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-rw-r--r--decoder/ff_klm.cc289
1 files changed, 106 insertions, 183 deletions
diff --git a/decoder/ff_klm.cc b/decoder/ff_klm.cc
index 24dcb9c3..ed6f731e 100644
--- a/decoder/ff_klm.cc
+++ b/decoder/ff_klm.cc
@@ -12,11 +12,9 @@
#include "lm/model.hh"
#include "lm/enumerate_vocab.hh"
-using namespace std;
+#include "lm/left.hh"
-static const unsigned char HAS_FULL_CONTEXT = 1;
-static const unsigned char HAS_EOS_ON_RIGHT = 2;
-static const unsigned char MASK = 7;
+using namespace std;
// -x : rules include <s> and </s>
// -n NAME : feature id is NAME
@@ -70,6 +68,8 @@ string KLanguageModel<Model>::usage(bool /*param*/,bool /*verbose*/) {
return "KLanguageModel";
}
+namespace {
+
struct VMapper : public lm::ngram::EnumerateVocab {
VMapper(vector<lm::WordIndex>* out) : out_(out), kLM_UNKNOWN_TOKEN(0) { out_->clear(); }
void Add(lm::WordIndex index, const StringPiece &str) {
@@ -82,181 +82,122 @@ struct VMapper : public lm::ngram::EnumerateVocab {
const lm::WordIndex kLM_UNKNOWN_TOKEN;
};
-template <class Model>
-class KLanguageModelImpl {
+#pragma pack(push)
+#pragma pack(1)
- // returns the number of unscored words at the left edge of a span
- inline int UnscoredSize(const void* state) const {
- return *(static_cast<const char*>(state) + unscored_size_offset_);
- }
-
- inline void SetUnscoredSize(int size, void* state) const {
- *(static_cast<char*>(state) + unscored_size_offset_) = size;
- }
+struct BoundaryAnnotatedState {
+ lm::ngram::ChartState state;
+ bool seen_bos, seen_eos;
+};
- static inline const lm::ngram::State& RemnantLMState(const void* state) {
- return *static_cast<const lm::ngram::State*>(state);
- }
+#pragma pack(pop)
+
+template <class Model> class BoundaryRuleScore {
+ public:
+ BoundaryRuleScore(const Model &m, BoundaryAnnotatedState &state) :
+ back_(m, state.state),
+ bos_(state.seen_bos),
+ eos_(state.seen_eos),
+ penalty_(0.0),
+ end_sentence_(m.GetVocabulary().EndSentence()) {
+ bos_ = false;
+ eos_ = false;
+ }
- inline void SetRemnantLMState(const lm::ngram::State& lmstate, void* state) const {
- // if we were clever, we could use the memory pointed to by state to do all
- // the work, avoiding this copy
- memcpy(state, &lmstate, ngram_->StateSize());
- }
+ void BeginSentence() {
+ back_.BeginSentence();
+ bos_ = true;
+ }
- lm::WordIndex IthUnscoredWord(int i, const void* state) const {
- const lm::WordIndex* const mem = reinterpret_cast<const lm::WordIndex*>(static_cast<const char*>(state) + unscored_words_offset_);
- return mem[i];
- }
+ void BeginNonTerminal(const BoundaryAnnotatedState &sub) {
+ back_.BeginNonTerminal(sub.state, 0.0f);
+ bos_ = sub.seen_bos;
+ eos_ = sub.seen_eos;
+ }
- void SetIthUnscoredWord(int i, lm::WordIndex index, void *state) const {
- lm::WordIndex* mem = reinterpret_cast<lm::WordIndex*>(static_cast<char*>(state) + unscored_words_offset_);
- mem[i] = index;
- }
+ void NonTerminal(const BoundaryAnnotatedState &sub) {
+ back_.NonTerminal(sub.state, 0.0f);
+ // cdec only calls this if there's content.
