mmaped_dict.rb in prometheus-client-mmap-0.7.0.beta24

- old
+ new

@@ -39,25 +39,20 @@
       rescue StandardError => e
         raise ParsingError, "exception #{e} while processing metrics file #{path}"
       end
 
       def read_value(key)
-        @mutex.synchronize do
-          init_value(key) unless @positions.key?(key)
+        init_value(key) unless @positions.key?(key)
 
-          pos = @positions[key]
-          @m[pos..pos + 7].unpack('d')[0]
-        end
+        @m.get_double(@positions[key])
       end
 
       def write_value(key, value)
-        @mutex.synchronize do
-          init_value(key) unless @positions.key?(key)
+        init_value(key) unless @positions.key?(key)
 
-          pos = @positions[key]
-          @m[pos..pos + 7] = [value].pack('d')
-        end
+        pos = @positions[key]
+        @m[pos..pos + 7] = [value].pack('d')
       end
 
       def path
         @m.filepath if @m
       end
@@ -69,24 +64,27 @@
         Prometheus::Client.logger.warn("munmap raised error #{e}")
       end
 
       private
 
-      # Initialize a value. Lock must be held by caller.
       def init_value(key)
-        until @m.try_add_entry(key, 0.0) do
-          filepath = @m.filepath
-          size = @m.size
-          @m.close
+        @mutex.synchronize do
+          return if @positions.key?(key)
 
-          File.truncate(filepath, size * 2)
-          @m = Helper::MmapedFile.open(filepath)
-        end
+          until @m.try_add_entry(key, 0.0) do
+            filepath = @m.filepath
+            size = @m.size
+            @m.close
 
-        # Update how much space we've used.
-        @used = @m.used
+            File.truncate(filepath, size * 2)
+            @m = Helper::MmapedFile.open(filepath)
+          end
 
-        @positions[key] = @used - 8
+          # Update how much space we've used.
+          @used = @m.used
+
+          @positions[key] = @used - 8
+        end
       end
 
       # Yield (key, pos). No locking is performed.
       def read_all_positions
         @m.entries.map do |data, encoded_len, _, absolute_pos|