From 96a32415ab43377cf1575bd3f4f2980f58028209 Mon Sep 17 00:00:00 2001 From: Determinant Date: Fri, 14 Aug 2015 11:51:42 +0800 Subject: add implementation for kaldi io (by ymz) --- .../src/tools/openfst/include/fst/accumulator.h | 745 +++++++++++++++++++++ 1 file changed, 745 insertions(+) create mode 100644 kaldi_io/src/tools/openfst/include/fst/accumulator.h (limited to 'kaldi_io/src/tools/openfst/include/fst/accumulator.h') diff --git a/kaldi_io/src/tools/openfst/include/fst/accumulator.h b/kaldi_io/src/tools/openfst/include/fst/accumulator.h new file mode 100644 index 0000000..81d1847 --- /dev/null +++ b/kaldi_io/src/tools/openfst/include/fst/accumulator.h @@ -0,0 +1,745 @@ +// accumulator.h + +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// +// Copyright 2005-2010 Google, Inc. +// Author: riley@google.com (Michael Riley) +// +// \file +// Classes to accumulate arc weights. Useful for weight lookahead. + +#ifndef FST_LIB_ACCUMULATOR_H__ +#define FST_LIB_ACCUMULATOR_H__ + +#include +#include +#include +using std::tr1::unordered_map; +using std::tr1::unordered_multimap; +#include +using std::vector; + +#include +#include +#include +#include +#include + +namespace fst { + +// This class accumulates arc weights using the semiring Plus(). +template +class DefaultAccumulator { + public: + typedef A Arc; + typedef typename A::StateId StateId; + typedef typename A::Weight Weight; + + DefaultAccumulator() {} + + DefaultAccumulator(const DefaultAccumulator &acc) {} + + void Init(const Fst& fst, bool copy = false) {} + + void SetState(StateId) {} + + Weight Sum(Weight w, Weight v) { + return Plus(w, v); + } + + template + Weight Sum(Weight w, ArcIterator *aiter, ssize_t begin, + ssize_t end) { + Weight sum = w; + aiter->Seek(begin); + for (ssize_t pos = begin; pos < end; aiter->Next(), ++pos) + sum = Plus(sum, aiter->Value().weight); + return sum; + } + + bool Error() const { return false; } + + private: + void operator=(const DefaultAccumulator &); // Disallow +}; + + +// This class accumulates arc weights using the log semiring Plus() +// assuming an arc weight has a WeightConvert specialization to +// and from log64 weights. +template +class LogAccumulator { + public: + typedef A Arc; + typedef typename A::StateId StateId; + typedef typename A::Weight Weight; + + LogAccumulator() {} + + LogAccumulator(const LogAccumulator &acc) {} + + void Init(const Fst& fst, bool copy = false) {} + + void SetState(StateId) {} + + Weight Sum(Weight w, Weight v) { + return LogPlus(w, v); + } + + template + Weight Sum(Weight w, ArcIterator *aiter, ssize_t begin, + ssize_t end) { + Weight sum = w; + aiter->Seek(begin); + for (ssize_t pos = begin; pos < end; aiter->Next(), ++pos) + sum = LogPlus(sum, aiter->Value().weight); + return sum; + } + + bool Error() const { return false; } + + private: + double LogPosExp(double x) { return log(1.0F + exp(-x)); } + + Weight LogPlus(Weight w, Weight v) { + double f1 = to_log_weight_(w).Value(); + double f2 = to_log_weight_(v).Value(); + if (f1 > f2) + return to_weight_(f2 - LogPosExp(f1 - f2)); + else + return to_weight_(f1 - LogPosExp(f2 - f1)); + } + + WeightConvert to_log_weight_; + WeightConvert to_weight_; + + void operator=(const LogAccumulator &); // Disallow +}; + + +// Stores shareable data for fast log accumulator copies. +class FastLogAccumulatorData { + public: + FastLogAccumulatorData() {} + + vector *Weights() { return &weights_; } + vector *WeightPositions() { return &weight_positions_; } + double *WeightEnd() { return &(weights_[weights_.size() - 1]); }; + int RefCount() const { return ref_count_.count(); } + int IncrRefCount() { return ref_count_.Incr(); } + int DecrRefCount() { return ref_count_.Decr(); } + + private: + // Cummulative weight per state for all states s.t. # of arcs > + // arc_limit_ with arcs in order. Special first element per state + // being Log64Weight::Zero(); + vector weights_; + // Maps from state to corresponding beginning weight position in + // weights_. Position -1 means no pre-computed weights for that + // state. + vector weight_positions_; + RefCounter ref_count_; // Reference count. + + DISALLOW_COPY_AND_ASSIGN(FastLogAccumulatorData); +}; + + +// This class accumulates arc weights using the log semiring Plus() +// assuming an arc weight has a WeightConvert specialization to and +// from log64 weights. The member function Init(fst) has to be called +// to setup pre-computed weight information. +template +class FastLogAccumulator { + public: + typedef A Arc; + typedef typename A::StateId StateId; + typedef typename A::Weight Weight; + + explicit FastLogAccumulator(ssize_t arc_limit = 20, ssize_t arc_period = 10) + : arc_limit_(arc_limit), + arc_period_(arc_period), + data_(new FastLogAccumulatorData()), + error_(false) {} + + FastLogAccumulator(const FastLogAccumulator &acc) + : arc_limit_(acc.arc_limit_), + arc_period_(acc.arc_period_), + data_(acc.data_), + error_(acc.error_) { + data_->IncrRefCount(); + } + + ~FastLogAccumulator() { + if (!data_->DecrRefCount()) + delete data_; + } + + void SetState(StateId s) { + vector &weights = *data_->Weights(); + vector &weight_positions = *data_->WeightPositions(); + + if (weight_positions.size() <= s) { + FSTERROR() << "FastLogAccumulator::SetState: invalid state id."; + error_ = true; + return; + } + + ssize_t pos = weight_positions[s]; + if (pos >= 0) + state_weights_ = &(weights[pos]); + else + state_weights_ = 0; + } + + Weight Sum(Weight w, Weight v) { + return LogPlus(w, v); + } + + template + Weight Sum(Weight w, ArcIterator *aiter, ssize_t begin, + ssize_t end) { + if (error_) return Weight::NoWeight(); + Weight sum = w; + // Finds begin and end of pre-stored weights + ssize_t index_begin = -1, index_end = -1; + ssize_t stored_begin = end, stored_end = end; + if (state_weights_ != 0) { + index_begin = begin > 0 ? (begin - 1)/ arc_period_ + 1 : 0; + index_end = end / arc_period_; + stored_begin = index_begin * arc_period_; + stored_end = index_end * arc_period_; + } + // Computes sum before pre-stored weights + if (begin < stored_begin) { + ssize_t pos_end = min(stored_begin, end); + aiter->Seek(begin); + for (ssize_t pos = begin; pos < pos_end; aiter->Next(), ++pos) + sum = LogPlus(sum, aiter->Value().weight); + } + // Computes sum between pre-stored weights + if (stored_begin < stored_end) { + sum = LogPlus(sum, LogMinus(state_weights_[index_end], + state_weights_[index_begin])); + } + // Computes sum after pre-stored weights + if (stored_end < end) { + ssize_t pos_start = max(stored_begin, stored_end); + aiter->Seek(pos_start); + for (ssize_t pos = pos_start; pos < end; aiter->Next(), ++pos) + sum = LogPlus(sum, aiter->Value().weight); + } + return sum; + } + + template + void Init(const F &fst, bool copy = false) { + if (copy) + return; + vector &weights = *data_->Weights(); + vector &weight_positions = *data_->WeightPositions(); + if (!weights.empty() || arc_limit_ < arc_period_) { + FSTERROR() << "FastLogAccumulator: initialization error."; + error_ = true; + return; + } + weight_positions.reserve(CountStates(fst)); + + ssize_t weight_position = 0; + for(StateIterator siter(fst); !siter.Done(); siter.Next()) { + StateId s = siter.Value(); + if (fst.NumArcs(s) >= arc_limit_) { + double sum = FloatLimits::PosInfinity(); + weight_positions.push_back(weight_position); + weights.push_back(sum); + ++weight_position; + ssize_t narcs = 0; + for(ArcIterator aiter(fst, s); !aiter.Done(); aiter.Next()) { + const A &arc = aiter.Value(); + sum = LogPlus(sum, arc.weight); + // Stores cumulative weight distribution per arc_period_. + if (++narcs % arc_period_ == 0) { + weights.push_back(sum); + ++weight_position; + } + } + } else { + weight_positions.push_back(-1); + } + } + } + + bool Error() const { return error_; } + + private: + double LogPosExp(double x) { + return x == FloatLimits::PosInfinity() ? + 0.0 : log(1.0F + exp(-x)); + } + + double LogMinusExp(double x) { + return x == FloatLimits::PosInfinity() ? + 0.0 : log(1.0F - exp(-x)); + } + + Weight LogPlus(Weight w, Weight v) { + double f1 = to_log_weight_(w).Value(); + double f2 = to_log_weight_(v).Value(); + if (f1 > f2) + return to_weight_(f2 - LogPosExp(f1 - f2)); + else + return to_weight_(f1 - LogPosExp(f2 - f1)); + } + + double LogPlus(double f1, Weight v) { + double f2 = to_log_weight_(v).Value(); + if (f1 == FloatLimits::PosInfinity()) + return f2; + else if (f1 > f2) + return f2 - LogPosExp(f1 - f2); + else + return f1 - LogPosExp(f2 - f1); + } + + Weight LogMinus(double f1, double f2) { + if (f1 >= f2) { + FSTERROR() << "FastLogAcumulator::LogMinus: f1 >= f2 with f1 = " << f1 + << " and f2 = " << f2; + error_ = true; + return Weight::NoWeight(); + } + if (f2 == FloatLimits::PosInfinity()) + return to_weight_(f1); + else + return to_weight_(f1 - LogMinusExp(f2 - f1)); + } + + WeightConvert to_log_weight_; + WeightConvert to_weight_; + + ssize_t arc_limit_; // Minimum # of arcs to pre-compute state + ssize_t arc_period_; // Save cumulative weights per 'arc_period_'. + bool init_; // Cumulative weights initialized? + FastLogAccumulatorData *data_; + double *state_weights_; + bool error_; + + void operator=(const FastLogAccumulator &); // Disallow +}; + + +// Stores shareable data for cache log accumulator copies. +// All copies share the same cache. +template +class CacheLogAccumulatorData { + public: + typedef A Arc; + typedef typename A::StateId StateId; + typedef typename A::Weight Weight; + + CacheLogAccumulatorData(bool gc, size_t gc_limit) + : cache_gc_(gc), cache_limit_(gc_limit), cache_size_(0) {} + + ~CacheLogAccumulatorData() { + for(typename unordered_map::iterator it = cache_.begin(); + it != cache_.end(); + ++it) + delete it->second.weights; + } + + bool CacheDisabled() const { return cache_gc_ && cache_limit_ == 0; } + + vector *GetWeights(StateId s) { + typename unordered_map::iterator it = cache_.find(s); + if (it != cache_.end()) { + it->second.recent = true; + return it->second.weights; + } else { + return 0; + } + } + + void AddWeights(StateId s, vector *weights) { + if (cache_gc_ && cache_size_ >= cache_limit_) + GC(false); + cache_.insert(make_pair(s, CacheState(weights, true))); + if (cache_gc_) + cache_size_ += weights->capacity() * sizeof(double); + } + + int RefCount() const { return ref_count_.count(); } + int IncrRefCount() { return ref_count_.Incr(); } + int DecrRefCount() { return ref_count_.Decr(); } + + private: + // Cached information for a given state. + struct CacheState { + vector* weights; // Accumulated weights for this state. + bool recent; // Has this state been accessed since last GC? + + CacheState(vector *w, bool r) : weights(w), recent(r) {} + }; + + // Garbage collect: Delete from cache states that have not been + // accessed since the last GC ('free_recent = false') until + // 'cache_size_' is 2/3 of 'cache_limit_'. If it does not free enough + // memory, start deleting recently accessed states. + void GC(bool free_recent) { + size_t cache_target = (2 * cache_limit_)/3 + 1; + typename unordered_map::iterator it = cache_.begin(); + while (it != cache_.end() && cache_size_ > cache_target) { + CacheState &cs = it->second; + if (free_recent || !cs.recent) { + cache_size_ -= cs.weights->capacity() * sizeof(double); + delete cs.weights; + cache_.erase(it++); + } else { + cs.recent = false; + ++it; + } + } + if (!free_recent && cache_size_ > cache_target) + GC(true); + } + + unordered_map cache_; // Cache + bool cache_gc_; // Enable garbage collection + size_t cache_limit_; // # of bytes cached + size_t cache_size_; // # of bytes allowed before GC + RefCounter ref_count_; + + DISALLOW_COPY_AND_ASSIGN(CacheLogAccumulatorData); +}; + +// This class accumulates arc weights using the log semiring Plus() +// has a WeightConvert specialization to and from log64 weights. It +// is similar to the FastLogAccumator. However here, the accumulated +// weights are pre-computed and stored only for the states that are +// visited. The member function Init(fst) has to be called to setup +// this accumulator. +template +class CacheLogAccumulator { + public: + typedef A Arc; + typedef typename A::StateId StateId; + typedef typename A::Weight Weight; + + explicit CacheLogAccumulator(ssize_t arc_limit = 10, bool gc = false, + size_t gc_limit = 10 * 1024 * 1024) + : arc_limit_(arc_limit), fst_(0), data_( + new CacheLogAccumulatorData(gc, gc_limit)), s_(kNoStateId), + error_(false) {} + + CacheLogAccumulator(const CacheLogAccumulator &acc) + : arc_limit_(acc.arc_limit_), fst_(acc.fst_ ? acc.fst_->Copy() : 0), + data_(acc.data_), s_(kNoStateId), error_(acc.error_) { + data_->IncrRefCount(); + } + + ~CacheLogAccumulator() { + if (fst_) + delete fst_; + if (!data_->DecrRefCount()) + delete data_; + } + + // Arg 'arc_limit' specifies minimum # of arcs to pre-compute state. + void Init(const Fst &fst, bool copy = false) { + if (copy) { + delete fst_; + } else if (fst_) { + FSTERROR() << "CacheLogAccumulator: initialization error."; + error_ = true; + return; + } + fst_ = fst.Copy(); + } + + void SetState(StateId s, int depth = 0) { + if (s == s_) + return; + s_ = s; + + if (data_->CacheDisabled() || error_) { + weights_ = 0; + return; + } + + if (!fst_) { + FSTERROR() << "CacheLogAccumulator::SetState: incorrectly initialized."; + error_ = true; + weights_ = 0; + return; + } + + weights_ = data_->GetWeights(s); + if ((weights_ == 0) && (fst_->NumArcs(s) >= arc_limit_)) { + weights_ = new vector; + weights_->reserve(fst_->NumArcs(s) + 1); + weights_->push_back(FloatLimits::PosInfinity()); + data_->AddWeights(s, weights_); + } + } + + Weight