(), None); /// ``` /// pub fn levenshtein<'a, D>(&'a self, dfa: D) -> SearchStream<'a> where D: Into<MaybeOwned<'a, levenshtein_automata::DFA>> { struct Adapter<'a>(MaybeOwned<'a, levenshtein_automata::DFA>); impl<'a> fst::Automaton for Adapter<'a> { type State = u32; fn start(&self) -> u32 { self.0.initial_state() } fn is_match(&self, state: &u32) -> bool { match self.0.distance(*state) { LevenshteinDistance::Exact(_) => true, LevenshteinDistance::AtLeast(_) => false, } } fn can_match(&self, state: &u32) -> bool { *state != levenshtein_automata::SINK_STATE } fn accept(&self, state: &u32, byte: u8) -> u32 { self.0.transition(*state, byte) } } self.create_stream(Adapter(dfa.into())) } /// Creates a `SearchStream` for a `LevenshteinAutomatonBuilder` and the given `query`. /// /// # Example /// ``` /// use fst::Streamer; /// use porigon::{LevenshteinAutomatonBuilder, Searchable}; /// /// let items = vec!( /// ("bar".as_bytes(), 1), /// ("fob".as_bytes(), 2), /// ("foo".as_bytes(), 3), /// ("foo_bar".as_bytes(), 4) /// ); /// let searchable = Searchable::build_from_iter(items).unwrap(); /// let levenshtein_builder = LevenshteinAutomatonBuilder::new(1, false); /// /// let dfa = levenshtein_builder.build_dfa("foo"); /// let mut strm = searchable.levenshtein_exact_match(&levenshtein_builder, "foo"); /// assert_eq!(strm.next(), Some(("fob".as_bytes(), 2, 0))); /// assert_eq!(strm.next(), Some(("foo".as_bytes(), 3, 0))); /// assert_eq!(strm.next(), None); /// ``` /// pub fn levenshtein_exact_match<'a>(&'a self, builder: &LevenshteinAutomatonBuilder, query: &'a str) -> SearchStream<'a> { self.levenshtein(builder.build_dfa(query)) } /// Creates a `SearchStream` for a `LevenshteinAutomatonBuilder` and the given `query`. /// /// # Example /// ``` /// use fst::Streamer; /// use porigon::{LevenshteinAutomatonBuilder, Searchable}; /// /// let items = vec!( /// ("bar".as_bytes(), 1), /// ("fob".as_bytes(), 2), /// ("foo".as_bytes(), 3), /// ("foo_bar".as_bytes(), 4) /// ); /// let searchable = Searchable::build_from_iter(items).unwrap(); /// let levenshtein_builder = LevenshteinAutomatonBuilder::new(1, false); /// /// let dfa = levenshtein_builder.build_dfa("foo"); /// let mut strm = searchable.levenshtein_starts_with(&levenshtein_builder, "foo"); /// assert_eq!(strm.next(), Some(("fob".as_bytes(), 2, 0))); /// assert_eq!(strm.next(), Some(("foo".as_bytes(), 3, 0))); /// assert_eq!(strm.next(), Some(("foo_bar".as_bytes(), 4, 0))); /// assert_eq!(strm.next(), None); /// ``` /// pub fn levenshtein_starts_with<'a>(&'a self, builder: &LevenshteinAutomatonBuilder, query: &'a str) -> SearchStream<'a> { self.levenshtein(builder.build_prefix_dfa(query)) } /// Creates a `SearchStream` from a `Subsequence` matcher for the given `query`. /// /// # Example /// ``` /// use fst::Streamer; /// use porigon::Searchable; /// /// let items = vec!(("bar_foo".as_bytes(), 2), ("foo".as_bytes(), 0), ("foo_bar".as_bytes(), 1)); /// let searchable = Searchable::build_from_iter(items).unwrap(); /// /// let mut strm = searchable.subsequence("fb"); /// assert_eq!(strm.next(), Some(("foo_bar".as_bytes(), 1, 0))); /// assert_eq!