in_tail.rb in fluentd-0.10.9

- old
+ new

@@ -40,10 +40,13 @@
 
     if @pos_file
       @pf_file = File.open(@pos_file, File::RDWR|File::CREAT)
       @pf_file.sync = true
       @pf = PositionFile.parse(@pf_file)
+    else
+      $log.warn "'pos_file PATH' parameter is not set to a 'tail' source."
+      $log.warn "this parameter is highly recommended to save the position to resume tailing."
     end
 
     configure_parser(conf)
   end
 
@@ -59,11 +62,11 @@
       pe = @pf ? @pf[path] : NullPositionEntry.instance
       h = Handler.new(path, pe, method(:receive_lines))
       @loop.attach h
     }
     handlers.each {|h|
-      h.on_change  # initialize call
+      h.on_change(nil, nil)  # initialize call  # TODO prev, cur
     }
     @thread = Thread.new(&method(:run))
   end
 
   def shutdown
@@ -114,18 +117,18 @@
         @pos = @pe.read_pos
       else
         # seek to the end of file first.
         # logs never duplicate but may be lost if fluent is down.
         @pos = stat.size
-        @pe.update(@inode, stat.size)
+        @pe.update(@inode, @pos)
       end
       @buffer = ''
       @callback = callback
       super(path)
     end
 
-    def on_change
+    def on_change(prev, cur)
       lines = []
       inode = nil
 
       File.open(path) {|f|
         stat = f.lstat
@@ -168,10 +171,10 @@
         @inode = inode
       else
         @pe.update_pos(@pos)
       end
 
-      @callback.call(lines)
+      @callback.call(lines) unless lines.empty?
 
     rescue Errno::ENOENT
       # moved or deleted
       @pos = 0
     # TODO rescue