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presence.nvim/lua/deps/msgpack.lua
Andrew Kwon 66bd159dd3 Allow cancelling presence on remote nvim instances
- Add msgpack lib
- Restructure to have lib and deps folders
- Add cancellation methods and invoke remote cancellation on update
2021-01-10 22:28:01 -08:00

509 lines
13 KiB
Lua

local table = require("table")
local string = require("string")
local luabit = require("bit")
local tostr = string.char
local double_decode_count = 0
local double_encode_count = 0
-- cache bitops
local band, rshift = luabit.band, luabit.brshift
if not rshift then -- luajit differ from luabit
rshift = luabit.rshift
end
local function byte_mod(x,v)
if x < 0 then
x = x + 256
end
return (x%v)
end
-- buffer
local strbuf = "" -- for unpacking
local strary = {} -- for packing
local function strary_append_int16(n,h)
if n < 0 then
n = n + 65536
end
table.insert( strary, tostr(h, math.floor(n / 256), n % 256 ) )
end
local function strary_append_int32(n,h)
if n < 0 then
n = n + 4294967296
end
table.insert(strary, tostr(h,
math.floor(n / 16777216),
math.floor(n / 65536) % 256,
math.floor(n / 256) % 256,
n % 256 ))
end
local doubleto8bytes
local strary_append_double = function(n)
-- assume double
double_encode_count = double_encode_count + 1
local b = doubleto8bytes(n)
table.insert( strary, tostr(0xcb))
table.insert( strary, string.reverse(b) ) -- reverse: make big endian double precision
end
--- IEEE 754
-- out little endian
doubleto8bytes = function(x)
local function grab_byte(v)
return math.floor(v / 256), tostr(math.fmod(math.floor(v), 256))
end
local sign = 0
if x < 0 then sign = 1; x = -x end
local mantissa, exponent = math.frexp(x)
if x == 0 then -- zero
mantissa, exponent = 0, 0
elseif x == 1/0 then
mantissa, exponent = 0, 2047
else
mantissa = (mantissa * 2 - 1) * math.ldexp(0.5, 53)
exponent = exponent + 1022
end
local v, byte = "" -- convert to bytes
x = mantissa
for _ = 1,6 do
_, byte = grab_byte(x); v = v..byte -- 47:0
end
x, byte = grab_byte(exponent * 16 + x); v = v..byte -- 55:48
x, byte = grab_byte(sign * 128 + x); v = v..byte -- 63:56
return v, x
end
local function bitstofrac(ary)
local x = 0
local cur = 0.5
for _, v in ipairs(ary) do
x = x + cur * v
cur = cur / 2
end
return x
end
local function bytestobits(ary)
local out={}
for _, v in ipairs(ary) do
for j = 0, 7, 1 do
table.insert(out, band( rshift(v,7-j), 1 ) )
end
end
return out
end
-- get little endian
local function bytestodouble(v)
-- sign:1bit
-- exp: 11bit (2048, bias=1023)
local sign = math.floor(v:byte(8) / 128)
local exp = band( v:byte(8), 127 ) * 16 + rshift( v:byte(7), 4 ) - 1023 -- bias
-- frac: 52 bit
local fracbytes = {
band( v:byte(7), 15 ), v:byte(6), v:byte(5), v:byte(4), v:byte(3), v:byte(2), v:byte(1) -- big endian
}
local bits = bytestobits(fracbytes)
for _ = 1, 4 do table.remove(bits,1) end
if sign == 1 then sign = -1 else sign = 1 end
local frac = bitstofrac(bits)
if exp == -1023 and frac==0 then return 0 end
if exp == 1024 and frac==0 then return 1/0 *sign end
local real = math.ldexp(1+frac,exp)
return real * sign
end
--- packers
local packers = {}
packers.dynamic = function(data)
local t = type(data)
return packers[t](data)
end
packers["nil"] = function()
table.insert( strary, tostr(0xc0))
end
packers.boolean = function(data)
if data then -- pack true
table.insert( strary, tostr(0xc3))
else -- pack false
table.insert( strary, tostr(0xc2))
end
end
packers.number = function(n)
if math.floor(n) == n then -- integer
if n >= 0 then -- positive integer
if n < 128 then -- positive fixnum
table.insert( strary, tostr(n))
elseif n < 256 then -- uint8
table.insert(strary, tostr(0xcc,n))
elseif n < 65536 then -- uint16
strary_append_int16(n,0xcd)
elseif n < 4294967296 then -- uint32
strary_append_int32(n,0xce)
