computercraft/lib/lns.lua
2023-10-09 06:54:35 -04:00

84 lines
1.9 KiB
Lua

-- Desc: LNS Client
-- Auth: Layla Manley
-- Link: https://gitea.layla.gg/layla/computercraft
local cache = {}
local cache_file = "/var/cache/lns_cache.db"
settings.define("lns_client.allow_dynamic_lns_hosts", {
description = "Allow dynamic LNS hosts",
type = "boolean",
default = false
})
settings.define("lns_client.lns_server", {
description = "LNS Server Rednet ID",
type = "number",
default = 8
})
function _load_cache()
if fs.exists(cache_file) then
db = fs.open(cache_file, "r")
db_contents = db.readAll()
db.close()
cache = textutils.unserialize(db_contents)
end
end
function _save_cache()
db = fs.open(cache_file, "w")
db.write(textutils.serialize(cache))
db.close()
end
function server()
local lns_server_id = settings.get("lns_client.lns_server")
local allow_dynamic_lns_hosts = settings.get("lns_client.allow_dynamic_lns_hosts")
if allow_dynamic_lns_hosts then
lns_server_id = rednet.lookup("lns", lns_server)
if lns_server_id == nil then
io.write("LNS Server not found!\n")
return nil
end
end
return lns_server_id
end
function lookup(remote_hostname)
_load_cache()
if cache[remote_hostname] ~= nil then
return cache[remote_hostname]
end
local data = {
["action"] = "lookup",
["hostname"] = remote_hostname
}
local lns_server_id = server()
rednet.send(lns_server_id, data, "lns")
while true do
id, msg = rednet.receive("lns")
if id == lns_server_id then
if msg == nil then
return nil
else
cache[remote_hostname] = msg
_save_cache()
return msg
end
end
end
end
function clear_cache()
cache = {}
_save_cache()
print("Cleared cache!")
end