How to use org.apache.hadoop.hdfs.server.protocol

private static long getCapacity(DatanodeStorageReport report, StorageType t) {
 long capacity = 0L;
 for(StorageReport r : report.getStorageReports()) {
  if (r.getStorage().getStorageType() == t) {
   capacity += r.getCapacity();
  }
 }
 return capacity;
}

private static long getMaxRemaining(DatanodeStorageReport report, StorageType t) {
 long max = 0L;
 for(StorageReport r : report.getStorageReports()) {
  if (r.getStorage().getStorageType() == t) {
   if (r.getRemaining() > max) {
    max = r.getRemaining();
   }
  }
 }
 return max;
}

StorageReport toStorageReport() {
 return new StorageReport(
   new DatanodeStorage(storageID, state, storageType),
   false, capacity, dfsUsed, remaining, blockPoolUsed, nonDfsUsed);
}

void updateState(StorageReport r) {
 capacity = r.getCapacity();
 dfsUsed = r.getDfsUsed();
 nonDfsUsed = r.getNonDfsUsed();
 remaining = r.getRemaining();
 blockPoolUsed = r.getBlockPoolUsed();
}

BackupJournalManager(NamenodeRegistration bnReg,
  NamenodeRegistration nnReg) {
 journalInfo = new JournalInfo(nnReg.getLayoutVersion(),
   nnReg.getClusterID(), nnReg.getNamespaceID());
 this.bnReg = bnReg;
}

public void updateFromStorage(DatanodeStorage storage) {
 state = storage.getState();
 storageType = storage.getStorageType();
}

/** @return blocks with locations. */
public BlocksWithLocations getBlocks(DatanodeInfo datanode, long size, long
  minBlockSize)
  throws IOException {
 return namenode.getBlocks(datanode, size, minBlockSize);
}

 @Override
 protected Void doWork() throws IOException {
  cachedActiveProxy.rollEditLog();
  return null;
 }
};

 @Override
 public Long apply(RemoteEditLog log) {
  if (null == log) {
   return HdfsServerConstants.INVALID_TXID;
  }
  return log.getStartTxId();
 }
};

@Override // NodeRegistration
public String getAddress() {
 return getXferAddr();
}

@Override
public boolean equals(Object o) {
 if (!(o instanceof RemoteEditLog)) return false;
 return this.compareTo((RemoteEditLog)o) == 0;
}

public RemoteEditLogManifest(List<RemoteEditLog> logs, long committedTxnId) {
 this.logs = logs;
 this.committedTxnId = committedTxnId;
 checkState();
}

 public static BlockStatus fromCode(int code) {
  for (BlockStatus bs : BlockStatus.values()) {
   if (bs.code == code) {
    return bs;
   }
  }
  return null;
 }
}

 void startLogSegment(long txId) throws IOException {
  backupNode.startLogSegment(journalInfo, 0, txId);
 }
}

Capability(boolean isSupported) {
 supported = isSupported;
 int bits = ordinal() - 1;
 mask = (bits < 0) ? 0 : (1L << bits);
}
public long getMask() {

 @Override
 Double getUtilization(DatanodeStorageReport r, final StorageType t) {
  long capacity = 0L;
  long dfsUsed = 0L;
  for(StorageReport s : r.getStorageReports()) {
   if (s.getStorage().getStorageType() == t) {
    capacity += s.getCapacity();
    dfsUsed += s.getDfsUsed();
   }
  }
  return capacity == 0L? null: dfsUsed*100.0/capacity;
 }
}

private long getRemaining(DatanodeStorageReport report, StorageType t) {
 long remaining = 0L;
 for(StorageReport r : report.getStorageReports()) {
  if (r.getStorage().getStorageType() == t) {
   if (r.getRemaining() >= defaultBlockSize) {
    remaining += r.getRemaining();
   }
  }
 }
 return remaining;
}

 @Override
 Double getUtilization(DatanodeStorageReport r, final StorageType t) {
  long capacity = 0L;
  long blockPoolUsed = 0L;
  for(StorageReport s : r.getStorageReports()) {
   if (s.getStorage().getStorageType() == t) {
    capacity += s.getCapacity();
    blockPoolUsed += s.getBlockPoolUsed();
   }
  }
  return capacity == 0L? null: blockPoolUsed*100.0/capacity;
 }
}

@Override
void accumulateSpaces(DatanodeStorageReport r) {
 for(StorageReport s : r.getStorageReports()) {
  final StorageType t = s.getStorage().getStorageType();
  totalCapacities.add(t, s.getCapacity());
  totalUsedSpaces.add(t, s.getDfsUsed());
 }
}

@Override
void accumulateSpaces(DatanodeStorageReport r) {
 for(StorageReport s : r.getStorageReports()) {
  final StorageType t = s.getStorage().getStorageType();
  totalCapacities.add(t, s.getCapacity());
  totalUsedSpaces.add(t, s.getBlockPoolUsed());
 }
}