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util/serialization.lua @ 9255:2aa40526df7b
mod_vcard_legacy: Respond to attempts to set the legacy vcard-temp
author | Kim Alvefur <zash@zash.se> |
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date | Tue, 21 Aug 2018 17:16:27 +0200 |
parent | 9060:69bc3144c2b7 |
child | 9341:009dad867e52 |
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-- Prosody IM -- Copyright (C) 2008-2010 Matthew Wild -- Copyright (C) 2008-2010 Waqas Hussain -- Copyright (C) 2018 Kim Alvefur -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- local getmetatable = getmetatable; local next, type = next, type; local s_format = string.format; local s_gsub = string.gsub; local s_rep = string.rep; local s_char = string.char; local s_match = string.match; local t_concat = table.concat; local pcall = pcall; local envload = require"util.envload".envload; local pos_inf, neg_inf = math.huge, -math.huge; local m_log = math.log; local m_log10 = math.log10 or function (n) return m_log(n, 10); end local m_floor = math.floor; -- luacheck: ignore 143/math local m_type = math.type or function (n) return n % 1 == 0 and n <= 9007199254740992 and n >= -9007199254740992 and "integer" or "float"; end; local char_to_hex = {}; for i = 0,255 do char_to_hex[s_char(i)] = s_format("%02x", i); end local function to_hex(s) return (s_gsub(s, ".", char_to_hex)); end local function fatal_error(obj, why) error("Can't serialize "..type(obj) .. (why and ": ".. why or "")); end local function default_fallback(x, why) return s_format("nil --[[%s: %s]]", type(x), why or "fail"); end local string_escapes = { ['\a'] = [[\a]]; ['\b'] = [[\b]]; ['\f'] = [[\f]]; ['\n'] = [[\n]]; ['\r'] = [[\r]]; ['\t'] = [[\t]]; ['\v'] = [[\v]]; ['\\'] = [[\\]]; ['\"'] = [[\"]]; ['\''] = [[\']]; } for i = 0, 255 do local c = s_char(i); if not string_escapes[c] then string_escapes[c] = s_format("\\%03d", i); end end local default_keywords = { ["do"] = true; ["and"] = true; ["else"] = true; ["break"] = true; ["if"] = true; ["end"] = true; ["goto"] = true; ["false"] = true; ["in"] = true; ["for"] = true; ["then"] = true; ["local"] = true; ["or"] = true; ["nil"] = true; ["true"] = true; ["until"] = true; ["elseif"] = true; ["function"] = true; ["not"] = true; ["repeat"] = true; ["return"] = true; ["while"] = true; }; local function new(opt) if type(opt) ~= "table" then opt = { preset = opt }; end local types = { table = true; string = true; number = true; boolean = true; ["nil"] = true; }; -- presets if opt.preset == "debug" then opt.preset = "oneline"; opt.freeze = true; opt.fatal = false; opt.fallback = default_fallback; end if opt.preset == "oneline" then opt.indentwith = opt.indentwith or ""; opt.itemstart = opt.itemstart or " "; opt.itemlast = opt.itemlast or ""; opt.tend = opt.tend or " }"; elseif opt.preset == "compact" then opt.indentwith = opt.indentwith or ""; opt.itemstart = opt.itemstart or ""; opt.itemlast = opt.itemlast or ""; opt.equals = opt.equals or "="; end local fallback = opt.fatal and fatal_error or opt.fallback or default_fallback; local function ser(v) return (types[type(v)] or fallback)(v); end local keywords = opt.keywords or default_keywords; -- indented local indentwith = opt.indentwith or "\t"; local itemstart = opt.itemstart or "\n"; local itemsep = opt.itemsep or ";"; local itemlast = opt.itemlast or ";\n"; local tstart = opt.tstart or "{"; local tend = opt.tend or "}"; local kstart = opt.kstart or "["; local kend = opt.kend or "]"; local equals = opt.equals or " = "; local unquoted = opt.unquoted == nil and "^[%a_][%w_]*$" or opt.unquoted; local hex = opt.hex; local freeze = opt.freeze; local precision = opt.precision or 10; -- serialize one table, recursively -- t - table being serialized -- o - array where tokens are added, concatenate to get final result -- - also used to detect cycles -- l - position in o of where to insert next token -- d - depth, used for indentation local function serialize_table(t, o, l, d) if o[t] or d > 127 then o[l], l = fallback(t, "recursion"), l + 1; return l; end o[t] = true; if freeze then -- opportunity to do pre-serialization local mt = getmetatable(t); local fr = (freeze ~= true and freeze[mt]); local mf = mt and mt.__freeze; local tag; if type(fr) == "string" then tag = fr; fr = mf; elseif mt then tag = mt.__type; end if type(fr) == "function" then t = fr(t); if type(tag) == "string" then o[l], l = tag, l + 1; end end end o[l], l = tstart, l + 1; local indent = s_rep(indentwith, d); local numkey = 1; local ktyp, vtyp; for k,v in next,t do o[l], l = itemstart, l + 1; o[l], l = indent, l + 1; ktyp, vtyp = type(k), type(v); if k == numkey then -- next index in array part -- assuming that these are found in order numkey = numkey + 1; elseif unquoted and ktyp == "string" and not keywords[k] and s_match(k, unquoted) then -- unquoted keys o[l], l = k, l + 1; o[l], l = equals, l + 1; else -- quoted keys o[l], l = kstart, l + 1; if ktyp == "table" then l = serialize_table(k, o, l, d+1); else o[l], l = ser(k), l + 1; end -- = o[l], o[l+1], l = kend, equals, l + 2; end -- the value if vtyp == "table" then l = serialize_table(v, o, l, d+1); else o[l], l = ser(v), l + 1; end -- last item? if next(t, k) ~= nil then o[l], l = itemsep, l + 1; else o[l], l = itemlast, l + 1; end end if next(t) ~= nil then o[l], l = s_rep(indentwith, d-1), l + 1; end o[l], l = tend, l +1; return l; end function types.table(t) local o = {}; serialize_table(t, o, 1, 1); return t_concat(o); end local function serialize_string(s) return '"' .. s_gsub(s, "[%z\1-\31\"\'\\\127-\255]", string_escapes) .. '"'; end if hex then function types.string(s) local esc = serialize_string(s); if #esc > (#s*2+2+#hex) then return hex .. '"' .. to_hex(s) .. '"'; end return esc; end else types.string = serialize_string; end function types.number(t) if m_type(t) == "integer" then return s_format("%d", t); elseif t == pos_inf then return "(1/0)"; elseif t == neg_inf then return "(-1/0)"; elseif t ~= t then return "(0/0)"; end local log = m_floor(m_log10(t)); if log > precision then return s_format("%.18e", t); else return s_format("%.18g", t); end end -- Are these faster than tostring? types["nil"] = function() return "nil"; end function types.boolean(t) return t and "true" or "false"; end return ser; end local function deserialize(str) if type(str) ~= "string" then return nil; end str = "return "..str; local f, err = envload(str, "@data", {}); if not f then return nil, err; end local success, ret = pcall(f); if not success then return nil, ret; end return ret; end return { new = new; serialize = function (x, opt) return new(opt)(x); end; deserialize = deserialize; };