REF simplify readwrite and network code

drawing/Network.lua

@@ -84,24 +84,31 @@ return function(update_freq)
       return rx, tx
    end
 
+   local compute_speed = function(x0, x1)
+      -- mask overflow
+      if x1 > x0 then
+         return (x1 - x0) * update_freq
+      else
+         return 0
+      end
+   end
+
    local prev_rx_bits, prev_tx_bits = read_interfaces()
 
    local update = function(cr)
-      local dspeed, uspeed = 0, 0
       local rx_bits, tx_bits = read_interfaces()
-
+      Common.annotated_scale_plot_set(
-      -- mask overflow
+         dnload,
-      if rx_bits > prev_rx_bits then
+         cr,
-         dspeed = (rx_bits - prev_rx_bits) * update_freq
+         compute_speed(prev_rx_bits, rx_bits)
-      end
+      )
-      if tx_bits > prev_tx_bits then
+      Common.annotated_scale_plot_set(
-         uspeed = (tx_bits - prev_tx_bits) * update_freq
+         upload,
-      end
+         cr,
+         compute_speed(prev_tx_bits, tx_bits)
+      )
       prev_rx_bits = rx_bits
       prev_tx_bits = tx_bits
-
-      Common.annotated_scale_plot_set(dnload, cr, dspeed)
-      Common.annotated_scale_plot_set(upload, cr, uspeed)
    end
 
    -----------------------------------------------------------------------------

drawing/ReadWrite.lua

@@ -85,26 +85,31 @@ return function(update_freq)
       return read_bytes * BLOCK_SIZE_BYTES, write_bytes * BLOCK_SIZE_BYTES
    end
 
-   reads.byte_cnt = 0
+   local prev_read_bytes, prev_write_bytes = read_devices()
-   writes.byte_cnt = 0
-   reads.prev_byte_cnt, writes.prev_byte_cnt = read_devices()
 
-   local update_stat = function(cr, stat, byte_cnt)
+   local compute_rate = function(x0, x1)
-      local delta_bytes = byte_cnt - stat.prev_byte_cnt
+      -- mask overflow
-      stat.prev_byte_cnt = byte_cnt
+      if x1 > x0 then
-
+         return (x1 - x0) * update_freq
-      local plot_value = 0
+      else
-      if delta_bytes > 0 then
+         return 0
-         local bps = delta_bytes * update_freq
-         plot_value = bps
       end
-      Common.annotated_scale_plot_set(stat, cr, plot_value)
    end
 
    local update = function(cr)
-      local read_byte_cnt, write_byte_cnt = read_devices()
+      local read_bytes, write_bytes = read_devices()
-      update_stat(cr, reads, read_byte_cnt)
+      Common.annotated_scale_plot_set(
-      update_stat(cr, writes, write_byte_cnt)
+         reads,
+         cr,
+         compute_rate(prev_read_bytes, read_bytes)
+      )
+      Common.annotated_scale_plot_set(
+         writes,
+         cr,
+         compute_rate(prev_write_bytes, write_bytes)
+      )
+      prev_read_bytes = read_bytes
+      prev_write_bytes = write_bytes
    end
 
    -----------------------------------------------------------------------------