Added GroupByTransformerAggregator.

src/main/java/org/kairosdb/aggregator/GroupByTransformerAggregator.java

@@ -0,0 +1,136 @@
+package org.kairosdb.aggregator;
+
+
+import com.google.inject.Inject;
+import org.kairosdb.core.DataPoint;
+import org.kairosdb.core.annotation.FeatureComponent;
+import org.kairosdb.core.annotation.FeatureProperty;
+import org.kairosdb.core.datastore.DataPointGroup;
+import org.kairosdb.core.groupby.GroupByResult;
+import org.kairosdb.core.groupby.TagGroupByResult;
+import org.kairosdb.plugin.Aggregator;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+import java.util.function.BiFunction;
+import java.util.stream.Collectors;
+
+
+@FeatureComponent(
+        name = "group_by_transformer",
+        description = "Uppercase or lowercase groupBy values."
+)
+public class GroupByTransformerAggregator implements Aggregator {
+    @Inject
+    public GroupByTransformerAggregator() {
+    }
+
+    @FeatureProperty(
+            name = "action",
+            label = "Action",
+            description = "Action to perform. Options are lowercase or uppercase.",
+            default_value = "lowercase"
+    )
+    private String action = "";
+
+    @FeatureProperty(
+            name = "tag_names",
+            label = "Tag Names",
+            description = "List of tag names that the action will be performed on."
+    )    private List<String> tagNames = Collections.emptyList();
+
+    private final BiFunction<String, String, String> toLowercase = (key, value) -> tagNames.contains(key) ? value.toLowerCase() : value;
+    private final BiFunction<String, String, String> toUppercase = (key, value) -> tagNames.contains(key) ? value.toUpperCase() : value;
+    private BiFunction<String, String, String> actionFunction = toLowercase;
+
+    @SuppressWarnings("unused")
+    public void setAction(String action) {
+        this.action = action;
+        actionFunction = "lowercase".equalsIgnoreCase(action) ? toLowercase : toUppercase;
+    }
+
+    @SuppressWarnings("unused")
+    public void setTagNames(List<String> tagNames) {
+        this.tagNames = tagNames;
+    }
+
+    @Override
+    public DataPointGroup aggregate(DataPointGroup dataPointGroup) {
+        if (!action.isEmpty() && tagNames.isEmpty()) {
+            throw new IllegalArgumentException("TagNames cannot be empty");
+        }
+        var groupBys = dataPointGroup.getGroupByResult();
+        var modifiedGroupBys = groupBys.stream().map(this::convert).collect(Collectors.toList());
+        return new GroupByDataPointGroup(dataPointGroup, modifiedGroupBys);
+    }
+
+    private GroupByResult convert(GroupByResult groupBy) {
+        if (groupBy instanceof TagGroupByResult) {
+            var tagGroupBy = (TagGroupByResult) groupBy;
+            tagGroupBy.getTagResults().replaceAll(actionFunction);
+            return tagGroupBy;
+        } else {
+            return groupBy;
+        }
+    }
+
+    @Override
+    public boolean canAggregate(String groupType) {
+        return true;
+    }
+
+    @Override
+    public String getAggregatedGroupType(String s) {
+        return null;
+    }
+
+    @Override
+    public void init() {
+    }
+
+    private static class GroupByDataPointGroup implements DataPointGroup {
+        private final List<GroupByResult> groupByResults;
+        private final DataPointGroup dataPointGroup;
+
+        public GroupByDataPointGroup(DataPointGroup dataPointGroup, List<GroupByResult> groupByResults) {
+            this.groupByResults = groupByResults;
+            this.dataPointGroup = dataPointGroup;
+        }
+
+        @Override
+        public String getName() {
+            return dataPointGroup.getName();
+        }
+
+        @Override
+        public List<GroupByResult> getGroupByResult() {
+            return groupByResults;
+        }
+
+        @Override
+        public void close() {
+            dataPointGroup.close();
+        }
+
+        @Override
+        public boolean hasNext() {
+            return dataPointGroup.hasNext();
+        }
+
+        @Override
+        public DataPoint next() {
+            return dataPointGroup.next();
+        }
+
+        @Override
+        public Set<String> getTagNames() {
+            return dataPointGroup.getTagNames();
+        }
+
+        @Override
+        public Set<String> getTagValues(String s) {
+            return dataPointGroup.getTagValues(s);
+        }
+    }
+}

src/main/java/org/kairosdb/csvconverter/CsvConverter.java

@@ -41,7 +41,10 @@
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.text.SimpleDateFormat;
-import java.util.*;
+import java.util.Collection;
+import java.util.Date;
+import java.util.TimeZone;
+import java.util.TreeMap;
 
 @PluginName(name = "CsvConverter", description = "Converts response JSON to CSV format")
 public class CsvConverter implements QueryPostProcessingPlugin {

src/main/java/org/kairosdb/csvconverter/CsvConverterModule.java

@@ -17,12 +17,14 @@
 package org.kairosdb.csvconverter;
 
 import com.google.inject.AbstractModule;
+import org.kairosdb.aggregator.GroupByTransformerAggregator;
 
 @SuppressWarnings("unused")
 public class CsvConverterModule extends AbstractModule {
 
     @Override
     protected void configure() {
         bind(CsvConverter.class);
+        bind(GroupByTransformerAggregator.class);
     }
 }