loggstuff.erl

%% use sync log so we can check if it caused a wrap event
    %% and record the timestamp/num entries for the new wrapfile
    %% (ie, collect metadata about each wrapfile.N, for faster seeking)
    disk_log:blog(State#state.log, Line),
    
    %% Fun used to write index marker, if we need to this insertion:
    WriteIndexFun = fun(FileOffset) ->
            Info = disk_log:info(State#state.log),
            NoItems = proplists:get_value(no_items, Info),
            CurrFile = proplists:get_value(current_file, Info),
            %% store an index marker:
            IndexMarker = #indexmarker{ log=State#state.log, 
                                        n=CurrFile, 
                                        numitems=NoItems, 
                                        timestamp=Ts, 
                                        byteoffset=FileOffset }, 
            ?INFO("Writing index marker, NewI:~p NoItems:~p", [NewInsertionCounter, NoItems]),
            disk_log:log(?INDEXMARKERNAME(State#state.uid), IndexMarker),
            array:set(array:size(State#state.indexmarkers), IndexMarker, State#state.indexmarkers)
    end,
                            
    %% Check for wrap msg
    receive 
        %% always write indexmarker if we wrap:
        {disk_log, _Node, _Log, {wrap, _NoLostItems}} ->
            NewIndexMarkers = WriteIndexFun(0),
            ?INFO("Writing index marker due to wrap. I:~p Marker:~p", 
                  [NewInsertionCounter, hd(NewIndexMarkers)])
        after 0 ->
            %% otherwise, write it if we are at an Nth boundary
            case WasN of
                true ->
                    NewIndexMarkers = WriteIndexFun(Offset),
                    ?INFO("Writing index marker due to Nth. I:~p Marker:~p", 
                          [NewInsertionCounter, hd(NewIndexMarkers)]);
                %% Otherwise only write if this was the first ever entry to the log
                false ->
                    case NewInsertionCounter =:= 1 of
                        true ->
                            NewIndexMarkers = WriteIndexFun(0),
                            ?INFO("Writing index marker due to very first entry. I:~p Marker:~p", 
                                  [NewInsertionCounter, hd(NewIndexMarkers)]);
                        false -> 
                            NewIndexMarkers = State#state.indexmarkers
                    end
            end
    end,