Author: suresh
Date: Fri Jun 11 18:15:17 2010
New Revision: 953803
URL: http://svn.apache.org/viewvc?rev=953803&view=rev
Log:
HDFS-1110. Reuses objects for commonly used file names in namenode to reduce
the heap usage. Contributed by Suresh Srinivas.
Added:
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/NameCache.java
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/NameDistributionVisitor.java
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/util/ByteArray.java
hadoop/hdfs/trunk/src/test/hdfs/org/apache/hadoop/hdfs/server/namenode/TestNameCache.java
Modified:
hadoop/hdfs/trunk/CHANGES.txt
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/DFSConfigKeys.java
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/OfflineImageViewer.java
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/TextWriterImageVisitor.java
Modified: hadoop/hdfs/trunk/CHANGES.txt
URL:
http://svn.apache.org/viewvc/hadoop/hdfs/trunk/CHANGES.txt?rev=953803&r1=953802&r2=953803&view=diff
==============================================================================
--- hadoop/hdfs/trunk/CHANGES.txt (original)
+++ hadoop/hdfs/trunk/CHANGES.txt Fri Jun 11 18:15:17 2010
@@ -9,6 +9,9 @@ Trunk (unreleased changes)
IMPROVEMENTS
+ HDFS-1110. Reuses objects for commonly used file names in namenode to
+ reduce the heap usage. (suresh)
+
HDFS-1096. fix for prev. commit. (boryas)
HDFS-1096. allow dfsadmin/mradmin refresh of superuser proxy group
Modified: hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/DFSConfigKeys.java
URL:
http://svn.apache.org/viewvc/hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/DFSConfigKeys.java?rev=953803&r1=953802&r2=953803&view=diff
==============================================================================
--- hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/DFSConfigKeys.java
(original)
+++ hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/DFSConfigKeys.java Fri
Jun 11 18:15:17 2010
@@ -205,4 +205,6 @@ public class DFSConfigKeys extends Commo
public static final String DFS_NAMENODE_KRB_HTTPS_USER_NAME_KEY =
"dfs.namenode.kerberos.https.principal";
public static final String DFS_SECONDARY_NAMENODE_USER_NAME_KEY =
"dfs.secondary.namenode.kerberos.principal";
public static final String DFS_SECONDARY_NAMENODE_KRB_HTTPS_USER_NAME_KEY =
"dfs.secondary.namenode.kerberos.https.principal";
+ public static final String DFS_NAMENODE_NAME_CACHE_THRESHOLD_KEY =
"dfs.namenode.name.cache.threshold";
+ public static final int DFS_NAMENODE_NAME_CACHE_THRESHOLD_DEFAULT = 10;
}
Modified:
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
URL:
http://svn.apache.org/viewvc/hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java?rev=953803&r1=953802&r2=953803&view=diff
==============================================================================
---
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
(original)
+++
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
Fri Jun 11 18:15:17 2010
@@ -43,6 +43,7 @@ import org.apache.hadoop.hdfs.protocol.H
import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
import org.apache.hadoop.hdfs.server.common.HdfsConstants.BlockUCState;
import org.apache.hadoop.hdfs.server.common.HdfsConstants.StartupOption;
+import org.apache.hadoop.hdfs.util.ByteArray;
import static org.apache.hadoop.hdfs.server.common.Util.now;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.security.UserGroupInformation;
@@ -64,6 +65,12 @@ class FSDirectory implements Closeable {
private static final long UNKNOWN_DISK_SPACE = -1;
private final int lsLimit; // max list limit
+ /**
+ * Caches frequently used file names used in {...@link INode} to reuse
+ * byte[] objects and reduce heap usage.
