if not modules then modules = { } end modules ['util-sac'] = {
version = 1.001,
comment = "companion to luat-lib.mkiv",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
-- experimental string access (some 3 times faster than file access when messing
-- with bytes)
local byte, sub = string.byte, string.sub
local tonumber = tonumber
utilities = utilities or { }
local streams = { }
utilities.streams = streams
function streams.open(filename,zerobased)
local f = filename and io.loaddata(filename)
if f then
return { f, 1, #f, zerobased or false }
end
end
function streams.openstring(f,zerobased)
if f then
return { f, 1, #f, zerobased or false }
end
end
function streams.getstring(f)
if f then
return f[1]
end
end
function streams.close()
-- dummy
end
function streams.size(f)
return f and f[3] or 0
end
streams.getsize = streams.size
function streams.setposition(f,i)
if f[4] then
-- zerobased
if i <= 0 then
f[2] = 1
else
f[2] = i + 1
end
else
if i <= 1 then
f[2] = 1
else
f[2] = i
end
end
end
function streams.getposition(f)
if f[4] then
-- zerobased
return f[2] - 1
else
return f[2]
end
end
function streams.look(f,n,chars)
local b = f[2]
local e = b + n - 1
if chars then
return sub(f[1],b,e)
else
return byte(f[1],b,e)
end
end
function streams.skip(f,n)
f[2] = f[2] + n
end
function streams.readbyte(f)
local i = f[2]
f[2] = i + 1
return byte(f[1],i)
end
function streams.readbytes(f,n)
local i = f[2]
local j = i + n
f[2] = j
return byte(f[1],i,j-1)
end
function streams.readbytetable(f,n)
local i = f[2]
local j = i + n
f[2] = j
return { byte(f[1],i,j-1) }
end
function streams.skipbytes(f,n)
f[2] = f[2] + n
end
function streams.readchar(f)
local i = f[2]
f[2] = i + 1
return sub(f[1],i,i)
end
function streams.readstring(f,n)
local i = f[2]
local j = i + n
f[2] = j
return sub(f[1],i,j-1)
end
function streams.readinteger1(f) -- one byte
local i = f[2]
f[2] = i + 1
local n = byte(f[1],i)
if n >= 0x80 then
return n - 0x100
else
return n
end
end
streams.readcardinal1 = streams.readbyte -- one byte
streams.readcardinal = streams.readcardinal1
streams.readinteger = streams.readinteger1
function streams.readcardinal2(f)
local i = f[2]
local j = i + 1
f[2] = j + 1
local a, b = byte(f[1],i,j)
return 0x100 * a + b
end
function streams.readcardinal2le(f)
local i = f[2]
local j = i + 1
f[2] = j + 1
local b, a = byte(f[1],i,j)
return 0x100 * a + b
end
function streams.readinteger2(f)
local i = f[2]
local j = i + 1
f[2] = j + 1
local a, b = byte(f[1],i,j)
if a >= 0x80 then
return 0x100 * a + b - 0x10000
else
return 0x100 * a + b
end
end
function streams.readinteger2le(f)
local i = f[2]
local j = i + 1
f[2] = j + 1
local b, a = byte(f[1],i,j)
if a >= 0x80 then
return 0x100 * a + b - 0x10000
else
return 0x100 * a + b
end
end
function streams.readcardinal3(f)
local i = f[2]
local j = i + 2
f[2] = j + 1
local a, b, c = byte(f[1],i,j)
return 0x10000 * a + 0x100 * b + c
end
function streams.readcardinal3le(f)
local i = f[2]
local j = i + 2
f[2] = j + 1
local c, b, a = byte(f[1],i,j)
return 0x10000 * a + 0x100 * b + c
end
function streams.readinteger3(f)
local i = f[2]
local j = i + 3
f[2] = j + 1
local a, b, c = byte(f[1],i,j)
if a >= 0x80 then
return 0x10000 * a + 0x100 * b + c - 0x1000000
else
return 0x10000 * a + 0x100 * b + c
end
end
function streams.readinteger3le(f)
