Add zzlib

inflate-bit32.lua

@@ -0,0 +1,279 @@
+-- zzlib-bit32 - zlib decompression in Lua - version using bit/bit32 libraries
+
+-- Copyright (c) 2016-2020 Francois Galea <fgalea at free.fr>
+-- This program is free software. It comes without any warranty, to
+-- the extent permitted by applicable law. You can redistribute it
+-- and/or modify it under the terms of the Do What The Fuck You Want
+-- To Public License, Version 2, as published by Sam Hocevar. See
+-- the COPYING file or http://www.wtfpl.net/ for more details.
+
+
+local inflate = {}
+
+local bit = bit32 or bit
+
+inflate.band = bit.band
+inflate.rshift = bit.rshift
+
+function inflate.bitstream_init(file)
+  local bs = {
+    file = file,  -- the open file handle
+    buf = nil,    -- character buffer
+    len = nil,    -- length of character buffer
+    pos = 1,      -- position in char buffer
+    b = 0,        -- bit buffer
+    n = 0,        -- number of bits in buffer
+  }
+  -- get rid of n first bits
+  function bs:flushb(n)
+    self.n = self.n - n
+    self.b = bit.rshift(self.b,n)
+  end
+  -- peek a number of n bits from stream
+  function bs:peekb(n)
+    while self.n < n do
+      if self.pos > self.len then
+        self.buf = self.file:read(4096)
+        self.len = self.buf:len()
+        self.pos = 1
+      end
+      self.b = self.b + bit.lshift(self.buf:byte(self.pos),self.n)
+      self.pos = self.pos + 1
+      self.n = self.n + 8
+    end
+    return bit.band(self.b,bit.lshift(1,n)-1)
+  end
+  -- get a number of n bits from stream
+  function bs:getb(n)
+    local ret = bs:peekb(n)
+    self.n = self.n - n
+    self.b = bit.rshift(self.b,n)
+    return ret
+  end
+  -- get next variable-size of maximum size=n element from stream, according to Huffman table
+  function bs:getv(hufftable,n)
+    local e = hufftable[bs:peekb(n)]
+    local len = bit.band(e,15)
+    local ret = bit.rshift(e,4)
+    self.n = self.n - len
+    self.b = bit.rshift(self.b,len)
+    return ret
+  end
+  function bs:close()
+    if self.file then
+      self.file:close()
+    end
+  end
+  if type(file) == "string" then
+    bs.file = nil
+    bs.buf = file
+  else
+    bs.buf = file:read(4096)
+  end
+  bs.len = bs.buf:len()
+  return bs
+end
+
+local function hufftable_create(depths)
+  local nvalues = #depths
+  local nbits = 1
+  local bl_count = {}
+  local next_code = {}
+  for i=1,nvalues do
+    local d = depths[i]
+    if d > nbits then
+      nbits = d
+    end
+    bl_count[d] = (bl_count[d] or 0) + 1
+  end
+  local table = {}
+  local code = 0
+  bl_count[0] = 0
+  for i=1,nbits do
+    code = (code + (bl_count[i-1] or 0)) * 2
+    next_code[i] = code
+  end
+  for i=1,nvalues do
+    local len = depths[i] or 0
+    if len > 0 then
+      local e = (i-1)*16 + len
+      local code = next_code[len]
+      local rcode = 0
+      for j=1,len do
+        rcode = rcode + bit.lshift(bit.band(1,bit.rshift(code,j-1)),len-j)
+      end
+      for j=0,2^nbits-1,2^len do
+        table[j+rcode] = e
+      end