+ */
+ private final NameCache<ByteArray> nameCache;
+
/** Access an existing dfs name directory. */
FSDirectory(FSNamesystem ns, Configuration conf) {
this(new FSImage(), ns, conf);
@@ -72,6 +79,7 @@ class FSDirectory implements Closeable {
NameNode.LOG.info("set FSImage.restoreFailedStorage");
fsImage.setRestoreFailedStorage(true);
}
+
fsImage.setCheckpointDirectories(FSImage.getCheckpointDirs(conf, null),
FSImage.getCheckpointEditsDirs(conf, null));
}
@@ -86,6 +94,13 @@ class FSDirectory implements Closeable {
DFSConfigKeys.DFS_LIST_LIMIT, DFSConfigKeys.DFS_LIST_LIMIT_DEFAULT);
this.lsLimit = configuredLimit>0 ?
configuredLimit : DFSConfigKeys.DFS_LIST_LIMIT_DEFAULT;
+
+ int threshold = conf.getInt(
+ DFSConfigKeys.DFS_NAMENODE_NAME_CACHE_THRESHOLD_KEY,
+ DFSConfigKeys.DFS_NAMENODE_NAME_CACHE_THRESHOLD_DEFAULT);
+ NameNode.LOG.info("Caching file names occuring more than " + threshold
+ + " times ");
+ nameCache = new NameCache<ByteArray>(threshold);
}
private FSNamesystem getFSNamesystem() {
@@ -119,6 +134,7 @@ class FSDirectory implements Closeable {
}
synchronized (this) {
this.ready = true;
+ this.nameCache.initialized();
this.notifyAll();
}
}
@@ -270,6 +286,7 @@ class FSDirectory implements Closeable {
try {
newParent = rootDir.addToParent(src, newNode, parentINode,
false, propagateModTime);
+ cacheName(newNode);
} catch (FileNotFoundException e) {
return null;
}
@@ -1396,7 +1413,9 @@ class FSDirectory implements Closeable {
long childDiskspace, boolean inheritPermission)
throws QuotaExceededException, UnresolvedLinkException {
byte[][] components = INode.getPathComponents(src);
- child.setLocalName(components[components.length-1]);
+ byte[] path = components[components.length-1];
+ child.setLocalName(path);
+ cacheName(child);
INode[] inodes = new INode[components.length];
synchronized (rootDir) {
rootDir.getExistingPathINodes(components, inodes, false);
@@ -1852,4 +1871,20 @@ class FSDirectory implements Closeable {
}
return newNode;
}
+
+ /**
+ * Caches frequently used file names to reuse file name objects and
+ * reduce heap size.
+ */
+ void cacheName(INode inode) {
+ // Name is cached only for files
+ if (inode.isDirectory() || inode.isLink()) {
+ return;
+ }
+ ByteArray name = new ByteArray(inode.getLocalNameBytes());
+ name = nameCache.put(name);
+ if (name != null) {
+ inode.setLocalName(name.getBytes());
+ }
+ }
}
Added:
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/NameCache.java
URL:
http://svn.apache.org/viewvc/hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/NameCache.java?rev=953803&view=auto
==============================================================================
---
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/NameCache.java
(added)
+++
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/NameCache.java
Fri Jun 11 18:15:17 2010
@@ -0,0 +1,155 @@
+/**
+ * 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.hadoop.hdfs.server.namenode;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * Caches frequently used names to facilitate reuse.
+ * (example: byte[] representation of the file name in {...@link INode}).
+ *
+ * This class is used by initially adding all the file names. Cache
+ * tracks the number of times a name is used in a transient map. It promotes
+ * a name used more than {...@code useThreshold} to the cache.
+ *
+ * One all the names are added, {...@link #initialized()} should be called to
+ * finish initialization. The transient map where use count is tracked is
+ * discarded and cache is ready for use.
+ *
+ * <p>
+ * This class must be synchronized externally.
