/usr/include/fst/state-table.h is in libfst-dev 1.5.3+r3-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | // See www.openfst.org for extensive documentation on this weighted
// finite-state transducer library.
//
// Classes for representing the mapping between state tuples and state IDs.
#ifndef FST_LIB_STATE_TABLE_H_
#define FST_LIB_STATE_TABLE_H_
#include <deque>
#include <utility>
#include <vector>
#include <fst/bi-table.h>
#include <fst/expanded-fst.h>
#include <fst/filter-state.h>
namespace fst {
// STATE TABLES - these determine the bijective mapping between state
// tuples (e.g. in composition triples of two FST states and a
// composition filter state) and their corresponding state IDs.
// They are classes, templated on state tuples, of the form:
//
// template <class T>
// class StateTable {
// public:
// typedef typename T StateTuple;
//
// // Required constructors.
// StateTable();
// StateTable(const StateTable &);
//
// // Lookup state ID by tuple. If it doesn't exist, then add it.
// StateId FindState(const StateTuple &);
// // Lookup state tuple by state ID.
// const StateTuple<StateId> &Tuple(StateId) const;
// // # of stored tuples.
// StateId Size() const;
// };
//
// A state tuple has the form:
//
// template <class S>
// struct StateTuple {
// typedef typename S StateId;
//
// // Required constructors.
// StateTuple();
// StateTuple(const StateTuple &);
// };
// An implementation using a hash map for the tuple to state ID mapping.
// The state tuple T must have == defined. H is the hash function.
template <class T, class H>
class HashStateTable : public HashBiTable<typename T::StateId, T, H> {
public:
typedef T StateTuple;
typedef typename StateTuple::StateId StateId;
using HashBiTable<StateId, T, H>::FindId;
using HashBiTable<StateId, T, H>::FindEntry;
using HashBiTable<StateId, T, H>::Size;
HashStateTable() : HashBiTable<StateId, T, H>() {}
// Reserves space for table_size elements.
explicit HashStateTable(size_t table_size)
: HashBiTable<StateId, T, H>(table_size) {}
StateId FindState(const StateTuple &tuple) { return FindId(tuple); }
const StateTuple &Tuple(StateId s) const { return FindEntry(s); }
};
// An implementation using a hash map for the tuple to state ID mapping.
// The state tuple T must have == defined. H is the hash function.
template <class T, class H>
class CompactHashStateTable
: public CompactHashBiTable<typename T::StateId, T, H> {
public:
typedef T StateTuple;
typedef typename StateTuple::StateId StateId;
using CompactHashBiTable<StateId, T, H>::FindId;
using CompactHashBiTable<StateId, T, H>::FindEntry;
using CompactHashBiTable<StateId, T, H>::Size;
CompactHashStateTable() : CompactHashBiTable<StateId, T, H>() {}
// Reserves space for 'table_size' elements.
explicit CompactHashStateTable(size_t table_size)
: CompactHashBiTable<StateId, T, H>(table_size) {}
StateId FindState(const StateTuple &tuple) { return FindId(tuple); }
const StateTuple &Tuple(StateId s) const { return FindEntry(s); }
};
// An implementation using a vector for the tuple to state mapping.
// It is passed a function object FP that should fingerprint tuples
// uniquely to an integer that can used as a vector index. Normally,
// VectorStateTable constructs the FP object. The user can instead
// pass in this object; in that case, VectorStateTable takes its
// ownership.
template <class T, class FP>
class VectorStateTable : public VectorBiTable<typename T::StateId, T, FP> {
public:
typedef T StateTuple;
typedef typename StateTuple::StateId StateId;
using VectorBiTable<StateId, T, FP>::FindId;
using VectorBiTable<StateId, T, FP>::FindEntry;
using VectorBiTable<StateId, T, FP>::Size;
using VectorBiTable<StateId, T, FP>::Fingerprint;
// Reserves space for 'table_size' elements.