(strm.next(), None); /// ``` /// pub fn subsequence<'a>(&'a self, query: &'a str) -> SearchStream<'a> { let automaton = Subsequence::new(query); self.create_stream(automaton) } /// Construct a Searchable from an `Iterator<Item=(&[u8], u64)>`. /// /// # Example /// ``` /// use porigon::Searchable; /// /// let searchable = Searchable::build_from_iter(vec!( /// ("bar".as_bytes(), 1), /// ("foo".as_bytes(), 2), /// )).unwrap(); /// ``` pub fn build_from_iter<'a, I>(iter: I) -> Result<Searchable, fst::Error> where I: IntoIterator<Item=(&'a [u8], u64)> { // group items by key let (deduped_iter, duplicates) = streams::dedupe_from_iter(iter); // build map let map = Map::from_iter(deduped_iter)?; Ok(Self { map: map.into(), duplicates, }) } } #[cfg(test)] mod tests { use super::*; type TestResult = Result<(), Box<dyn std::error::Error>>; impl<'a> SearchStream<'a> { fn into_vec(mut self) -> Vec<(String, u64, Score)> { let mut items = Vec::new(); while let Some((key, index, score)) = self.next() { items.push((String::from_utf8(key.to_vec()).unwrap(), index, score)); } items } } #[test] fn test_build() -> TestResult { let items = vec!(("bar".as_bytes(), 1), ("foo".as_bytes(), 0)); let searchable = Searchable::build_from_iter(items)?; let results = searchable.map.as_ref().stream().into_str_vec()?; assert_eq!(results.len(), 2); assert_eq!(results, vec![("bar".to_string(), 1), ("foo".to_string(), 0)]); Ok(()) } #[test] fn test_searchable_exact_match() -> TestResult { let items = vec!(("fo".as_bytes(), 1), ("foo".as_bytes(), 0), ("foobar".as_bytes(), 2)); let searchable = Searchable::build_from_iter(items)?; // negative match let results = searchable.exact_match("bar").into_vec(); assert_eq!(results.len(), 0); // positive match let results = searchable.exact_match("foo").into_vec(); assert_eq!(results.len(), 1); assert_eq!(results, vec!(("foo".to_string(), 0, 0))); Ok(()) } #[test] fn test_searchable_starts_with() -> TestResult { let items = vec!(("fo".as_bytes(), 1), ("foo".as_bytes(), 0), ("foobar".as_bytes(), 2)); let searchable = Searchable::build_from_iter(items)?; // negative match let results = searchable.starts_with("b").into_vec(); assert_eq!(results.len(), 0); // positive match let results = searchable.starts_with("foo").into_vec(); assert_eq!(results.len(), 2); assert_eq!(results, vec!(("foo".to_string(), 0, 0), ("foobar".to_string(), 2, 0))); Ok(()) } #[test] fn test_searchable_subsequence() -> TestResult { let items = vec!(("bar_foo".as_bytes(), 2), ("foo".as_bytes(), 0), ("foo_bar".as_bytes(), 1)); let searchable = Searchable::build_from_iter(items)?; // negative match let results = searchable.subsequence("m").into_vec(); assert_eq!(results.len(), 0); // positive match let results = searchable.subsequence("fb").into_vec(); assert_eq!(results.len(), 1); assert_eq!(results, vec!(("foo_bar".to_string(), 1, 0))); // other positive match let results = searchable.subsequence("bf").into_vec(); assert_eq!(results.len(), 1); assert_eq!(results, vec!(("bar_foo".to_string(), 2, 0))); Ok(()) } #[test] fn test_scored_stream() -> TestResult { let items = vec!(("fo".as_bytes(), 1), ("foo".as_bytes(), 0), ("foobar".as_bytes(), 2)); let searchable = Searchable::build_from_iter(items)?; // use key let results = searchable.starts_with("foo").rescore(|key, _, _| key.len() as u64).into_vec(); assert_eq!