dumper.lua

--[[ DataDumper.lua
Copyright (c) 2007 Olivetti-Engineering SA

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.
]]

if global then
    global("TheSim","WorldSim")
end
--use a string buffer for the serialization to nuke memory spike --(only used in fastmode)
USE_SAVEBUFFER = MAIN == 1 or WORLDGEN_MAIN == 1

local dumplua_closure = [[
local closures = {}
local function closure(t)
    closures[#closures+1] = t
    t[1] = assert(loadstring(t[1]))
    return t[1]
end

for _,t in pairs(closures) do
    for i = 2,#t do
        debug.setupvalue(t[1], i-1, t[i])
    end
end
]]

local lua_reserved_keywords = {
'and', 'break', 'do', 'else', 'elseif', 'end', 'false', 'for',
'function', 'if', 'in', 'local', 'nil', 'not', 'or', 'repeat',
'return', 'then', 'true', 'until', 'while' }

local function keys(t)
    local res = {}
    local oktypes = { stringstring = true, numbernumber = true }
    local function cmpfct(a,b)
        if oktypes[type(a)..type(b)] then
            return a < b
        else
            return type(a) < type(b)
        end
    end
    for k in pairs(t) do
        res[#res+1] = k
    end
    table.sort(res, cmpfct)
    return res
end

local c_functions = {}
for _,lib in pairs{'_G', 'string', 'table', 'math', 'coroutine', 'package', 'debug'} do
    local t = _G[lib] or {}
    lib = lib .. "."
    if lib == "_G." then lib = "" end
    for k,v in pairs(t) do
        if type(v) == 'function' and not pcall(string.dump, v) then
            c_functions[v] = lib..k
        end
    end
end


function DataDumper(value, varname, fastmode, ident)
    local defined, dumplua = {}, nil

    local sim = USE_SAVEBUFFER and (WorldSim or TheSim) or nil

    -- Local variables for speed optimization
    local string_format, type, string_dump, string_rep = string.format, type, string.dump, string.rep
    local tostring, pairs, table_concat = tostring, pairs, table.concat
    local keycache, strvalcache, out, closure_cnt = {}, {}, {}, 0
    setmetatable(strvalcache, {__index = function(t,value)
        local res = string_format('%q', value)
        t[value] = res
        return res
    end})
    local fcts = {
        string = function(value) return strvalcache[value] end,
        number = function(value) return value end,
        boolean = function(value) return tostring(value) end,
        ['nil'] = function(value) return 'nil' end,
        ['function'] = function(value)
            return string_format("loadstring(%q)", string_dump(value))
        end,
        userdata = function(value)
            -- find the variable name
            local var
            local i = 1
            while true do
                local n, v = debug.getlocal(3, i)
                if not n then break end
                if n=="subpath" then
                    var = v
                end
                --print(n,v)
                i = i + 1
            end

