cambridge/libs/binser.lua

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2019-05-22 22:57:34 -05:00
-- binser.lua
--[[
Copyright (c) 2016 Calvin Rose
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
]]
local assert = assert
local error = error
local select = select
local pairs = pairs
local getmetatable = getmetatable
local setmetatable = setmetatable
local tonumber = tonumber
local type = type
local loadstring = loadstring or load
local concat = table.concat
local char = string.char
local byte = string.byte
local format = string.format
local sub = string.sub
local dump = string.dump
local floor = math.floor
local frexp = math.frexp
local unpack = unpack or table.unpack
-- Lua 5.3 frexp polyfill
-- From https://github.com/excessive/cpml/blob/master/modules/utils.lua
if not frexp then
local log, abs, floor = math.log, math.abs, math.floor
local log2 = log(2)
frexp = function(x)
if x == 0 then return 0, 0 end
local e = floor(log(abs(x)) / log2 + 1)
return x / 2 ^ e, e
end
end
-- NIL = 202
-- FLOAT = 203
-- TRUE = 204
-- FALSE = 205
-- STRING = 206
-- TABLE = 207
-- REFERENCE = 208
-- CONSTRUCTOR = 209
-- FUNCTION = 210
-- RESOURCE = 211
-- INT64 = 212
local mts = {}
local ids = {}
local serializers = {}
local deserializers = {}
local resources = {}
local resources_by_name = {}
local function pack(...)
return {...}, select("#", ...)
end
local function not_array_index(x, len)
return type(x) ~= "number" or x < 1 or x > len or x ~= floor(x)
end
local function type_check(x, tp, name)
assert(type(x) == tp,
format("Expected parameter %q to be of type %q.", name, tp))
end
local bigIntSupport = false
local isInteger
if math.type then -- Detect Lua 5.3
local mtype = math.type
bigIntSupport = loadstring[[
local char = string.char
return function(n)
local nn = n < 0 and -(n + 1) or n
local b1 = nn // 0x100000000000000
local b2 = nn // 0x1000000000000 % 0x100
local b3 = nn // 0x10000000000 % 0x100
local b4 = nn // 0x100000000 % 0x100
local b5 = nn // 0x1000000 % 0x100
local b6 = nn // 0x10000 % 0x100
local b7 = nn // 0x100 % 0x100
local b8 = nn % 0x100
if n < 0 then
b1, b2, b3, b4 = 0xFF - b1, 0xFF - b2, 0xFF - b3, 0xFF - b4
b5, b6, b7, b8 = 0xFF - b5, 0xFF - b6, 0xFF - b7, 0xFF - b8
end
return char(212, b1, b2, b3, b4, b5, b6, b7, b8)
end]]()
isInteger = function(x)
return mtype(x) == 'integer'
end
else
isInteger = function(x)
return floor(x) == x
end
end
-- Copyright (C) 2012-2015 Francois Perrad.
-- number serialization code modified from https://github.com/fperrad/lua-MessagePack
-- Encode a number as a big-endian ieee-754 double, big-endian signed 64 bit integer, or a small integer
local function number_to_str(n)
if isInteger(n) then -- int
if n <= 100 and n >= -27 then -- 1 byte, 7 bits of data
return char(n + 27)
elseif n <= 8191 and n >= -8192 then -- 2 bytes, 14 bits of data
n = n + 8192
return char(128 + (floor(n / 0x100) % 0x100), n % 0x100)
elseif bigIntSupport then
return bigIntSupport(n)
end
end
local sign = 0
if n < 0.0 then
sign = 0x80
n = -n
end
local m, e = frexp(n) -- mantissa, exponent
if m ~= m then
return char(203, 0xFF, 0xF8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00)
elseif m == 1/0 then
if sign == 0 then
return char(203, 0x7F, 0xF0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00)
else
return char(203, 0xFF, 0xF0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00)
end
end
e = e + 0x3FE
if e < 1 then -- denormalized numbers
m = m * 2 ^ (52 + e)
e = 0
else
m = (m * 2 - 1) * 2 ^ 52
end
return char(203,
sign + floor(e / 0x10),
(e % 0x10) * 0x10 + floor(m / 0x1000000000000),
floor(m / 0x10000000000) % 0x100,
floor(m / 0x100000000) % 0x100,
floor(m / 0x1000000) % 0x100,
floor(m / 0x10000) % 0x100,
floor(m / 0x100) % 0x100,
m % 0x100)
end
-- Copyright (C) 2012-2015 Francois Perrad.
