Add benchmark

bench.lua

@@ -0,0 +1,61 @@
+function json_decode_file( file )
+  local json = require( "json" )
+
+  local str = ""
+  for line in io.lines( file ) do
+    str = str .. line
+  end
+
+  return json.decode( str )
+end
+
+function bench( width, height )
+  local graphs = json_decode_file( "../graphs.json" )
+
+  require( "cairo" )
+  require( "conkygraph" )
+
+  -- HACK
+  local j = 0
+  for k, v in pairs( graphs ) do
+    j = j + 1
+  end
+
+  local w = width
+  local h = height / j
+
+  local cs = cairo_image_surface_create( cairo.FORMAT_RGB24, width, height )
+  local cr = cairo_create( cs )
+
+  cairo.set_source_rgb( cr, 1, 1, 1 )
+  cairo.paint( cr )
+
+  -- Fill with random data
+  for k1, v in pairs( graphs ) do
+    for k2, f in pairs( v.functions ) do
+      local d = width / f.dx
+      f.data = {}
+
+      for i = 1, d do
+        table.insert( f.data, math.sin( i ) )
+      end
+    end
+  end
+
+  local start = os.clock()
+
+  local i = 0
+  for k1, g in pairs( graphs ) do
+    for k2, f in pairs( g.functions ) do
+      cairo_graph( cr, 0, i * h, w, h, f )
+    end
+
+    i = i + 1
+  end
+
+  print( "Time: " .. os.clock() - start )
+
+  cairo.surface_write_to_png( cs, "bench.png" )
+end
+
+bench( 1280, 1024 )