OC-Tsuki/extras/crescent/tsar.lua
2020-05-24 23:50:51 -04:00

98 lines
2.2 KiB
Lua

local magic = 0x5f7d
local magic_rev = 0x7d5f
local header_fmt = "I2I2I2I2I2I6I6"
local en = string.unpack("=I2", string.char(0x7d, 0x5f)) == magic -- true = LE, false = BE
local function get_end(e)
return (e and "<") or ">"
end
local function read_header(dat)
local e = get_end(en)
local m = string.unpack(e.."I2", dat)
if m ~= magic and m ~= magic_rev then return nil, "bad magic" end
if m ~= magic then
e = get_end(not en)
end
local ent = {}
ent.magic, ent.namesize, ent.mode, ent.uid, ent.gid, ent.filesize, ent.mtime = string.unpack(e..header_fmt, dat)
return ent
end
local arc = {}
function arc:fetch(path)
for i=1, #self.tbl do
if (self.tbl[i].name == path and self.tbl[i].mode & 32768 > 0) then
self.seek(self.tbl[i].pos-self.seek(0))
return self.read(self.tbl[i].filesize), self.tbl[i]
end
end
return nil, "file not found"
end
function arc:exists(path)
for i=1, #self.tbl do
if (self.tbl[i].name == path) then
return true
end
end
return false
end
function arc:list(path)
if path:sub(#path) ~= "/" then path = path .. "/" end
local ent = {}
for i=1, #self.tbl do
if (self.tbl[i].name:sub(1, #path) == path and not self.tbl[i].name:find("/", #path+1, false)) then
ent[#ent+1] = self.tbl[i].name
end
end
return ent
end
function arc:close()
self.close()
end
function load_tsar(addr, path)
local fs = component.proxy(addr)
local h = fs.open(path)
status("loading initramfs... "..lsc())
local dat = ""
local buf = ""
repeat
buf = fs.read(h, math.huge)
if (buf) then
dat = dat .. buf
end
y = y - 1
status("loading initramfs... "..lsc())
until not buf or buf == ""
local idx = 1
local function read(a)
local dat = buf:sub(idx, idx+a-1)
idx = idx + a
return dat
end
local function seek(a)
idx = idx + a
return idx
end
local function close()end
local tbl = {}
local lname = ""
while lname ~= "TRAILER!!!" do
y = y - 1
status("loading initramfs... "..lsc())
local dat = read(22)
local et = read_header(dat)
et.name = read(et.namesize)
et.pos = seek(et.namesize & 1)
seek(et.filesize + (et.filesize & 1))
lname = et.name
if lname ~= "TRAILER!!!" then
tbl[#tbl+1] = et
end
end
return setmetatable({tbl = tbl, read = read, seek = seek, close = close}, {__index=arc})
end