-- number deserialization code also modified from https://github.com/fperrad/lua-MessagePack
local function number_from_str(str, index)
local b = byte(str, index)
if b < 128 then
return b - 27, index + 1
elseif b < 192 then
return byte(str, index + 1) + 0x100 * (b - 128) - 8192, index + 2
end
local b1, b2, b3, b4, b5, b6, b7, b8 = byte(str, index + 1, index + 8)
if b == 212 then
local flip = b1 >= 128
if flip then -- negative
b1, b2, b3, b4 = 0xFF - b1, 0xFF - b2, 0xFF - b3, 0xFF - b4
b5, b6, b7, b8 = 0xFF - b5, 0xFF - b6, 0xFF - b7, 0xFF - b8
end
local n = ((((((b1 * 0x100 + b2) * 0x100 + b3) * 0x100 + b4) * 0x100 + b5) * 0x100 + b6) * 0x100 + b7) * 0x100 + b8
if flip then
return (-n) - 1, index + 9
else
return n, index + 9
end
end
local sign = b1 > 0x7F and -1 or 1
local e = (b1 % 0x80) * 0x10 + floor(b2 / 0x10)
local m = ((((((b2 % 0x10) * 0x100 + b3) * 0x100 + b4) * 0x100 + b5) * 0x100 + b6) * 0x100 + b7) * 0x100 + b8
local n
if e == 0 then
if m == 0 then
n = sign * 0.0
else
n = sign * (m / 2 ^ 52) * 2 ^ -1022
end
elseif e == 0x7FF then
if m == 0 then
n = sign * (1/0)
else
n = 0.0/0.0
end
else
n = sign * (1.0 + m / 2 ^ 52) * 2 ^ (e - 0x3FF)
end
return n, index + 9
end
local types = {}
types["nil"] = function(x, visited, accum)
accum[#accum + 1] = "\202"
end
function types.number(x, visited, accum)
accum[#accum + 1] = number_to_str(x)
end
function types.boolean(x, visited, accum)
accum[#accum + 1] = x and "\204" or "\205"
end
function types.string(x, visited, accum)
local alen = #accum
if visited[x] then
accum[alen + 1] = "\208"
accum[alen + 2] = number_to_str(visited[x])
else
visited[x] = visited.next
visited.next = visited.next + 1
accum[alen + 1] = "\206"
accum[alen + 2] = number_to_str(#x)
accum[alen + 3] = x
end
end
local function check_custom_type(x, visited, accum)
local res = resources[x]
if res then
accum[#accum + 1] = "\211"
types[type(res)](res, visited, accum)
return true
end
local mt = getmetatable(x)
local id = mt and ids[mt]
if id then
if x == visited.temp then
error("Infinite loop in constructor.")
end
visited.temp = x
accum[#accum + 1] = "\209"
types[type(id)](id, visited, accum)
local args, len = pack(serializers[id](x))
accum[#accum + 1] = number_to_str(len)
for i = 1, len do
local arg = args[i]
types[type(arg)](arg, visited, accum)
end
visited[x] = visited.next
visited.next = visited.next + 1
return true
end
end
function types.userdata(x, visited, accum)
if visited[x] then
accum[#accum + 1] = "\208"
accum[#accum + 1] = number_to_str(visited[x])
else
if check_custom_type(x, visited, accum) then return end
error("Cannot serialize this userdata.")
end
end
function types.table(x, visited, accum)
if visited[x] then
accum[#accum + 1] = "\208"
accum[#accum + 1] = number_to_str(visited[x])
else
if check_custom_type(x, visited, accum) then return end
visited[x] = visited.next
visited.next = visited.next + 1
local xlen = #x
accum[#accum + 1] = "\207"
accum[#accum + 1] = number_to_str(xlen)
for i = 1, xlen do
local v = x[i]
types[type(v)](v, visited, accum)
end
local key_count = 0
for k in pairs(x) do
if not_array_index(k, xlen) then
key_count = key_count + 1
end
end
accum[#accum + 1] = number_to_str(key_count)
for k, v in pairs(x) do
if not_array_index(k, xlen) then
types[type(k)](k, visited, accum)
types[type(v)](v, visited, accum)
end
end
end
end
types["function"] = function(x, visited, accum)
if visited[x] then
accum[#accum + 1] = "\208"
accum[#accum + 1] = number_to_str(visited[x])
else
if check_custom_type(x, visited, accum) then return end
visited[x] = visited.next
visited.next = visited.next + 1
local str = dump(x)
accum[#accum + 1] = "\210"
accum[#accum + 1] = number_to_str(#str)
accum[#accum + 1] = str
end
end
types.cdata = function(x, visited, accum)
if visited[x] then
accum[#accum + 1] = "\208"
accum[#accum + 1] = number_to_str(visited[x])
else
if check_custom_type(x, visited, #accum) then return end
error("Cannot serialize this cdata.")
