checkstyle fix

core/server/master/src/main/java/alluxio/master/file/InodeTtlChecker.java

@@ -63,7 +63,7 @@ public void heartbeat() throws InterruptedException {
     Set<TtlBucket> expiredBuckets = mTtlBuckets.pollExpiredBuckets(System.currentTimeMillis());
     Set<Inode> failedInodes = new HashSet();
     for (TtlBucket bucket : expiredBuckets) {
-        for (long inodeId : bucket.getInodes()) {
+      for (long inodeId : bucket.getInodes()) {
         // Throw if interrupted.
         if (Thread.interrupted()) {
           throw new InterruptedException("InodeTtlChecker interrupted.");
@@ -87,8 +87,9 @@ public void heartbeat() throws InterruptedException {
             inode = mTtlBuckets.loadInode(inodeId);
             // Check again if this inode is indeed expired.
             if (inode == null || inode.getTtl() == Constants.NO_TTL
-                || inode.getCreationTimeMs() + inode.getTtl() > System.currentTimeMillis())
+                || inode.getCreationTimeMs() + inode.getTtl() > System.currentTimeMillis()) {
               continue;
+            }
             TtlAction ttlAction = inode.getTtlAction();
             LOG.info("Path {} TTL has expired, performing action {}", path.getPath(), ttlAction);
             switch (ttlAction) {
@@ -148,7 +149,7 @@ public void heartbeat() throws InterruptedException {
     }
     // Put back those failed-to-expire inodes for next round retry.
     if (!failedInodes.isEmpty()) {
-      for(Inode inode : failedInodes) {
+      for (Inode inode : failedInodes) {
         mTtlBuckets.insert(inode);
       }
     }

core/server/master/src/main/java/alluxio/master/file/meta/TtlBucket.java

@@ -17,10 +17,6 @@
 import com.google.common.base.Objects;
 
 import java.util.Collection;
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.ConcurrentSkipListSet;
 import javax.annotation.concurrent.ThreadSafe;
 
@@ -89,7 +85,6 @@ public Collection<Long> getInodes() {
     return mInodeList;
   }
 
-
   /**
    * Adds a inode to the bucket.
    *

core/server/master/src/main/java/alluxio/master/file/meta/TtlBucketList.java

@@ -30,7 +30,6 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentSkipListSet;
-import java.util.concurrent.atomic.AtomicLong;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 
@@ -61,6 +60,11 @@ public TtlBucketList(ReadOnlyInodeStore inodeStore) {
     mBucketList = new ConcurrentSkipListSet<>();
   }
 
+  /**
+   * Load inode from inode store on processing the provided inode id.
+   * @param inodeId
+   * @return Inode
+   */
   public Inode loadInode(long inodeId) {
     return mInodeStore.get(inodeId).orElseGet(null);
   }
@@ -126,10 +130,11 @@ public void insert(Inode inode) {
       bucket = getBucketContaining(inode);
       if (bucket == null) {
         long ttlEndTimeMs = inode.getCreationTimeMs() + inode.getTtl();
-        // No bucket contains the inode, so a new bucket should be added with an appropriate interval
-        // start. Assume the list of buckets have continuous intervals, and the first interval starts
-        // at 0, then ttlEndTimeMs should be in number (ttlEndTimeMs / interval) interval, so the
-        // start time of this interval should be (ttlEndTimeMs / interval) * interval.
+        // No bucket contains the inode, so a new bucket should be added with an appropriate
+        // interval start. Assume the list of buckets have continuous intervals, and the
+        // first interval starts at 0, then ttlEndTimeMs should be in number
+        // (ttlEndTimeMs / interval) interval, so the start time of this interval should be
+        // (ttlEndTimeMs / interval) * interval.
         long interval = TtlBucket.getTtlIntervalMs();
         bucket = new TtlBucket(interval == 0 ? ttlEndTimeMs : ttlEndTimeMs / interval * interval);
         if (!mBucketList.add(bucket)) {
@@ -139,23 +144,24 @@ public void insert(Inode inode) {
         }
       }
       bucket.addInode(inode);
-      /* if we added to the bucket but it got concurrently polled by InodeTtlChecker, we're not sure
-       this newly-added inode will be processed by the checker, so we need to try insert again.
-       Resolve for (c.f. ALLUXIO-2821) */
+      /* if we added to the bucket but it got concurrently polled by InodeTtlChecker,
+      we're not sure this newly-added inode will be processed by the checker,
+      so we need to try insert again. Resolve for (c.f. ALLUXIO-2821) */
       if (mBucketList.contains(bucket)) {
         break;
       }
     }
   }
 
   /**
-   * Removes an inode from the bucket containing it if the inode is in one of the buckets, otherwise,
-   * do nothing.
+   * Removes an inode from the bucket containing it if the inode is in one
+   * of the buckets, otherwise, do nothing.
    *
    * <p>
    * Assume that no inode in the buckets has ttl value that equals {@link Constants#NO_TTL}.
-   * If an inode with valid ttl value is inserted to the buckets and its ttl value is going to be set
-   * to {@link Constants#NO_TTL} later, be sure to remove the inode from the buckets first.
+   * If an inode with valid ttl value is inserted to the buckets and its ttl value is
+   * going to be set to {@link Constants#NO_TTL} later, be sure to remove the inode
+   * from the buckets first.
    *
    * @param inode the inode to be removed
    */
@@ -178,7 +184,7 @@ public void remove(InodeView inode) {
    */
   public Set<TtlBucket> pollExpiredBuckets(long time) {
     Set<TtlBucket> expiredBuckets = new HashSet<>();
-    TtlBucket upperBound = new TtlBucket(time- TtlBucket.getTtlIntervalMs());
+    TtlBucket upperBound = new TtlBucket(time - TtlBucket.getTtlIntervalMs());
     while (!mBucketList.isEmpty() && mBucketList.first().compareTo(upperBound) <= 0) {
       expiredBuckets.add(mBucketList.pollFirst());
     }
@@ -198,7 +204,7 @@ public CheckpointName getCheckpointName() {
   public void writeToCheckpoint(OutputStream output) throws IOException, InterruptedException {
     CheckpointOutputStream cos = new CheckpointOutputStream(output, CheckpointType.LONGS);
     for (TtlBucket bucket : mBucketList) {
-      for(long inodeId : bucket.getInodes()) {
+      for (long inodeId : bucket.getInodes()) {
         cos.writeLong(inodeId);
       }
     }

tests/src/test/java/alluxio/client/fs/TtlIntegrationTest.java

@@ -235,10 +235,10 @@ public void expireADirectory() throws Exception {
     // Individual children file's ttl should not be changed.
     Random random = new Random();
     int fileNum = random.nextInt(numFiles);
-    URIStatus anyFileStatus = mFileSystem.getStatus(new AlluxioURI("/" + directoryName +
-        "/" + fileNamePrefix + fileNum));
-    assert(anyFileStatus.getFileInfo().getTtl() ==
-        (fileNum % 2 == 0 ? TTL_INTERVAL_MS * 2000 : TTL_INTERVAL_MS * 1000));
+    URIStatus anyFileStatus = mFileSystem.getStatus(new AlluxioURI("/" + directoryName
+        + "/" + fileNamePrefix + fileNum));
+    assert (anyFileStatus.getFileInfo().getTtl()
+        == (fileNum % 2 == 0 ? TTL_INTERVAL_MS * 2000 : TTL_INTERVAL_MS * 1000));
 
     CommonUtils.sleepMs(4 * TTL_INTERVAL_MS);
     HeartbeatScheduler.execute(HeartbeatContext.MASTER_TTL_CHECK);