penpot/backend/src/app/http/websocket.clj
2022-10-03 13:40:33 +02:00

351 lines
11 KiB
Clojure

;; This Source Code Form is subject to the terms of the Mozilla Public
;; License, v. 2.0. If a copy of the MPL was not distributed with this
;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
;;
;; Copyright (c) KALEIDOS INC
(ns app.http.websocket
"A penpot notification service for file cooperative edition."
(:require
[app.common.exceptions :as ex]
[app.common.logging :as l]
[app.common.pprint :as pp]
[app.common.spec :as us]
[app.db :as db]
[app.metrics :as mtx]
[app.msgbus :as mbus]
[app.util.time :as dt]
[app.util.websocket :as ws]
[clojure.core.async :as a]
[clojure.spec.alpha :as s]
[integrant.core :as ig]
[yetti.websocket :as yws]))
(def recv-labels
(into-array String ["recv"]))
(def send-labels
(into-array String ["send"]))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; WEBSOCKET HOOKS
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(def state (atom {}))
(defn- on-connect
[{:keys [metrics]} wsp]
(let [created-at (dt/now)]
(swap! state assoc (::ws/id @wsp) wsp)
(mtx/run! metrics
:id :websocket-active-connections
:inc 1)
(fn []
(swap! state dissoc (::ws/id @wsp))
(mtx/run! metrics :id :websocket-active-connections :dec 1)
(mtx/run! metrics
:id :websocket-session-timing
:val (/ (inst-ms (dt/diff created-at (dt/now))) 1000.0)))))
(defn- on-rcv-message
[{:keys [metrics]} _ message]
(mtx/run! metrics
:id :websocket-messages-total
:labels recv-labels
:inc 1)
message)
(defn- on-snd-message
[{:keys [metrics]} _ message]
(mtx/run! metrics
:id :websocket-messages-total
:labels send-labels
:inc 1)
message)
;; REPL HELPERS
(defn repl-get-connections-for-file
[file-id]
(->> (vals @state)
(filter #(= file-id (-> % deref ::file-subscription :file-id)))
(map deref)
(map ::ws/id)))
(defn repl-get-connections-for-team
[team-id]
(->> (vals @state)
(filter #(= team-id (-> % deref ::team-subscription :team-id)))
(map deref)
(map ::ws/id)))
(defn repl-close-connection
[id]
(when-let [wsp (get @state id)]
(a/>!! (::ws/close-ch @wsp) [8899 "closed from server"])
(a/close! (::ws/close-ch @wsp))))
(defn repl-get-connection-info
[id]
(when-let [wsp (get @state id)]
{:id id
:created-at (::created-at @wsp)
:profile-id (::profile-id @wsp)
:session-id (::session-id @wsp)
:user-agent (::ws/user-agent @wsp)
:ip-addr (::ws/remote-addr @wsp)
:last-activity-at (::ws/last-activity-at @wsp)
:http-session-id (::ws/http-session-id @wsp)
:subscribed-file (-> wsp deref ::file-subscription :file-id)
:subscribed-team (-> wsp deref ::team-subscription :team-id)}))
(defn repl-print-connection-info
[id]
(some-> id repl-get-connection-info pp/pprint))
(defn repl-print-connection-info-for-file
[file-id]
(some->> (repl-get-connections-for-file file-id)
(map repl-get-connection-info)
(pp/pprint)))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; WEBSOCKET HANDLER
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defmulti handle-message
(fn [_ _ message]
(:type message)))
(defmethod handle-message :connect
[cfg wsp _]
(let [msgbus (:msgbus cfg)
conn-id (::ws/id @wsp)
profile-id (::profile-id @wsp)
session-id (::session-id @wsp)
output-ch (::ws/output-ch @wsp)
xform (remove #(= (:session-id %) session-id))
channel (a/chan (a/dropping-buffer 16) xform)]
(l/trace :fn "handle-message" :event "connect" :conn-id conn-id)
;; Subscribe to the profile channel and forward all messages to
;; websocket output channel (send them to the client).