local i = f[2]
local j = i + 3
f[2] = j + 1
local c, b, a = byte(f[1],i,j)
if a >= 0x80 then
return 0x10000 * a + 0x100 * b + c - 0x1000000
else
return 0x10000 * a + 0x100 * b + c
end
end
function streams.readcardinal4(f)
local i = f[2]
local j = i + 3
f[2] = j + 1
local a, b, c, d = byte(f[1],i,j)
return 0x1000000 * a + 0x10000 * b + 0x100 * c + d
end
function streams.readcardinal4le(f)
local i = f[2]
local j = i + 3
f[2] = j + 1
local d, c, b, a = byte(f[1],i,j)
return 0x1000000 * a + 0x10000 * b + 0x100 * c + d
end
function streams.readinteger4(f)
local i = f[2]
local j = i + 3
f[2] = j + 1
local a, b, c, d = byte(f[1],i,j)
if a >= 0x80 then
return 0x1000000 * a + 0x10000 * b + 0x100 * c + d - 0x100000000
else
return 0x1000000 * a + 0x10000 * b + 0x100 * c + d
end
end
function streams.readinteger4le(f)
local i = f[2]
local j = i + 3
f[2] = j + 1
local d, c, b, a = byte(f[1],i,j)
if a >= 0x80 then
return 0x1000000 * a + 0x10000 * b + 0x100 * c + d - 0x100000000
else
return 0x1000000 * a + 0x10000 * b + 0x100 * c + d
end
end
function streams.readfixed2(f)
local i = f[2]
local j = i + 1
f[2] = j + 1
local a, b = byte(f[1],i,j)
if a >= 0x80 then
tonumber((a - 0x100) .. "." .. b)
else
tonumber((a ) .. "." .. b)
end
end
function streams.readfixed4(f)
local i = f[2]
local j = i + 3
f[2] = j + 1
local a, b, c, d = byte(f[1],i,j)
if a >= 0x80 then
tonumber((0x100 * a + b - 0x10000) .. "." .. (0x100 * c + d))
else
tonumber((0x100 * a + b ) .. "." .. (0x100 * c + d))
end
end
if bit32 then
local extract = bit32.extract
local band = bit32.band
function streams.read2dot14(f)
local i = f[2]
local j = i + 1
f[2] = j + 1
local a, b = byte(f[1],i,j)
if a >= 0x80 then
local n = -(0x100 * a + b)
return - (extract(n,14,2) + (band(n,0x3FFF) / 16384.0))
else
local n = 0x100 * a + b
return (extract(n,14,2) + (band(n,0x3FFF) / 16384.0))
end
end
end
function streams.skipshort(f,n)
f[2] = f[2] + 2*(n or 1)
end
function streams.skiplong(f,n)
f[2] = f[2] + 4*(n or 1)
end
if sio and sio.readcardinal2 then
local readcardinal1 = sio.readcardinal1
local readcardinal2 = sio.readcardinal2
local readcardinal3 = sio.readcardinal3
local readcardinal4 = sio.readcardinal4
local readinteger1 = sio.readinteger1
local readinteger2 = sio.readinteger2
local readinteger3 = sio.readinteger3
local readinteger4 = sio.readinteger4
local readfixed2 = sio.readfixed2
local readfixed4 = sio.readfixed4
local read2dot14 = sio.read2dot14
local readbytes = sio.readbytes
local readbytetable = sio.readbytetable
function streams.readcardinal1(f)
local i = f[2]
f[2] = i + 1
return readcardinal1(f[1],i)
end
function streams.readcardinal2(f)
local i = f[2]
f[2] = i + 2
return readcardinal2(f[1],i)
end
function streams.readcardinal3(f)
local i = f[2]
f[2] = i + 3
return readcardinal3(f[1],i)
end
function streams.readcardinal4(f)
local i = f[2]
f[2] = i + 4
return readcardinal4(f[1],i)
end
function streams.readinteger1(f)
local i = f[2]
f[2] = i + 1
return readinteger1(f[1],i)
end
function streams.readinteger2(f)
local i = f[2]
f[2] = i + 2
return readinteger2(f[1],i)
end
function streams.readinteger3(f)
local i = f[2]
f[2] = i + 3
return readinteger3(f[1],i)
end
function streams.readinteger4(f)
local i = f[2]
f[2] = i + 4
return readinteger4(f[1],i)
end
-- function streams.readfixed2(f) -- needs recent luatex
