[HDFS-9377] Fix findbugs warnings in FSDirSnapshotOp

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: namenode
• Target Version/s: 2.8.0
• Hadoop Flags: Reviewed
• Assignee: Mingliang Liu
• Reporter: Mingliang Liu
• Created: 04/Nov/15 22:06
• Updated: 30/Aug/16 01:23
• Resolved: 05/Nov/15 23:00

Description

I ran findbugs version 3.0.1 and find there is a findbugs warning in FSDirSnapshotOp, brought by HDFS-9231.

It's caused by unused variable and the fix is simple.

findbugsXml.xml

<BugInstance rank="17" category="STYLE" instanceHash="e553cd68a81bb1d8aaf6eba15aa9d322" instanceOccurrenceNum="0" priority="2" abbrev="DLS" type="DLS_DEAD_LOCAL_STORE" cweid="563" instanceOccurrenceMax="0">
<ShortMessage>Dead store to local variable</ShortMessage>
<LongMessage>
Dead store to sfi in org.apache.hadoop.hdfs.server.namenode.FSDirSnapshotOp.getSnapshotFiles(FSDirectory, List, String)
</LongMessage>
<Class classname="org.apache.hadoop.hdfs.server.namenode.FSDirSnapshotOp" primary="true">
<SourceLine start="41" classname="org.apache.hadoop.hdfs.server.namenode.FSDirSnapshotOp" sourcepath="org/apache/hadoop/hdfs/server/namenode/FSDirSnapshotOp.java" sourcefile="FSDirSnapshotOp.java" end="279">
<Message>At FSDirSnapshotOp.java:[lines 41-279]</Message>
</SourceLine>
<Message>
In class org.apache.hadoop.hdfs.server.namenode.FSDirSnapshotOp
</Message>
</Class>
<Method isStatic="true" classname="org.apache.hadoop.hdfs.server.namenode.FSDirSnapshotOp" name="getSnapshotFiles" primary="true" signature="(Lorg/apache/hadoop/hdfs/server/namenode/FSDirectory;Ljava/util/List;Ljava/lang/String;)Ljava/util/Collection;">
<SourceLine endBytecode="85" startBytecode="0" start="174" classname="org.apache.hadoop.hdfs.server.namenode.FSDirSnapshotOp" sourcepath="org/apache/hadoop/hdfs/server/namenode/FSDirSnapshotOp.java" sourcefile="FSDirSnapshotOp.java" end="197"/>
<Message>
In method org.apache.hadoop.hdfs.server.namenode.FSDirSnapshotOp.getSnapshotFiles(FSDirectory, List, String)
</Message>
</Method>
<LocalVariable register="4" name="sfi" pc="16" role="LOCAL_VARIABLE_NAMED">
<Message>Local variable named sfi</Message>
</LocalVariable>
<SourceLine endBytecode="14" startBytecode="14" start="175" classname="org.apache.hadoop.hdfs.server.namenode.FSDirSnapshotOp" primary="true" sourcepath="org/apache/hadoop/hdfs/server/namenode/FSDirSnapshotOp.java" sourcefile="FSDirSnapshotOp.java" end="175">
<Message>At FSDirSnapshotOp.java:[line 175]</Message>
</SourceLine>
<Property name="edu.umd.cs.findbugs.detect.DeadLocalStoreProperty.METHOD_RESULT" value="true"/>
<Property name="edu.umd.cs.findbugs.detect.DeadLocalStoreProperty.LOCAL_NAME" value="sfi"/>
<Property name="edu.umd.cs.findbugs.detect.DeadLocalStoreProperty.NO_LOADS" value="true"/>
</BugInstance>

Issue Links

• is broken by: HDFS-9231 fsck doesn't list correct file path when Bad Replicas/Blocks are in a snapshot