C style code. Should be ~4secs or lower based on local testing. (#559)

1. Use Unsafe
2. Fit hashtable in L2 cache.
3. If we can find a good hash function, it can fit in L1 cache even.
4. Improve temperature parsing by using a lookup table

calculate_average_vemanaNonIdiomatic.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+#
+#  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.
+#
+
+# Basics
+JAVA_OPTS=""
+JAVA_OPTS="$JAVA_OPTS --enable-preview"
+JAVA_OPTS="$JAVA_OPTS --add-exports java.base/jdk.internal.ref=ALL-UNNAMED"
+JAVA_OPTS="$JAVA_OPTS --add-opens java.base/java.nio=ALL-UNNAMED"
+
+# JIT parameters
+JAVA_OPTS="$JAVA_OPTS -XX:+AlwaysCompileLoopMethods"
+
+# GC parameters
+JAVA_OPTS="$JAVA_OPTS -XX:+UseParallelGC"
+
+
+java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_vemanaNonIdiomatic "$@"

prepare_vemanaNonIdiomatic.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+#
+#  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.
+#
+
+source "$HOME/.sdkman/bin/sdkman-init.sh"
+sdk use java 21.0.1-graal 1>&2
+