1 files changed, 63 insertions, 0 deletions
diff --git a/src/arrow/cpp/src/gandiva/regex_util.cc b/src/arrow/cpp/src/gandiva/regex_util.cc
new file mode 100644
index 000000000..abdd579d1
--- /dev/null
+++ b/src/arrow/cpp/src/gandiva/regex_util.cc
@@ -0,0 +1,63 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#include "gandiva/regex_util.h"
+
+namespace gandiva {
+
+const std::set<char> RegexUtil::pcre_regex_specials_ = {
+    '[', ']', '(', ')', '|', '^', '-', '+', '*', '?', '{', '}', '$', '\\', '.'};
+
+Status RegexUtil::SqlLikePatternToPcre(const std::string& sql_pattern, char escape_char,
+                                       std::string& pcre_pattern) {
+  /// Characters that are considered special by pcre regex. These needs to be
+  /// escaped with '\\'.
+  pcre_pattern.clear();
+  for (size_t idx = 0; idx < sql_pattern.size(); ++idx) {
+    auto cur = sql_pattern.at(idx);
+
+    // Escape any char that is special for pcre regex
+    if (pcre_regex_specials_.find(cur) != pcre_regex_specials_.end()) {
+      pcre_pattern += "\\";
+    }
+
+    if (cur == escape_char) {
+      // escape char must be followed by '_', '%' or the escape char itself.
+      ++idx;
+      ARROW_RETURN_IF(
+          idx == sql_pattern.size(),
+          Status::Invalid("Unexpected escape char at the end of pattern ", sql_pattern));
+
+      cur = sql_pattern.at(idx);
+      if (cur == '_' || cur == '%' || cur == escape_char) {
+        pcre_pattern += cur;
+      } else {
+        return Status::Invalid("Invalid escape sequence in pattern ", sql_pattern,
+                               " at offset ", idx);
+      }
+    } else if (cur == '_') {
+      pcre_pattern += '.';
+    } else if (cur == '%') {
+      pcre_pattern += ".*";
+    } else {
+      pcre_pattern += cur;
+    }
+  }
+  return Status::OK();
+}
+
+}  // namespace gandiva