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opus/sys/network/transport.lua
2018-01-24 17:39:38 -05:00

131 lines
3.1 KiB
Lua

--[[
Low level socket protocol implementation.
* sequencing
* background read buffering
]]--
local Event = require('event')
local os = _G.os
local computerId = os.getComputerID()
local transport = {
timers = { },
sockets = { },
UID = 0,
}
_G.transport = transport
function transport.open(socket)
transport.UID = transport.UID + 1
transport.sockets[socket.sport] = socket
socket.activityTimer = os.clock()
socket.uid = transport.UID
end
function transport.read(socket)
local data = table.remove(socket.messages, 1)
if data then
return unpack(data)
end
end
function transport.write(socket, data)
--debug('>> ' .. Util.tostring({ type = 'DATA', seq = socket.wseq }))
socket.transmit(socket.dport, socket.dhost, data)
--local timerId = os.startTimer(3)
--transport.timers[timerId] = socket
--socket.timers[socket.wseq] = timerId
socket.wseq = socket.wseq + 1
end
function transport.ping(socket)
--debug('>> ' .. Util.tostring({ type = 'DATA', seq = socket.wseq }))
if os.clock() - socket.activityTimer > 10 then
socket.activityTimer = os.clock()
socket.transmit(socket.dport, socket.dhost, {
type = 'PING',
seq = -1,
})
local timerId = os.startTimer(3)
transport.timers[timerId] = socket
socket.timers[-1] = timerId
end
end
function transport.close(socket)
transport.sockets[socket.sport] = nil
end
Event.on('timer', function(_, timerId)
local socket = transport.timers[timerId]
if socket and socket.connected then
print('transport timeout - closing socket ' .. socket.sport)
socket:close()
transport.timers[timerId] = nil
end
end)
Event.on('modem_message', function(_, _, dport, dhost, msg, distance)
if dhost == computerId and msg then
local socket = transport.sockets[dport]
if socket and socket.connected then
--if msg.type then debug('<< ' .. Util.tostring(msg)) end
if msg.type == 'DISC' then
-- received disconnect from other end
if socket.connected then
os.queueEvent('transport_' .. socket.uid)
end
socket.connected = false
socket:close()
elseif msg.type == 'ACK' then
local ackTimerId = socket.timers[msg.seq]
if ackTimerId then
os.cancelTimer(ackTimerId)
socket.timers[msg.seq] = nil
socket.activityTimer = os.clock()
transport.timers[ackTimerId] = nil
end
elseif msg.type == 'PING' then
socket.activityTimer = os.clock()
socket.transmit(socket.dport, socket.dhost, {
type = 'ACK',
seq = msg.seq,
})
elseif msg.type == 'DATA' and msg.data then
socket.activityTimer = os.clock()
if msg.seq ~= socket.rseq then
print('transport seq error - closing socket ' .. socket.sport)
socket:close()
else
socket.rseq = socket.rseq + 1
table.insert(socket.messages, { msg.data, distance })
-- use resume instead ??
if not socket.messages[2] then -- table size is 1
os.queueEvent('transport_' .. socket.uid)
end
--debug('>> ' .. Util.tostring({ type = 'ACK', seq = msg.seq }))
--socket.transmit(socket.dport, socket.dhost, {
-- type = 'ACK',
-- seq = msg.seq,
--})
end
end
end
end
end)