Reduce the size of scripts so that they take at most 6 clusters (3072kb)

Author: Lethja

demo/extra/exbench.lua

@@ -2,7 +2,7 @@ if not LIB then print("Please run bench.lua from the same working directory inst
 
 local function benchmark_md5sum()
     local it, s = 2, pcall(require, "md5sum")
-    local bm = BenchmarkStart("Checksum MD5", it)
+    local bm = BS("Checksum MD5", it)
     local file = io.open(arg[0], "rb")
 
     if not s or not file then
@@ -16,12 +16,12 @@ local function benchmark_md5sum()
         file:seek("set", 0)
     end
     file:close()
-    BenchmarkEnd(bm)
+    BE(bm)
 end
 
 local function benchmark_sha256()
     local it, s = 1, pcall(require, "s256sum")
-    local bm = BenchmarkStart("Checksum SHA256", it)
+    local bm = BS("Checksum SHA256", it)
     local file = io.open(arg[0], "rb")
 
     if not s or not file then
@@ -35,7 +35,7 @@ local function benchmark_sha256()
         file:seek("set", 0)
     end
     file:close()
-    BenchmarkEnd(bm)
+    BE(bm)
 end
 
 benchmark_md5sum()

demo/extra/md5sum.lua

@@ -1,159 +1,102 @@
 #!/usr/bin/env lua
 
---- Read a files hash from it's current point to the end
---- @param file file The file to read to the end
---- @return string The md5 checksum result of the file
+--- Read file hash
+--- @param file file The file to read (to end)
+--- @return string MD5 checksum
 function md5_file(file)
-	local function Md5Transform(chunk, A, B, C, D) -- Core MD5 transformation
-		local F = function(x, y, z)
-			return (x & y) | (~x & z)
+	local function Md5Transform(chunk, A, B, C, D)
+		local F = function(x, y, z) return (x & y) | (~x & z) end
+		local G = function(x, y, z) return (x & z) | (y & ~z) end
+		local H = function(x, y, z) return x ~ y ~ z end
+		local I = function(x, y, z) return y ~ (x | ~z) end
+		local function LS(x, n) return ((x << n) | (x >> (32 - n))) & 0xFFFFFFFF end
+		local wo, sh = {}, {{ 7, 12, 17, 22 }, { 5,  9, 14, 20 }, { 4, 11, 16, 23 }, { 6, 10, 15, 21 }}
+		for i = 0, 15 do
+			local o = i * 4 + 1
+			wo[i + 1] =
+			string.byte(chunk, o) |
+			(string.byte(chunk, o + 1) << 8) |
+			(string.byte(chunk, o + 2) << 16) |
+			(string.byte(chunk, o + 3) << 24)
 		end
-
-		local G = function(x, y, z)
-			return (x & z) | (y & ~z)
-		end
-
-		local H = function(x, y, z)
-			return x ~ y ~ z
-		end
-
-		local I = function(x, y, z)
-			return y ~ (x | ~z)
-		end
-
-		local function LShift32(x, n)
-			return ((x << n) | (x >> (32 - n))) & 0xFFFFFFFF
-		end
-
-		local words, shifts = {}, {
-			{ 7, 12, 17, 22 },
-			{ 5,  9, 14, 20 },
-			{ 4, 11, 16, 23 },
-			{ 6, 10, 15, 21 },
-		}
-
-		for i = 0, 15 do -- Break the chunk into 16 little-endian 32-bit words
-			local offset = i * 4 + 1
-			words[i + 1] = string.byte(chunk, offset) |
-					(string.byte(chunk, offset + 1) << 8) |
-					(string.byte(chunk, offset + 2) << 16) |
-					(string.byte(chunk, offset + 3) << 24)
-		end
-
 		local a, b, c, d = A, B, C, D
-
-		for i = 1, 64 do -- Main loop: 64 rounds of transformations
+		for i = 1, 64 do
 			local f, g
-			local round = math.floor((i - 1) / 16) + 1
-			local shift = shifts[round][(i - 1) % 4 + 1]
-
-			if round == 1 then
+			local r = math.floor((i - 1) / 16) + 1
+			local s = sh[r][(i - 1) % 4 + 1]
+			if r == 1 then
 				f = F(b, c, d)
 				g = (i - 1) % 16
-			elseif round == 2 then
+			elseif r == 2 then
 				f = G(b, c, d)
 				g = (5 * (i - 1) + 1) % 16
-			elseif round == 3 then
+			elseif r == 3 then
 				f = H(b, c, d)
 				g = (3 * (i - 1) + 5) % 16
-			elseif round == 4 then
+			elseif r == 4 then
 				f = I(b, c, d)
 				g = (7 * (i - 1)) % 16
 			end
-
-			local temp = d
+			local t = d
 			d = c
 			c = b
-			b = (b + LShift32((a + f + words[g + 1] +
-					T[i]) & 0xFFFFFFFF, shift)) & 0xFFFFFFFF
-			a = temp
+			b = (b + LS((a + f + wo[g + 1] + T[i]) & 0xFFFFFFFF, s)) & 0xFFFFFFFF
+			a = t
 		end
-
-		-- Add chunk's hash to the result so far
 		A = (A + a) & 0xFFFFFFFF
 		B = (B + b) & 0xFFFFFFFF
 		C = (C + c) & 0xFFFFFFFF
 		D = (D + d) & 0xFFFFFFFF
-
 		return A, B, C, D
 	end
-
 	local function Md5Pad(messageLength)
-		local msg_len = messageLength * 8 -- Message length in bits
-		local padding = "\128" -- Initial padding
-		local pad_len = (56 - (messageLength % 64)) -- 448 mod 512
-
-		if pad_len <= 0 then
-			pad_len = pad_len + 64
-		end
-
-		padding = padding .. string.rep("\0", pad_len - 1)
-
-		-- Append the original message length as a 64-bit little-endian integer
-		for i = 0, 7 do
-			padding = padding .. string.char((msg_len >> (8 * i)) & 0xFF)
-		end
-
-		return padding
+		local ml = messageLength * 8
+		local p = "\128"
+		local pl = (56 - (messageLength % 64))
+		if pl <= 0 then pl = pl + 64 end
+		p = p .. string.rep("\0", pl - 1)
+		for i = 0, 7 do p = p .. string.char((ml >> (8 * i)) & 0xFF) end
+		return p
 	end
-
-    local A, B, C, D, len = 0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0
+    local A, B, C, D, l = 0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0
 
