--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/goodjava/lucene/backup/Backup.java	Sat May 09 23:14:13 2020 -0600
@@ -0,0 +1,103 @@
+package goodjava.lucene.backup;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+import java.util.ArrayList;
+import java.util.Map;
+import java.util.Arrays;
+import goodjava.io.IoUtils;
+import goodjava.rpc.RpcServer;
+import goodjava.rpc.RpcCall;
+import goodjava.rpc.RpcResult;
+import goodjava.logging.Logger;
+import goodjava.logging.LoggerFactory;
+import goodjava.lucene.logging.LogFile;
+import goodjava.lucene.logging.LoggingIndexWriter;
+import goodjava.lucene.logging.LogOutputStream;
+
+
+class Backup {
+	private static final Logger logger = LoggerFactory.getLogger(Backup.class);
+
+	private final File dir;
+
+	Backup(File dir) {
+		this.dir = dir;
+	}
+
+	synchronized void handle(RpcServer rpc,RpcCall call) {
+		try {
+			handle2(rpc,call);
+		} catch(IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	void handle2(RpcServer rpc,RpcCall call) throws IOException {
+		dir.mkdirs();
+		//logger.info(call.cmd+" "+Arrays.asList(call.args));
+		String fileName = null;
+		if( call.cmd.equals("check") ) {
+			// nothing
+		} else if( call.cmd.equals("add") || call.cmd.equals("append")  ) {
+			fileName = (String)call.args[2];
+			File f = new File(dir,fileName);
+			LogFile log = new LogFile(f);
+			LogOutputStream out = log.output();
+			IoUtils.copyAll(call.in,out);
+			out.commit();
+			out.close();
+			logger.info(call.cmd+" "+fileName+" "+call.lenIn);
+		} else
+			throw new RuntimeException("cmd "+call.cmd);
+		List logInfo = (List)call.args[1];
+		logger.info("check "+logInfo);
+		RpcResult result = new RpcResult("ok");
+		for( Object obj : logInfo ) {
+			Map fileInfo = (Map)obj;
+			String name = (String)fileInfo.get("name");
+			File f = new File(dir,name);
+			if( !f.exists() ) {
+				if( name.equals(fileName) )  logger.error("missing");
+				result = new RpcResult("missing",name);
+				break;
+			}
+			long end = (Long)fileInfo.get("end");
+			LogFile log = new LogFile(f);
+			long logEnd = log.end();
+			if( logEnd > end ) {
+				logger.error("logEnd > end - shouldn't happen, file="+name+" logEnd="+logEnd+" end="+end);
+				result = new RpcResult("missing",name);
+				break;
+			}
+			if( logEnd < end ) {
+				if( name.equals(fileName) )  logger.error("incomplete");
+				result = new RpcResult("incomplete",name,logEnd);
+				break;
+			}
+		}
+		if( call.cmd.equals("add") ) {
+			boolean complete = true;
+			List<LogFile> logs = new ArrayList<LogFile>();
+			for( Object obj : logInfo ) {
+				Map fileInfo = (Map)obj;
+				String name = (String)fileInfo.get("name");
+				File f = new File(dir,name);
+				if( !f.exists() ) {
+					complete = false;
+					break;
+				}
+				logs.add( new LogFile(f) );
+			}
+			if( complete ) {
+				File index = new File(dir,"index");
+				LoggingIndexWriter.writeIndex(logs,index);
+				logger.info("write index");
+			}
+		}
+		rpc.write(result);
+	}
+
+
+}