-- local i = f[2]
-- f[2] = i + 2
-- return readfixed2(f[1],i)
-- end
-- function streams.readfixed4(f) -- needs recent luatex
-- local i = f[2]
-- f[2] = i + 4
-- return readfixed4(f[1],i)
-- end
function streams.read2dot4(f)
local i = f[2]
f[2] = i + 2
return read2dot4(f[1],i)
end
function streams.readbytes(f,n)
local i = f[2]
local s = f[3]
local p = i + n
if p > s then
f[2] = s + 1
else
f[2] = p
end
return readbytes(f[1],i,n)
end
function streams.readbytetable(f,n)
local i = f[2]
local s = f[3]
local p = i + n
if p > s then
f[2] = s + 1
else
f[2] = p
end
return readbytetable(f[1],i,n)
end
streams.readbyte = streams.readcardinal1
streams.readsignedbyte = streams.readinteger1
streams.readcardinal = streams.readcardinal1
streams.readinteger = streams.readinteger1
end
if sio and sio.readcardinaltable then
local readcardinaltable = sio.readcardinaltable
local readintegertable = sio.readintegertable
function utilities.streams.readcardinaltable(f,n,b)
local i = f[2]
local s = f[3]
local p = i + n * b
if p > s then
f[2] = s + 1
else
f[2] = p
end
return readcardinaltable(f[1],i,n,b)
end
function utilities.streams.readintegertable(f,n,b)
local i = f[2]
local s = f[3]
local p = i + n * b
if p > s then
f[2] = s + 1
else
f[2] = p
end
return readintegertable(f[1],i,n,b)
end
else
local readcardinal1 = streams.readcardinal1
local readcardinal2 = streams.readcardinal2
local readcardinal3 = streams.readcardinal3
local readcardinal4 = streams.readcardinal4
function streams.readcardinaltable(f,n,b)
local i = f[2]
local s = f[3]
local p = i + n * b
if p > s then
f[2] = s + 1
else
f[2] = p
end
local t = { }
if b == 1 then for i=1,n do t[i] = readcardinal1(f[1],i) end
elseif b == 2 then for i=1,n do t[i] = readcardinal2(f[1],i) end
elseif b == 3 then for i=1,n do t[i] = readcardinal3(f[1],i) end
elseif b == 4 then for i=1,n do t[i] = readcardinal4(f[1],i) end end
return t
end
local readinteger1 = streams.readinteger1
local readinteger2 = streams.readinteger2
local readinteger3 = streams.readinteger3
local readinteger4 = streams.readinteger4
function streams.readintegertable(f,n,b)
local i = f[2]
local s = f[3]
local p = i + n * b
if p > s then
f[2] = s + 1
else
f[2] = p
end
local t = { }
if b == 1 then for i=1,n do t[i] = readinteger1(f[1],i) end
elseif b == 2 then for i=1,n do t[i] = readinteger2(f[1],i) end
elseif b == 3 then for i=1,n do t[i] = readinteger3(f[1],i) end
elseif b == 4 then for i=1,n do t[i] = readinteger4(f[1],i) end end
return t
end
end
-- For practical reasons we put this here. It's less efficient but ok when we don't
-- have much access.
do
local files = utilities.files
if files then
local openfile = files.open
local openstream = streams.open
local openstring = streams.openstring
local setmetatable = setmetatable
function io.newreader(str,method)
local f, m
if method == "string" then
f = openstring(str)
m = streams
elseif method == "stream" then
f = openstream(str)
m = streams
else
f = openfile(str,"rb")
m = files
end
if f then
local t = { }
setmetatable(t, {
__index = function(t,k)
local r = m[k]
if k == "close" then
if f then
m.close(f)
f = nil
end
return function() end
elseif r then
local v = function(_,a,b) return r(f,a,b) end
t[k] = v
return v
else
print("unknown key",k)
end
end
} )
return t
end
end
end
end