else -- lua cannot handle uint64, so double
strary_append_double(n)
end
else -- negative integer
if n >= -32 then -- negative fixnum
table.insert( strary, tostr( 0xe0 + ((n+256)%32)) )
elseif n >= -128 then -- int8
table.insert( strary, tostr(0xd0,byte_mod(n,0x100)))
elseif n >= -32768 then -- int16
strary_append_int16(n,0xd1)
elseif n >= -2147483648 then -- int32
strary_append_int32(n,0xd2)
else -- lua cannot handle int64, so double
strary_append_double(n)
end
end
else -- floating point
strary_append_double(n)
end
end
packers.string = function(data)
local n = #data
if n < 32 then
table.insert( strary, tostr( 0xa0+n ) )
elseif n < 65536 then
strary_append_int16(n,0xda)
elseif n < 4294967296 then
strary_append_int32(n,0xdb)
else
error("overflow")
end
table.insert( strary, data)
end
packers["function"] = function()
error("unimplemented:function")
end
packers.userdata = function()
error("unimplemented:userdata")
end
packers.thread = function()
error("unimplemented:thread")
end
packers.table = function(data)
local is_map,ndata,nmax = false,0,0
for k,_ in pairs(data) do
if type(k) == "number" then
if k > nmax then nmax = k end
else is_map = true end
ndata = ndata+1
end
if is_map then -- pack as map
if ndata < 16 then
table.insert( strary, tostr(0x80+ndata))
elseif ndata < 65536 then
strary_append_int16(ndata,0xde)
elseif ndata < 4294967296 then
strary_append_int32(ndata,0xdf)
else
error("overflow")
end
for k,v in pairs(data) do
packers[type(k)](k)
packers[type(v)](v)
end
else -- pack as array
if nmax < 16 then
table.insert( strary, tostr( 0x90+nmax ) )
elseif nmax < 65536 then
strary_append_int16(nmax,0xdc)
elseif nmax < 4294967296 then
strary_append_int32(nmax,0xdd)
else
error("overflow")
end
for i=1,nmax do packers[type(data[i])](data[i]) end
end
end
-- types decoding
local types_map = {
[0xc0] = "nil",
[0xc2] = "false",
[0xc3] = "true",
[0xca] = "float",
[0xcb] = "double",
[0xcc] = "uint8",
[0xcd] = "uint16",
[0xce] = "uint32",
[0xcf] = "uint64",
[0xd0] = "int8",
[0xd1] = "int16",
[0xd2] = "int32",
[0xd3] = "int64",
[0xda] = "raw16",
[0xdb] = "raw32",
[0xdc] = "array16",
[0xdd] = "array32",
[0xde] = "map16",
[0xdf] = "map32",
}
local type_for = function(n)
if types_map[n] then return types_map[n]
elseif n < 0xc0 then
if n < 0x80 then return "fixnum_posi"
elseif n < 0x90 then return "fixmap"
elseif n < 0xa0 then return "fixarray"
else return "fixraw" end
elseif n > 0xdf then return "fixnum_neg"
else return "undefined" end
end
local types_len_map = {
uint16 = 2, uint32 = 4, uint64 = 8,
int16 = 2, int32 = 4, int64 = 8,
float = 4, double = 8,
}
--- unpackers
local unpackers = {}
local unpack_number = function(offset,ntype,nlen)
local b1,b2,b3,b4,b5,b6,b7,b8
if nlen>=2 then
b1,b2 = string.byte( strbuf, offset+1, offset+2 )
end
if nlen>=4 then
b3,b4 = string.byte( strbuf, offset+3, offset+4 )
end
if nlen>=8 then
b5,b6,b7,b8 = string.byte( strbuf, offset+5, offset+8 )
end
if ntype == "uint16_t" then
return b1 * 256 + b2
elseif ntype == "uint32_t" then
return b1*65536*256 + b2*65536 + b3 * 256 + b4
elseif ntype == "int16_t" then
local n = b1 * 256 + b2
local nn = (65536 - n)*-1
if nn == -65536 then nn = 0 end
return nn
elseif ntype == "int32_t" then
local n = b1*65536*256 + b2*65536 + b3 * 256 + b4
local nn = ( 4294967296 - n ) * -1
if nn == -4294967296 then nn = 0 end
return nn
elseif ntype == "double_t" then
local s = tostr(b8,b7,b6,b5,b4,b3,b2,b1)
double_decode_count = double_decode_count + 1
local n = bytestodouble( s )
return n
else
error("unpack_number: not impl:" .. ntype )
end
end
local function unpacker_number(offset)
local obj_type = type_for( string.byte( strbuf, offset+1, offset+1 ) )
local nlen = types_len_map[obj_type]
local ntype
if (obj_type == "float") then
error("float is not implemented")
else
ntype = obj_type .. "_t"
end