+      next_code[len] = next_code[len] + 1
+    end
+  end
+  return table,nbits
+end
+
+local function block_loop(out,bs,nlit,ndist,littable,disttable)
+  local lit
+  repeat
+    lit = bs:getv(littable,nlit)
+    if lit < 256 then
+      table.insert(out,lit)
+    elseif lit > 256 then
+      local nbits = 0
+      local size = 3
+      local dist = 1
+      if lit < 265 then
+        size = size + lit - 257
+      elseif lit < 285 then
+        nbits = bit.rshift(lit-261,2)
+        size = size + bit.lshift(bit.band(lit-261,3)+4,nbits)
+      else
+        size = 258
+      end
+      if nbits > 0 then
+        size = size + bs:getb(nbits)
+      end
+      local v = bs:getv(disttable,ndist)
+      if v < 4 then
+        dist = dist + v
+      else
+        nbits = bit.rshift(v-2,1)
+        dist = dist + bit.lshift(bit.band(v,1)+2,nbits)
+        dist = dist + bs:getb(nbits)
+      end
+      local p = #out-dist+1
+      while size > 0 do
+        table.insert(out,out[p])
+        p = p + 1
+        size = size - 1
+      end
+    end
+  until lit == 256
+end
+
+local function block_dynamic(out,bs)
+  local order = { 17, 18, 19, 1, 9, 8, 10, 7, 11, 6, 12, 5, 13, 4, 14, 3, 15, 2, 16 }
+  local hlit = 257 + bs:getb(5)
+  local hdist = 1 + bs:getb(5)
+  local hclen = 4 + bs:getb(4)
+  local depths = {}
+  for i=1,hclen do
+    local v = bs:getb(3)
+    depths[order[i]] = v
+  end
+  for i=hclen+1,19 do
+    depths[order[i]] = 0
+  end
+  local lengthtable,nlen = hufftable_create(depths)
+  local i=1
+  while i<=hlit+hdist do
+    local v = bs:getv(lengthtable,nlen)
+    if v < 16 then
+      depths[i] = v
+      i = i + 1
+    elseif v < 19 then
+      local nbt = {2,3,7}
+      local nb = nbt[v-15]
+      local c = 0
+      local n = 3 + bs:getb(nb)
+      if v == 16 then
+        c = depths[i-1]
+      elseif v == 18 then
+        n = n + 8
+      end
+      for j=1,n do
+        depths[i] = c
+        i = i + 1
+      end
+    else
+      error("wrong entry in depth table for literal/length alphabet: "..v);
+    end
+  end
+  local litdepths = {} for i=1,hlit do table.insert(litdepths,depths[i]) end
+  local littable,nlit = hufftable_create(litdepths)
+  local distdepths = {} for i=hlit+1,#depths do table.insert(distdepths,depths[i]) end
+  local disttable,ndist = hufftable_create(distdepths)
+  block_loop(out,bs,nlit,ndist,littable,disttable)
+end
+
+local function block_static(out,bs)
+  local cnt = { 144, 112, 24, 8 }
+  local dpt = { 8, 9, 7, 8 }
+  local depths = {}
+  for i=1,4 do
+    local d = dpt[i]
+    for j=1,cnt[i] do
+      table.insert(depths,d)
+    end
+  end
+  local littable,nlit = hufftable_create(depths)
+  depths = {}
+  for i=1,32 do
+    depths[i] = 5
+  end
+  local disttable,ndist = hufftable_create(depths)
+  block_loop(out,bs,nlit,ndist,littable,disttable)
+end
+
+local function block_uncompressed(out,bs)
+  bs:flushb(bit.band(bs.n,7))
+  local len = bs:getb(16)
+  if bs.n > 0 then
+    error("Unexpected.. should be zero remaining bits in buffer.")
