mirror of
https://github.com/moses-smt/mosesdecoder.git
synced 2024-12-27 14:05:29 +03:00
107 lines
3.5 KiB
C++
107 lines
3.5 KiB
C++
#include "search/nbest.hh"
|
|
|
|
#include "util/pool.hh"
|
|
#include "moses/Util.h"
|
|
|
|
#include <algorithm>
|
|
#include <functional>
|
|
#include <queue>
|
|
#include <cassert>
|
|
#include <cmath>
|
|
|
|
namespace search {
|
|
|
|
NBestList::NBestList(std::vector<PartialEdge> &partials, util::Pool &entry_pool, std::size_t keep) {
|
|
assert(!partials.empty());
|
|
std::vector<PartialEdge>::iterator end;
|
|
if (partials.size() > keep) {
|
|
end = partials.begin() + keep;
|
|
NTH_ELEMENT4(partials.begin(), end, partials.end(), std::greater<PartialEdge>());
|
|
} else {
|
|
end = partials.end();
|
|
}
|
|
for (std::vector<PartialEdge>::const_iterator i(partials.begin()); i != end; ++i) {
|
|
queue_.push(QueueEntry(entry_pool.Allocate(QueueEntry::Size(i->GetArity())), *i));
|
|
}
|
|
}
|
|
|
|
Score NBestList::TopAfterConstructor() const {
|
|
assert(revealed_.empty());
|
|
return queue_.top().GetScore();
|
|
}
|
|
|
|
const std::vector<Applied> &NBestList::Extract(util::Pool &pool, std::size_t n) {
|
|
while (revealed_.size() < n && !queue_.empty()) {
|
|
MoveTop(pool);
|
|
}
|
|
return revealed_;
|
|
}
|
|
|
|
Score NBestList::Visit(util::Pool &pool, std::size_t index) {
|
|
if (index + 1 < revealed_.size())
|
|
return revealed_[index + 1].GetScore() - revealed_[index].GetScore();
|
|
if (queue_.empty())
|
|
return -INFINITY;
|
|
if (index + 1 == revealed_.size())
|
|
return queue_.top().GetScore() - revealed_[index].GetScore();
|
|
assert(index == revealed_.size());
|
|
|
|
MoveTop(pool);
|
|
|
|
if (queue_.empty()) return -INFINITY;
|
|
return queue_.top().GetScore() - revealed_[index].GetScore();
|
|
}
|
|
|
|
Applied NBestList::Get(util::Pool &pool, std::size_t index) {
|
|
assert(index <= revealed_.size());
|
|
if (index == revealed_.size()) MoveTop(pool);
|
|
return revealed_[index];
|
|
}
|
|
|
|
void NBestList::MoveTop(util::Pool &pool) {
|
|
assert(!queue_.empty());
|
|
QueueEntry entry(queue_.top());
|
|
queue_.pop();
|
|
RevealedRef *const children_begin = entry.Children();
|
|
RevealedRef *const children_end = children_begin + entry.GetArity();
|
|
Score basis = entry.GetScore();
|
|
for (RevealedRef *child = children_begin; child != children_end; ++child) {
|
|
Score change = child->in_->Visit(pool, child->index_);
|
|
if (change != -INFINITY) {
|
|
assert(change < 0.001);
|
|
QueueEntry new_entry(pool.Allocate(QueueEntry::Size(entry.GetArity())), basis + change, entry.GetArity(), entry.GetNote(), entry.GetRange());
|
|
std::copy(children_begin, child, new_entry.Children());
|
|
RevealedRef *update = new_entry.Children() + (child - children_begin);
|
|
update->in_ = child->in_;
|
|
update->index_ = child->index_ + 1;
|
|
std::copy(child + 1, children_end, update + 1);
|
|
queue_.push(new_entry);
|
|
}
|
|
// Gesmundo, A. and Henderson, J. Faster Cube Pruning, IWSLT 2010.
|
|
if (child->index_) break;
|
|
}
|
|
|
|
// Convert QueueEntry to Applied. This leaves some unused memory.
|
|
void *overwrite = entry.Children();
|
|
for (unsigned int i = 0; i < entry.GetArity(); ++i) {
|
|
RevealedRef from(*(static_cast<const RevealedRef*>(overwrite) + i));
|
|
*(static_cast<Applied*>(overwrite) + i) = from.in_->Get(pool, from.index_);
|
|
}
|
|
revealed_.push_back(Applied(entry.Base()));
|
|
}
|
|
|
|
NBestComplete NBest::Complete(std::vector<PartialEdge> &partials) {
|
|
assert(!partials.empty());
|
|
NBestList *list = list_pool_.construct(partials, entry_pool_, config_.keep);
|
|
return NBestComplete(
|
|
list,
|
|
partials.front().CompletedState(), // All partials have the same state
|
|
list->TopAfterConstructor());
|
|
}
|
|
|
|
const std::vector<Applied> &NBest::Extract(History history) {
|
|
return static_cast<NBestList*>(history)->Extract(entry_pool_, config_.size);
|
|
}
|
|
|
|
} // namespace search
|