chore: add cast_decimal benchmark

arrow-cast/Cargo.toml

@@ -77,3 +77,7 @@ harness = false
 [[bench]]
 name = "parse_decimal"
 harness = false
+
+[[bench]]
+name = "cast_decimal"
+harness = false

arrow-cast/benches/cast_decimal.rs

@@ -0,0 +1,46 @@
+// 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.
+
+use arrow_array::{ArrayRef, Decimal128Array};
+use arrow_cast::{cast_with_options, CastOptions};
+use arrow_schema::DataType;
+use criterion::*;
+use std::sync::Arc;
+
+fn criterion_benchmark(c: &mut Criterion) {
+    let decimals: ArrayRef = Arc::new(
+        Decimal128Array::from(vec![
+            0,
+            1234,
+            -1234,
+            1234567,
+            -1234567,
+            i128::MAX,
+            i128::MIN,
+        ])
+        .with_precision_and_scale(24, 2)
+        .unwrap(),
+    );
+    let options = CastOptions::default();
+    let d = black_box(decimals);
+    c.bench_function("cast_decimal", |b| {
+        b.iter(|| cast_with_options(&d, &DataType::Decimal128(6, 2), &options).unwrap());
+    });
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);