refactor filer proto chunk variable from mtime to modified_ts_ns

other/java/client/src/main/java/seaweedfs/client/ReadChunks.java

@@ -83,7 +83,7 @@ public class ReadChunks {
                     prevX,
                     point.x,
                     chunk.getFileId(),
-                    chunk.getMtime(),
+                    chunk.getModifiedTsNs(),
                     prevX - chunk.getOffset(),
                     chunk.getOffset() == prevX && chunk.getSize() == prevX - startPoint.x,
                     chunk.getCipherKey().toByteArray(),
@@ -100,7 +100,7 @@ public class ReadChunks {
 
         public Point(long x, FilerProto.FileChunk chunk, boolean isStart) {
             this.x = x;
-            this.ts = chunk.getMtime();
+            this.ts = chunk.getModifiedTsNs();
             this.chunk = chunk;
             this.isStart = isStart;
         }

other/java/client/src/main/java/seaweedfs/client/SeaweedWrite.java

@@ -98,7 +98,7 @@ public class SeaweedWrite {
                 .setFileId(fileId)
                 .setOffset(offset)
                 .setSize(bytesLength)
-                .setMtime(System.currentTimeMillis() / 10000L)
+                .setModifiedTsNs(System.nanoTime())
                 .setETag(etag)
                 .setCipherKey(cipherKeyString);
     }

other/java/client/src/main/proto/filer.proto

@@ -132,7 +132,7 @@ message FileChunk {
     string file_id = 1; // to be deprecated
     int64 offset = 2;
     uint64 size = 3;
-    int64 mtime = 4;
+    int64 modified_ts_ns = 4;
     string e_tag = 5;
     string source_file_id = 6; // to be deprecated
     FileId fid = 7;