Merge pull request #2882 from ganmacs/fix-round

Fix bug available_buffer_space_ratios which is set 0 or 1

lib/fluent/plugin/buffer.rb

@@ -758,13 +758,13 @@ def write_step_by_step(metadata, data, format, splits_count, &block)
 
       def statistics
         stage_size, queue_size = @stage_size, @queue_size
-        buffer_space = 1.0 - ((stage_size + queue_size * 1.0) / @total_limit_size).round
+        buffer_space = 1.0 - ((stage_size + queue_size * 1.0) / @total_limit_size)
         stats = {
           'stage_length' => @stage.size,
           'stage_byte_size' => stage_size,
           'queue_length' => @queue.size,
           'queue_byte_size' => queue_size,
-          'available_buffer_space_ratios' => buffer_space * 100,
+          'available_buffer_space_ratios' => (buffer_space * 100).round(1),
           'total_queued_size' => stage_size + queue_size,
         }
 

test/plugin/test_buffer.rb

@@ -1202,4 +1202,24 @@ def create_chunk_es(metadata, es)
       assert chunk.singleton_class.ancestors.include?(Fluent::Plugin::Buffer::Chunk::Decompressable)
     end
   end
+
+  sub_test_case '#statistics' do
+    setup do
+      @p = create_buffer({ "total_limit_size" => 1024 })
+      dm = create_metadata(Time.parse('2020-03-13 16:00:00 +0000').to_i, nil, nil)
+
+      (class << @p; self; end).module_eval do
+        define_method(:resume) {
+          queued = [create_chunk(dm, ["a" * (1024 - 102)]).enqueued!]
+          return {}, queued
+        }
+      end
+
+      @p.start
+    end
+
+    test 'returns available_buffer_space_ratios' do
+      assert_equal 10.0, @p.statistics['buffer']['available_buffer_space_ratios']
+    end
+  end
 end