+ if (sub.seen_bos) {
+ bos_ = true;
+ penalty_ -= 100.0f;
+ }
+ if (eos_) penalty_ -= 100.0f;
+ eos_ |= sub.seen_eos;
+ }
- inline bool GetFlag(const void *state, unsigned char flag) const {
- return (*(static_cast<const char*>(state) + is_complete_offset_) & flag);
- }
+ void Terminal(lm::WordIndex word) {
+ back_.Terminal(word);
+ if (eos_) penalty_ -= 100.0f;
+ if (word == end_sentence_) eos_ = true;
+ }
- inline void SetFlag(bool on, unsigned char flag, void *state) const {
- if (on) {
- *(static_cast<char*>(state) + is_complete_offset_) |= flag;
- } else {
- *(static_cast<char*>(state) + is_complete_offset_) &= (MASK ^ flag);
+ float Finish() {
+ return penalty_ + back_.Finish();
}
- }
- inline bool HasFullContext(const void *state) const {
- return GetFlag(state, HAS_FULL_CONTEXT);
- }
+ private:
+ lm::ngram::RuleScore<Model> back_;
+ bool &bos_, &eos_;
- inline void SetHasFullContext(bool flag, void *state) const {
- SetFlag(flag, HAS_FULL_CONTEXT, state);
- }
+ float penalty_;
+
+ lm::WordIndex end_sentence_;
+};
+
+} // namespace
+template <class Model>
+class KLanguageModelImpl {
public:
- double LookupWords(const TRule& rule, const vector<const void*>& ant_states, double* pest_sum, double* oovs, double* est_oovs, void* remnant) {
- double sum = 0.0;
- double est_sum = 0.0;
- int num_scored = 0;
- int num_estimated = 0;
- if (oovs) *oovs = 0;
- if (est_oovs) *est_oovs = 0;
- bool saw_eos = false;
- bool has_some_history = false;
- lm::ngram::State state = ngram_->NullContextState();
+ double LookupWords(const TRule& rule, const vector<const void*>& ant_states, double* oovs, void* remnant) {
+ *oovs = 0;
const vector<WordID>& e = rule.e();
- bool context_complete = false;
- for (int j = 0; j < e.size(); ++j) {
- if (e[j] < 1) { // handle non-terminal substitution
- const void* astate = (ant_states[-e[j]]);
- int unscored_ant_len = UnscoredSize(astate);
- for (int k = 0; k < unscored_ant_len; ++k) {
- const lm::WordIndex cur_word = IthUnscoredWord(k, astate);
- const bool is_oov = (cur_word == 0);
- double p = 0;
- if (cur_word == kSOS_) {
- state = ngram_->BeginSentenceState();
- if (has_some_history) { // this is immediately fully scored, and bad
- p = -100;
- context_complete = true;
- } else { // this might be a real <s>
- num_scored = max(0, order_ - 2);
- }
- } else {
- const lm::ngram::State scopy(state);
- p = ngram_->Score(scopy, cur_word, state);
- if (saw_eos) { p = -100; }
- saw_eos = (cur_word == kEOS_);
- }
- has_some_history = true;
- ++num_scored;
- if (!context_complete) {
- if (num_scored >= order_) context_complete = true;
- }
- if (context_complete) {
- sum += p;
- if (oovs && is_oov) (*oovs)++;
- } else {
- if (remnant)
- SetIthUnscoredWord(num_estimated, cur_word, remnant);
- ++num_estimated;
- est_sum += p;
- if (est_oovs && is_oov) (*est_oovs)++;
- }
- }
- saw_eos = GetFlag(astate, HAS_EOS_ON_RIGHT);
- if (HasFullContext(astate)) { // this is equivalent to the "star" in Chiang 2007
- state = RemnantLMState(astate);
- context_complete = true;
- }
- } else { // handle terminal
- const WordID cdec_word_or_class = ClassifyWordIfNecessary(e[j]); // in future,
+ BoundaryRuleScore<Model> ruleScore(*ngram_, *static_cast<BoundaryAnnotatedState*>(remnant));
+ unsigned i = 0;
