added a lz16 stream library, depending on lzss

lz16/liblz16.lua

@@ -0,0 +1,78 @@
+local lz = require "lzss"
+local buffer = require "buffer"
+
+lz16 = {}
+
+local function cint(n,l)
+ local t={}
+ for i = 0, 7 do
+  t[i+1] = (n >> (i * 8)) & 0xFF
+ end
+ return string.reverse(string.char(table.unpack(t)):sub(1,l))
+end
+local function toint(s)
+ s=s or ""
+ local n = 0
+ local i = 1
+ while true do
+  local p = s:sub(i,i)
+  if p == "" then break end
+  local b = string.byte(p)
+  n = n << 8
+  n = n | b
+  i=i+1
+ end
+ return n
+end
+
+local function readBuffer(fi)
+ local stream = {}
+ if fi:read(4) ~= "lz16" and not tO.f then
+  return false, "not an lz16 archive"
+ end
+ function stream.read()
+  local len = toint(fi:read(2) or "\0\0")
+  if len < 1 then
+   print("nothing")
+   coroutine.yield()
+   return nil
+  end
+  coroutine.yield()
+  return lz.decompress(fi:read(len))
+ end
+ function stream.close()
+  fi:close()
+ end
+ return buffer.new("r",stream)
+end
+
+local function writeBuffer(fo)
+ local stream = {}
+ function stream:write(data)
+  local cblock = lz.compress(data)
+  fo:write(cint(cblock:len(),2)..cblock)
+  return cblock:len()+2
+ end
+ function stream.close()
+  fo:close()
+ end
+ fo:write("lz16") -- write header
+ return buffer.new("w",stream)
+end
+
+function lz16.buffer(stream)
+ if stream.mode.w then
+  print("write")
+  return writeBuffer(stream)
+ end
+ return readBuffer(stream)
+end
+
+function lz16.open(fname, mode)
+ local f = io.open(fname, mode)
+ if not f then return false end
+ f.mode.b = true
+ return lz16.buffer(f)
+end
+
+return lz16