end
end
types.thread = function() error("Cannot serialize threads.") end
local function deserialize_value(str, index, visited)
local t = byte(str, index)
if not t then return end
if t < 128 then
return t - 27, index + 1
elseif t < 192 then
return byte(str, index + 1) + 0x100 * (t - 128) - 8192, index + 2
elseif t == 202 then
return nil, index + 1
elseif t == 203 then
return number_from_str(str, index)
elseif t == 204 then
return true, index + 1
elseif t == 205 then
return false, index + 1
elseif t == 206 then
local length, dataindex = deserialize_value(str, index + 1, visited)
local nextindex = dataindex + length
local substr = sub(str, dataindex, nextindex - 1)
visited[#visited + 1] = substr
return substr, nextindex
elseif t == 207 then
local count, nextindex = number_from_str(str, index + 1)
local ret = {}
visited[#visited + 1] = ret
for i = 1, count do
ret[i], nextindex = deserialize_value(str, nextindex, visited)
end
count, nextindex = number_from_str(str, nextindex)
for i = 1, count do
local k, v
k, nextindex = deserialize_value(str, nextindex, visited)
v, nextindex = deserialize_value(str, nextindex, visited)
ret[k] = v
end
return ret, nextindex
elseif t == 208 then
local ref, nextindex = number_from_str(str, index + 1)
return visited[ref], nextindex
elseif t == 209 then
local count
local name, nextindex = deserialize_value(str, index + 1, visited)
count, nextindex = number_from_str(str, nextindex)
local args = {}
for i = 1, count do
args[i], nextindex = deserialize_value(str, nextindex, visited)
end
local ret = deserializers[name](unpack(args))
visited[#visited + 1] = ret
return ret, nextindex
elseif t == 210 then
local length, dataindex = deserialize_value(str, index + 1, visited)
local nextindex = dataindex + length
local ret = loadstring(sub(str, dataindex, nextindex - 1))
visited[#visited + 1] = ret
return ret, nextindex
elseif t == 211 then
local res, nextindex = deserialize_value(str, index + 1, visited)
return resources_by_name[res], nextindex
elseif t == 212 then
return number_from_str(str, index)
else
error("Could not deserialize type byte " .. t .. ".")
end
end
local function serialize(...)
local visited = {next = 1}
local accum = {}
for i = 1, select("#", ...) do
local x = select(i, ...)
types[type(x)](x, visited, accum)
end
return concat(accum)
end
local function make_file_writer(file)
return setmetatable({}, {
__newindex = function(_, _, v)
file:write(v)
end
})
end
local function serialize_to_file(path, mode, ...)
local file, err = io.open(path, mode)
assert(file, err)
local visited = {next = 1}
local accum = make_file_writer(file)
for i = 1, select("#", ...) do
local x = select(i, ...)
types[type(x)](x, visited, accum)
end
-- flush the writer
file:flush()
file:close()
end
local function writeFile(path, ...)
return serialize_to_file(path, "wb", ...)
end
local function appendFile(path, ...)
return serialize_to_file(path, "ab", ...)
end
local function deserialize(str, index)
assert(type(str) == "string", "Expected string to deserialize.")
local vals = {}
index = index or 1
local visited = {}
local len = 0
local val
while index do
val, index = deserialize_value(str, index, visited)
if index then
len = len + 1
vals[len] = val
end
end
return vals, len
end
local function deserializeN(str, n, index)
assert(type(str) == "string", "Expected string to deserialize.")
n = n or 1
assert(type(n) == "number", "Expected a number for parameter n.")
assert(n > 0 and floor(n) == n, "N must be a poitive integer.")
local vals = {}
index = index or 1
local visited = {}
local len = 0
local val
while index and len < n do
val, index = deserialize_value(str, index, visited)
if index then
len = len + 1
vals[len] = val
end
end
vals[len + 1] = index
return unpack(vals, 1, n + 1)
end
local function readFile(path)
local file, err = io.open(path, "rb")
if file == nil then
return nil, 0
end
local str = file:read("*all")
file:close()
return deserialize(str)
end
local function default_deserialize(metatable)
return function(...)
local ret = {}
for i = 1, select("#", ...), 2 do
ret[select(i, ...)] = select(i + 1, ...)
end
return setmetatable(ret, metatable)
end
end
local function default_serialize(x)
assert(type(x) == "table",
"Default serialization for custom types only works for tables.")
local args = {}
local len = 0
for k, v in pairs(x) do
args[len + 1], args[len + 2] = k, v
len = len + 2
end
return unpack(args, 1, len)
end
-- Templating
local function normalize_template(template)
local ret = {}
for i = 1, #template do
ret[i] = template[i]
end
local non_array_part = {}
-- The non-array part of the template (nested templates) have to be deterministic, so they are sorted.