+ *
+ * @param <K> name to be added to the cache
+ */
+class NameCache<K> {
+ /**
+ * Class for tracking use count of a name
+ */
+ private class UseCount {
+ int count;
+ final K value; // Internal value for the name
+
+ UseCount(final K value) {
+ count = 1;
+ this.value = value;
+ }
+
+ void increment() {
+ count++;
+ }
+
+ int get() {
+ return count;
+ }
+ }
+
+ static final Log LOG = LogFactory.getLog(NameCache.class.getName());
+
+ /** indicates initialization is in progress */
+ private boolean initialized = false;
+
+ /** names used more than {...@code useThreshold} is added to the cache */
+ private final int useThreshold;
+
+ /** of times a cache look up was successful */
+ private int lookups = 0;
+
+ /** Cached names */
+ final HashMap<K, K> cache = new HashMap<K, K>();
+
+ /** Names and with number of occurrences tracked during initialization */
+ Map<K, UseCount> transientMap = new HashMap<K, UseCount>();
+
+ /**
+ * Constructor
+ * @param useThreshold names occurring more than this is promoted to the
+ * cache
+ */
+ NameCache(int useThreshold) {
+ this.useThreshold = useThreshold;
+ }
+
+ /**
+ * Add a given name to the cache or track use count.
+ * exist. If the name already exists, then the internal value is returned.
+ *
+ * @param name name to be looked up
+ * @return internal value for the name if found; otherwise null
+ */
+ K put(final K name) {
+ K internal = cache.get(name);
+ if (internal != null) {
+ lookups++;
+ return internal;
+ }
+
+ // Track the usage count only during initialization
+ if (!initialized) {
+ UseCount useCount = transientMap.get(name);
+ if (useCount != null) {
+ useCount.increment();
+ if (useCount.get() >= useThreshold) {
+ promote(name);
+ }
+ return useCount.value;
+ }
+ useCount = new UseCount(name);
+ transientMap.put(name, useCount);
+ }
+ return null;
+ }
+
+ /**
+ * Lookup count when a lookup for a name returned cached object
+ * @return number of successful lookups
+ */
+ int getLookupCount() {
+ return lookups;
+ }
+
+ /**
+ * Size of the cache
+ * @return Number of names stored in the cache
+ */
+ int size() {
+ return cache.size();
+ }
+
+ /**
+ * Mark the name cache as initialized. The use count is no longer tracked
+ * and the transient map used for initializing the cache is discarded to
+ * save heap space.
+ */
+ void initialized() {
+ LOG.info("initialized with " + size() + " entries " + lookups + "
lookups");
+ this.initialized = true;
+ transientMap.clear();
+ transientMap = null;
+ }
+
+ /** Promote a frequently used name to the cache */
+ private void promote(final K name) {
+ transientMap.remove(name);
+ cache.put(name, name);
+ lookups += useThreshold;
+ }
+}
Added:
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/NameDistributionVisitor.java
URL:
http://svn.apache.org/viewvc/hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/NameDistributionVisitor.java?rev=953803&view=auto
==============================================================================
---
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/NameDistributionVisitor.java
(added)
+++
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/NameDistributionVisitor.java
Fri Jun 11 18:15:17 2010
@@ -0,0 +1,115 @@
+/**
+ * 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.hadoop.hdfs.tools.offlineImageViewer;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map.Entry;
+
+/**
+ * File name distribution visitor.