Sum(Weight w, Weight v) { + return LogPlus(w, v); + } + + template + Weight Sum(Weight w, Iterator *aiter, ssize_t begin, + ssize_t end) { + if (weights_ == 0) { + Weight sum = w; + aiter->Seek(begin); + for (ssize_t pos = begin; pos < end; aiter->Next(), ++pos) + sum = LogPlus(sum, aiter->Value().weight); + return sum; + } else { + if (weights_->size() <= end) + for (aiter->Seek(weights_->size() - 1); + weights_->size() <= end; + aiter->Next()) + weights_->push_back(LogPlus(weights_->back(), + aiter->Value().weight)); + return LogPlus(w, LogMinus((*weights_)[end], (*weights_)[begin])); + } + } + + template + size_t LowerBound(double w, Iterator *aiter) { + if (weights_ != 0) { + return lower_bound(weights_->begin() + 1, + weights_->end(), + w, + std::greater()) + - weights_->begin() - 1; + } else { + size_t n = 0; + double x = FloatLimits::PosInfinity(); + for(aiter->Reset(); !aiter->Done(); aiter->Next(), ++n) { + x = LogPlus(x, aiter->Value().weight); + if (x < w) break; + } + return n; + } + } + + bool Error() const { return error_; } + + private: + double LogPosExp(double x) { + return x == FloatLimits::PosInfinity() ? + 0.0 : log(1.0F + exp(-x)); + } + + double LogMinusExp(double x) { + return x == FloatLimits::PosInfinity() ? + 0.0 : log(1.0F - exp(-x)); + } + + Weight LogPlus(Weight w, Weight v) { + double f1 = to_log_weight_(w).Value(); + double f2 = to_log_weight_(v).Value(); + if (f1 > f2) + return to_weight_(f2 - LogPosExp(f1 - f2)); + else + return to_weight_(f1 - LogPosExp(f2 - f1)); + } + + double LogPlus(double f1, Weight v) { + double f2 = to_log_weight_(v).Value(); + if (f1 == FloatLimits::PosInfinity()) + return f2; + else if (f1 > f2) + return f2 - LogPosExp(f1 - f2); + else + return f1 - LogPosExp(f2 - f1); + } + + Weight LogMinus(double f1, double f2) { + if (f1 >= f2) { + FSTERROR() << "CacheLogAcumulator::LogMinus: f1 >= f2 with f1 = " << f1 + << " and f2 = " << f2; + error_ = true; + return Weight::NoWeight(); + } + if (f2 == FloatLimits::PosInfinity()) + return to_weight_(f1); + else + return to_weight_(f1 - LogMinusExp(f2 - f1)); + } + + WeightConvert to_log_weight_; + WeightConvert to_weight_; + + ssize_t arc_limit_; // Minimum # of arcs to cache a state + vector *weights_; // Accumulated weights for cur. state + const Fst* fst_; // Input fst + CacheLogAccumulatorData *data_; // Cache data + StateId s_; // Current state + bool error_; + + void operator=(const CacheLogAccumulator &); // Disallow +}; + + +// Stores shareable data for replace accumulator copies. +template +class ReplaceAccumulatorData { + public: + typedef typename Accumulator::Arc Arc; + typedef typename Arc::StateId StateId; + typedef typename Arc::Label Label; + typedef T StateTable; + typedef typename T::StateTuple StateTuple; + + ReplaceAccumulatorData() : state_table_(0) {} + + ReplaceAccumulatorData(const vector &accumulators) + : state_table_(0), accumulators_(accumulators) {} + + ~ReplaceAccumulatorData() { + for (size_t i = 0; i < fst_array_.size(); ++i) + delete fst_array_[i]; + for (size_t i = 0; i < accumulators_.size(); ++i) + delete accumulators_[i]; + } + + void Init(const vector*> > &fst_tuples, + const StateTable *state_table) { + state_table_ = state_table; + accumulators_.resize(fst_tuples.size()); + for (size_t i = 0; i < accumulators_.size(); ++i) { + if (!accumulators_[i]) + accumulators_[i] = new