From 95c9d091ef0083285410231bb202d203e0336cf1 Mon Sep 17 00:00:00 2001
From: Karl Heinz Marbaise <kama@soebes.de>
Date: Wed, 3 Jan 2024 20:21:23 +0100
Subject: [PATCH] Adding khmarbaise

---
 calculate_average_khmarbaise.sh               | 19 ++++++
 .../onebrc/CalculateAverage_khmarbaise.java   | 61 +++++++++++++++++++
 2 files changed, 80 insertions(+)
 create mode 100755 calculate_average_khmarbaise.sh
 create mode 100644 src/main/java/dev/morling/onebrc/CalculateAverage_khmarbaise.java

diff --git a/calculate_average_khmarbaise.sh b/calculate_average_khmarbaise.sh
new file mode 100755
index 0000000..16c5980
--- /dev/null
+++ b/calculate_average_khmarbaise.sh
@@ -0,0 +1,19 @@
+#!/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="-Duser.language=en-US"
+time java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_khmarbaise
diff --git a/src/main/java/dev/morling/onebrc/CalculateAverage_khmarbaise.java b/src/main/java/dev/morling/onebrc/CalculateAverage_khmarbaise.java
new file mode 100644
index 0000000..9bcf0a9
--- /dev/null
+++ b/src/main/java/dev/morling/onebrc/CalculateAverage_khmarbaise.java
@@ -0,0 +1,61 @@
+/*
+ *  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.
+ */
+package dev.morling.onebrc;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.DoubleSummaryStatistics;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static java.util.stream.Collectors.groupingBy;
+
+public class CalculateAverage_khmarbaise {
+
+    private static final Path MEASUREMENT_FILES = Path.of("./measurements.txt");
+
+    private record MeasurementRecord(String city, Double measuredValue) {
+    }
+
+    private static final Function<String, MeasurementRecord> toMeasurementRecord = line -> {
+        var posOf = line.indexOf(";");
+        var city = line.substring(0, posOf);
+        var measuredValue = line.substring(posOf + 1);
+        return new MeasurementRecord(city, Double.parseDouble(measuredValue));
+    };
+
+    private static final Function<Map.Entry<String, DoubleSummaryStatistics>, String> MIN_AVG_MAX = s -> String.format("%s=%.1f/%.1f/%.1f", s.getKey(),
+            s.getValue().getMin(), s.getValue().getAverage(), s.getValue().getMax());
+
+    public static void main(String[] args) throws IOException {
+        try (Stream<String> lines = Files.lines(MEASUREMENT_FILES)) {
+            var collect = lines
+                    .parallel()
+                    .map(toMeasurementRecord)
+                    .collect(groupingBy(MeasurementRecord::city, Collectors.summarizingDouble(MeasurementRecord::measuredValue)))
+                    .entrySet()
+                    .stream()
+                    .sorted(Map.Entry.comparingByKey())
+                    .map(MIN_AVG_MAX)
+                    .collect(Collectors.joining(", "));
+
+            System.out.println("{" + collect + "}");
+        }
+    }
+}