1 files changed, 52 insertions, 0 deletions
diff --git a/dtrain/ksampler.h b/dtrain/ksampler.h
new file mode 100644
index 00000000..a28b69c9
--- /dev/null
+++ b/dtrain/ksampler.h
@@ -0,0 +1,52 @@
+#ifndef _DTRAIN_KSAMPLER_H_
+#define _DTRAIN_KSAMPLER_H_
+
+#include "kbest.h"
+#include "sample_hg.h"
+#include "sampler.h"
+
+namespace dtrain
+{
+
+/*
+ * KSampler
+ *
+ */
+struct KSampler : public DecoderObserver
+{
+  const size_t k_;
+  KBestList kb;
+  MT19937* rng;
+
+  explicit KSampler( const size_t k, MT19937* prng ) :
+    k_(k), rng(prng) {}
+
+  virtual void
+  NotifyTranslationForest( const SentenceMetadata& smeta, Hypergraph* hg )
+  {
+    Sample( *hg );
+  }
+
+  KBestList* GetKBest() { return &kb; }
+
+  void Sample( const Hypergraph& forest ) {
+    kb.sents.clear();
+    kb.feats.clear();
+    kb.model_scores.clear();
+    kb.scores.clear();
+    std::vector<HypergraphSampler::Hypothesis> samples;
+    HypergraphSampler::sample_hypotheses(forest, k_, rng, &samples);
+    for ( size_t i = 0; i < k_; ++i ) {
+      kb.sents.push_back( samples[i].words );
+      kb.feats.push_back( samples[i].fmap );
+      kb.model_scores.push_back( log(samples[i].model_score) );
+    }
+  }
+};
+
+
+} // namespace
+
+
+#endif
+