            error("Cannot dump userdata ("..tostring(value).." - "..(var or "unknown")..")")
        end,
        thread = function() error("Cannot dump threads") end,
    }
    local function test_defined(value, path)
        if defined[value] then
            if path:match("^getmetatable.*%)$") then
                if not USE_SAVEBUFFER then
                    out[#out+1] = string_format("s%s, %s)\n", path:sub(2,-2), defined[value])
                else
                    sim:AppendSaveString(string_format("s%s, %s)\n", path:sub(2,-2), defined[value]))
                end
            else
                if not USE_SAVEBUFFER then
                    out[#out+1] = path .. " = " .. defined[value] .. "\n"
                else
                    sim:AppendSaveString(path)
                    sim:AppendSaveString(" = ")
                    sim:AppendSaveString(defined[value])
                    sim:AppendSaveString("\n")
                end
            end
            return true
        end
        defined[value] = path
    end
    local function make_key(t, key)
        local s
        if type(key) == 'string' and key:match('^[_%a][_%w]*$') then
            s = key .. "="
        else
            s = "[" .. dumplua(key, 0) .. "]="
        end
        t[key] = s
        return s
    end
    for _,k in ipairs(lua_reserved_keywords) do
        keycache[k] = '["'..k..'"] = '
    end
    if fastmode then
        fcts.table = function (value)
            -- Table value
            local numidx = 1
            if not USE_SAVEBUFFER then
                out[#out+1] = "{"
            else
                sim:AppendSaveString("{")
            end
            for key,val in pairs(value) do
                if key == numidx then
                    numidx = numidx + 1
                else
                    if not USE_SAVEBUFFER then
                        out[#out+1] = keycache[key]
                    else
                        sim:AppendSaveString(keycache[key])
                    end
                end
                local str = dumplua(val)
                if not USE_SAVEBUFFER then
                    out[#out+1] = str..","
                else
                    sim:AppendSaveString(str)
                    sim:AppendSaveString(",")
                end
            end
            if not USE_SAVEBUFFER then
                if string.sub(out[#out], -1) == "," then
                    out[#out] = string.sub(out[#out], 1, -2);
                end
                out[#out+1] = "}"
            else
                sim:RemoveLastCommaSaveString()
                sim:AppendSaveString("}")
            end
            return ""
        end
    else
        fcts.table = function (value, ident, path)
            if test_defined(value, path) then return "nil" end
            -- Table value
            local sep, str, numidx, totallen = " ", {}, 1, 0
            local meta, metastr = (debug or getfenv()).getmetatable(value)
            if meta then
                ident = ident + 1
                metastr = dumplua(meta, ident, "getmetatable("..path..")")
                totallen = totallen + #metastr + 16
            end
            for _,key in pairs(keys(value)) do
                local val = value[key]
                local s = ""
                local subpath = path
                if key == numidx then
                    subpath = subpath .. "[" .. numidx .. "]"
                    numidx = numidx + 1
                else
                    s = keycache[key]
                    if not s:match "^%[" then subpath = subpath .. "." end
                    subpath = subpath .. s:gsub("%s*=%s*$","")
                end
                s = s .. dumplua(val, ident+1, subpath)
                str[#str+1] = s
                totallen = totallen + #s + 2
            end
            if totallen > 80 then
                sep = "\n" .. string_rep("  ", ident+1)
            end
            str = "{"..sep..table_concat(str, ","..sep).." "..sep:sub(1,-3).."}"
            if meta then
                sep = sep:sub(1,-3)
                return "setmetatable("..sep..str..","..sep..metastr..sep:sub(1,-3)..")"
            end
            return str
        end
        fcts['function'] = function (value, ident, path)
            if test_defined(value, path) then return "nil" end
            if c_functions[value] then
                return c_functions[value]
            elseif debug == nil or debug.getupvalue(value, 1) == nil then
                return string_format("loadstring(%q)", string_dump(value))
            end
            closure_cnt = closure_cnt + 1
            local res = {string.dump(value)}
            for i = 1,math.huge do
                local name, v = debug.getupvalue(value,i)
                if name == nil then break end
                res[i+1] = v
            end
            return "closure " .. dumplua(res, ident, "closures["..closure_cnt.."]")
        end
    end
    function dumplua(value, ident, path)
        return fcts[type(value)](value, ident, path)
    end
    if varname == nil then
        varname = "return "
    elseif varname:match("^[%a_][%w_]*$") then
        varname = varname .. " = "
    end
    if fastmode then
        if USE_SAVEBUFFER then
            sim:InitSaveString()
        end
        setmetatable(keycache, {__index = make_key })
        if not USE_SAVEBUFFER then
            out[1] = varname
            table.insert(out,dumplua(value, 0))
            return table.concat(out)
        else
            sim:AppendSaveString(varname)
            sim:AppendSaveString(dumplua(value, 0))
            return sim:GetSaveString()
        end
    else
        --don't use the savebuffer on the slow path
        --data being shuffled in front of the dumped lua, would need some rewiring to make that work
        local _USE_SAVEBUFFER = USE_SAVEBUFFER
        USE_SAVEBUFFER = false
        setmetatable(keycache, {__index = make_key })
        local items = {}
        for i=1,10 do items[i] = '' end
        items[3] = dumplua(value, ident or 0, "t")
        if closure_cnt > 0 then
            items[1], items[6] = dumplua_closure:match("(.*\n)\n(.*)")
            out[#out+1] = ""
        end
        if #out > 0 then
            items[2], items[4] = "local t = ", "\n"
            items[5] = table.concat(out)
            items[7] = varname .. "t"
        else
            items[2] = varname
        end
        USE_SAVEBUFFER = _USE_SAVEBUFFER
        return table.concat(items)
    end
end