195 lines
4.9 KiB
Elixir
195 lines
4.9 KiB
Elixir
defmodule Floof do
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@moduledoc """
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Documentation for `Floof`.
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"""
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require Logger
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def accept(port, opts \\ []) do
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{:ok, socket} =
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:gen_tcp.listen(
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port,
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[
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:binary,
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packet: 4,
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active: false,
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reuseaddr: true
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] ++ opts
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)
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Logger.info("Accepting connections on #{port}")
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loop_acceptor(socket)
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:ok = :gen_tcp.close(socket)
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end
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defp loop_acceptor(socket) do
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{:ok, client} = :gen_tcp.accept(socket)
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{:ok, pid} =
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Task.Supervisor.start_child(Floof.TaskSupervisor, fn ->
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serve(client, %{}, nil)
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:ok = :gen_tcp.close(client)
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end)
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:ok = :gen_tcp.controlling_process(client, pid)
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# switch to active now that we handed over the client
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:inet.setopts(client, [{:active, true}])
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Floof.Distributor.register(pid)
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loop_acceptor(socket)
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end
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def connect(host, port, sesskey \\ nil) do
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{:ok, socket} =
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:gen_tcp.connect(host, port,
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packet: 4,
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active: true
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)
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Floof.Distributor.register(self())
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Logger.info("Established connection to #{inspect(host)}:#{port}")
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if sesskey != nil do
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{:ok, encd} = :FloofProtocol.encode(:ProtoMessage, {:session, {:attach, sesskey}})
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:ok = :gen_tcp.send(socket, encd)
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end
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serve(socket, %{}, nil)
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:ok = :gen_tcp.close(socket)
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end
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defp serve(client, backlog, sesskey) do
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receive do
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{:tcp, _, message} ->
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message =
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if :erlang.is_binary(message) do
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message
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else
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:erlang.list_to_binary(message)
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end
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{:ok, dcd} = :FloofProtocol.decode(:ProtoMessage, message)
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backlog = handle_incoming(client, backlog, dcd)
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serve(client, backlog, sesskey)
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{:fwdxfer, {dcdhash, dcd}} ->
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:ok = send_summary(client, :requestpull, [dcdhash])
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serve(client, Map.put(backlog, dcdhash, dcd), sesskey)
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{:SessionPushed, key} ->
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{backlog, added_hashs} = extract_backlog(key, backlog, MapSet.new())
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:ok = send_summary(client, :requestpull, added_hashs)
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serve(client, backlog, key)
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{:tcp_closed, _} ->
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# put all the backlogged stuff back if possible
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if sesskey != nil do
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for item <- backlog do
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Floof.SessionManager.push(sesskey, item)
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end
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Floof.SessionManager.deattach(sesskey, self())
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end
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x ->
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Logger.warn("unable to handle request: #{inspect(x)}")
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serve(client, backlog, sesskey)
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end
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end
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defp handle_incoming(client, backlog, dcd) do
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Logger.debug("got packet #{inspect(dcd)}")
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case dcd do
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{:session, {:attach, key}} ->
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Floof.Distributor.register_key(key, self())
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if Floof.SessionManager.attach(key, self()) do
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send(self(), {:SessionPushed, key})
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end
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backlog
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{:summary, {:Summary, direction, hashes}} ->
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case direction do
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:requestpull ->
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{to_pull, to_drop} = partition_hashes(hashes)
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if not Enum.empty?(to_pull) do
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:ok = send_summary(client, :pull, to_pull)
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end
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if not Enum.empty?(to_pull) do
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:ok = send_summary(client, :drop, to_drop)
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end
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backlog
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:pull ->
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for mhash <- hashes do
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case Map.fetch(backlog, mhash) do
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{:ok, item} ->
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{:ok, encd} = :FloofProtocol.encode(:ProtoMessage, {:xfer, item})
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:ok = :gen_tcp.send(client, encd)
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:error ->
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nil
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end
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end
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backlog
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:drop ->
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Map.drop(backlog, hashes)
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end
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{:xfer, xf} ->
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mhash = Floof.Message.emit(xf)
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# notify the remote end that we successfully consumed the message
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# non-fatal if this fails
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send_summary(client, :drop, [mhash])
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backlog
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end
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end
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defp extract_backlog(key, backlog, added_ids) do
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case Floof.SessionManager.pop(key) do
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:empty ->
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{backlog, added_ids}
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{:value, {mhash, entry}} ->
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extract_backlog(key, Map.put(backlog, mhash, entry), MapSet.put(added_ids, mhash))
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end
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end
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defp send_summary(client, direction, dcdids) do
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if not Enum.empty?(dcdids) do
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dat = {:Summary, direction, Enum.to_list(dcdids)}
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{:ok, encd} = :FloofProtocol.encode(:ProtoMessage, {:summary, dat})
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:gen_tcp.send(client, encd)
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else
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:ok
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end
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end
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defp partition_hashes(xs) do
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xs
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|> Floof.Distributor.have_we_multi()
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|> Enum.to_list()
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|> partition_list(MapSet.new(), MapSet.new())
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end
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defp partition_list([], lo, hi) do
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{lo, hi}
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end
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defp partition_list([{key, cnd} | xs], lo, hi) do
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{lo2, hi2} =
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if cnd do
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{lo, MapSet.put(hi, key)}
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else
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{MapSet.put(lo, key), hi}
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end
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partition_list(xs, lo2, hi2)
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end
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end
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