add support for dlopen'd feature functions

1 files changed, 26 insertions, 0 deletions

diff --git a/decoder/ff_external.h b/decoder/ff_external.h
new file mode 100644
index 00000000..283e58e8
--- /dev/null
+++ b/decoder/ff_external.h
@@ -0,0 +1,26 @@
+#ifndef _FFEXTERNAL_H_
+#define _FFEXTERNAL_H_
+
+#include "ff.h"
+
+// dynamically loaded feature function
+class ExternalFeature : public FeatureFunction {
+ public:
+  ExternalFeature(const std::string& param);
+  ~ExternalFeature();
+  virtual void PrepareForInput(const SentenceMetadata& smeta);
+  virtual void FinalTraversalFeatures(const void* context,
+                                      SparseVector<double>* features) const;
+ protected:
+  virtual void TraversalFeaturesImpl(const SentenceMetadata& smeta,
+                                     const Hypergraph::Edge& edge,
+                                     const std::vector<const void*>& ant_contexts,
+                                     FeatureVector* features,
+                                     FeatureVector* estimated_features,
+                                     void* context) const;
+ private:
+  void* lib_handle;
+  FeatureFunction* ff_ext;
+};
+
+#endif