LuciferYang commented on code in PR #46972:
URL: https://github.com/apache/spark/pull/46972#discussion_r1639285020
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/mathExpressions.scala:
##########
@@ -1162,41 +1140,27 @@ case class Unhex(child: Expression, failOnError:
Boolean = false)
override def dataType: DataType = BinaryType
protected override def nullSafeEval(num: Any): Any = {
- val result = Hex.unhex(num.asInstanceOf[UTF8String].getBytes)
- if (failOnError && result == null) {
- // The failOnError is set only from `ToBinary` function - hence we might
safely set `hint`
- // parameter to `try_to_binary`.
- throw QueryExecutionErrors.invalidInputInConversionError(
- BinaryType,
- num.asInstanceOf[UTF8String],
- UTF8String.fromString("HEX"),
- "try_to_binary")
+ try {
+ Hex.unhex(num.asInstanceOf[UTF8String].toString)
Review Comment:
The improvement to the `unhex` function seems effective in isolated cases,
but IIRC, `UTF8String.toString` always incurs an additional Array Copy overhead
compared to `UTF8String.getBytes`. Is this really better?
Therefore, should we add a offline test to evaluate the effectiveness of the
improvement for the `Unhex` sql function, possibly focusing on both short and
long strings?
##########
sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/HexBenchmark.scala:
##########
@@ -0,0 +1,79 @@
+/*
+ * 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.catalyst.expressions
+
+import java.util.Locale
+
+import org.apache.commons.codec.binary.{Hex => ApacheHex}
+
+import org.apache.spark.benchmark.{Benchmark, BenchmarkBase}
+import org.apache.spark.unsafe.types.UTF8String
+
+/**
+ * Benchmark for hex
+ * To run this benchmark:
+ * {{{
+ * 1. without sbt:
+ * bin/spark-submit --class <this class> --jars <spark core test jar>
<spark catalyst test jar>
+ * 2. build/sbt "catalyst/Test/runMain <this class>"
+ * 3. generate result:
+ * SPARK_GENERATE_BENCHMARK_FILES=1 build/sbt "catalyst/Test/runMain
<this class>"
+ * Results will be written to "benchmarks/HexBenchmark-results.txt".
+ * }}}
+ */
+object HexBenchmark extends BenchmarkBase {
+
+ private val hexStrings = {
+ var tmp = Seq("", "A", "AB", "ABC", "ABCD", "123ABCDEF")
+ tmp = tmp ++ tmp.map(_.toLowerCase(Locale.ROOT))
+ (2 to 4).foreach { i => tmp = tmp ++ tmp.map(x => x * i) }
+ tmp.map(UTF8String.fromString(_).toString)
+ }
+
+ override def runBenchmarkSuite(mainArgs: Array[String]): Unit = {
+ runBenchmark("Hex Comparison") {
+ val N = 1_000_000
+ val benchmark = new Benchmark(s"Cardinality $N", N, 3, output = output)
+ benchmark.addCase("Apache") { _ =>
Review Comment:
nit: Perhaps `Commons Codec` would be more appropriate?
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
