Refactored and improved search: approximate matching and splitting feature names into tokens.

1 files changed, 60 insertions, 0 deletions

diff --git a/search/keyword_matcher.cpp b/search/keyword_matcher.cpp
new file mode 100644
index 0000000000..54553c7a39
--- /dev/null
+++ b/search/keyword_matcher.cpp
@@ -0,0 +1,60 @@
+#include "keyword_matcher.hpp"
+#include "delimiters.hpp"
+#include "../base/string_utils.hpp"
+#include "../std/numeric.hpp"
+
+namespace search
+{
+namespace impl
+{
+
+KeywordMatcher::KeywordMatcher(strings::UniString * pKeywords,
+                               size_t keywordsCount,
+                               strings::UniString const & prefix,
+                               uint32_t maxKeywordMatchCost, uint32_t maxPrefixMatchCost,
+                               StringMatchFn keywordMatchFn, StringMatchFn prefixMatchFn)
+  : m_pKewords(pKeywords), m_prefix(prefix),
+    m_maxKeywordMatchCost(maxKeywordMatchCost),
+    m_maxPrefixMatchCost(maxPrefixMatchCost),
+    m_keywordMatchFn(keywordMatchFn),
+    m_prefixMatchFn(prefixMatchFn),
+    m_minKeywordMatchCost(keywordsCount, m_maxKeywordMatchCost + 1),
+    m_minPrefixMatchCost(m_maxPrefixMatchCost + 1)
+{
+}
+
+void KeywordMatcher::ProcessName(string const & name)
+{
+  search::Delimiters delims;
+  for (strings::TokenizeIterator<search::Delimiters> iter(name, delims); iter; ++iter)
+  {
+    strings::UniString const s = iter.GetUniString();
+
+    for (size_t i = 0; i < m_minKeywordMatchCost.size(); ++i)
+    {
+      m_minKeywordMatchCost[i] = min(m_minKeywordMatchCost[i],
+                                     m_keywordMatchFn(&m_pKewords[i][0], m_pKewords[i].size(),
+                                                      &s[0], s.size(),
+                                                      m_minKeywordMatchCost[i]));
+    }
+
+    if (!m_prefix.empty())
+    {
+      m_minPrefixMatchCost = min(m_minPrefixMatchCost,
+                                 m_prefixMatchFn(&m_prefix[0], m_prefix.size(),
+                                                 &s[0], s.size(),
+                                                 m_minPrefixMatchCost));
+    }
+    else
+      m_minPrefixMatchCost = 0;
+  }
+}
+
+uint32_t KeywordMatcher::GetMatchScore() const
+{
+  return accumulate(m_minKeywordMatchCost.begin(), m_minKeywordMatchCost.end(),
+                    m_minPrefixMatchCost);
+}
+
+}  // namespace search::impl
+}  // namespace search