add implementation jgrateron

1 files changed, 166 insertions, 0 deletions

diff --git a/src/main/java/dev/morling/onebrc/CalculateAverage_jgrateron.java b/src/main/java/dev/morling/onebrc/CalculateAverage_jgrateron.java
new file mode 100644
index 0000000..36e66cd
--- /dev/null
+++ b/src/main/java/dev/morling/onebrc/CalculateAverage_jgrateron.java
@@ -0,0 +1,166 @@
+/*
+ *  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.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Queue;
+import java.util.TreeMap;
+import java.util.stream.Collectors;
+
+public class CalculateAverage_jgrateron {
+    private static final String FILE = "./measurements.txt";
+    private static int MAX_LINES = 100000;
+
+    public static void main(String[] args) throws IOException, InterruptedException {
+        //long startTime = System.nanoTime();
+
+        var tasks = new ArrayList<TaskCalcular>();
+        try (var reader = new BufferedReader(new FileReader(FILE))) {
+            String line;
+            var listaLineas = new LinkedList<String>();
+            while ((line = reader.readLine()) != null) {
+                listaLineas.add(line);
+                if (listaLineas.size() > MAX_LINES) {
+                    var taskCalcular = new TaskCalcular(listaLineas);
+                    listaLineas = new LinkedList<String>();
+                    tasks.add(taskCalcular);
+                }
+            }
+            if (listaLineas.size() > 0) {
+                var taskCalcular = new TaskCalcular(listaLineas);
+                tasks.add(taskCalcular);
+            }
+        }
+        // combinar todas las particiones
+        var totalMediciones = new TreeMap<String, Medicion>();
+        for (var task : tasks) {
+            task.join();
+            var mediciones = task.getMediciones();
+            for (var entry : mediciones.entrySet()) {
+                var medicion = totalMediciones.get(entry.getKey());
+                if (medicion == null) {
+                    totalMediciones.put(entry.getKey(), entry.getValue());
+                }
+                else {
+                    var otraMed = entry.getValue();
+                    medicion.update(otraMed.count, otraMed.tempMin, otraMed.tempMax, otraMed.tempSum);
+                }
+            }
+        }
+        var result = totalMediciones.entrySet().stream()//
+                .map(e -> e.getKey() + "=" + e.getValue())//
+                .collect(Collectors.joining(", "));
+
+        System.out.println("{" + result + "}");
+
+        //System.out.println("Total: " + (System.nanoTime() - startTime) / 1000000);
+    }
+
+    /*
+     * 
+     */
+    static class TaskCalcular {
+
+        private Queue<String> listaLineas;
+        private Map<String, Medicion> mediciones;
+        private Thread hilo;
+
+        public TaskCalcular(Queue<String> listaLineas) {
+            this.listaLineas = listaLineas;
+            mediciones = new HashMap<String, Medicion>();
+            hilo = Thread.ofPlatform().unstarted(() -> {
+                run();
+            });
+            hilo.start();
+        }
+
+        public void join() throws InterruptedException {
+            hilo.join();
+        }
+
+        public void run() {
+            String linea;
+            int pos;
+            while ((linea = listaLineas.poll()) != null) {
+                pos = linea.indexOf(";");
+                var estacion = linea.substring(0, pos);
+                var temp = Double.parseDouble(linea.substring(pos + 1));
+                var medicion = mediciones.get(estacion);
+                if (medicion == null) {
+                    medicion = new Medicion(estacion, 1, temp, temp, temp);
+                    mediciones.put(estacion, medicion);
+                }
+                else {
+                    medicion.update(1, temp, temp, temp);
+                }
+            }
+        }
+
+        public Map<String, Medicion> getMediciones() {
+            return mediciones;
+        }
+    }
+
+    /*
+     * 
+     */
+    static class Medicion implements Comparable<Medicion> {
+        private String estacion;
+        private int count;
+        private double tempMin;
+        private double tempMax;
+        private double tempSum;
+
+        public Medicion(String estacion, int count, double tempMin, double tempMax, double tempSum) {
+            super();
+            this.estacion = estacion;
+            this.count = count;
+            this.tempMin = tempMin;
+            this.tempMax = tempMax;
+            this.tempSum = tempSum;
+        }
+
+        public void update(int count, double tempMin, double tempMax, double tempSum) {
+            this.count += count;
+            if (tempMin < this.tempMin) {
+                this.tempMin = tempMin;
+            }
+            if (tempMax > this.tempMax) {
+                this.tempMax = tempMax;
+            }
+            this.tempSum += tempSum;
+        }
+
+        @Override
+        public String toString() {
+            double tempPro = tempSum / count;
+            return "%.1f/%.1f/%.1f".formatted(tempMin, tempPro, tempMax);
+        }
+
+        @Override
+        public int compareTo(Medicion medicion) {
+            return estacion.compareTo(medicion.estacion);
+        }
+    }
+
+}