+ * <p>
+ * It analyzes file names in fsimage and prints the following information:
+ * <li>Number of unique file names</li>
+ * <li>Number file names and the corresponding number range of files that use
+ * these same names</li>
+ * <li>Heap saved if the file name objects are reused</li>
+ */
+public class NameDistributionVisitor extends TextWriterImageVisitor {
+ HashMap<String, Integer> counts = new HashMap<String, Integer>();
+
+ public NameDistributionVisitor(String filename, boolean printToScreen)
+ throws IOException {
+ super(filename, printToScreen);
+ }
+
+ @Override
+ void finish() throws IOException {
+ final int BYTEARRAY_OVERHEAD = 24;
+
+ write("Total unique file names " + counts.size());
+ // Columns: Frequency of file occurrence, savings in heap, total files
using
+ // the name and number of file names
+ final long stats[][] = { { 100000, 0, 0, 0 },
+ { 10000, 0, 0, 0 },
+ { 1000, 0, 0, 0 },
+ { 100, 0, 0, 0 },
+ { 10, 0, 0, 0 },
+ { 5, 0, 0, 0 },
+ { 4, 0, 0, 0 },
+ { 3, 0, 0, 0 },
+ { 2, 0, 0, 0 }};
+
+ int highbound = Integer.MIN_VALUE;
+ for (Entry<String, Integer> entry : counts.entrySet()) {
+ highbound = Math.max(highbound, entry.getValue());
+ for (int i = 0; i < stats.length; i++) {
+ if (entry.getValue() >= stats[i][0]) {
+ stats[i][1] += (BYTEARRAY_OVERHEAD + entry.getKey().length())
+ * (entry.getValue() - 1);
+ stats[i][2] += entry.getValue();
+ stats[i][3]++;
+ break;
+ }
+ }
+ }
+
+ long lowbound = 0;
+ long totalsavings = 0;
+ for (long[] stat : stats) {
+ lowbound = stat[0];
+ totalsavings += stat[1];
+ String range = lowbound == highbound ? " " + lowbound :
+ " between " + lowbound + "-" + highbound;
+ write("\n" + stat[3] + " names are used by " + stat[2] + " files"
+ + range + " times. Heap savings ~" + stat[1] + " bytes.");
+ highbound = (int) stat[0] - 1;
+ }
+ write("\n\nTotal saved heap ~" + totalsavings + "bytes.\n");
+ super.finish();
+ }
+
+ @Override
+ void visit(ImageElement element, String value) throws IOException {
+ if (element == ImageElement.INODE_PATH) {
+ String filename = value.substring(value.lastIndexOf("/") + 1);
+ if (counts.containsKey(filename)) {
+ counts.put(filename, counts.get(filename) + 1);
+ } else {
+ counts.put(filename, 1);
+ }
+ }
+ }
+
+ @Override
+ void leaveEnclosingElement() throws IOException {
+ }
+
+ @Override
+ void start() throws IOException {
+ }
+
+ @Override
+ void visitEnclosingElement(ImageElement element) throws IOException {
+ }
+
+ @Override
+ void visitEnclosingElement(ImageElement element, ImageElement key,
+ String value) throws IOException {
+ }
+}
Modified:
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/OfflineImageViewer.java
URL:
http://svn.apache.org/viewvc/hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/OfflineImageViewer.java?rev=953803&r1=953802&r2=953803&view=diff
==============================================================================
---
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/OfflineImageViewer.java
(original)
+++
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/OfflineImageViewer.java
Fri Jun 11 18:15:17 2010
@@ -72,6 +72,9 @@ public class OfflineImageViewer {
" -maxSize specifies the range [0, maxSize] of file sizes to be\n" +
" analyzed (128GB by default).\n" +
" -step defines the granularity of the distribution. (2MB by
default)\n" +
+ " * NameDistribution: This processor analyzes the file names\n" +
+ " in the image and prints total number of file names and how
frequently" +
+ " file names are reused.\n" +
"\n" +
"Required command line arguments:\n" +
"-i,--inputFile <arg> FSImage file to process.\n" +
@@ -233,6 +236,8 @@ public class OfflineImageViewer {
long maxSize = Long.parseLong(cmd.getOptionValue("maxSize", "0"));
int step = Integer.parseInt(cmd.getOptionValue("step", "0"));
v = new FileDistributionVisitor(outputFile, maxSize, step);
+ } else if (processor.equals("NameDistribution")) {
+ v = new NameDistributionVisitor(outputFile, printToScreen);
} else {
v = new LsImageVisitor(outputFile, printToScreen);
skipBlocks = false;
Modified:
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/TextWriterImageVisitor.java
