Add case insensitive and dot-all modes to RegExpTree dictionary

docs/en/sql-reference/dictionaries/index.md

@@ -2361,6 +2361,12 @@ Result:
 └────────────────────────────────────────┴───────────────────────────────────────────────────────────────────────────────────────┘
 ```
 
+#### Matching Modes
+
+Pattern matching behavior can be modified with certain dictionary settings:
+- `regexp_dict_flag_case_insensitive`: Use case-insensitive matching (defaults to `false`). Can be overridden in individual expressions with `(?i)` and `(?-i)`.
+- `regexp_dict_flag_dotall`: Allow '.' to match newline characters (defaults to `false`).
+
 ### Use Regular Expression Tree Dictionary in ClickHouse Cloud
 
 Above used `YAMLRegExpTree` source works in ClickHouse Open Source but not in ClickHouse Cloud. To use regexp tree dictionaries in ClickHouse could, first create a regexp tree dictionary from a YAML file locally in ClickHouse Open Source, then dump this dictionary into a CSV file using the `dictionary` table function and the [INTO OUTFILE](../statements/select/into-outfile.md) clause.

src/Core/Settings.h

@@ -1053,6 +1053,8 @@ class IColumn;
     \
     M(Bool, format_display_secrets_in_show_and_select, false, "Do not hide secrets in SHOW and SELECT queries.", IMPORTANT) \
     M(Bool, regexp_dict_allow_hyperscan, true, "Allow regexp_tree dictionary using Hyperscan library.", 0) \
+    M(Bool, regexp_dict_flag_case_insensitive, false, "Use case-insensitive matching for a regexp_tree dictionary. Can be overridden in individual expressions with (?i) and (?-i).", 0) \
+    M(Bool, regexp_dict_flag_dotall, false, "Allow '.' to match newline characters for a regexp_tree dictionary.", 0) \
     \
     M(Bool, dictionary_use_async_executor, false, "Execute a pipeline for reading from a dictionary with several threads. It's supported only by DIRECT dictionary with CLICKHOUSE source.", 0) \
     M(Bool, precise_float_parsing, false, "Prefer more precise (but slower) float parsing algorithm", 0) \

src/Dictionaries/RegExpTreeDictionary.cpp

@@ -206,6 +206,8 @@ void RegExpTreeDictionary::initRegexNodes(Block & block)
 
         re2_st::RE2::Options regexp_options;
         regexp_options.set_log_errors(false);
+        regexp_options.set_case_sensitive(!flag_case_insensitive);
+        regexp_options.set_dot_nl(flag_dotall);
         RegexTreeNodePtr node = std::make_shared<RegexTreeNode>(id, parent_id, regex, regexp_options);
 
         int num_captures = std::min(node->searcher.NumberOfCapturingGroups() + 1, 10);
@@ -330,11 +332,20 @@ void RegExpTreeDictionary::loadData()
         std::vector<unsigned int> flags;
         std::vector<size_t> lengths;
 
+        // Notes:
+        // - Always set HS_FLAG_SINGLEMATCH because we only care about whether a pattern matches at least once
+        // - HS_FLAG_CASELESS is supported by hs_compile_lit_multi, so we should set it if flag_case_insensitive is set.
+        // - HS_FLAG_DOTALL is not supported by hs_compile_lit_multi, but the '.' wildcard can't appear in any of the simple regexps
+        //   anyway, so even if flag_dotall is set, we only need to configure the RE2 searcher, and don't need to set any Hyperscan flags.
+        unsigned int flag_bits = HS_FLAG_SINGLEMATCH;
+        if (flag_case_insensitive)
+            flag_bits |= HS_FLAG_CASELESS;
+
         for (const std::string & simple_regexp : simple_regexps)
         {
             patterns.push_back(simple_regexp.data());
             lengths.push_back(simple_regexp.size());
-            flags.push_back(HS_FLAG_SINGLEMATCH);
+            flags.push_back(flag_bits);
         }
 
         hs_database_t * db = nullptr;
@@ -380,12 +391,16 @@ RegExpTreeDictionary::RegExpTreeDictionary(
     const DictionaryStructure & structure_,
     DictionarySourcePtr source_ptr_,
     Configuration configuration_,
-    bool use_vectorscan_)
+    bool use_vectorscan_,
+    bool flag_case_insensitive_,
+    bool flag_dotall_)
     : IDictionary(id_),
       structure(structure_),
       source_ptr(source_ptr_),
       configuration(configuration_),
       use_vectorscan(use_vectorscan_),
+      flag_case_insensitive(flag_case_insensitive_),
+      flag_dotall(flag_dotall_),
       logger(&Poco::Logger::get("RegExpTreeDictionary"))
 {
     if (auto * ch_source = typeid_cast<ClickHouseDictionarySource *>(source_ptr.get()))
@@ -859,7 +874,14 @@ void registerDictionaryRegExpTree(DictionaryFactory & factory)
 
         auto context = copyContextAndApplySettingsFromDictionaryConfig(global_context, config, config_prefix);
 