(results.len(), 2); assert_eq!(results, vec!(("foo".to_string(), 0, 3), ("foobar".to_string(), 2, 6))); // use index let results = searchable.starts_with("foo").rescore(|_, idx, _| (idx * 2) as u64).into_vec(); assert_eq!(results.len(), 2); assert_eq!(results, vec!(("foo".to_string(), 0, 0), ("foobar".to_string(), 2, 4))); Ok(()) } #[test] fn test_filter() -> TestResult { let items = vec!(("fo".as_bytes(), 1), ("foo".as_bytes(), 0), ("foobar".as_bytes(), 2)); let searchable = Searchable::build_from_iter(items)?; let results = searchable .starts_with("foo") .filter(|key, _, _| key != "foobar".as_bytes()) .into_vec(); assert_eq!(results.len(), 1); assert_eq!(results, vec!(("foo".to_string(), 0, 0))); let results = searchable .starts_with("foo") .filter(|key, _, _| key == "foobar".as_bytes()) .into_vec(); assert_eq!(results.len(), 1); assert_eq!(results, vec!(("foobar".to_string(), 2, 0))); Ok(()) } #[test] fn test_map() -> TestResult { let items = vec!(("fo".as_bytes(), 1), ("foo".as_bytes(), 2), ("foobar".as_bytes(), 3)); let searchable = Searchable::build_from_iter(items)?; let results = searchable .starts_with("foo") .map(|key, index, score| (key, index * 2, score)) .into_vec(); assert_eq!(results.len(), 2); assert_eq!(results, vec!(("foo".to_string(), 4, 0), ("foobar".to_string(), 6, 0))); Ok(()) } #[test] fn test_duplicates() -> TestResult { let items = vec!(("foo".as_bytes(), 0), ("foo".as_bytes(), 1), ("foobar".as_bytes(), 2)); let searchable = Searchable::build_from_iter(items)?; let results = searchable.exact_match("foo").into_vec(); assert_eq!(results.len(), 2); assert_eq!(results, vec!(("foo".to_string(), 0, 0), ("foo".to_string(), 1, 0))); Ok(()) } #[test] fn test_levenshtein() -> TestResult { let items = vec!( ("bar".as_bytes(), 0), ("baz".as_bytes(), 1), ("boz".as_bytes(), 2), ("coz".as_bytes(), 3), ("fob".as_bytes(), 4), ("foo".as_bytes(), 5), ("foobar".as_bytes(), 6), ("something else".as_bytes(), 7), ); let searchable = Searchable::build_from_iter(items)?; let dfa_builder_1 = LevenshteinAutomatonBuilder::new(1, false); let dfa_builder_2 = LevenshteinAutomatonBuilder::new(2, false); let results = searchable.levenshtein_exact_match(&dfa_builder_1, "foo").into_vec(); assert_eq!(results.len(), 2); assert_eq!(results, vec!(("fob".to_string(), 4, 0), ("foo".to_string(), 5, 0))); let results = searchable.levenshtein_starts_with(&dfa_builder_1, "foo").into_vec(); assert_eq!(results.len(), 3); assert_eq!(results, vec!(("fob".to_string(), 4, 0), ("foo".to_string(), 5, 0), ("foobar".to_string(), 6, 0))); let results = searchable.levenshtein_exact_match(&dfa_builder_2, "bar").into_vec(); assert_eq!(results.len(), 3); assert_eq!(results, vec!(("bar".to_string(), 0, 0), ("baz".to_string(), 1, 0), ("boz".to_string(), 2, 0))); let dfa = dfa_builder_2.build_prefix_dfa("bar"); let results = searchable .levenshtein(&dfa) .rescore( |key, _, _| match dfa.eval(key) { LevenshteinDistance::Exact(d) => d as u64, LevenshteinDistance::AtLeast(_) => 0, } ) .into_vec(); assert_eq!(results.len(), 3); assert_eq!(results, vec!(("bar".to_string(), 0, 0), ("baz".to_string(), 1, 1), ("boz".to_string(), 2, 2))); Ok(()) } }