Performing proper serialization of LSH index.

Author: mariusmuja

src/cpp/flann/algorithms/lsh_index.h

@@ -181,10 +181,8 @@ class LshIndex : public NNIndex<Distance>
     	ar & key_size_;
     	ar & multi_probe_level_;
 
-    	if (Archive::is_loading::value) {
-            // Building the index is so fast we can afford not storing it
-            buildIndex();
-    	}
+    	ar & xor_masks_;
+    	ar & tables_;
 
     	if (Archive::is_loading::value) {
             index_params_["algorithm"] = getType();

src/cpp/flann/util/lsh_table.h

@@ -297,6 +297,33 @@ class LshTable
         }
     }
 
+    template<typename Archive>
+    void serialize(Archive& ar)
+    {
+    	int val;
+    	if (Archive::is_saving::value) {
+    		val = (int)speed_level_;
+    	}
+    	ar & val;
+    	if (Archive::is_loading::value) {
+    		speed_level_ = (SpeedLevel) val;
+    	}
+
+    	ar & key_size_;
+    	ar & mask_;
+
+    	if (speed_level_==kArray) {
+    		ar & buckets_speed_;
+    	}
+    	if (speed_level_==kBitsetHash || speed_level_==kHash) {
+    		ar & buckets_space_;
+    	}
+		if (speed_level_==kBitsetHash) {
+			ar & key_bitset_;
+		}
+    }
+    friend struct serialization::access;
+
     /** The vector of all the buckets if they are held for speed
      */
     BucketsSpeed buckets_speed_;

src/cpp/flann/util/serialization.h

@@ -2,6 +2,7 @@
 #define SERIALIZATION_H_
 
 #include <vector>
+#include <map>
 #include <stdio.h>
 
 namespace flann
@@ -116,6 +117,36 @@ struct Serializer<std::vector<T> >
     }
 };
 
+// serializer for std::vector
+template<typename K, typename V>
+struct Serializer<std::map<K,V> >
+{
+    template<typename InputArchive>
+    static inline void load(InputArchive& ar, std::map<K,V>& map_val)
+    {
+        size_t size;
+        ar & size;
+        for (size_t i = 0; i < size; ++i)
+        {
+            K key;
+            ar & key;
+            V value;
+            ar & value;
+            map_val[key] = value;
+        }
+    }
+
+    template<typename OutputArchive>
+    static inline void save(OutputArchive& ar, const std::map<K,V>& map_val)
+    {
+        ar & map_val.size();
+        for (typename std::map<K,V>::const_iterator i=map_val.begin(); i!=map_val.end(); ++i) {
+            ar & i->first;
+            ar & i->second;
+        }
+    }
+};
+
 template<typename T>
 struct Serializer<T*>
 {