-        return std::make_unique<RegExpTreeDictionary>(dict_id, dict_struct, std::move(source_ptr), configuration, context->getSettings().regexp_dict_allow_hyperscan);
+        return std::make_unique<RegExpTreeDictionary>(
+            dict_id,
+            dict_struct,
+            std::move(source_ptr),
+            configuration,
+            context->getSettings().regexp_dict_allow_hyperscan,
+            context->getSettings().regexp_dict_flag_case_insensitive,
+            context->getSettings().regexp_dict_flag_dotall);
     };
 
     factory.registerLayout("regexp_tree", create_layout, true);

src/Dictionaries/RegExpTreeDictionary.h

@@ -49,7 +49,9 @@ class RegExpTreeDictionary : public IDictionary
         const DictionaryStructure & structure_,
         DictionarySourcePtr source_ptr_,
         Configuration configuration_,
-        bool use_vectorscan_);
+        bool use_vectorscan_,
+        bool flag_case_insensitive_,
+        bool flag_dotall_);
 
     std::string getTypeName() const override { return name; }
 
@@ -85,7 +87,8 @@ class RegExpTreeDictionary : public IDictionary
 
     std::shared_ptr<const IExternalLoadable> clone() const override
     {
-        return std::make_shared<RegExpTreeDictionary>(getDictionaryID(), structure, source_ptr->clone(), configuration, use_vectorscan);
+        return std::make_shared<RegExpTreeDictionary>(
+            getDictionaryID(), structure, source_ptr->clone(), configuration, use_vectorscan, flag_case_insensitive, flag_dotall);
     }
 
     ColumnUInt8::Ptr hasKeys(const Columns &, const DataTypes &) const override
@@ -189,6 +192,8 @@ class RegExpTreeDictionary : public IDictionary
     using RegexTreeNodePtr = std::shared_ptr<RegexTreeNode>;
 
     bool use_vectorscan;
+    bool flag_case_insensitive;
+    bool flag_dotall;
 
     std::vector<std::string> simple_regexps;
     std::vector<UInt64>      regexp_ids;

tests/queries/0_stateless/02504_regexp_dictionary_yaml_source.reference

@@ -27,3 +27,15 @@ GitHub Documentation
 ['GitHub Documentation','GitHub']
 Documentation
 ['Documentation']
+['foo','(?i)foo','(?-i)foo']
+['(?i)foo']
+['hello.*world','(?i)hello.*world','(?-i)hello.*world']
+[]
+['(?i)hello.*world']
+[]
+['foo','(?i)foo','(?-i)foo']
+['foo','(?i)foo']
+['hello.*world','(?i)hello.*world','(?-i)hello.*world']
+['hello.*world','(?i)hello.*world','(?-i)hello.*world']
+['hello.*world','(?i)hello.*world']
+['hello.*world','(?i)hello.*world']

tests/queries/0_stateless/02504_regexp_dictionary_yaml_source.sh

@@ -239,10 +239,66 @@ select dictGet('regexp_dict3', 'tag', '/docs');
 select dictGetAll('regexp_dict3', 'tag', '/docs');
 "
 
+# Test case-insensitive and dot-all match modes
+cat > "$yaml" <<EOL
+- regexp: 'foo'
+  pattern: 'foo'
+- regexp: '(?i)foo'
+  pattern: '(?i)foo'
+- regexp: '(?-i)foo'
+  pattern: '(?-i)foo'
+- regexp: 'hello.*world'
+  pattern: 'hello.*world'
+- regexp: '(?i)hello.*world'
+  pattern: '(?i)hello.*world'
+- regexp: '(?-i)hello.*world'
+  pattern: '(?-i)hello.*world'
+EOL
+
+$CLICKHOUSE_CLIENT -n --query="
+drop dictionary if exists regexp_dict4;
+create dictionary regexp_dict4
+(
+    regexp String,
+    pattern String
+)
+PRIMARY KEY(regexp)
+SOURCE(YAMLRegExpTree(PATH '$yaml'))
+LIFETIME(0)
+LAYOUT(regexp_tree);
+
+select dictGetAll('regexp_dict4', 'pattern', 'foo');
+select dictGetAll('regexp_dict4', 'pattern', 'FOO');
+select dictGetAll('regexp_dict4', 'pattern', 'hello world');
+select dictGetAll('regexp_dict4', 'pattern', 'hello\nworld');
+select dictGetAll('regexp_dict4', 'pattern', 'HELLO WORLD');
+select dictGetAll('regexp_dict4', 'pattern', 'HELLO\nWORLD');
+
+drop dictionary if exists regexp_dict4;
+create dictionary regexp_dict4
+(
+    regexp String,
+    pattern String
+)
+PRIMARY KEY(regexp)
+SOURCE(YAMLRegExpTree(PATH '$yaml'))
+LIFETIME(0)
+LAYOUT(regexp_tree)
+SETTINGS(regexp_dict_flag_case_insensitive = true, regexp_dict_flag_dotall = true);
+
+select dictGetAll('regexp_dict4', 'pattern', 'foo');
+select dictGetAll('regexp_dict4', 'pattern', 'FOO');
+select dictGetAll('regexp_dict4', 'pattern', 'hello world');
+select dictGetAll('regexp_dict4', 'pattern', 'hello\nworld');
+select dictGetAll('regexp_dict4', 'pattern', 'HELLO WORLD');
+select dictGetAll('regexp_dict4', 'pattern', 'HELLO\nWORLD');
+"
+
 $CLICKHOUSE_CLIENT -n --query="
 drop dictionary regexp_dict1;
 drop dictionary regexp_dict2;
 drop dictionary regexp_dict3;
+drop dictionary regexp_dict4;
 "
 
 rm -rf "$USER_FILES_PATH/test_02504"