[SPARK-48551][SQL] Perf improvement for escapePathName

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/ExternalCatalogUtils.scala

@@ -40,7 +40,7 @@ object ExternalCatalogUtils {
   // The following string escaping code is mainly copied from Hive (o.a.h.h.common.FileUtils).
   //////////////////////////////////////////////////////////////////////////////////////////////////
 
-  val charToEscape = {
+  final val charToEscape = {
     val bitSet = new java.util.BitSet(128)
 
     /**
@@ -63,25 +63,36 @@ object ExternalCatalogUtils {
     bitSet
   }
 
-  def needsEscaping(c: Char): Boolean = {
+  private final val HEX_CHARS = "0123456789ABCDEF".toCharArray
+
+  @inline final def needsEscaping(c: Char): Boolean = {
     c < charToEscape.size() && charToEscape.get(c)
   }
 
   def escapePathName(path: String): String = {
-    val builder = new StringBuilder()
-    path.foreach { c =>
-      if (needsEscaping(c)) {
-        builder.append('%')
-        builder.append(f"${c.asInstanceOf[Int]}%02X")
-      } else {
-        builder.append(c)
+    var firstIndex = 0
+    val length = path.length
+    while (firstIndex < length && !needsEscaping(path.charAt(firstIndex))) {
+      firstIndex += 1
+    }
+    if (firstIndex == 0) {
+      path
+    } else {
+      val sb = new java.lang.StringBuilder(length + 16)
+      sb.append(path.substring(0, firstIndex))
+      while(firstIndex < length) {
+        val c = path.charAt(firstIndex)
+        if (needsEscaping(c)) {
+          sb.append('%').append(HEX_CHARS((c & 0xF0) >> 4)).append(HEX_CHARS(c & 0x0F))
+        } else {
+          sb.append(c)
+        }
+        firstIndex += 1
       }
+      sb.toString()
     }
-
-    builder.toString()
   }
 
-
   def unescapePathName(path: String): String = {
     val sb = new StringBuilder
     var i = 0

sql/core/src/test/scala/org/apache/spark/sql/EscapePathBenchmark.scala

@@ -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.
+ */
+
+package org.apache.spark.sql
+
+import org.apache.spark.benchmark.{Benchmark, BenchmarkBase}
+import org.apache.spark.sql.catalyst.catalog.ExternalCatalogUtils
+
+object EscapePathBenchmark extends BenchmarkBase {
+  override def runBenchmarkSuite(mainArgs: Array[String]): Unit = {
+    val N = 1000000
+    runBenchmark("Escape") {
+      val benchmark = new Benchmark("Escape Tests", N, 10, output = output)
+      val paths = Seq(
+        "https://issues.apache.org/jira/browse/SPARK-48551",
+        "https...issues.apache.org/jira/browse/SPARK-48551",
+        "https...issues.apache.org.jira/browse/SPARK-48551",
+        "https...issues.apache.org.jira.browse/SPARK-48551",
+        "https...issues.apache.org.jira.browse.SPARK-48551")
+      benchmark.addCase("Legacy") { _ =>
+        (1 to N).foreach(_ => paths.foreach(escapePathNameLegacy))
+      }
+
+      benchmark.addCase("New") { _ =>
+        (1 to N).foreach(_ => {
+          paths.foreach(ExternalCatalogUtils.escapePathName)
+        })
+      }
+      benchmark.run()
+    }
+  }
+
+  /**
+   * Legacy implementation of escapePathName before Spark 4.0
+   */
+  def escapePathNameLegacy(path: String): String = {
+    val builder = new StringBuilder()
+    path.foreach { c =>
+      if (ExternalCatalogUtils.needsEscaping(c)) {
+        builder.append('%')
+        builder.append(f"${c.asInstanceOf[Int]}%02X")
+      } else {
+        builder.append(c)
+      }
+    }
+
+    builder.toString()
+  }
+}