static int dm_sendFileToOtherMachine_chunkSize = 100*1024; // 1024*1024;

svoid dm_sendFileToOtherMachine(File f, S computerID, S remotePath) {
  dm_evalOnOtherMachine(computerID, formatFunctionCallWithSemicolon backupFile(
    formatFunctionCall fileRelativeToUserDirUnlessAbsolute(quote(remotePath))
  ));
  for (LongRange r : chunks(fileSize(f), dm_sendFileToOtherMachine_chunkSize)) {
    print("Sending file chunk " + r + " of " + f + " to " + computerID + ":" + remotePath);
    dm_evalOnOtherMachine(computerID,
      formatFunctionCallWithSemicolon saveBinaryFilePart_base64(
        formatFunctionCall fileRelativeToUserDirUnlessAbsolute(quote(remotePath)),
        r.start + "L",
        quote(base64encode(loadBinaryFileChunk(f, r)))));
  }
  dm_evalOnOtherMachine(computerID, formatFunctionCallWithSemicolon truncateFile(
    formatFunctionCall fileRelativeToUserDirUnlessAbsolute(quote(remotePath)),
    fileSize(f) + "L"));
}

// works only for files under user dir. sends them to same path
// in remote user dir.
svoid dm_sendFileToOtherMachine(File f, S computerID) {
  S path = assertNotNull(f2s(f) + " is not in " + userDir(), pathRelativeToUserDir(f));
  dm_sendFileToOtherMachine(f, computerID, path);
}