add ability for client code to provide InputStream of input data in addition to File

It would be needed when input data file does not reside in the same jar
but you could still use getResourceAsStream() to read the data inside a file

processing/src/test/java/io/druid/query/aggregation/AggregationTestHelper.java

@@ -29,6 +29,7 @@ import com.google.common.base.Throwables;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.common.io.CharSource;
+import com.google.common.io.Closeables;
 import com.google.common.io.Files;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.metamx.common.guava.CloseQuietly;
@@ -62,10 +63,13 @@ import io.druid.segment.Segment;
 import io.druid.segment.incremental.IncrementalIndex;
 import io.druid.segment.incremental.OnheapIncrementalIndex;
 import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.IOUtils;
 import org.apache.commons.io.LineIterator;
 
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.util.Iterator;
@@ -145,6 +149,25 @@ public class AggregationTestHelper
     }
   }
 
+  public Sequence<Row> createIndexAndRunQueryOnSegment(
+      InputStream inputDataStream,
+      String parserJson,
+      String aggregators,
+      long minTimestamp,
+      QueryGranularity gran,
+      int maxRowCount,
+      String groupByQueryJson
+  ) throws Exception
+  {
+    File segmentDir = Files.createTempDir();
+    try {
+      createIndex(inputDataStream, parserJson, aggregators, segmentDir, minTimestamp, gran, maxRowCount);
+      return runQueryOnSegments(Lists.newArrayList(segmentDir), groupByQueryJson);
+    } finally {
+      FileUtils.deleteDirectory(segmentDir);
+    }
+  }
+
   public void createIndex(
       File inputDataFile,
       String parserJson,
@@ -155,29 +178,54 @@ public class AggregationTestHelper
       int maxRowCount
   ) throws Exception
   {
-    StringInputRowParser parser = mapper.readValue(parserJson, StringInputRowParser.class);
-
-    LineIterator iter = FileUtils.lineIterator(inputDataFile, "UTF-8");
-
-    List<AggregatorFactory> aggregatorSpecs = mapper.readValue(
-        aggregators,
-        new TypeReference<List<AggregatorFactory>>()
-        {
-        }
-    );
-
     createIndex(
-        iter,
-        parser,
-        aggregatorSpecs.toArray(new AggregatorFactory[0]),
+        new FileInputStream(inputDataFile),
+        parserJson,
+        aggregators,
         outDir,
         minTimestamp,
         gran,
-        true,
         maxRowCount
     );
   }
 
+  public void createIndex(
+      InputStream inputDataStream,
+      String parserJson,
+      String aggregators,
+      File outDir,
+      long minTimestamp,
+      QueryGranularity gran,
+      int maxRowCount
+  ) throws Exception
+  {
+    try {
+      StringInputRowParser parser = mapper.readValue(parserJson, StringInputRowParser.class);
+
+      LineIterator iter = IOUtils.lineIterator(inputDataStream, "UTF-8");
+      List<AggregatorFactory> aggregatorSpecs = mapper.readValue(
+          aggregators,
+          new TypeReference<List<AggregatorFactory>>()
+          {
+          }
+      );
+
+      createIndex(
+          iter,
+          parser,
+          aggregatorSpecs.toArray(new AggregatorFactory[0]),
+          outDir,
+          minTimestamp,
+          gran,
+          true,
+          maxRowCount
+      );
+    }
+    finally {
+      Closeables.close(inputDataStream, true);
+    }
+  }
+
   public void createIndex(
       Iterator rows,
       InputRowParser parser,