URL:
http://svn.apache.org/viewvc/hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/TextWriterImageVisitor.java?rev=953803&r1=953802&r2=953803&view=diff
==============================================================================
---
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/TextWriterImageVisitor.java
(original)
+++
hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/TextWriterImageVisitor.java
Fri Jun 11 18:15:17 2010
@@ -96,11 +96,11 @@ abstract class TextWriterImageVisitor ex
if(printToScreen)
System.out.print(toWrite);
- try {
- fw.write(toWrite);
- } catch (IOException e) {
- okToWrite = false;
- throw e;
- }
+ try {
+ fw.write(toWrite);
+ } catch (IOException e) {
+ okToWrite = false;
+ throw e;
+ }
}
}
Added: hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/util/ByteArray.java
URL:
http://svn.apache.org/viewvc/hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/util/ByteArray.java?rev=953803&view=auto
==============================================================================
--- hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/util/ByteArray.java
(added)
+++ hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/util/ByteArray.java Fri
Jun 11 18:15:17 2010
@@ -0,0 +1,52 @@
+/**
+ * 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.hadoop.hdfs.util;
+
+import java.util.Arrays;
+
+/**
+ * Wrapper for byte[] to use byte[] as key in HashMap
+ */
+public class ByteArray {
+ private int hash = 0; // cache the hash code
+ private final byte[] bytes;
+
+ public ByteArray(byte[] bytes) {
+ this.bytes = bytes;
+ }
+
+ public byte[] getBytes() {
+ return bytes;
+ }
+
+ @Override
+ public int hashCode() {
+ if (hash == 0) {
+ hash = Arrays.hashCode(bytes);
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (!(o instanceof ByteArray)) {
+ return false;
+ }
+ return Arrays.equals(bytes, ((ByteArray)o).bytes);
+ }
+}
Added:
hadoop/hdfs/trunk/src/test/hdfs/org/apache/hadoop/hdfs/server/namenode/TestNameCache.java
URL:
http://svn.apache.org/viewvc/hadoop/hdfs/trunk/src/test/hdfs/org/apache/hadoop/hdfs/server/namenode/TestNameCache.java?rev=953803&view=auto
==============================================================================
---
hadoop/hdfs/trunk/src/test/hdfs/org/apache/hadoop/hdfs/server/namenode/TestNameCache.java
(added)
+++
hadoop/hdfs/trunk/src/test/hdfs/org/apache/hadoop/hdfs/server/namenode/TestNameCache.java
Fri Jun 11 18:15:17 2010
@@ -0,0 +1,75 @@
+/**
+ * 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.hadoop.hdfs.server.namenode;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+/**
+ * Test for {...@link NameCache} class
+ */
+public class TestNameCache {
+ @Test
+ public void testDictionary() throws Exception {
+ // Create dictionary with useThreshold 2
+ NameCache<String> cache =
+ new NameCache<String>(2);
+ String[] matching = {"part1", "part10000000", "fileabc", "abc",
"filepart"};
+ String[] notMatching = {"spart1", "apart", "abcd", "def"};
+
+ for (String s : matching) {
+ // Add useThreshold times so the names are promoted to dictionary
+ cache.put(s);
+ assertTrue(s == cache.put(s));
+ }
+ for (String s : notMatching) {
+ // Add < useThreshold times so the names are not promoted to dictionary
+ cache.put(s);
+ }
+
+ // Mark dictionary as initialized
+ cache.initialized();
+
+ for (String s : matching) {
+ verifyNameReuse(cache, s, true);
+ }
+ // Check dictionary size
+ assertEquals(matching.length, cache.size());
+
+ for (String s : notMatching) {
+ verifyNameReuse(cache, s, false);
+ }
+ }
+
+ private void verifyNameReuse(NameCache<String> cache, String s, boolean
reused) {
+ cache.put(s);
+ int lookupCount = cache.getLookupCount();
+ if (reused) {
+ // Dictionary returns non null internal value
+ assertNotNull(cache.put(s));
+ // Successful lookup increments lookup count
+ assertEquals(lookupCount + 1, cache.getLookupCount());
+ } else {
+ // Dictionary returns null - since name is not in the dictionary
+ assertNull(cache.put(s));
+ // Lookup count remains the same
+ assertEquals(lookupCount, cache.getLookupCount());
+ }
+ }
+}
