92 lines
1.7 KiB
Lua
92 lines
1.7 KiB
Lua
-- bi-directional http-channel
|
|
-- with long-poll GET and POST on the same URL
|
|
|
|
local function Channel(http, url, cfg)
|
|
cfg = cfg or {}
|
|
local extra_headers = cfg.extra_headers or {}
|
|
local timeout = cfg.timeout or 1
|
|
local long_poll_timeout = cfg.long_poll_timeout or 30
|
|
local error_retry = cfg.error_retry or 10
|
|
|
|
-- assemble post-header with json content
|
|
local post_headers = { "Content-Type: application/json" }
|
|
for _,header in pairs(cfg.extra_headers) do
|
|
table.insert(post_headers, header)
|
|
end
|
|
|
|
local recv_listeners = {}
|
|
local run = true
|
|
|
|
local recv_loop
|
|
|
|
recv_loop = function()
|
|
assert(run)
|
|
|
|
-- long-poll GET
|
|
http.fetch({
|
|
url = url,
|
|
extra_headers = extra_headers,
|
|
timeout = long_poll_timeout
|
|
}, function(res)
|
|
if res.succeeded and res.code == 200 then
|
|
local data = minetest.parse_json(res.data)
|
|
|
|
if data then
|
|
for _,listener in pairs(recv_listeners) do
|
|
if #data > 0 then
|
|
-- array received
|
|
for _, entry in ipairs(data) do
|
|
listener(entry)
|
|
end
|
|
else
|
|
-- single item received
|
|
listener(data)
|
|
end
|
|
end
|
|
end
|
|
-- reschedule immediately
|
|
minetest.after(0, recv_loop)
|
|
else
|
|
-- error, retry after some time
|
|
minetest.after(error_retry, recv_loop)
|
|
end
|
|
end)
|
|
end
|
|
|
|
|
|
local send = function(data)
|
|
assert(run)
|
|
-- POST
|
|
|
|
http.fetch({
|
|
url = url,
|
|
extra_headers = post_headers,
|
|
timeout = timeout,
|
|
post_data = minetest.write_json(data)
|
|
}, function()
|
|
-- TODO: error-handling
|
|
end)
|
|
end
|
|
|
|
local receive = function(listener)
|
|
table.insert(recv_listeners, listener)
|
|
end
|
|
|
|
local close = function()
|
|
run = false
|
|
end
|
|
|
|
recv_loop();
|
|
|
|
return {
|
|
send = send,
|
|
receive = receive,
|
|
close = close
|
|
}
|
|
|
|
end
|
|
|
|
|
|
|
|
return Channel
|