explicit VectorStateTable(FP *fp = 0, size_t table_size = 0)
: VectorBiTable<StateId, T, FP>(fp, table_size) {}
StateId FindState(const StateTuple &tuple) { return FindId(tuple); }
const StateTuple &Tuple(StateId s) const { return FindEntry(s); }
};
// An implementation using a vector and a compact hash table. The
// selecting functor S returns true for tuples to be hashed in the
// vector. The fingerprinting functor FP returns a unique fingerprint
// for each tuple to be hashed in the vector (these need to be
// suitable for indexing in a vector). The hash functor H is used when
// hashing tuple into the compact hash table.
template <class T, class S, class FP, class H>
class VectorHashStateTable
: public VectorHashBiTable<typename T::StateId, T, S, FP, H> {
public:
typedef T StateTuple;
typedef typename StateTuple::StateId StateId;
using VectorHashBiTable<StateId, T, S, FP, H>::FindId;
using VectorHashBiTable<StateId, T, S, FP, H>::FindEntry;
using VectorHashBiTable<StateId, T, S, FP, H>::Size;
using VectorHashBiTable<StateId, T, S, FP, H>::Selector;
using VectorHashBiTable<StateId, T, S, FP, H>::Fingerprint;
using VectorHashBiTable<StateId, T, S, FP, H>::Hash;
VectorHashStateTable(S *s, FP *fp, H *h, size_t vector_size = 0,
size_t tuple_size = 0)
: VectorHashBiTable<StateId, T, S, FP, H>(s, fp, h, vector_size,
tuple_size) {}
StateId FindState(const StateTuple &tuple) { return FindId(tuple); }
const StateTuple &Tuple(StateId s) const { return FindEntry(s); }
};
// An implementation using a hash map for the tuple to state ID
// mapping. This version permits erasing of states. The state tuple T
// must have == defined and its default constructor must produce a
// tuple that will never be seen. F is the hash function.
template <class T, class F>
class ErasableStateTable : public ErasableBiTable<typename T::StateId, T, F> {
public:
typedef T StateTuple;
typedef typename StateTuple::StateId StateId;
using ErasableBiTable<StateId, T, F>::FindId;
using ErasableBiTable<StateId, T, F>::FindEntry;
using ErasableBiTable<StateId, T, F>::Size;
using ErasableBiTable<StateId, T, F>::Erase;
ErasableStateTable() : ErasableBiTable<StateId, T, F>() {}
StateId FindState(const StateTuple &tuple) { return FindId(tuple); }
const StateTuple &Tuple(StateId s) const { return FindEntry(s); }
};
//
// COMPOSITION STATE TUPLES AND TABLES
//
// The composition state table has the form:
//
// template <class A, class F>
// class ComposeStateTable {
// public:
// typedef A Arc;
// typedef F FilterState;
// typedef typename A::StateId StateId;
// typedef ComposeStateTuple<StateId> StateTuple;
//
// // Required constructors.
// ComposeStateTable(const Fst<Arc> &fst1, const Fst<Arc> &fst2);
// ComposeStateTable(const ComposeStateTable<A, F> &table);
// // Lookup state ID by tuple. If it doesn't exist, then add it.
// StateId FindState(const StateTuple &);
// // Lookup state tuple by state ID.
// const StateTuple<StateId> &Tuple(StateId) const;
// // # of stored tuples.
// StateId Size() const;
// // Return true if error encountered
// bool Error() const;
// };
// Represents the composition state.
//
// template <class S, class F>
// class StateTuple {
// public:
// typedef S StateId;
// typedef F FilterState;
// // Required constructors.
// StateTuple();
// StateTuple(StateId s1, StateId s2, const FilterState &f);
// StateId StateId1() const;
// StateId StateId2() const;
// FilterState GetFilterState() const;
// std::pair<StateId, StateId> StatePair() const;
// size_t Hash() const;
// friend bool operator==(const StateTuple& x, const StateTuple &y);
// }
//
template <typename S, typename F>
class DefaultComposeStateTuple {
public:
typedef S StateId;
typedef F FilterState;
DefaultComposeStateTuple()
: state_pair_(kNoStateId, kNoStateId),
filter_state_(FilterState::NoState()) {}
DefaultComposeStateTuple(StateId s1, StateId s2, const FilterState &f)
: state_pair_(s1, s2), filter_state_(f) {}
StateId StateId1() const { return state_pair_.first; }
StateId StateId2() const { return state_pair_.second; }
FilterState GetFilterState() const { return filter_state_; }
const std::pair<StateId, StateId> &StatePair() const { return state_pair_; }
friend bool operator==(const DefaultComposeStateTuple &x,
const DefaultComposeStateTuple &y) {
return (&x == &y) || (x.state_pair_ == y.state_pair_ &&
x.filter_state_ == y.filter_state_);
}
size_t Hash() const {
return StateId1() + StateId2() * 7853 + GetFilterState().Hash() * 7867;
}
private:
std::pair<StateId, StateId> state_pair_;
FilterState filter_state_; // State of composition filter
};
// Specialization for TrivialFilterState that does not explicitely store
// the filter state since it is always the unique non-blocking state.
