Moved lzlib to the libs directory (cleaner)

libs/lzlib/gzip.lua

@@ -0,0 +1,83 @@
+
+--[===================================================================[
+TODO:
+	- add a nice header with license and stuff..
+	- detect plain text files
+	- proper testing
+	- improve implementation?
+	- check gzopen flags for consistency (ex: strategy flag)
+--]===================================================================]
+
+local io = require 'io'
+local zlib = require 'zlib'
+
+local error, assert, setmetatable, tostring = error, assert, setmetatable, tostring
+
+local _M = {}
+
+function _M.open(filename, mode)
+	mode = mode or 'r'
+	local r = mode:find('r', 1, true) and true
+	local w = mode:find('w', 1, true) and true
+	local level = -1
+
+	local lstart, lend = mode:find('%d')
+	if (lstart and lend) then
+		level = mode:sub(lstart, lend)
+	end
+
+	if (not (r or w)) then
+		error('file open mode must specify read or write operation')
+	end
+
+	local f, z
+
+	local mt = {
+		__index = {
+			read = function(self, ...)
+				return z:read(...)
+			end,
+			write = function(self, ...)
+				return z:write(...)
+			end,
+			seek = function(self, ...)
+				error 'seek not supported on gzip files'
+			end,
+			lines = function(self, ...)
+				return z:lines(...)
+			end,
+			flush = function(self, ...)
+				return z:flush(...) and f:flush()
+			end,
+			close = function(self, ...)
+				return z:close() and f:close()
+			end,
+		},
+		__tostring = function(self)
+			return 'gzip object (' .. mode .. ') [' .. tostring(z) .. '] [' .. tostring(f) .. ']'
+		end,
+	}
+
+	if r then
+		f = assert(io.open(filename, 'rb'))
+		z = assert(zlib.inflate(f))
+	else
+		f = assert(io.open(filename, 'wb'))
+		z = assert(zlib.deflate(f, level, nil, 15 + 16))
+	end
+
+	return setmetatable({}, mt)
+end
+
+function _M.lines(filename)
+	local gz = _M.open(filename, 'r')
+	return function()
+		local line = gz and gz:read()
+		if line == nil then
+			gz:close()
+		end
+		return line
+	end
+end
+
+return _M