My own solution -- memory mapping the files, running in parallel threads, using a state machine to parse the file (#466)

* Golang implementation

* Speed up by avoiding copying the lines

* Memory mapping

* Add script for testing

* Now passing most of the tests

* Refactor to composed method

* Now using integer math throughout

* Now using a state machine for parsing!

* Refactoring state names

* Enabling profiling

* Running in parallel!

* Fully parallel!

* Refactor

* Improve type safety of methods

* The rounding problem is due to difference between Javas and Gos printf implementation

* Converting my solution to Java

* Merging results

* Splitting the file in several buffers

* Made it parallel!

* Removed test file

* Removed go implementation

* Removed unused files

* Add header to .sh file

---------

Co-authored-by: Matteo Vaccari <mvaccari@thoughtworks.com>

calculate_average_xpmatteo.sh

@@ -0,0 +1,20 @@
+#!/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.
+#
+
+JAVA_OPTS="--enable-preview"
+java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_xpmatteo
+