+ if (e.size()) {
+ if (e[i] == kCDEC_SOS) {
+ ++i;
+ ruleScore.BeginSentence();
+ } else if (e[i] <= 0) { // special case for left-edge NT
+ ruleScore.BeginNonTerminal(*static_cast<const BoundaryAnnotatedState*>(ant_states[-e[0]]));
+ ++i;
+ }
+ }
+ for (; i < e.size(); ++i) {
+ if (e[i] <= 0) {
+ ruleScore.NonTerminal(*static_cast<const BoundaryAnnotatedState*>(ant_states[-e[i]]));
+ } else {
+ const WordID cdec_word_or_class = ClassifyWordIfNecessary(e[i]); // in future,
// maybe handle emission
const lm::WordIndex cur_word = MapWord(cdec_word_or_class); // map to LM's id
- double p = 0;
- const bool is_oov = (cur_word == 0);
- if (cur_word == kSOS_) {
- state = ngram_->BeginSentenceState();
- if (has_some_history) { // this is immediately fully scored, and bad
- p = -100;
- context_complete = true;
- } else { // this might be a real <s>
- num_scored = max(0, order_ - 2);
- }
- } else {
- const lm::ngram::State scopy(state);
- p = ngram_->Score(scopy, cur_word, state);
- if (saw_eos) { p = -100; }
- saw_eos = (cur_word == kEOS_);
- }
- has_some_history = true;
- ++num_scored;
- if (!context_complete) {
- if (num_scored >= order_) context_complete = true;
- }
- if (context_complete) {
- sum += p;
- if (oovs && is_oov) (*oovs)++;
- } else {
- if (remnant)
- SetIthUnscoredWord(num_estimated, cur_word, remnant);
- ++num_estimated;
- est_sum += p;
- if (est_oovs && is_oov) (*est_oovs)++;
- }
+ if (cur_word == 0) (*oovs) += 1.0;
+ ruleScore.Terminal(cur_word);
}
}
- if (pest_sum) *pest_sum = est_sum;
- if (remnant) {
- state.ZeroRemaining();
- SetFlag(saw_eos, HAS_EOS_ON_RIGHT, remnant);
- SetRemnantLMState(state, remnant);
- SetUnscoredSize(num_estimated, remnant);
- SetHasFullContext(context_complete || (num_scored >= order_), remnant);
- }
- return sum;
+ double ret = ruleScore.Finish();
+ static_cast<BoundaryAnnotatedState*>(remnant)->state.ZeroRemaining();
+ return ret;
}
// this assumes no target words on final unary -> goal rule. is that ok?
// for <s> (n-1 left words) and (n-1 right words) </s>
- double FinalTraversalCost(const void* state, double* oovs) {
+ double FinalTraversalCost(const void* state_void, double* oovs) {
+ const BoundaryAnnotatedState &annotated = *static_cast<const BoundaryAnnotatedState*>(state_void);
if (add_sos_eos_) { // rules do not produce <s> </s>, so do it here
- SetRemnantLMState(ngram_->BeginSentenceState(), dummy_state_);
- SetHasFullContext(1, dummy_state_);
- SetUnscoredSize(0, dummy_state_);
- dummy_ants_[1] = state;
- *oovs = 0;
- return LookupWords(*dummy_rule_, dummy_ants_, NULL, oovs, NULL, NULL);
+ assert(!annotated.seen_bos);
+ assert(!annotated.seen_eos);
+ lm::ngram::ChartState cstate;
+ lm::ngram::RuleScore<Model> ruleScore(*ngram_, cstate);
+ ruleScore.BeginSentence();
+ ruleScore.NonTerminal(annotated.state, 0.0f);
+ ruleScore.Terminal(kEOS_);
+ return ruleScore.Finish();
} else { // rules DO produce <s> ... </s>
- double p = 0;
- if (!GetFlag(state, HAS_EOS_ON_RIGHT)) { p -= 100; }
- if (UnscoredSize(state) > 0) { // are there unscored words
- if (kSOS_ != IthUnscoredWord(0, state)) {
- p -= 100 * UnscoredSize(state);
- }
- }
- return p;
+ double ret = 0.0;
+ if (!annotated.seen_bos) ret -= 100.0;
+ if (!annotated.seen_eos) ret -= 100.0;
