mirror of
https://github.com/moses-smt/mosesdecoder.git
synced 2024-12-27 05:55:02 +03:00
116 lines
4.3 KiB
C++
116 lines
4.3 KiB
C++
#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;
|
|
unsigned char lowest_niceness = 255;
|
|
// Select victim or return if complete.
|
|
{
|
|
Arity completed = 0;
|
|
for (Arity i = 0; i != arity; ++i) {
|
|
if (top_nt[i].Complete()) {
|
|
++completed;
|
|
} else if (top_nt[i].Niceness() < lowest_niceness) {
|
|
lowest_niceness = top_nt[i].Niceness();
|
|
victim = i;
|
|
victim_completed = completed;
|
|
}
|
|
}
|
|
if (lowest_niceness == 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);
|
|
}
|
|
|
|
#ifndef NDEBUG
|
|
Score before = top.GetScore();
|
|
#endif
|
|
// top is now the continuation.
|
|
FastScore(context, victim, victim - victim_completed, incomplete, old_value, top);
|
|
// TODO: dedupe?
|
|
generate_.push(top);
|
|
assert(lowest_niceness != 254 || top.GetScore() == before);
|
|
|
|
// 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
|