-- This means that inherently non deterministicly sortable keys (tables, functions) should NOT be used
-- in templates. Looking for way around this.
for k in pairs(template) do
if not_array_index(k, #template) then
non_array_part[#non_array_part + 1] = k
end
end
table.sort(non_array_part)
for i = 1, #non_array_part do
local name = non_array_part[i]
ret[#ret + 1] = {name, normalize_template(template[name])}
end
return ret
end
local function templatepart_serialize(part, argaccum, x, len)
local extras = {}
local extracount = 0
for k, v in pairs(x) do
extras[k] = v
extracount = extracount + 1
end
for i = 1, #part do
extracount = extracount - 1
if type(part[i]) == "table" then
extras[part[i][1]] = nil
len = templatepart_serialize(part[i][2], argaccum, x[part[i][1]], len)
else
extras[part[i]] = nil
len = len + 1
argaccum[len] = x[part[i]]
end
end
if extracount > 0 then
argaccum[len + 1] = extras
else
argaccum[len + 1] = nil
end
return len + 1
end
local function templatepart_deserialize(ret, part, values, vindex)
for i = 1, #part do
local name = part[i]
if type(name) == "table" then
local newret = {}
ret[name[1]] = newret
vindex = templatepart_deserialize(newret, name[2], values, vindex)
else
ret[name] = values[vindex]
vindex = vindex + 1
end
end
local extras = values[vindex]
if extras then
for k, v in pairs(extras) do
ret[k] = v
end
end
return vindex + 1
end
local function template_serializer_and_deserializer(metatable, template)
return function(x)
argaccum = {}
local len = templatepart_serialize(template, argaccum, x, 0)
return unpack(argaccum, 1, len)
end, function(...)
local ret = {}
local len = select("#", ...)
local args = {...}
templatepart_deserialize(ret, template, args, 1)
return setmetatable(ret, metatable)
end
end
local function register(metatable, name, serialize, deserialize)
name = name or metatable.name
serialize = serialize or metatable._serialize
deserialize = deserialize or metatable._deserialize
if not serialize then
if metatable._template then
local t = normalize_template(metatable._template)
serialize, deserialize = template_serializer_and_deserializer(metatable, t)
elseif not deserialize then
serialize = default_serialize
deserialize = default_deserialize(metatable)
else
serialize = metatable
end
end
type_check(metatable, "table", "metatable")
type_check(name, "string", "name")
type_check(serialize, "function", "serialize")
type_check(deserialize, "function", "deserialize")
assert(not ids[metatable], "Metatable already registered.")
assert(not mts[name], ("Name %q already registered."):format(name))
mts[name] = metatable
ids[metatable] = name
serializers[name] = serialize
deserializers[name] = deserialize
return metatable
end
local function unregister(item)
local name, metatable
if type(item) == "string" then -- assume name
name, metatable = item, mts[item]
else -- assume metatable
name, metatable = ids[item], item
end
type_check(name, "string", "name")
type_check(metatable, "table", "metatable")
mts[name] = nil
ids[metatable] = nil
serializers[name] = nil
deserializers[name] = nil
return metatable
end
local function registerClass(class, name)
name = name or class.name
if class.__instanceDict then -- middleclass
register(class.__instanceDict, name)
else -- assume 30log or similar library
register(class, name)
end
return class
end
local function registerResource(resource, name)
type_check(name, "string", "name")
assert(not resources[resource],
"Resource already registered.")
assert(not resources_by_name[name],
format("Resource %q already exists.", name))
resources_by_name[name] = resource
resources[resource] = name
return resource
end
local function unregisterResource(name)
type_check(name, "string", "name")
assert(resources_by_name[name], format("Resource %q does not exist.", name))
local resource = resources_by_name[name]
resources_by_name[name] = nil
resources[resource] = nil
return resource
end
return {
-- aliases
s = serialize,
d = deserialize,
dn = deserializeN,
r = readFile,
w = writeFile,
a = appendFile,
serialize = serialize,
deserialize = deserialize,
deserializeN = deserializeN,
readFile = readFile,
writeFile = writeFile,
appendFile = appendFile,
register = register,
unregister = unregister,
registerResource = registerResource,
unregisterResource = unregisterResource,
registerClass = registerClass
}