+ return ret;
}
}
@@ -282,6 +223,7 @@ class KLanguageModelImpl {
public:
KLanguageModelImpl(const string& filename, const string& mapfile, bool explicit_markers) :
kCDEC_UNK(TD::Convert("<unk>")) ,
+ kCDEC_SOS(TD::Convert("<s>")) ,
add_sos_eos_(!explicit_markers) {
{
VMapper vm(&cdec2klm_map_);
@@ -291,18 +233,9 @@ class KLanguageModelImpl {
}
order_ = ngram_->Order();
cerr << "Loaded " << order_ << "-gram KLM from " << filename << " (MapSize=" << cdec2klm_map_.size() << ")\n";
- state_size_ = ngram_->StateSize() + 2 + (order_ - 1) * sizeof(lm::WordIndex);
- unscored_size_offset_ = ngram_->StateSize();
- is_complete_offset_ = unscored_size_offset_ + 1;
- unscored_words_offset_ = is_complete_offset_ + 1;
// special handling of beginning / ending sentence markers
- dummy_state_ = new char[state_size_];
- memset(dummy_state_, 0, state_size_);
- dummy_ants_.push_back(dummy_state_);
- dummy_ants_.push_back(NULL);
- dummy_rule_.reset(new TRule("[DUMMY] ||| [BOS] [DUMMY] ||| [1] [2] </s> ||| X=0"));
- kSOS_ = MapWord(TD::Convert("<s>"));
+ kSOS_ = MapWord(kCDEC_SOS);
assert(kSOS_ > 0);
kEOS_ = MapWord(TD::Convert("</s>"));
assert(kEOS_ > 0);
@@ -350,13 +283,13 @@ class KLanguageModelImpl {
~KLanguageModelImpl() {
delete ngram_;
- delete[] dummy_state_;
}
- int ReserveStateSize() const { return state_size_; }
+ int ReserveStateSize() const { return sizeof(BoundaryAnnotatedState); }
private:
const WordID kCDEC_UNK;
+ const WordID kCDEC_SOS;
lm::WordIndex kSOS_; // <s> - requires special handling.
lm::WordIndex kEOS_; // </s>
Model* ngram_;
@@ -367,15 +300,8 @@ class KLanguageModelImpl {
// the sentence) with 0, and anything else with -100
int order_;
- int state_size_;
- int unscored_size_offset_;
- int is_complete_offset_;
- int unscored_words_offset_;
- char* dummy_state_;
- vector<const void*> dummy_ants_;
vector<lm::WordIndex> cdec2klm_map_;
vector<WordID> word2class_map_; // if this is a class-based LM, this is the word->class mapping
- TRulePtr dummy_rule_;
};
template <class Model>
@@ -393,7 +319,7 @@ KLanguageModel<Model>::KLanguageModel(const string& param) {
}
fid_ = FD::Convert(featname);
oov_fid_ = FD::Convert(featname+"_OOV");
- cerr << "FID: " << oov_fid_ << endl;
+ // cerr << "FID: " << oov_fid_ << endl;
SetStateSize(pimpl_->ReserveStateSize());
}
@@ -416,13 +342,9 @@ void KLanguageModel<Model>::TraversalFeaturesImpl(const SentenceMetadata& /* sme
void* state) const {
double est = 0;
double oovs = 0;
- double est_oovs = 0;
- features->set_value(fid_, pimpl_->LookupWords(*edge.rule_, ant_states, &est, &oovs, &est_oovs, state));
- estimated_features->set_value(fid_, est);
- if (oov_fid_) {
- if (oovs) features->set_value(oov_fid_, oovs);
- if (est_oovs) estimated_features->set_value(oov_fid_, est_oovs);
- }
+ features->set_value(fid_, pimpl_->LookupWords(*edge.rule_, ant_states, &oovs, state));
+ if (oovs && oov_fid_)
+ features->set_value(oov_fid_, oovs);
}
template <class Model>
@@ -469,3 +391,4 @@ boost::shared_ptr<FeatureFunction> KLanguageModelFactory::Create(std::string par
std::string KLanguageModelFactory::usage(bool params,bool verbose) const {
return KLanguageModel<lm::ngram::Model>::usage(params, verbose);
}
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-29 14:00:36 +0000