template <typename S>
class DefaultComposeStateTuple<S, TrivialFilterState> {
public:
typedef S StateId;
typedef TrivialFilterState FilterState;
DefaultComposeStateTuple()
: state_pair_(kNoStateId, kNoStateId) {}
DefaultComposeStateTuple(StateId s1, StateId s2, const FilterState &)
: state_pair_(s1, s2) {}
StateId StateId1() const { return state_pair_.first; }
StateId StateId2() const { return state_pair_.second; }
FilterState GetFilterState() const { return TrivialFilterState(true); }
const std::pair<StateId, StateId> &StatePair() const { return state_pair_; }
friend bool operator==(const DefaultComposeStateTuple &x,
const DefaultComposeStateTuple &y) {
return (&x == &y) || (x.state_pair_ == y.state_pair_);
}
size_t Hash() const {
return StateId1() + StateId2() * 7853;
}
private:
std::pair<StateId, StateId> state_pair_;
};
// Hashing of composition state tuples.
template <typename T>
class ComposeHash {
public:
size_t operator()(const T &t) const { return t.Hash(); }
};
// A HashStateTable over composition tuples.
template <typename A, typename FS,
typename T = DefaultComposeStateTuple<typename A::StateId, FS>,
typename H = CompactHashStateTable<T, ComposeHash<T>> >
class GenericComposeStateTable : public H {
public:
typedef A Arc;
typedef FS FilterState;
typedef typename A::StateId StateId;
typedef T StateTuple;
GenericComposeStateTable(const Fst<A> &fst1, const Fst<A> &fst2) {}
// Reserves space for 'table_size' elements.
GenericComposeStateTable(const Fst<A> &fst1, const Fst<A> &fst2,
size_t table_size)
: H(table_size) {}
bool Error() const { return false; }
private:
void operator=(
const GenericComposeStateTable<A, FS, T, H> &table); // disallow
};
// Fingerprint for general composition tuples.
template <typename T>
class ComposeFingerprint {
public:
typedef T StateTuple;
typedef typename StateTuple::StateId StateId;
// Required but suboptimal constructor.
ComposeFingerprint() : mult1_(8192), mult2_(8192) {
LOG(WARNING) << "TupleFingerprint: # of FST states should be provided.";
}
// Constructor is provided the sizes of the input FSTs
ComposeFingerprint(StateId nstates1, StateId nstates2)
: mult1_(nstates1), mult2_(nstates1 * nstates2) {}
size_t operator()(const StateTuple &tuple) {
return tuple.StateId1() + tuple.StateId2() * mult1_ +
tuple.GetFilterState().Hash() * mult2_;
}
private:
ssize_t mult1_;
ssize_t mult2_;
};
// Useful when the first composition state determines the tuple.
template <typename T>
class ComposeState1Fingerprint {
public:
typedef T StateTuple;
size_t operator()(const StateTuple &tuple) { return tuple.StateId1(); }
};
// Useful when the second composition state determines the tuple.
template <typename T>
class ComposeState2Fingerprint {
public:
typedef T StateTuple;
size_t operator()(const StateTuple &tuple) { return tuple.StateId2(); }
};
// A VectorStateTable over composition tuples. This can be used when
// the product of number of states in FST1 and FST2 (and the
// composition filter state hash) is manageable. If the FSTs are not
// expanded Fsts, they will first have their states counted.
template <typename A, typename T>
class ProductComposeStateTable
: public VectorStateTable<T, ComposeFingerprint<T>> {
public:
typedef A Arc;
typedef typename A::StateId StateId;
typedef T StateTuple;
typedef VectorStateTable<StateTuple, ComposeFingerprint<StateTuple>>
StateTable;
// Reserves space for 'table_size' elements.
