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The following commit(s) were added to refs/heads/master by this push:
new 57e8318 ZOOKEEPER-3335: Improve the usage of Collections
57e8318 is described below
commit 57e8318bc98dd3563085e08b0fcfcbc6a1c5fbcc
Author: Beluga Behr <[email protected]>
AuthorDate: Tue Apr 9 15:35:40 2019 +0200
ZOOKEEPER-3335: Improve the usage of Collections
Author: Beluga Behr <[email protected]>
Reviewers: [email protected]
Closes #870 from BELUGABEHR/ZOOKEEPER-3335 and squashes the following
commits:
2a1d80347 [Beluga Behr] Reverted variable name change to lessen diff
384d46755 [Beluga Behr] ZOOKEEPER-3335: Improve the usage of Collections
---
.../main/java/org/apache/zookeeper/ClientCnxn.java | 5 +++--
.../org/apache/zookeeper/ClientCnxnSocket.java | 4 ++--
.../org/apache/zookeeper/ClientCnxnSocketNIO.java | 6 ++---
.../apache/zookeeper/ClientCnxnSocketNetty.java | 6 ++---
.../src/main/java/org/apache/zookeeper/ZKUtil.java | 13 +++++------
.../zookeeper/server/PrepRequestProcessor.java | 21 +++++++++--------
.../org/apache/zookeeper/server/ZKDatabase.java | 26 +++++++++++++---------
.../apache/zookeeper/server/ZooKeeperServer.java | 3 +--
.../zookeeper/server/persistence/FileTxnLog.java | 8 +++----
.../zookeeper/server/quorum/CommitProcessor.java | 20 ++++++++---------
.../apache/zookeeper/server/quorum/Learner.java | 7 +++---
.../zookeeper/test/RestoreCommittedLogTest.java | 3 ++-
12 files changed, 64 insertions(+), 58 deletions(-)
diff --git
a/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxn.java
b/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxn.java
index 0cae4a4..b155698 100644
--- a/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxn.java
+++ b/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxn.java
@@ -30,14 +30,15 @@ import java.net.SocketAddress;
import java.net.SocketException;
import java.nio.ByteBuffer;
import java.util.HashSet;
+import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Iterator;
-import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import java.util.Map.Entry;
+import java.util.Queue;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.LinkedBlockingQueue;
@@ -132,7 +133,7 @@ public class ClientCnxn {
/**
* These are the packets that have been sent and are waiting for a
response.
*/
- private final LinkedList<Packet> pendingQueue = new LinkedList<Packet>();
+ private final Queue<Packet> pendingQueue = new ArrayDeque<>();
/**
* These are the packets that need to be sent.
diff --git
a/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocket.java
b/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocket.java
index ba3806c..dc1c71a 100644
--- a/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocket.java
+++ b/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocket.java
@@ -23,7 +23,7 @@ import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.text.MessageFormat;
-import java.util.List;
+import java.util.Queue;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.atomic.AtomicLong;
@@ -208,7 +208,7 @@ abstract class ClientCnxnSocket {
* @throws IOException
* @throws InterruptedException
*/
- abstract void doTransport(int waitTimeOut, List<Packet> pendingQueue,
+ abstract void doTransport(int waitTimeOut, Queue<Packet> pendingQueue,
ClientCnxn cnxn)
throws IOException, InterruptedException;
diff --git
a/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocketNIO.java
b/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocketNIO.java
index 4c97721..feb0e2f 100644
---
a/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocketNIO.java
+++
b/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocketNIO.java
@@ -27,7 +27,7 @@ import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
-import java.util.List;
+import java.util.Queue;
import java.util.Set;
import java.util.concurrent.LinkedBlockingDeque;
@@ -65,7 +65,7 @@ public class ClientCnxnSocketNIO extends ClientCnxnSocket {
* @throws InterruptedException
* @throws IOException
*/
- void doIO(List<Packet> pendingQueue, ClientCnxn cnxn)
+ void doIO(Queue<Packet> pendingQueue, ClientCnxn cnxn)
throws InterruptedException, IOException {
SocketChannel sock = (SocketChannel) sockKey.channel();
if (sock == null) {
@@ -340,7 +340,7 @@ public class ClientCnxnSocketNIO extends ClientCnxnSocket {
}
@Override
- void doTransport(int waitTimeOut, List<Packet> pendingQueue, ClientCnxn
cnxn)
+ void doTransport(int waitTimeOut, Queue<Packet> pendingQueue, ClientCnxn
cnxn)
throws IOException, InterruptedException {
selector.select(waitTimeOut);
Set<SelectionKey> selected;
diff --git
a/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocketNetty.java
b/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocketNetty.java
index 2f000fc..9955075 100755
---
a/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocketNetty.java
+++
b/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocketNetty.java
@@ -22,7 +22,7 @@ import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.util.Iterator;
-import java.util.List;
+import java.util.Queue;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
@@ -262,7 +262,7 @@ public class ClientCnxnSocketNetty extends ClientCnxnSocket
{
@Override
void doTransport(int waitTimeOut,
- List<Packet> pendingQueue,
+ Queue<Packet> pendingQueue,
ClientCnxn cnxn)
throws IOException, InterruptedException {
try {
@@ -352,7 +352,7 @@ public class ClientCnxnSocketNetty extends ClientCnxnSocket
{
/**
* doWrite handles writing the packets from outgoingQueue via network to
server.
