Memory mapped buffers, ints instead of floats and epsilon GC (#451)

* Modify baseline version to improve performance

- Consume and process stream in parallel with memory map buffers, parsing it directly
- Use int instead of float/double to store values
- Use Epsilon GC and graal

* Update src/main/java/dev/morling/onebrc/CalculateAverage_adriacabeza.java

* Update calculate_average_adriacabeza.sh

---------

Co-authored-by: Gunnar Morling <gunnar.morling@googlemail.com>

calculate_average_adriacabeza.sh

@@ -0,0 +1,22 @@
+#!/bin/sh
+#
+#  Copyright 2023 The original authors
+#
+#  Licensed 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.
+#
+# sdk use java 21.0.1-graal 1>&2
+
+
+JAVA_OPTS="-XX:+UseStringDeduplication -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC"
+java --enable-preview  -classpath target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_adriacabeza
+