ProductComposeStateTable(const Fst<A> &fst1, const Fst<A> &fst2,
size_t table_size = 0)
: StateTable(new ComposeFingerprint<StateTuple>(CountStates(fst1),
CountStates(fst2)),
table_size) {}
ProductComposeStateTable(const ProductComposeStateTable<A, T> &table)
: StateTable(new ComposeFingerprint<StateTuple>(table.Fingerprint())) {}
bool Error() const { return false; }
private:
void operator=(const ProductComposeStateTable<A, T> &table); // disallow
};
// A VectorStateTable over composition tuples. This can be used when
// FST1 is a string (satisfies kStringProperties) and FST2 is
// epsilon-free and deterministic. It should be used with a
// composition filter that creates at most one filter state per tuple
// under these conditions (e.g. SequenceComposeFilter or
// MatchComposeFilter).
template <typename A, typename T>
class StringDetComposeStateTable
: public VectorStateTable<T, ComposeState1Fingerprint<T>> {
public:
typedef A Arc;
typedef typename A::StateId StateId;
typedef T StateTuple;
typedef VectorStateTable<StateTuple, ComposeState1Fingerprint<StateTuple>>
StateTable;
StringDetComposeStateTable(const Fst<A> &fst1, const Fst<A> &fst2)
: error_(false) {
uint64 props1 = kString;
uint64 props2 = kIDeterministic | kNoIEpsilons;
if (fst1.Properties(props1, true) != props1 ||
fst2.Properties(props2, true) != props2) {
FSTERROR() << "StringDetComposeStateTable: 1st Fst not a string or"
<< " 2nd Fst not output-deterministic and epsilon-free";
error_ = true;
}
}
StringDetComposeStateTable(const StringDetComposeStateTable<A, T> &table)
: StateTable(table), error_(table.error_) {}
bool Error() const { return error_; }
private:
bool error_;
void operator=(const StringDetComposeStateTable<A, T> &table); // disallow
};
// A VectorStateTable over composition tuples. This can be used when
// FST2 is a string (satisfies kStringProperties) and FST1 is
// epsilon-free and deterministic. It should be used with a
// composition filter that creates at most one filter state per tuple
// under these conditions (e.g. SequenceComposeFilter or
// MatchComposeFilter).
template <typename A, typename T>
class DetStringComposeStateTable
: public VectorStateTable<T, ComposeState2Fingerprint<T>> {
public:
typedef A Arc;
typedef typename A::StateId StateId;
typedef T StateTuple;
typedef VectorStateTable<StateTuple, ComposeState2Fingerprint<StateTuple>>
StateTable;
DetStringComposeStateTable(const Fst<A> &fst1, const Fst<A> &fst2)
: error_(false) {
uint64 props1 = kODeterministic | kNoOEpsilons;
uint64 props2 = kString;
if (fst1.Properties(props1, true) != props1 ||
fst2.Properties(props2, true) != props2) {
FSTERROR() << "StringDetComposeStateTable: 2nd Fst not a string or"
<< " 1st Fst not input deterministic and epsilon-free";
error_ = true;
}
}
DetStringComposeStateTable(const DetStringComposeStateTable<A, T> &table)
: StateTable(table), error_(table.error_) {}
bool Error() const { return error_; }
private:
bool error_;
void operator=(const DetStringComposeStateTable<A, T> &table); // disallow
};
// An ErasableStateTable over composition tuples. The Erase(StateId) method
// can be called if the user either is sure that composition will never return
// to that tuple or doesn't care that if it does, it is assigned a new
// state ID.
template <typename A, typename T>
class ErasableComposeStateTable
: public ErasableStateTable<T, ComposeHash<T>> {
public:
typedef A Arc;
typedef typename A::StateId StateId;
typedef T StateTuple;
ErasableComposeStateTable(const Fst<A> &fst1, const Fst<A> &fst2) {}
bool Error() const { return false; }
private:
void operator=(const ErasableComposeStateTable<A, T> &table); // disallow
};
} // namespace fst
#endif // FST_LIB_STATE_TABLE_H__
|