return offset+nlen+1,unpack_number(offset+1,ntype,nlen)
end
local function unpack_map(offset,n)
local r = {}
local k,v
for _ = 1, n do
offset,k = unpackers.dynamic(offset)
assert(offset)
offset,v = unpackers.dynamic(offset)
assert(offset)
r[k] = v
end
return offset,r
end
local function unpack_array(offset,n)
local r = {}
for i=1,n do
offset,r[i] = unpackers.dynamic(offset)
assert(offset)
end
return offset,r
end
function unpackers.dynamic(offset)
if offset >= #strbuf then error("need more data") end
local obj_type = type_for( string.byte( strbuf, offset+1, offset+1 ) )
return unpackers[obj_type](offset)
end
function unpackers.undefined()
error("unimplemented:undefined")
end
unpackers["nil"] = function(offset)
return offset+1,nil
end
unpackers["false"] = function(offset)
return offset+1,false
end
unpackers["true"] = function(offset)
return offset+1,true
end
unpackers.fixnum_posi = function(offset)
return offset+1, string.byte(strbuf, offset+1, offset+1)
end
unpackers.uint8 = function(offset)
return offset+2, string.byte(strbuf, offset+2, offset+2)
end
unpackers.uint16 = unpacker_number
unpackers.uint32 = unpacker_number
unpackers.uint64 = unpacker_number
unpackers.fixnum_neg = function(offset)
-- alternative to cast below:
local n = string.byte( strbuf, offset+1, offset+1)
local nn = ( 256 - n ) * -1
return offset+1, nn
end
unpackers.int8 = function(offset)
local i = string.byte( strbuf, offset+2, offset+2 )
if i > 127 then
i = (256 - i ) * -1
end
return offset+2, i
end
unpackers.int16 = unpacker_number
unpackers.int32 = unpacker_number
unpackers.int64 = unpacker_number
unpackers.float = unpacker_number
unpackers.double = unpacker_number
unpackers.fixraw = function(offset)
local n = byte_mod( string.byte( strbuf, offset+1, offset+1) ,0x1f+1)
-- print("unpackers.fixraw: offset:", offset, "#buf:", #buf, "n:",n )
local b
if ( #strbuf - 1 - offset ) < n then
error("require more data")
end
if n > 0 then
b = string.sub( strbuf, offset + 1 + 1, offset + 1 + 1 + n - 1 )
else
b = ""
end
return offset+n+1, b
end
unpackers.raw16 = function(offset)
local n = unpack_number(offset+1,"uint16_t",2)
if ( #strbuf - 1 - 2 - offset ) < n then
error("require more data")
end
local b = string.sub( strbuf, offset+1+1+2, offset+1 + 1+2 + n - 1 )
return offset+n+3, b
end
unpackers.raw32 = function(offset)
local n = unpack_number(offset+1,"uint32_t",4)
if ( #strbuf - 1 - 4 - offset ) < n then
error( "require more data (possibly bug)")
end
local b = string.sub( strbuf, offset+1+ 1+4, offset+1 + 1+4 +n -1 )
return offset+n+5,b
end
unpackers.fixarray = function(offset)
return unpack_array( offset+1,byte_mod( string.byte( strbuf, offset+1,offset+1),0x0f+1))
end
unpackers.array16 = function(offset)
return unpack_array(offset+3,unpack_number(offset+1,"uint16_t",2))
end
unpackers.array32 = function(offset)
return unpack_array(offset+5,unpack_number(offset+1,"uint32_t",4))
end
unpackers.fixmap = function(offset)
return unpack_map(offset+1,byte_mod( string.byte( strbuf, offset+1,offset+1),0x0f+1))
end
unpackers.map16 = function(offset)
return unpack_map(offset+3,unpack_number(offset+1,"uint16_t",2))
end
unpackers.map32 = function(offset)
return unpack_map(offset+5,unpack_number(offset+1,"uint32_t",4))
end
-- Main functions
local ljp_pack = function(data)
strary={}
packers.dynamic(data)
local s = table.concat(strary,"")
return s
end
local ljp_unpack = function(s,offset)
if offset == nil then offset = 0 end
if type(s) ~= "string" then return false,"invalid argument" end
local data
strbuf = s
offset,data = unpackers.dynamic(offset)
return offset,data
end
local function ljp_stat()
return {
double_decode_count = double_decode_count,
double_encode_count = double_encode_count
}
end
local msgpack = {
pack = ljp_pack,
unpack = ljp_unpack,
stat = ljp_stat
}
return msgpack