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authorKenneth Heafield <github@kheafield.com>2012-12-14 12:39:04 -0800
committerKenneth Heafield <github@kheafield.com>2012-12-14 12:39:04 -0800
commitde53e2e98acd0e2d07efb39bef430bd598908aa8 (patch)
treed6b4b8f72c9a417a371c90dcd17071f0f9e6440d /klm/search/vertex_generator.hh
parent7b61618f1c9d7704bb6791b9098871ec1fbdce89 (diff)
Updated incremental, updated kenlm. Incremental assumes <s>
Diffstat (limited to 'klm/search/vertex_generator.hh')
-rw-r--r--klm/search/vertex_generator.hh72
1 files changed, 62 insertions, 10 deletions
diff --git a/klm/search/vertex_generator.hh b/klm/search/vertex_generator.hh
index 60e86112..da563c2d 100644
--- a/klm/search/vertex_generator.hh
+++ b/klm/search/vertex_generator.hh
@@ -2,9 +2,11 @@
#define SEARCH_VERTEX_GENERATOR__
#include "search/edge.hh"
+#include "search/types.hh"
#include "search/vertex.hh"
#include <boost/unordered_map.hpp>
+#include <boost/version.hpp>
namespace lm {
namespace ngram {
@@ -15,21 +17,44 @@ class ChartState;
namespace search {
class ContextBase;
-class Final;
-class VertexGenerator {
+#if BOOST_VERSION > 104200
+// Parallel structure to VertexNode.
+struct Trie {
+ Trie() : under(NULL) {}
+
+ VertexNode *under;
+ boost::unordered_map<uint64_t, Trie> extend;
+};
+
+void AddHypothesis(ContextBase &context, Trie &root, const NBestComplete &end);
+
+#endif // BOOST_VERSION
+
+// Output makes the single-best or n-best list.
+template <class Output> class VertexGenerator {
public:
- VertexGenerator(ContextBase &context, Vertex &gen);
+ VertexGenerator(ContextBase &context, Vertex &gen, Output &nbest) : context_(context), gen_(gen), nbest_(nbest) {
+ gen.root_.InitRoot();
+ }
void NewHypothesis(PartialEdge partial) {
- const lm::ngram::ChartState &state = partial.CompletedState();
- std::pair<Existing::iterator, bool> ret(existing_.insert(std::make_pair(hash_value(state), partial)));
- if (!ret.second && ret.first->second < partial) {
- ret.first->second = partial;
- }
+ nbest_.Add(existing_[hash_value(partial.CompletedState())], partial);
}
- void FinishedSearch();
+ void FinishedSearch() {
+#if BOOST_VERSION > 104200
+ Trie root;
+ root.under = &gen_.root_;
+ for (typename Existing::iterator i(existing_.begin()); i != existing_.end(); ++i) {
+ AddHypothesis(context_, root, nbest_.Complete(i->second));
+ }
+ existing_.clear();
+ root.under->SortAndSet(context_);
+#else
+ UTIL_THROW(util::Exception, "Upgrade Boost to >= 1.42.0 to use incremental search.");
+#endif
+ }
const Vertex &Generating() const { return gen_; }
@@ -38,8 +63,35 @@ class VertexGenerator {
Vertex &gen_;
- typedef boost::unordered_map<uint64_t, PartialEdge> Existing;
+ typedef boost::unordered_map<uint64_t, typename Output::Combine> Existing;
Existing existing_;
+
+ Output &nbest_;
+};
+
+// Special case for root vertex: everything should come together into the root
+// node. In theory, this should happen naturally due to state collapsing with
+// <s> and </s>. If that's the case, VertexGenerator is fine, though it will
+// make one connection.
+template <class Output> class RootVertexGenerator {
+ public:
+ RootVertexGenerator(Vertex &gen, Output &out) : gen_(gen), out_(out) {}
+
+ void NewHypothesis(PartialEdge partial) {
+ out_.Add(combine_, partial);
+ }
+
+ void FinishedSearch() {
+ gen_.root_.InitRoot();
+ NBestComplete completed(out_.Complete(combine_));
+ gen_.root_.SetEnd(completed.history, completed.score);
+ }
+
+ private:
+ Vertex &gen_;
+
+ typename Output::Combine combine_;
+ Output &out_;
};
} // namespace search