1 files changed, 55 insertions, 9 deletions

diff --git a/utils/fast_sparse_vector.h b/utils/fast_sparse_vector.h
index 4aae2039..1301581a 100644
--- a/utils/fast_sparse_vector.h
+++ b/utils/fast_sparse_vector.h
@@ -7,6 +7,8 @@
 // important: indexes are integers
 // important: iterators may return elements in any order
 
+#include "config.h"
+
 #include <cmath>
 #include <cstring>
 #include <climits>
@@ -16,6 +18,12 @@
 
 #include <boost/static_assert.hpp>
 
+#if HAVE_BOOST_ARCHIVE_TEXT_OARCHIVE_HPP
+#include <boost/serialization/map.hpp>
+#endif
+
+#include "fdict.h"
+
 // this is architecture dependent, it should be
 // detected in some way but it's probably easiest (for me)
 // to just set it
@@ -235,6 +243,13 @@ class FastSparseVector {
     }
     return *this;
   }
+  FastSparseVector<T> erase_zeros(const T& EPSILON = 1e-4) const {
+    FastSparseVector<T> o;
+    for (const_iterator it = begin(); it != end(); ++it) {
+      if (fabs(it->second) > EPSILON) o.set_value(it->first, it->second);
+    }
+    return o;
+  }
   const_iterator begin() const {
     return const_iterator(*this, false);
   }
@@ -327,8 +342,45 @@ class FastSparseVector {
   } data_;
   unsigned char local_size_;
   bool is_remote_;
+
+#if HAVE_BOOST_ARCHIVE_TEXT_OARCHIVE_HPP
+ private:
+  friend class boost::serialization::access;
+  template<class Archive>
+  void save(Archive & ar, const unsigned int version) const {
+    (void) version;
+    int eff_size = size();
+    const_iterator it = this->begin();
+    if (eff_size > 0) {
+      // 0 index is reserved as empty
+      if (it->first == 0) { ++it; --eff_size; }
+    }
+    ar & eff_size;
+    while (it != this->end()) {
+      const std::pair<const std::string&, const T&> wire_pair(FD::Convert(it->first), it->second);
+      ar & wire_pair;
+      ++it;
+    }
+  }
+  template<class Archive>
+  void load(Archive & ar, const unsigned int version) {
+    (void) version;
+    this->clear();
+    int sz; ar & sz;
+    for (int i = 0; i < sz; ++i) {
+      std::pair<std::string, T> wire_pair;
+      ar & wire_pair;
+      this->set_value(FD::Convert(wire_pair.first), wire_pair.second);
+    }
+  }
+  BOOST_SERIALIZATION_SPLIT_MEMBER()
+#endif
 };
 
+#if HAVE_BOOST_ARCHIVE_TEXT_OARCHIVE_HPP
+BOOST_CLASS_TRACKING(FastSparseVector<double>,track_never)
+#endif
+
 template <typename T>
 const FastSparseVector<T> operator+(const FastSparseVector<T>& x, const FastSparseVector<T>& y) {
   if (x.size() > y.size()) {
@@ -344,15 +396,9 @@ const FastSparseVector<T> operator+(const FastSparseVector<T>& x, const FastSpar
 
 template <typename T>
 const FastSparseVector<T> operator-(const FastSparseVector<T>& x, const FastSparseVector<T>& y) {
-  if (x.size() > y.size()) {
-    FastSparseVector<T> res(x);
-    res -= y;
-    return res;
-  } else {
-    FastSparseVector<T> res(y);
-    res -= x;
-    return res;
-  }
+  FastSparseVector<T> res(x);
+  res -= y;
+  return res;
 }
 
 template <class T>