1 files changed, 90 insertions, 0 deletions
diff --git a/search/ranking_utils.hpp b/search/ranking_utils.hpp
new file mode 100644
index 0000000000..75b94e4c50
--- /dev/null
+++ b/search/ranking_utils.hpp
@@ -0,0 +1,90 @@
+#pragma once
+
+#include "search/query_params.hpp"
+#include "search/search_model.hpp"
+
+#include "indexer/search_delimiters.hpp"
+#include "indexer/search_string_utils.hpp"
+
+#include "base/stl_add.hpp"
+#include "base/string_utils.hpp"
+
+#include "std/cstdint.hpp"
+#include "std/limits.hpp"
+#include "std/string.hpp"
+#include "std/vector.hpp"
+
+namespace search
+{
+struct QueryParams;
+
+namespace impl
+{
+bool Match(vector<strings::UniString> const & tokens, strings::UniString const & token);
+
+bool PrefixMatch(vector<strings::UniString> const & prefixes, strings::UniString const & token);
+}  // namespace impl
+
+// The order and numeric values are important here.  Please, check all
+// use-cases before changing this enum.
+enum NameScore
+{
+  NAME_SCORE_ZERO = 0,
+  NAME_SCORE_SUBSTRING_PREFIX = 1,
+  NAME_SCORE_SUBSTRING = 2,
+  NAME_SCORE_FULL_MATCH_PREFIX = 3,
+  NAME_SCORE_FULL_MATCH = 4,
+
+  NAME_SCORE_COUNT
+};
+
+template <typename TSlice>
+NameScore GetNameScore(string const & name, TSlice const & slice)
+{
+  if (slice.Empty())
+    return NAME_SCORE_ZERO;
+
+  vector<strings::UniString> tokens;
+  SplitUniString(NormalizeAndSimplifyString(name), MakeBackInsertFunctor(tokens), Delimiters());
+  return GetNameScore(tokens, slice);
+}
+
+template <typename TSlice>
+NameScore GetNameScore(vector<strings::UniString> const & tokens, TSlice const & slice)
+{
+  if (slice.Empty())
+    return NAME_SCORE_ZERO;
+
+  size_t const n = tokens.size();
+  size_t const m = slice.Size();
+
+  bool const lastTokenIsPrefix = slice.IsPrefix(m - 1);
+
+  NameScore score = NAME_SCORE_ZERO;
+  for (int offset = 0; offset + m <= n; ++offset)
+  {
+    bool match = true;
+    for (int i = 0; i < m - 1 && match; ++i)
+      match = match && impl::Match(slice.Get(i), tokens[offset + i]);
+    if (!match)
+      continue;
+
+    if (impl::Match(slice.Get(m - 1), tokens[offset + m - 1]))
+    {
+      if (m == n)
+        return NAME_SCORE_FULL_MATCH;
+      score = max(score, NAME_SCORE_SUBSTRING);
+    }
+    if (lastTokenIsPrefix && impl::PrefixMatch(slice.Get(m - 1), tokens[offset + m - 1]))
+    {
+      if (m == n)
+        return NAME_SCORE_FULL_MATCH_PREFIX;
+      score = max(score, NAME_SCORE_SUBSTRING_PREFIX);
+    }
+  }
+  return score;
+}
+
+string DebugPrint(NameScore score);
+
+}  // namespace search