Accumulator; + accumulators_[i]->Init(*(fst_tuples[i].second)); + fst_array_.push_back(fst_tuples[i].second->Copy()); + } + } + + const StateTuple &GetTuple(StateId s) const { + return state_table_->Tuple(s); + } + + Accumulator *GetAccumulator(size_t i) { return accumulators_[i]; } + + const Fst *GetFst(size_t i) const { return fst_array_[i]; } + + int RefCount() const { return ref_count_.count(); } + int IncrRefCount() { return ref_count_.Incr(); } + int DecrRefCount() { return ref_count_.Decr(); } + + private: + const T * state_table_; + vector accumulators_; + vector*> fst_array_; + RefCounter ref_count_; + + DISALLOW_COPY_AND_ASSIGN(ReplaceAccumulatorData); +}; + +// This class accumulates weights in a ReplaceFst. The 'Init' method +// takes as input the argument used to build the ReplaceFst and the +// ReplaceFst state table. It uses accumulators of type 'Accumulator' +// in the underlying FSTs. +template > +class ReplaceAccumulator { + public: + typedef typename Accumulator::Arc Arc; + typedef typename Arc::StateId StateId; + typedef typename Arc::Label Label; + typedef typename Arc::Weight Weight; + typedef T StateTable; + typedef typename T::StateTuple StateTuple; + + ReplaceAccumulator() + : init_(false), data_(new ReplaceAccumulatorData()), + error_(false) {} + + ReplaceAccumulator(const vector &accumulators) + : init_(false), + data_(new ReplaceAccumulatorData(accumulators)), + error_(false) {} + + ReplaceAccumulator(const ReplaceAccumulator &acc) + : init_(acc.init_), data_(acc.data_), error_(acc.error_) { + if (!init_) + FSTERROR() << "ReplaceAccumulator: can't copy unintialized accumulator"; + data_->IncrRefCount(); + } + + ~ReplaceAccumulator() { + if (!data_->DecrRefCount()) + delete data_; + } + + // Does not take ownership of the state table, the state table + // is own by the ReplaceFst + void Init(const vector*> > &fst_tuples, + const StateTable *state_table) { + init_ = true; + data_->Init(fst_tuples, state_table); + } + + void SetState(StateId s) { + if (!init_) { + FSTERROR() << "ReplaceAccumulator::SetState: incorrectly initialized."; + error_ = true; + return; + } + StateTuple tuple = data_->GetTuple(s); + fst_id_ = tuple.fst_id - 1; // Replace FST ID is 1-based + data_->GetAccumulator(fst_id_)->SetState(tuple.fst_state); + if ((tuple.prefix_id != 0) && + (data_->GetFst(fst_id_)->Final(tuple.fst_state) != Weight::Zero())) { + offset_ = 1; + offset_weight_ = data_->GetFst(fst_id_)->Final(tuple.fst_state); + } else { + offset_ = 0; + offset_weight_ = Weight::Zero(); + } + } + + Weight Sum(Weight w, Weight v) { + if (error_) return Weight::NoWeight(); + return data_->GetAccumulator(fst_id_)->Sum(w, v); + } + + template + Weight Sum(Weight w, ArcIterator *aiter, ssize_t begin, + ssize_t end) { + if (error_) return Weight::NoWeight(); + Weight sum = begin == end ? Weight::Zero() + : data_->GetAccumulator(fst_id_)->Sum( + w, aiter, begin ? begin - offset_ : 0, end - offset_); + if (begin == 0 && end != 0 && offset_ > 0) + sum = Sum(offset_weight_, sum); + return sum; + } + + bool Error() const { return error_; } + + private: + bool init_; + ReplaceAccumulatorData *data_; + Label fst_id_; + size_t offset_; + Weight offset_weight_; + bool error_; + + void operator=(const ReplaceAccumulator &); // Disallow +}; + +} // namespace fst + +#endif // FST_LIB_ACCUMULATOR_H__ -- cgit v1.2.3-70-g09d2