*/
- private void doWrite(List<Packet> pendingQueue, Packet p, ClientCnxn cnxn)
{
+ private void doWrite(Queue<Packet> pendingQueue, Packet p, ClientCnxn
cnxn) {
updateNow();
boolean anyPacketsSent = false;
while (true) {
diff --git a/zookeeper-server/src/main/java/org/apache/zookeeper/ZKUtil.java
b/zookeeper-server/src/main/java/org/apache/zookeeper/ZKUtil.java
index f9cfe4b..09aaf1b 100644
--- a/zookeeper-server/src/main/java/org/apache/zookeeper/ZKUtil.java
+++ b/zookeeper-server/src/main/java/org/apache/zookeeper/ZKUtil.java
@@ -18,11 +18,11 @@
package org.apache.zookeeper;
import java.io.File;
+import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collections;
-import java.util.Deque;
-import java.util.LinkedList;
import java.util.List;
+import java.util.Queue;
import org.apache.zookeeper.AsyncCallback.StringCallback;
import org.apache.zookeeper.AsyncCallback.VoidCallback;
@@ -124,15 +124,12 @@ public class ZKUtil {
*/
public static List<String> listSubTreeBFS(ZooKeeper zk, final String
pathRoot) throws
KeeperException, InterruptedException {
- Deque<String> queue = new LinkedList<String>();
+ Queue<String> queue = new ArrayDeque<>();
List<String> tree = new ArrayList<String>();
queue.add(pathRoot);
tree.add(pathRoot);
- while (true) {
- String node = queue.pollFirst();
- if (node == null) {
- break;
- }
+ while (!queue.isEmpty()) {
+ String node = queue.poll();
List<String> children = zk.getChildren(node, false);
for (final String child : children) {
final String childPath = node + "/" + child;
diff --git
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/PrepRequestProcessor.java
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/PrepRequestProcessor.java
index 6180f8b..d0a1ac9 100644
---
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/PrepRequestProcessor.java
+++
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/PrepRequestProcessor.java
@@ -71,9 +71,9 @@ import java.io.IOException;
import java.io.StringReader;
import java.nio.ByteBuffer;
import java.util.ArrayList;
+import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
-import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
@@ -905,14 +905,17 @@ public class PrepRequestProcessor extends
ZooKeeperCriticalThread implements
nextProcessor.processRequest(request);
}
- private List<ACL> removeDuplicates(List<ACL> acl) {
+ private List<ACL> removeDuplicates(final List<ACL> acls) {
+ if (acls == null || acls.isEmpty()) {
+ return Collections.emptyList();
+ }
- List<ACL> retval = new LinkedList<ACL>();
- if (acl != null) {
- for (ACL a : acl) {
- if (!retval.contains(a)) {
- retval.add(a);
- }
+ // This would be done better with a Set but ACL hashcode/equals do not
+ // allow for null values
+ final ArrayList<ACL> retval = new ArrayList<>(acls.size());
+ for (final ACL acl : acls) {
+ if (!retval.contains(acl)) {
+ retval.add(acl);
}
}
return retval;
@@ -960,7 +963,7 @@ public class PrepRequestProcessor extends
ZooKeeperCriticalThread implements
if (uniqacls == null || uniqacls.size() == 0) {
throw new KeeperException.InvalidACLException(path);
}
- List<ACL> rv = new LinkedList<ACL>();
+ List<ACL> rv = new ArrayList<>();
for (ACL a: uniqacls) {
LOG.debug("Processing ACL: {}", a);
if (a == null) {
diff --git
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZKDatabase.java
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZKDatabase.java
index 60ea98b..4ef43b4 100644
--- a/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZKDatabase.java
+++ b/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZKDatabase.java
@@ -21,11 +21,14 @@ package org.apache.zookeeper.server;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
import java.util.Collection;
+import java.util.Collections;
import java.util.Iterator;
-import java.util.LinkedList;
import java.util.List;
import java.util.Map;
+import java.util.Queue;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.ReentrantReadWriteLock;
@@ -84,7 +87,7 @@ public class ZKDatabase {
public static final int commitLogCount = 500;
protected static int commitLogBuffer = 700;
- protected LinkedList<Proposal> committedLog = new LinkedList<Proposal>();
+ protected Queue<Proposal> committedLog = new ArrayDeque<>();
protected ReentrantReadWriteLock logLock = new ReentrantReadWriteLock();
volatile private boolean initialized = false;