     while true do
-        local chunk = file:read(64) -- Read in chunks of 64 bytes (512 bits)
-
-        if not chunk then break end
-        len = len + #chunk
-
-		-- If it's the final chunk, apply padding
-        if #chunk < 64 then chunk = chunk .. Md5Pad(len) end
-        A, B, C, D = Md5Transform(chunk, A, B, C, D)
-
-		-- Stop processing after the padded block
-        if #chunk > 64 then break end
+        local c = file:read(64)
+        if not c then break end
+        l = l + #c
+        if #c < 64 then c = c .. Md5Pad(l) end
+        A, B, C, D = Md5Transform(c, A, B, C, D)
+        if #c > 64 then break end
     end
-
-	-- Format output as a hexadecimal string in little-endian order
     local function to_hex(x)
         return string.format("%02x%02x%02x%02x",
 				x & 0xFF, (x >> 8) & 0xFF, (x >> 16) & 0xFF, (x >> 24) & 0xFF)
     end
-
     return to_hex(A) .. to_hex(B) .. to_hex(C) .. to_hex(D)
 end
 
-local function PredefineConstants()
-	T = {} -- Predefined MD5 constants of sine-based shifts (T values)
-	for i = 1, 64 do
-		T[i] = math.floor(2 ^ 32 * math.abs(math.sin(i)))
-	end
+local function init()
+	T = {}
+	for i = 1, 64 do T[i] = math.floor(2 ^ 32 * math.abs(math.sin(i))) end
 end
 
-if LIB then PredefineConstants() return end
-
+if LIB then init() return end
 if #arg < 1 then
-	-- Show accurate Lua binary and script location
     print((arg[-1] or "?") .. " " .. (arg[0] or "?") .. " [FILE]...")
     os.exit(1)
 else
-	PredefineConstants()
-
+	init()
     for i = 1, #arg do
-        local file, err = io.open(arg[i], "rb")
-
-        if file then
-            local sum = md5_file(file)
-            file:close()
-
+        local f, e = io.open(arg[i], "rb")
+        if f then
+            local sum = md5_file(f) f:close()
             if sum then
                 print(sum .. "  " .. arg[i])
             else
-                print(arg[i] .. ": " .. "Unknown error")
-                os.exit(-1)
+                print(arg[i] .. ": " .. "Unknown error") os.exit(-1)
             end
         else
-            print(arg[i] .. ": " .. err)
-            os.exit(1)
+            print(arg[i] .. ": " .. e) os.exit(1)
         end
     end
 end