Make specifying query context booleans more consistent.

Before, some needed to be strings and some needed to be real booleans. Now
they can all be either one.

processing/src/main/java/io/druid/query/BaseQuery.java

@@ -193,6 +193,12 @@ public abstract class BaseQuery<T extends Comparable<T>> implements Query<T>
     return retVal == null ? defaultValue : retVal;
   }
 
+  @Override
+  public boolean getContextBoolean(String key, boolean defaultValue)
+  {
+    return parseBoolean(this, key, defaultValue);
+  }
+
   protected Map<String, Object> computeOverridenContext(Map<String, Object> overrides)
   {
     Map<String, Object> overridden = Maps.newTreeMap();

processing/src/main/java/io/druid/query/Query.java

@@ -81,6 +81,8 @@ public interface Query<T>
 
   <ContextType> ContextType getContextValue(String key, ContextType defaultValue);
 
+  boolean getContextBoolean(String key, boolean defaultValue);
+
   boolean isDescending();
 
   Ordering<T> getResultOrdering();

processing/src/main/java/io/druid/query/groupby/GroupByQueryHelper.java

@@ -81,7 +81,7 @@ public class GroupByQueryHelper
     );
     final IncrementalIndex index;
 
-    if (query.getContextValue("useOffheap", false)) {
+    if (query.getContextBoolean("useOffheap", false)) {
       index = new OffheapIncrementalIndex(
           // use granularity truncated min timestamp
           // since incoming truncated timestamps may precede timeStart

processing/src/main/java/io/druid/query/groupby/GroupByQueryQueryToolChest.java

@@ -130,7 +130,7 @@ public class GroupByQueryQueryToolChest extends QueryToolChest<Row, GroupByQuery
           return runner.run(query, responseContext);
         }
 
-        if (Boolean.valueOf(query.getContextValue(GROUP_BY_MERGE_KEY, "true"))) {
+        if (query.getContextBoolean(GROUP_BY_MERGE_KEY, true)) {
           return mergeGroupByResults(
               (GroupByQuery) query,
               runner,

processing/src/main/java/io/druid/query/timeseries/TimeseriesQuery.java

@@ -106,7 +106,7 @@ public class TimeseriesQuery extends BaseQuery<Result<TimeseriesResultValue>>
 
   public boolean isSkipEmptyBuckets()
   {
-    return Boolean.parseBoolean(getContextValue("skipEmptyBuckets", "false"));
+    return getContextBoolean("skipEmptyBuckets", false);
   }
 
   public TimeseriesQuery withQuerySegmentSpec(QuerySegmentSpec querySegmentSpec)

processing/src/main/java/io/druid/query/topn/TopNQueryEngine.java

@@ -119,7 +119,7 @@ public class TopNQueryEngine
       topNAlgorithm = new DimExtractionTopNAlgorithm(capabilities, query);
     } else if (selector.isAggregateAllMetrics()) {
       topNAlgorithm = new PooledTopNAlgorithm(capabilities, query, bufferPool);
-    } else if (selector.isAggregateTopNMetricFirst() || query.getContextValue("doAggregateTopNMetricFirst", false)) {
+    } else if (selector.isAggregateTopNMetricFirst() || query.getContextBoolean("doAggregateTopNMetricFirst", false)) {
       topNAlgorithm = new AggregateTopNMetricFirstAlgorithm(capabilities, query, bufferPool);
     } else {
       topNAlgorithm = new PooledTopNAlgorithm(capabilities, query, bufferPool);

processing/src/test/java/io/druid/query/datasourcemetadata/DataSourceMetadataQueryTest.java

@@ -81,7 +81,7 @@ public class DataSourceMetadataQueryTest
                                                         "useCache",
                                                         true,
                                                         "populateCache",
-                                                        true,
+                                                        "true",
                                                         "finalize",
                                                         true
                                                     )
@@ -101,8 +101,11 @@ public class DataSourceMetadataQueryTest
 
     Assert.assertEquals(1, serdeQuery.getContextValue("priority"));
     Assert.assertEquals(true, serdeQuery.getContextValue("useCache"));
-    Assert.assertEquals(true, serdeQuery.getContextValue("populateCache"));
+    Assert.assertEquals("true", serdeQuery.getContextValue("populateCache"));
     Assert.assertEquals(true, serdeQuery.getContextValue("finalize"));
+    Assert.assertEquals(true, serdeQuery.getContextBoolean("useCache", false));
+    Assert.assertEquals(true, serdeQuery.getContextBoolean("populateCache", false));
+    Assert.assertEquals(true, serdeQuery.getContextBoolean("finalize", false));
   }
 
   @Test

server/src/main/java/io/druid/segment/realtime/plumber/RealtimePlumber.java

@@ -266,7 +266,7 @@ public class RealtimePlumber implements Plumber
   @Override
   public <T> QueryRunner<T> getQueryRunner(final Query<T> query)
   {
-    final boolean skipIncrementalSegment = query.getContextValue(SKIP_INCREMENTAL_SEGMENT, false);
+    final boolean skipIncrementalSegment = query.getContextBoolean(SKIP_INCREMENTAL_SEGMENT, false);
     final QueryRunnerFactory<T, Query<T>> factory = conglomerate.findFactory(query);
     final QueryToolChest<T, Query<T>> toolchest = factory.getToolchest();