diff options
author | Avneesh Saluja <asaluja@gmail.com> | 2013-03-28 18:28:16 -0700 |
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committer | Avneesh Saluja <asaluja@gmail.com> | 2013-03-28 18:28:16 -0700 |
commit | 3d8d656fa7911524e0e6885647173474524e0784 (patch) | |
tree | 81b1ee2fcb67980376d03f0aa48e42e53abff222 /klm/search/edge_generator.cc | |
parent | be7f57fdd484e063775d7abf083b9fa4c403b610 (diff) | |
parent | 96fedabebafe7a38a6d5928be8fff767e411d705 (diff) |
fixed conflicts
Diffstat (limited to 'klm/search/edge_generator.cc')
-rw-r--r-- | klm/search/edge_generator.cc | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/klm/search/edge_generator.cc b/klm/search/edge_generator.cc new file mode 100644 index 00000000..eacf5de5 --- /dev/null +++ b/klm/search/edge_generator.cc @@ -0,0 +1,111 @@ +#include "search/edge_generator.hh" + +#include "lm/left.hh" +#include "lm/model.hh" +#include "lm/partial.hh" +#include "search/context.hh" +#include "search/vertex.hh" + +#include <numeric> + +namespace search { + +namespace { + +template <class Model> void FastScore(const Context<Model> &context, Arity victim, Arity before_idx, Arity incomplete, const PartialVertex &previous_vertex, PartialEdge update) { + lm::ngram::ChartState *between = update.Between(); + lm::ngram::ChartState *before = &between[before_idx], *after = &between[before_idx + 1]; + + float adjustment = 0.0; + const lm::ngram::ChartState &previous_reveal = previous_vertex.State(); + const PartialVertex &update_nt = update.NT()[victim]; + const lm::ngram::ChartState &update_reveal = update_nt.State(); + if ((update_reveal.left.length > previous_reveal.left.length) || (update_reveal.left.full && !previous_reveal.left.full)) { + adjustment += lm::ngram::RevealAfter(context.LanguageModel(), before->left, before->right, update_reveal.left, previous_reveal.left.length); + } + if ((update_reveal.right.length > previous_reveal.right.length) || (update_nt.RightFull() && !previous_vertex.RightFull())) { + adjustment += lm::ngram::RevealBefore(context.LanguageModel(), update_reveal.right, previous_reveal.right.length, update_nt.RightFull(), after->left, after->right); + } + if (update_nt.Complete()) { + if (update_reveal.left.full) { + before->left.full = true; + } else { + assert(update_reveal.left.length == update_reveal.right.length); + adjustment += lm::ngram::Subsume(context.LanguageModel(), before->left, before->right, after->left, after->right, update_reveal.left.length); + } + before->right = after->right; + // Shift the others shifted one down, covering after. + for (lm::ngram::ChartState *cover = after; cover < between + incomplete; ++cover) { + *cover = *(cover + 1); + } + } + update.SetScore(update.GetScore() + adjustment * context.LMWeight()); +} + +} // namespace + +template <class Model> PartialEdge EdgeGenerator::Pop(Context<Model> &context) { + assert(!generate_.empty()); + PartialEdge top = generate_.top(); + generate_.pop(); + PartialVertex *const top_nt = top.NT(); + const Arity arity = top.GetArity(); + + Arity victim = 0; + Arity victim_completed; + Arity incomplete; + // Select victim or return if complete. + { + Arity completed = 0; + unsigned char lowest_length = 255; + for (Arity i = 0; i != arity; ++i) { + if (top_nt[i].Complete()) { + ++completed; + } else if (top_nt[i].Length() < lowest_length) { + lowest_length = top_nt[i].Length(); + victim = i; + victim_completed = completed; + } + } + if (lowest_length == 255) { + return top; + } + incomplete = arity - completed; + } + + PartialVertex old_value(top_nt[victim]); + PartialVertex alternate_changed; + if (top_nt[victim].Split(alternate_changed)) { + PartialEdge alternate(partial_edge_pool_, arity, incomplete + 1); + alternate.SetScore(top.GetScore() + alternate_changed.Bound() - old_value.Bound()); + + alternate.SetNote(top.GetNote()); + + PartialVertex *alternate_nt = alternate.NT(); + for (Arity i = 0; i < victim; ++i) alternate_nt[i] = top_nt[i]; + alternate_nt[victim] = alternate_changed; + for (Arity i = victim + 1; i < arity; ++i) alternate_nt[i] = top_nt[i]; + + memcpy(alternate.Between(), top.Between(), sizeof(lm::ngram::ChartState) * (incomplete + 1)); + + // TODO: dedupe? + generate_.push(alternate); + } + + // top is now the continuation. + FastScore(context, victim, victim - victim_completed, incomplete, old_value, top); + // TODO: dedupe? + generate_.push(top); + + // Invalid indicates no new hypothesis generated. + return PartialEdge(); +} + +template PartialEdge EdgeGenerator::Pop(Context<lm::ngram::RestProbingModel> &context); +template PartialEdge EdgeGenerator::Pop(Context<lm::ngram::ProbingModel> &context); +template PartialEdge EdgeGenerator::Pop(Context<lm::ngram::TrieModel> &context); +template PartialEdge EdgeGenerator::Pop(Context<lm::ngram::QuantTrieModel> &context); +template PartialEdge EdgeGenerator::Pop(Context<lm::ngram::ArrayTrieModel> &context); +template PartialEdge EdgeGenerator::Pop(Context<lm::ngram::QuantArrayTrieModel> &context); + +} // namespace search |