fix NPE in compactionstats

patch by jbellis; reviewed by xedin for CASSANDRA-4318

CHANGES.txt

@@ -1,4 +1,5 @@
 1.1.2
+ * fix NPE in compactionstats (CASSANDRA-4318)
  * enforce 1m min keycache for auto (CASSANDRA-4306)
  * Have DeletedColumn.isMFD always return true (CASSANDRA-4307)
  * ex msg for cql3 order by constraints says primary filter can be an IN clause 

src/java/org/apache/cassandra/cache/AutoSavingCache.java

@@ -30,6 +30,7 @@ import java.util.concurrent.TimeUnit;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import org.apache.cassandra.config.CFMetaData;
 import org.apache.cassandra.config.DatabaseDescriptor;
 import org.apache.cassandra.db.compaction.CompactionInfo;
 import org.apache.cassandra.db.compaction.CompactionManager;
@@ -192,7 +193,10 @@ public class AutoSavingCache<K extends CacheKey, V> extends InstrumentingCache<K
             else
                 type = OperationType.UNKNOWN;
 
-            info = new CompactionInfo(type, 0, estimatedTotalBytes);
+            info = new CompactionInfo(new CFMetaData("system", cacheType.toString(), null, null, null),
+                                      type,
+                                      0,
+                                      estimatedTotalBytes);
         }
 
         public CompactionInfo getCompactionInfo()

src/java/org/apache/cassandra/db/compaction/AbstractCompactionIterable.java

@@ -53,7 +53,7 @@ public abstract class AbstractCompactionIterable extends CompactionInfo.Holder i
 
     public CompactionInfo getCompactionInfo()
     {
-        return new CompactionInfo(this.hashCode(),
+        return new CompactionInfo(controller.cfs.metadata,
                                   type,
                                   bytesRead,
                                   totalBytes);

src/java/org/apache/cassandra/db/compaction/CompactionController.java

@@ -42,7 +42,7 @@ public class CompactionController
 {
     private static Logger logger = LoggerFactory.getLogger(CompactionController.class);
 
-    private final ColumnFamilyStore cfs;
+    public final ColumnFamilyStore cfs;
     private final boolean deserializeRequired;
     private final IntervalTree<SSTableReader> overlappingTree;
 

src/java/org/apache/cassandra/db/compaction/CompactionInfo.java

@@ -34,38 +34,33 @@ public final class CompactionInfo implements Serializable
     private final long bytesComplete;
     private final long totalBytes;
 
-    public CompactionInfo(OperationType tasktype, long bytesComplete, long totalBytes)
-    {
-        this(null, tasktype, bytesComplete, totalBytes);
-    }
-
-    public CompactionInfo(Integer id, OperationType tasktype, long bytesComplete, long totalBytes)
+    public CompactionInfo(CFMetaData cfm, OperationType tasktype, long bytesComplete, long totalBytes)
     {
         this.tasktype = tasktype;
         this.bytesComplete = bytesComplete;
         this.totalBytes = totalBytes;
-        this.cfm = id == null ? null : Schema.instance.getCFMetaData(id);
+        this.cfm = cfm;
     }
 
     /** @return A copy of this CompactionInfo with updated progress. */
     public CompactionInfo forProgress(long bytesComplete, long totalBytes)
     {
-        return new CompactionInfo(cfm == null ? null : cfm.cfId, tasktype, bytesComplete, totalBytes);
+        return new CompactionInfo(cfm, tasktype, bytesComplete, totalBytes);
     }
 
     public Integer getId()
     {
-        return cfm == null ? null : cfm.cfId;
+        return cfm.cfId;
     }
 
     public String getKeyspace()
     {
-        return cfm == null ? null : cfm.ksName;
+        return cfm.ksName;
     }
 
     public String getColumnFamily()
     {
-        return cfm == null ? null : cfm.cfName;
+        return cfm.cfName;
     }
 
     public CFMetaData getCFMetaData()

src/java/org/apache/cassandra/db/compaction/CompactionManager.java

@@ -1204,7 +1204,7 @@ public class CompactionManager implements CompactionManagerMBean
         {
             try
             {
-                return new CompactionInfo(this.hashCode(),
+                return new CompactionInfo(sstable.metadata,
                                           OperationType.CLEANUP,
                                           scanner.getCurrentPosition(),
                                           scanner.getLengthInBytes());
@@ -1230,7 +1230,7 @@ public class CompactionManager implements CompactionManagerMBean
         {
             try
             {
-                return new CompactionInfo(this.hashCode(),
+                return new CompactionInfo(sstable.metadata,
                                           OperationType.SCRUB,
                                           dataFile.getFilePointer(),
                                           dataFile.length());

src/java/org/apache/cassandra/db/index/SecondaryIndexBuilder.java

@@ -47,7 +47,7 @@ public class SecondaryIndexBuilder extends CompactionInfo.Holder
 
     public CompactionInfo getCompactionInfo()
     {
-        return new CompactionInfo(this.hashCode(),
+        return new CompactionInfo(cfs.metadata,
                                   OperationType.INDEX_BUILD,
                                   iter.getBytesRead(),
                                   iter.getTotalBytes());