From c4dce942a69bb58521a476e91f052f9d54362961 Mon Sep 17 00:00:00 2001
From: ahr <ahr@ahr.local>
Date: Sun, 10 Dec 2017 17:53:53 +0100
Subject: [PATCH] parallelize csv generation

speedup 50% and more
---
 .../org/lucares/recommind/logs/Plotter.java   | 35 +++++++++++--------
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/pdb-plotting/src/main/java/org/lucares/recommind/logs/Plotter.java b/pdb-plotting/src/main/java/org/lucares/recommind/logs/Plotter.java
index 5fa4abb..3b9c3d7 100644
--- a/pdb-plotting/src/main/java/org/lucares/recommind/logs/Plotter.java
+++ b/pdb-plotting/src/main/java/org/lucares/recommind/logs/Plotter.java
@@ -20,10 +20,10 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.UUID;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Stream;
 
 import org.lucares.pdb.api.Entry;
-import org.lucares.pdb.api.GroupResult;
 import org.lucares.pdb.api.Result;
 import org.lucares.pdb.api.Tags;
 import org.lucares.pdb.plot.api.CustomAggregator;
@@ -75,6 +75,7 @@ public class Plotter {
 	public PlotResult plot(final PlotSettings plotSettings) throws InternalPlottingException {
 
 		LOGGER.trace("start plot: {}", plotSettings);
+		
 
 		final String tmpSubDir = uniqueDirectoryName();
 		final Path tmpDir = tmpBaseDir.resolve(tmpSubDir);
@@ -91,20 +92,26 @@ public class Plotter {
 
 			final Result result = db.get(query, groupBy);
 
-			int idCounter = 0;
-			for (final GroupResult groupResult : result.getGroups()) {
-
-				final Stream<Entry> entries = groupResult.asStream();
-
-				final CsvSummary csvSummary = toCsv(entries, tmpDir, dateFrom, dateTo, plotSettings);
-
-				final String title = title(groupResult.getGroupedBy(), csvSummary.getValues());
-				final DataSeries dataSerie = new DataSeries("id"+idCounter, title, csvSummary);
-				if (dataSerie.getValues() > 0) {
-					dataSeries.add(dataSerie);
+			final long start = System.nanoTime();
+			final AtomicInteger idCounter = new AtomicInteger(0);
+			result.getGroups().stream().parallel().forEach(groupResult -> {
+				try{
+					final Stream<Entry> entries = groupResult.asStream();
+	
+					final CsvSummary csvSummary = toCsv(entries, tmpDir, dateFrom, dateTo, plotSettings);
+	
+					final int id = idCounter.getAndIncrement();
+					final String title = title(groupResult.getGroupedBy(), csvSummary.getValues());
+					final DataSeries dataSerie = new DataSeries("id"+id, title, csvSummary);
+					if (dataSerie.getValues() > 0) {
+						dataSeries.add(dataSerie);
+					}
+				}catch (Exception e){
+					throw new IllegalStateException( e); // TODO handle
 				}
-				idCounter++;
-			}
+			});
+			METRICS_LOGGER.debug("csv generation took: " + (System.nanoTime() - start) / 1_000_000.0
+					+ "ms");
 
 			if (dataSeries.isEmpty()) {
 				throw new NoDataPointsException();