From 41c18b845c5379a3c8f5ecdfeea7dc05fde7dcf4 Mon Sep 17 00:00:00 2001
From: Yuri Gorshenin <y@maps.me>
Date: Wed, 8 Feb 2017 16:50:50 +0300
Subject: [PATCH] [base] Implemented SafeSmallSet.

---
 base/small_set.hpp      | 53 ++++++++++++++++++++++++++++++++++++++++-
 search/query_params.hpp | 34 +-------------------------
 2 files changed, 53 insertions(+), 34 deletions(-)

diff --git a/base/small_set.hpp b/base/small_set.hpp
index 35c7afe7a1..1e1995d38a 100644
--- a/base/small_set.hpp
+++ b/base/small_set.hpp
@@ -154,7 +154,7 @@ uint64_t constexpr SmallSet<UpperBound>::kNumBlocks;
 template <uint64_t UpperBound>
 uint64_t constexpr SmallSet<UpperBound>::kOne;
 
-template<uint64_t UpperBound>
+template <uint64_t UpperBound>
 std::string DebugPrint(SmallSet<UpperBound> const & set)
 {
   std::ostringstream os;
@@ -164,4 +164,55 @@ std::string DebugPrint(SmallSet<UpperBound> const & set)
   os << "]";
   return os.str();
 }
+
+// This is a delegate for SmallSet<>, that checks the validity of
+// argument in Insert(), Remove() and Contains() methods and does
+// nothing when the argument is not valid.
+template <uint64_t UpperBound>
+class SafeSmallSet
+{
+public:
+  using Set = SmallSet<UpperBound>;
+  using Iterator = typename Set::Iterator;
+
+  void Insert(uint64_t value)
+  {
+    if (IsValid(value))
+      m_set.Insert(value);
+  }
+
+  void Remove(uint64_t value)
+  {
+    if (IsValid(value))
+      m_set.Remove(value);
+  }
+
+  bool Contains(uint64_t value) const { return IsValid(value) && m_set.Contains(value); }
+
+  uint64_t Size() const { return m_set.Size(); }
+
+  void Clear() { m_set.Clear(); }
+
+  Iterator begin() const { return m_set.begin(); }
+  Iterator cbegin() const { return m_set.cbegin(); }
+
+  Iterator end() const { return m_set.end(); }
+  Iterator cend() const { return m_set.cend(); }
+
+private:
+  bool IsValid(uint64_t value) const { return value < UpperBound; }
+
+  Set m_set;
+};
+
+template <uint64_t UpperBound>
+std::string DebugPrint(SafeSmallSet<UpperBound> const & set)
+{
+  std::ostringstream os;
+  os << "SafeSmallSet<" << UpperBound << "> [" << set.Size() << ": ";
+  for (auto const & v : set)
+    os << v << " ";
+  os << "]";
+  return os.str();
+}
 }  // namespace base
diff --git a/search/query_params.hpp b/search/query_params.hpp
index 480ebee23c..d489deb6bc 100644
--- a/search/query_params.hpp
+++ b/search/query_params.hpp
@@ -23,39 +23,7 @@ class QueryParams
 public:
   using String = strings::UniString;
   using TypeIndices = vector<uint32_t>;
-
-  class Langs
-  {
-  public:
-    using Set = base::SmallSet<StringUtf8Multilang::kMaxSupportedLanguages>;
-    using Iterator = Set::Iterator;
-
-    void Insert(int8_t lang)
-    {
-      if (IsValid(lang))
-        m_set.Insert(lang);
-    }
-
-    bool Contains(int8_t lang) const { return IsValid(lang) ? m_set.Contains(lang) : false; }
-
-    void Clear() { m_set.Clear(); }
-
-    Iterator begin() const { return m_set.begin(); }
-    Iterator cbegin() const { return m_set.cbegin(); }
-
-    Iterator end() const { return m_set.end(); }
-    Iterator cend() const { return m_set.cend(); }
-
-  private:
-    friend string DebugPrint(Langs const & langs) { return DebugPrint(langs.m_set); }
-
-    bool IsValid(int8_t lang) const
-    {
-      return lang >= 0 && lang < StringUtf8Multilang::kMaxSupportedLanguages;
-    }
-
-    Set m_set;
-  };
+  using Langs = base::SafeSmallSet<StringUtf8Multilang::kMaxSupportedLanguages>;
 
   struct Token
   {