1 files changed, 79 insertions, 0 deletions
diff --git a/exec/java-exec/src/main/java/org/apache/drill/exec/resourcemgr/config/QueueAssignmentResult.java b/exec/java-exec/src/main/java/org/apache/drill/exec/resourcemgr/config/QueueAssignmentResult.java
new file mode 100644
index 000000000..5de2e34fe
--- /dev/null
+++ b/exec/java-exec/src/main/java/org/apache/drill/exec/resourcemgr/config/QueueAssignmentResult.java
@@ -0,0 +1,79 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.drill.exec.resourcemgr.config;
+
+import org.apache.drill.exec.ops.QueryContext;
+import org.apache.drill.shaded.guava.com.google.common.base.Preconditions;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Used to keep track of selected leaf and all rejected {@link ResourcePool} for the provided query.
+ * It is used by {@link ResourcePoolImpl#visitAndSelectPool(QueueAssignmentResult, QueryContext)} to store
+ * information about all the matching and non-matching ResourcePools for a query when ResourcePool selector is
+ * evaluated against query metadata. Later it is used by
+ * {@link ResourcePool#visitAndSelectPool(QueueAssignmentResult, QueryContext)} to apply
+ * {@link org.apache.drill.exec.resourcemgr.config.selectionpolicy.QueueSelectionPolicy} to select only one queue out of all
+ * the selected queues for a query. It also provides an API to dump all the debug information to know which pools were
+ * selected and rejected for a query.
+ */
+public class QueueAssignmentResult {
+  private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(QueueAssignmentResult.class);
+
+  private final List<ResourcePool> selectedLeafPools = new ArrayList<>();
+
+  private final List<ResourcePool> rejectedPools = new ArrayList<>();
+
+  public void addSelectedPool(ResourcePool pool) {
+    Preconditions.checkState(pool.isLeafPool(), "Selected pool %s is not a leaf pool",
+      pool.getPoolName());
+    selectedLeafPools.add(pool);
+  }
+
+  public void addRejectedPool(ResourcePool pool) {
+    rejectedPools.add(pool);
+  }
+
+  public List<ResourcePool> getSelectedLeafPools() {
+    return selectedLeafPools;
+  }
+
+  public List<ResourcePool> getRejectedPools() {
+    return rejectedPools;
+  }
+
+  public void logAssignmentResult(String queryId) {
+    logger.debug("For query {}. Details[{}]", queryId, toString());
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("Selected Leaf Pools: {");
+    for (ResourcePool pool : selectedLeafPools) {
+      sb.append(pool.getPoolName()).append(", ");
+    }
+    sb.append("} and Rejected pools: {");
+    for (ResourcePool pool : rejectedPools) {
+      sb.append(pool.getPoolName()).append(", ");
+    }
+    sb.append("}");
+    return sb.toString();
+  }
+}