Merge pull request #29964 from vespa-engine/vekterli/use-string-view-for-non-dict-match

Use `string_view` for standalone DFA fuzzy match function

4 files changed, 18 insertions, 7 deletions

diff --git a/searchlib/src/tests/attribute/dfa_fuzzy_matcher/dfa_fuzzy_matcher_test.cpp b/searchlib/src/tests/attribute/dfa_fuzzy_matcher/dfa_fuzzy_matcher_test.cpp
index 433ad9e7671..8ba8c62c5ff 100644
--- a/searchlib/src/tests/attribute/dfa_fuzzy_matcher/dfa_fuzzy_matcher_test.cpp
+++ b/searchlib/src/tests/attribute/dfa_fuzzy_matcher/dfa_fuzzy_matcher_test.cpp
@@ -197,7 +197,7 @@ dfa_fuzzy_match_in_dictionary_no_skip(std::string_view target, const StringEnumS
     size_t seeks = 0;
     for (;itr.valid(); ++itr) {
         auto word = store.get_value(itr.getKey().load_relaxed());
-        if (matcher.is_match(word)) {
+        if (matcher.is_match(std::string_view(word))) {
             ++matches;
             if (collect_matches) {
                 matched_words.push_back(word);
diff --git a/searchlib/src/vespa/searchlib/attribute/dfa_fuzzy_matcher.cpp b/searchlib/src/vespa/searchlib/attribute/dfa_fuzzy_matcher.cpp
index 9d6e2e9815d..5f3ab9cd3d8 100644
--- a/searchlib/src/vespa/searchlib/attribute/dfa_fuzzy_matcher.cpp
+++ b/searchlib/src/vespa/searchlib/attribute/dfa_fuzzy_matcher.cpp
@@ -54,6 +54,11 @@ DfaFuzzyMatcher::DfaFuzzyMatcher(std::string_view target, uint8_t max_edits, uin
     _successor = _prefix;
 }
 
+DfaFuzzyMatcher::DfaFuzzyMatcher(std::string_view target, uint8_t max_edits, uint32_t prefix_size, bool cased)
+    : DfaFuzzyMatcher(target, max_edits, prefix_size, cased, LevenshteinDfa::DfaType::Table)
+{
+}
+
 DfaFuzzyMatcher::~DfaFuzzyMatcher() = default;
 
 const char*
@@ -69,10 +74,10 @@ DfaFuzzyMatcher::skip_prefix(const char* word) const
 }
 
 bool
-DfaFuzzyMatcher::is_match(const char* word) const
+DfaFuzzyMatcher::is_match(std::string_view word) const
 {
     if (_prefix_size > 0) {
-        Utf8ReaderForZTS reader(word);
+        Utf8Reader reader(word.data(), word.size());
         size_t pos = 0;
         for (; pos < _prefix.size() && reader.hasMore(); ++pos) {
             uint32_t code_point = reader.getChar();
@@ -89,7 +94,7 @@ DfaFuzzyMatcher::is_match(const char* word) const
         if (pos != _prefix_size) {
             return false;
         }
-        word = reader.get_current_ptr();
+        word = word.substr(reader.getPos());
     }
     auto match = _dfa.match(word);
     return match.matches();
diff --git a/searchlib/src/vespa/searchlib/attribute/dfa_fuzzy_matcher.h b/searchlib/src/vespa/searchlib/attribute/dfa_fuzzy_matcher.h
index 51457129637..653af602c0d 100644
--- a/searchlib/src/vespa/searchlib/attribute/dfa_fuzzy_matcher.h
+++ b/searchlib/src/vespa/searchlib/attribute/dfa_fuzzy_matcher.h
@@ -27,9 +27,14 @@ private:
     const char* skip_prefix(const char* word) const;
 public:
     DfaFuzzyMatcher(std::string_view target, uint8_t max_edits, uint32_t prefix_size, bool cased, vespalib::fuzzy::LevenshteinDfa::DfaType dfa_type);
+    DfaFuzzyMatcher(std::string_view target, uint8_t max_edits, uint32_t prefix_size, bool cased); // Defaults to table-based DFA
     ~DfaFuzzyMatcher();
 
-    bool is_match(const char *word) const;
+    [[nodiscard]] static constexpr bool supports_max_edits(uint8_t edits) noexcept {
+        return (edits == 1 || edits == 2);
+    }
+
+    [[nodiscard]] bool is_match(std::string_view word) const;
 
     /*
      * If prefix size is nonzero then this variant of is_match()
@@ -40,7 +45,7 @@ public:
      * functionality in the dictionary.
      */
     template <typename DictionaryConstIteratorType>
-    bool is_match(const char* word, DictionaryConstIteratorType& itr, const DfaStringComparator::DataStoreType& data_store);
+    [[nodiscard]] bool is_match(const char* word, DictionaryConstIteratorType& itr, const DfaStringComparator::DataStoreType& data_store);
 };
 
 }
diff --git a/searchlib/src/vespa/searchlib/attribute/string_search_helper.cpp b/searchlib/src/vespa/searchlib/attribute/string_search_helper.cpp
index 75885aa0402..f1a643dc376 100644
--- a/searchlib/src/vespa/searchlib/attribute/string_search_helper.cpp
+++ b/searchlib/src/vespa/searchlib/attribute/string_search_helper.cpp
@@ -80,7 +80,8 @@ StringSearchHelper::isMatch(const char *src) const noexcept {
         return getRegex().valid() && getRegex().partial_match(std::string_view(src));
     }
     if (__builtin_expect(isFuzzy(), false)) {
-        return _dfa_fuzzy_matcher ? _dfa_fuzzy_matcher->is_match(src) : getFuzzyMatcher().isMatch(src);
+        return _dfa_fuzzy_matcher ? _dfa_fuzzy_matcher->is_match(std::string_view(src))
+                                  : getFuzzyMatcher().isMatch(std::string_view(src));
     }
     if (__builtin_expect(isCased(), false)) {
         int res = strncmp(_term, src, _termLen);