@@ -187,18 +190,21 @@ public class ZKDatabase {
}
- public synchronized List<Proposal> getCommittedLog() {
+ public synchronized Collection<Proposal> getCommittedLog() {
+ final Collection<Proposal> result;
ReadLock rl = logLock.readLock();
- // only make a copy if this thread isn't already holding a lock
- if(logLock.getReadHoldCount() <=0) {
+ // make a copy if this thread is not already holding a lock
+ if (logLock.getReadHoldCount() > 0) {
+ result = this.committedLog;
+ } else {
+ rl.lock();
try {
- rl.lock();
- return new LinkedList<Proposal>(this.committedLog);
+ result = new ArrayList<>(this.committedLog);
} finally {
rl.unlock();
}
}
- return this.committedLog;
+ return Collections.unmodifiableCollection(result);
}
/**
@@ -281,8 +287,8 @@ public class ZKDatabase {
try {
wl.lock();
if (committedLog.size() > commitLogCount) {
- committedLog.removeFirst();
- minCommittedLog = committedLog.getFirst().packet.getZxid();
+ committedLog.remove();
+ minCommittedLog = committedLog.peek().packet.getZxid();
}
if (committedLog.isEmpty()) {
minCommittedLog = request.zxid;
diff --git
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZooKeeperServer.java
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZooKeeperServer.java
index 01f5f9a..315a62e 100644
---
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZooKeeperServer.java
+++
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZooKeeperServer.java
@@ -30,7 +30,6 @@ import java.util.ArrayList;
import java.util.Arrays;
import java.util.Deque;
import java.util.HashMap;
-import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Random;
@@ -348,7 +347,7 @@ public class ZooKeeperServer implements SessionExpirer,
ServerStats.Provider {
}
// Clean up dead sessions
- List<Long> deadSessions = new LinkedList<Long>();
+ List<Long> deadSessions = new ArrayList<>();
for (Long session : zkDb.getSessions()) {
if (zkDb.getSessionWithTimeOuts().get(session) == null) {
deadSessions.add(session);
diff --git
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/persistence/FileTxnLog.java
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/persistence/FileTxnLog.java
index c739152..17b16cb 100644
---
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/persistence/FileTxnLog.java
+++
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/persistence/FileTxnLog.java
@@ -29,9 +29,10 @@ import java.io.InputStream;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
+import java.util.ArrayDeque;
import java.util.ArrayList;
-import java.util.LinkedList;
import java.util.List;
+import java.util.Queue;
import java.util.concurrent.TimeUnit;
import java.util.zip.Adler32;
import java.util.zip.Checksum;
@@ -148,8 +149,7 @@ public class FileTxnLog implements TxnLog {
File logDir;
private final boolean forceSync =
!System.getProperty("zookeeper.forceSync", "yes").equals("no");
long dbId;
- private LinkedList<FileOutputStream> streamsToFlush =
- new LinkedList<FileOutputStream>();
+ private final Queue<FileOutputStream> streamsToFlush = new ArrayDeque<>();
File logFileWrite = null;
private FilePadding filePadding = new FilePadding();
@@ -392,7 +392,7 @@ public class FileTxnLog implements TxnLog {
}
}
while (streamsToFlush.size() > 1) {
- streamsToFlush.removeFirst().close();
+ streamsToFlush.poll().close();
}
// Roll the log file if we exceed the size limit
diff --git
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/CommitProcessor.java
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/CommitProcessor.java
index 9982f15..aef8771 100644
---
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/CommitProcessor.java
+++
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/CommitProcessor.java
@@ -20,9 +20,11 @@ package org.apache.zookeeper.server.quorum;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import java.io.IOException;
+import java.util.ArrayDeque;
+import java.util.Deque;
import java.util.HashMap;
-import java.util.LinkedList;
import java.util.Map;
+import java.util.Queue;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.LinkedBlockingQueue;
@@ -96,8 +98,8 @@ public class CommitProcessor extends ZooKeeperCriticalThread
implements
* Requests that we are holding until commit comes in. Keys represent
* session ids, each value is a linked list of the session's requests.