+  end
+  local nlen = bs:getb(16)
+  if bit.bxor(len,nlen) ~= 65535 then
+    error("LEN and NLEN don't match")
+  end
+  for i=bs.pos,bs.pos+len-1 do
+    table.insert(out,bs.buf:byte(i,i))
+  end
+  bs.pos = bs.pos + len
+end
+
+function inflate.main(bs)
+  local last,type
+  local output = {}
+  repeat
+    local block
+    last = bs:getb(1)
+    type = bs:getb(2)
+    if type == 0 then
+      block_uncompressed(output,bs)
+    elseif type == 1 then
+      block_static(output,bs)
+    elseif type == 2 then
+      block_dynamic(output,bs)
+    else
+      error("unsupported block type")
+    end
+  until last == 1
+  bs:flushb(bit.band(bs.n,7))
+  return output
+end
+
+local crc32_table
+function inflate.crc32(s,crc)
+  if not crc32_table then
+    crc32_table = {}
+    for i=0,255 do
+      local r=i
+      for j=1,8 do
+        r = bit.bxor(bit.rshift(r,1),bit.band(0xedb88320,bit.bnot(bit.band(r,1)-1)))
+      end
+      crc32_table[i] = r
+    end
+  end
+  crc = bit.bnot(crc or 0)
+  for i=1,#s do
+    local c = s:byte(i)
+    crc = bit.bxor(crc32_table[bit.bxor(c,bit.band(crc,0xff))],bit.rshift(crc,8))
+  end
+  crc = bit.bnot(crc)
+  if crc<0 then
+    -- in Lua < 5.2, sign extension was performed
+    crc = crc + 4294967296
+  end
+  return crc
+end
+
+return inflate

zzlib.lua

@@ -0,0 +1,193 @@
+-- zzlib - zlib decompression in Lua - Implementation-independent code
+
+-- Copyright (c) 2016-2020 Francois Galea <fgalea at free.fr>
+-- This program is free software. It comes without any warranty, to
+-- the extent permitted by applicable law. You can redistribute it
+-- and/or modify it under the terms of the Do What The Fuck You Want
+-- To Public License, Version 2, as published by Sam Hocevar. See
+-- the COPYING file or http://www.wtfpl.net/ for more details.
+
+local base = string.gsub(@@LUA_SCRIPT_FILENAME@@, "(.*[/\\])(.*)", "%1")
+
+local unpack = table.unpack or unpack
+local infl = dofile(base.."/inflate-bit32.lua")
+
+local zzlib = {}
+
+local function arraytostr(array)
+  local tmp = {}
+  local size = #array
+  local pos = 1
+  local imax = 1
+  while size > 0 do
+    local bsize = size>=2048 and 2048 or size
+    local s = string.char(unpack(array,pos,pos+bsize-1))
+    pos = pos + bsize
+    size = size - bsize
+    local i = 1
+    while tmp[i] do
+      s = tmp[i]..s
+      tmp[i] = nil
+      i = i + 1
+    end
+    if i > imax then
+      imax = i
+    end
+    tmp[i] = s
+  end
+  local str = ""
+  for i=1,imax do
+    if tmp[i] then
+      str = tmp[i]..str
+    end
+  end
+  return str
+end
+
+local function inflate_gzip(bs)
+  local id1,id2,cm,flg = bs.buf:byte(1,4)
+  if id1 ~= 31 or id2 ~= 139 then
+    error("invalid gzip header")
+  end
+  if cm ~= 8 then
+    error("only deflate format is supported")
+  end
+  bs.pos=11
+  if infl.band(flg,4) ~= 0 then
+    local xl1,xl2 = bs.buf.byte(bs.pos,bs.pos+1)
+    local xlen = xl2*256+xl1
+    bs.pos = bs.pos+xlen+2
+  end
+  if infl.band(flg,8) ~= 0 then
+    local pos = bs.buf:find("\0",bs.pos)
+    bs.pos = pos+1
+  end
+  if infl.band(flg,16) ~= 0 then
+    local pos = bs.buf:find("\0",bs.pos)
+    bs.pos = pos+1
+  end
+  if infl.band(flg,2) ~= 0 then
+    -- TODO: check header CRC16
+    bs.pos = bs.pos+2
+  end
