Fixes and enhancements to partial match and PSI logic

* Fixes to partial match and PSI logic.
* Enhancements to perform ptxt-to-ctxt comparisons.

Co-authored-by: @hamishun

Author: jlhcrawford

CHANGES.md

@@ -7,6 +7,8 @@ HElib 2.2.1, October 2021
 
 * Improved NTT bechmark code
 * CI update
+* Improvements to partial match logic
+* Bug fixes
 
 HElib 2.2.0, September 2021
 =========================

include/helib/partialMatch.h

@@ -94,12 +94,24 @@ Matrix<Ctxt> calculateMasks(const EncryptedArray& ea,
   mask = mask.columns(columns);
   mask.inPlaceTranspose();
 
-  (mask -= database)
+  // FIXME: Avoid deep copy
+  // Ptxt Query
+  if constexpr (std::is_same_v<TXT, Ptxt<BGV>>) {
+    auto tmp = database.deepCopy();
+    (tmp -= mask)
       .apply([&](auto& entry) { mapTo01(ea, entry); })
       .apply([](auto& entry) { entry.negate(); })
       .apply([](auto& entry) { entry.addConstant(NTL::ZZX(1l)); });
 
-  return mask;
+    return tmp;
+  } else { // Ctxt Query
+    (mask -= database)
+      .apply([&](auto& entry) { mapTo01(ea, entry); })
+      .apply([](auto& entry) { entry.negate(); })
+      .apply([](auto& entry) { entry.addConstant(NTL::ZZX(1l)); });
+
+    return mask;
+  }
 }
 
 /**
@@ -569,8 +581,8 @@ class Database
    * match or no match respectively.
    **/
   template <typename TXT2>
-  Matrix<TXT2> contains(const Query_t& lookup_query,
-                        const Matrix<TXT2>& query_data) const;
+  auto contains(const Query_t& lookup_query,
+                const Matrix<TXT2>& query_data) const;
 
   // FIXME: Combination of TXT = ctxt and TXT2 = ptxt does not work
   /**
@@ -583,8 +595,8 @@ class Database
    * @return A `Matrix<TXT2>` containing a score on weighted matches.
    **/
   template <typename TXT2>
-  Matrix<TXT2> getScore(const Query_t& weighted_query,
-                        const Matrix<TXT2>& query_data) const;
+  auto getScore(const Query_t& weighted_query,
+                const Matrix<TXT2>& query_data) const;
 
   // TODO - correct name?
   /**
@@ -593,14 +605,16 @@ class Database
    **/
   long columns() { return data.dims(1); }
 
+  Matrix<TXT>& getData();
+
 private:
   Matrix<TXT> data;
   std::shared_ptr<const Context> context;
 };
 
 template <typename TXT>
 template <typename TXT2>
-inline Matrix<TXT2> Database<TXT>::contains(
+inline auto Database<TXT>::contains(
     const Query_t& lookup_query,
     const Matrix<TXT2>& query_data) const
 {
@@ -619,7 +633,7 @@ inline Matrix<TXT2> Database<TXT>::contains(
 
 template <typename TXT>
 template <typename TXT2>
-inline Matrix<TXT2> Database<TXT>::getScore(
+inline auto Database<TXT>::getScore(
     const Query_t& weighted_query,
     const Matrix<TXT2>& query_data) const
 {
@@ -633,6 +647,12 @@ inline Matrix<TXT2> Database<TXT>::getScore(
   return result;
 }
 
+template <typename TXT>
+inline Matrix<TXT>& Database<TXT>::getData()
+{
+  return data;
+}
+
 } // namespace helib
 
 #endif

utils/common/common.h

@@ -18,13 +18,13 @@
 
 #include <helib/helib.h>
 
-std::string stripExtension(const std::string& s)
+inline std::string stripExtension(const std::string& s)
 {
   std::size_t dotPos = s.find_last_of(".");
   return (dotPos == std::string::npos) ? s : s.substr(0, dotPos);
 }
 
-std::string readline(std::istream& is)
+inline std::string readline(std::istream& is)
 {
   std::string s;
   getline(is, s);