*/
- protected final Map<Long, LinkedList<Request>> pendingRequests =
- new HashMap<Long, LinkedList<Request>>(10000);
+ protected final Map<Long, Deque<Request>> pendingRequests =
+ new HashMap<>(10000);
/** The number of requests currently being processed */
protected final AtomicInteger numRequestsProcessing = new AtomicInteger(0);
@@ -200,13 +202,9 @@ public class CommitProcessor extends
ZooKeeperCriticalThread implements
if (needCommit(request)
|| pendingRequests.containsKey(request.sessionId))
{
// Add request to pending
- LinkedList<Request> requests = pendingRequests
- .get(request.sessionId);
- if (requests == null) {
- requests = new LinkedList<Request>();
- pendingRequests.put(request.sessionId, requests);
- }
- requests.addLast(request);
+ pendingRequests
+ .computeIfAbsent(request.sessionId, sid -> new
ArrayDeque<>())
+ .add(request);
}
else {
sendToNextProcessor(request);
@@ -248,7 +246,7 @@ public class CommitProcessor extends
ZooKeeperCriticalThread implements
/*
* Check if request is pending, if so, update it with the
committed info
*/
- LinkedList<Request> sessionQueue = pendingRequests
+ Deque<Request> sessionQueue = pendingRequests
.get(request.sessionId);
if (sessionQueue != null) {
// If session queue != null, then it is also not empty.
diff --git
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/Learner.java
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/Learner.java
index 307b644..e4d83e9 100644
---
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/Learner.java
+++
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/Learner.java
@@ -28,7 +28,8 @@ import java.net.ConnectException;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.nio.ByteBuffer;
-import java.util.LinkedList;
+import java.util.ArrayDeque;
+import java.util.Deque;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
@@ -396,8 +397,8 @@ public class Learner {
boolean snapshotNeeded = true;
boolean syncSnapshot = false;
readPacket(qp);
- LinkedList<Long> packetsCommitted = new LinkedList<Long>();
- LinkedList<PacketInFlight> packetsNotCommitted = new
LinkedList<PacketInFlight>();
+ Deque<Long> packetsCommitted = new ArrayDeque<>();
+ Deque<PacketInFlight> packetsNotCommitted = new ArrayDeque<>();
synchronized (zk) {
if (qp.getType() == Leader.DIFF) {
LOG.info("Getting a diff from the leader 0x{}",
Long.toHexString(qp.getZxid()));
diff --git
a/zookeeper-server/src/test/java/org/apache/zookeeper/test/RestoreCommittedLogTest.java
b/zookeeper-server/src/test/java/org/apache/zookeeper/test/RestoreCommittedLogTest.java
index 1cd0337..951458e 100644
---
a/zookeeper-server/src/test/java/org/apache/zookeeper/test/RestoreCommittedLogTest.java
+++
b/zookeeper-server/src/test/java/org/apache/zookeeper/test/RestoreCommittedLogTest.java
@@ -19,6 +19,7 @@
package org.apache.zookeeper.test;
import java.io.File;
+import java.util.Collection;
import java.util.List;
import org.apache.zookeeper.CreateMode;
@@ -74,7 +75,7 @@ public class RestoreCommittedLogTest extends ZKTestCase{
// start server again
zks = new ZooKeeperServer(tmpDir, tmpDir, 3000);
zks.startdata();
- List<Proposal> committedLog = zks.getZKDatabase().getCommittedLog();
+ Collection<Proposal> committedLog =
zks.getZKDatabase().getCommittedLog();
int logsize = committedLog.size();
LOG.info("committedLog size = {}", logsize);
Assert.assertTrue("log size != 0", (logsize != 0));
