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mirror of https://github.com/koreader/koreader synced 2024-11-04 12:00:25 +00:00
koreader/frontend/dump.lua
2017-04-14 11:40:35 -07:00

83 lines
2.7 KiB
Lua

--[[--
A simple serialization function which won't do uservalues, functions, or loops.
]]
local isUbuntuTouch = os.getenv("UBUNTU_APPLICATION_ISOLATION") ~= nil
local insert = table.insert
local indent_prefix = " "
local function _serialize(what, outt, indent, max_lv, history)
if not max_lv then
max_lv = math.huge
end
if indent > max_lv then
return
end
if type(what) == "table" then
history = history or {}
for up, item in ipairs(history) do
if item == what then
insert(outt, "nil --[[ LOOP:\n")
insert(outt, string.rep(indent_prefix, indent - up))
insert(outt, "^------- ]]")
return
end
end
local new_history = { what, unpack(history) }
local didrun = false
insert(outt, "{")
for k, v in pairs(what) do
if didrun then
insert(outt, ",")
end
insert(outt, "\n")
insert(outt, string.rep(indent_prefix, indent+1))
insert(outt, "[")
_serialize(k, outt, indent+1, max_lv, new_history)
insert(outt, "] = ")
_serialize(v, outt, indent+1, max_lv, new_history)
didrun = true
end
if didrun then
insert(outt, "\n")
insert(outt, string.rep(indent_prefix, indent))
end
insert(outt, "}")
elseif type(what) == "string" then
insert(outt, string.format("%q", what))
elseif type(what) == "number" then
if isUbuntuTouch then
-- FIXME: the `SDL_CreateRenderer` function in Ubuntu touch somehow
-- use a strange locale that formats number like this: 1.10000000000000g+02
-- which cannot be recognized by loadfile after the number is dumped.
-- Here the workaround is to preserve enough precision in "%.13e" format.
insert(outt, string.format("%.13e", what))
else
insert(outt, tostring(what))
end
elseif type(what) == "boolean" then
insert(outt, tostring(what))
elseif type(what) == "function" then
insert(outt, tostring(what))
elseif type(what) == "nil" then
insert(outt, "nil")
end
end
--[[--Serializes whatever is in `data` to a string that is parseable by Lua.
You can optionally specify a maximum recursion depth in `max_lv`.
@function dump
@param data the object you want serialized (table, string, number, boolean, nil)
@param max_lv optional maximum recursion depth
--]]
local function dump(data, max_lv)
local out = {}
_serialize(data, out, 0, max_lv)
return table.concat(out)
end
return dump