micro-optimizations on hotspots

encoding.lua

@@ -1,6 +1,8 @@
+local char, byte, floor = string.char, string.byte, math.floor
+
 -- https://gist.github.com/mebens/938502
 local function rshift(x, by)
-	return math.floor(x / 2 ^ by)
+	return floor(x / 2 ^ by)
 end
 
 -- https://stackoverflow.com/a/32387452
@@ -12,15 +14,15 @@ local function bitand(a, b)
 		  result = result + bitval      -- set the current bit
 	  end
 	  bitval = bitval * 2 -- shift left
-	  a = math.floor(a/2) -- shift right
-	  b = math.floor(b/2)
+	  a = floor(a/2) -- shift right
+	  b = floor(b/2)
 	end
 	return result
 end
 
 function mapsync.encode_uint16(int)
 	local a, b = int % 0x100, int / 0x100
-	return string.char(a, b)
+	return char(a, b)
 end
 
 function mapsync.encode_uint32(v)
@@ -28,11 +30,11 @@ function mapsync.encode_uint32(v)
 	local b2 = bitand( rshift(v, 8), 0xFF )
 	local b3 = bitand( rshift(v, 16), 0xFF )
 	local b4 = bitand( rshift(v, 24), 0xFF )
-	return string.char(b1, b2, b3, b4)
+	return char(b1, b2, b3, b4)
 end
 
 function mapsync.decode_uint16(str, ofs)
 	ofs = ofs or 0
-	local a, b = string.byte(str, ofs + 1, ofs + 2)
+	local a, b = byte(str, ofs + 1, ofs + 2)
 	return a + b * 0x100
 end