+  local result = arraytostr(infl.main(bs))
+  local crc = bs:getb(8)+256*(bs:getb(8)+256*(bs:getb(8)+256*bs:getb(8)))
+  bs:close()
+  if crc ~= infl.crc32(result) then
+    error("checksum verification failed")
+  end
+  return result
+end
+
+-- compute Adler-32 checksum
+local function adler32(s)
+  local s1 = 1
+  local s2 = 0
+  for i=1,#s do
+    local c = s:byte(i)
+    s1 = (s1+c)%65521
+    s2 = (s2+s1)%65521
+  end
+  return s2*65536+s1
+end
+
+local function inflate_zlib(bs)
+  local cmf = bs.buf:byte(1)
+  local flg = bs.buf:byte(2)
+  if (cmf*256+flg)%31 ~= 0 then
+    error("zlib header check bits are incorrect")
+  end
+  if infl.band(cmf,15) ~= 8 then
+    error("only deflate format is supported")
+  end
+  if infl.rshift(cmf,4) ~= 7 then
+    error("unsupported window size")
+  end
+  if infl.band(flg,32) ~= 0 then
+    error("preset dictionary not implemented")
+  end
+  bs.pos=3
+  local result = arraytostr(infl.main(bs))
+  local adler = ((bs:getb(8)*256+bs:getb(8))*256+bs:getb(8))*256+bs:getb(8)
+  bs:close()
+  if adler ~= adler32(result) then
+    error("checksum verification failed")
+  end
+  return result
+end
+
+function zzlib.gunzipf(filename)
+  local file,err = io.open(filename,"rb")
+  if not file then
+    return nil,err
+  end
+  return inflate_gzip(infl.bitstream_init(file))
+end
+
+function zzlib.gunzip(str)
+  return inflate_gzip(infl.bitstream_init(str))
+end
+
+function zzlib.inflate(str)
+  return inflate_zlib(infl.bitstream_init(str))
+end
+
+local function int2le(str,pos)
+  local a,b = str:byte(pos,pos+1)
+  return b*256+a
+end
+
+local function int4le(str,pos)
+  local a,b,c,d = str:byte(pos,pos+3)
+  return ((d*256+c)*256+b)*256+a
+end
+
+function zzlib.unzip(buf,filename)
+  local p = #buf-21
+  local quit = false
+  if int4le(buf,p) ~= 0x06054b50 then
+    -- not sure there is a reliable way to locate the end of central directory record
+    -- if it has a variable sized comment field
+    error(".ZIP file comments not supported")
+  end
+  local cdoffset = int4le(buf,p+16)
+  local nfiles = int2le(buf,p+10)
+  p = cdoffset+1
+  for i=1,nfiles do
+    if int4le(buf,p) ~= 0x02014b50 then
+      error("invalid central directory header signature")
+    end
+    local flag = int2le(buf,p+8)
+    local method = int2le(buf,p+10)
+    local crc = int4le(buf,p+16)
+    local namelen = int2le(buf,p+28)
+    local name = buf:sub(p+46,p+45+namelen)
+    if name == filename then
+      local headoffset = int4le(buf,p+42)
+      p = 1+headoffset
+      if int4le(buf,p) ~= 0x04034b50 then
+        error("invalid local header signature")
+      end
+      local csize = int4le(buf,p+18)
+      local extlen = int2le(buf,p+28)
+      p = p+30+namelen+extlen
+      if method == 0 then
+        -- no compression
+        result = buf:sub(p,p+csize-1)
+      else
+        -- DEFLATE compression
+        local bs = infl.bitstream_init(buf)
+        bs.pos = p
+        result = arraytostr(infl.main(bs))
+      end
+      if crc ~= infl.crc32(result) then
+        error("checksum verification failed")
+      end
+      return result
+    end
+    p = p+46+namelen+int2le(buf,p+30)+int2le(buf,p+32)
+  end
+  error("file '"..filename.."' not found in ZIP archive")
+end
+
+return zzlib