Github user denalex commented on a diff in the pull request:
https://github.com/apache/incubator-hawq/pull/1379#discussion_r201517046
--- Diff:
pxf/pxf-service/src/main/java/org/apache/hawq/pxf/service/UGICache.java ---
@@ -0,0 +1,143 @@
+package org.apache.hawq.pxf.service;
+
+/*
+ * 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.
+ */
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.DelayQueue;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.security.UserGroupInformation;
+
+public class UGICache {
+
+ private static final Log LOG = LogFactory.getLog(UGICache.class);
+ private Map<SessionId, UGICacheEntry> cache = new
ConcurrentHashMap<>();
+ @SuppressWarnings("unchecked")
+ // There is a separate DelayQueue for each segment (also being used
for locking)
+ private DelayQueue<UGICacheEntry>[] delayQueues =
(DelayQueue<UGICacheEntry>[])new DelayQueue[64];
+ private final UGIProvider ugiProvider;
+
+ public UGICache(UGIProvider provider) {
+ this.ugiProvider = provider;
+ for (int i = 0; i < delayQueues.length; i++) {
+ delayQueues[i] = new DelayQueue<>();
+ }
+ }
+
+ public UGICache() {
+ this(new UGIProvider());
+ }
+
+ // Create new proxy UGI if not found in cache and increment reference
count
+ public UGICacheEntry getTimedProxyUGI(SessionId session)
+ throws IOException {
+
+ Integer segmentId = session.getSegmentId();
+ String user = session.getUser();
+ synchronized (delayQueues[segmentId]) {
+ // Use the opportunity to cleanup any expired entries
+ cleanup(segmentId);
+ UGICacheEntry timedProxyUGI = cache.get(session);
+ if (timedProxyUGI == null) {
+ LOG.info(session.toString() + " Creating proxy user = " +
user);
+ UserGroupInformation proxyUGI =
ugiProvider.createProxyUGI(user);
+ timedProxyUGI = new UGICacheEntry(proxyUGI, session);
+ delayQueues[segmentId].offer(timedProxyUGI);
+ cache.put(session, timedProxyUGI);
+ }
+ timedProxyUGI.incrementCounter();
+ return timedProxyUGI;
+ }
+ }
+
+ // Poll segment expiration queue for all expired entries
+ // and clean them if possible
+ private void cleanup(Integer segmentId) {
--- End diff --
proper javadoc, please
---