(swap! wsp assoc ::profile-subscription channel)
(a/pipe channel output-ch false)
(mbus/sub! msgbus :topic profile-id :chan channel)))
(defmethod handle-message :disconnect
[cfg wsp _]
(let [msgbus (:msgbus cfg)
conn-id (::ws/id @wsp)
profile-id (::profile-id @wsp)
session-id (::session-id @wsp)
profile-ch (::profile-subscription @wsp)
fsub (::file-subscription @wsp)
tsub (::team-subscription @wsp)
message {:type :disconnect
:subs-id profile-id
:profile-id profile-id
:session-id session-id}]
(l/trace :fn "handle-message"
:event :disconnect
:conn-id conn-id)
(a/go
;; Close the main profile subscription
(a/close! profile-ch)
(a/<! (mbus/purge! msgbus [profile-ch]))
;; Close tram subscription if exists
(when-let [channel (:channel tsub)]
(a/close! channel)
(a/<! (mbus/purge! msgbus channel)))
(when-let [{:keys [topic channel]} fsub]
(a/close! channel)
(a/<! (mbus/purge! msgbus channel))
(a/<! (mbus/pub! msgbus :topic topic :message message))))))
(defmethod handle-message :subscribe-team
[cfg wsp {:keys [team-id] :as params}]
(let [msgbus (:msgbus cfg)
conn-id (::ws/id @wsp)
session-id (::session-id @wsp)
output-ch (::ws/output-ch @wsp)
prev-subs (get @wsp ::team-subscription)
xform (comp
(remove #(= (:session-id %) session-id))
(map #(assoc % :subs-id team-id)))
channel (a/chan (a/dropping-buffer 64) xform)]
(l/trace :fn "handle-message"
:event :subscribe-team
:team-id team-id
:conn-id conn-id)
(a/pipe channel output-ch false)
(let [state {:team-id team-id :channel channel :topic team-id}]
(swap! wsp assoc ::team-subscription state))
(a/go
;; Close previous subscription if exists
(when-let [channel (:channel prev-subs)]
(a/close! channel)
(a/<! (mbus/purge! msgbus channel))))
(a/go
(a/<! (mbus/sub! msgbus :topic team-id :chan channel)))))
(defmethod handle-message :subscribe-file
[cfg wsp {:keys [file-id] :as params}]
(let [msgbus (:msgbus cfg)
conn-id (::ws/id @wsp)
profile-id (::profile-id @wsp)
session-id (::session-id @wsp)
output-ch (::ws/output-ch @wsp)
prev-subs (::file-subscription @wsp)
xform (comp (remove #(= (:session-id %) session-id))
(map #(assoc % :subs-id file-id)))
channel (a/chan (a/dropping-buffer 64) xform)]
(l/trace :fn "handle-message"
:event :subscribe-file
:file-id file-id
:conn-id conn-id)
(let [state {:file-id file-id :channel channel :topic file-id}]
(swap! wsp assoc ::file-subscription state))
(a/go
;; Close previous subscription if exists
(when-let [channel (:channel prev-subs)]
(a/close! channel)
(a/<! (mbus/purge! msgbus channel))))
;; Message forwarding
(a/go
(loop []
(when-let [{:keys [type] :as message} (a/<! channel)]
(when (or (= :join-file type)
(= :leave-file type)
(= :disconnect type))
(let [message {:type :presence
:file-id file-id
:session-id session-id
:profile-id profile-id}]
(a/<! (mbus/pub! msgbus :topic file-id :message message))))
(a/>! output-ch message)
(recur))))
(a/go
;; Subscribe to file topic
(a/<! (mbus/sub! msgbus :topic file-id :chan channel))
;; Notifify the rest of participants of the new connection.
(let [message {:type :join-file
:file-id file-id
:subs-id file-id
:session-id session-id
:profile-id profile-id}]
(a/<! (mbus/pub! msgbus :topic file-id :message message))))))
(defmethod handle-message :unsubscribe-file
[cfg wsp {:keys [file-id] :as params}]
(let [msgbus (:msgbus cfg)
conn-id (::ws/id @wsp)
session-id (::session-id @wsp)
profile-id (::profile-id @wsp)
subs (::file-subscription @wsp)
message {:type :leave-file
:file-id file-id
:session-id session-id
:profile-id profile-id}]
(l/trace :fn "handle-message"
:event :unsubscribe-file
:file-id file-id
:conn-id conn-id)
(a/go
(when (= (:file-id subs) file-id)
(let [channel (:channel subs)]
(a/close! channel)
(a/<! (mbus/purge! msgbus channel))
(a/<! (mbus/pub! msgbus :topic file-id :message message)))))))
(defmethod handle-message :keepalive
[_ _ _]
(l/trace :fn "handle-message" :event :keepalive)
(a/go :nothing))
(defmethod handle-message :pointer-update
[cfg wsp {:keys [file-id] :as message}]
(let [msgbus (:msgbus cfg)
profile-id (::profile-id @wsp)
session-id (::session-id @wsp)
subs (::file-subscription @wsp)
message (-> message
(assoc :subs-id file-id)
(assoc :profile-id profile-id)
(assoc :session-id session-id))]
(a/go
;; Only allow receive pointer updates when active subscription
(when subs
(a/<! (mbus/pub! msgbus :topic file-id :message message))))))
(defmethod handle-message :default
[_ wsp message]
(let [conn-id (::ws/id @wsp)]
(l/warn :hint "received unexpected message"
:message message
:conn-id conn-id)
(a/go :none)))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; HTTP HANDLER
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(s/def ::msgbus ::mbus/msgbus)
(s/def ::session-id ::us/uuid)
(s/def ::handler-params
(s/keys :req-un [::session-id]))
(defmethod ig/pre-init-spec ::handler [_]
(s/keys :req-un [::msgbus ::db/pool ::mtx/metrics]))
(defmethod ig/init-key ::handler
[_ cfg]
(fn [{:keys [profile-id params] :as req} respond raise]
(let [{:keys [session-id]} (us/conform ::handler-params params)]
(cond
(not profile-id)
(raise (ex/error :type :authentication
:hint "Authentication required."))
(not (yws/upgrade-request? req))
(raise (ex/error :type :validation
:code :websocket-request-expected
:hint "this endpoint only accepts websocket connections"))
:else
(do
(l/trace :hint "websocket request" :profile-id profile-id :session-id session-id)
(->> (ws/handler
::ws/on-rcv-message (partial on-rcv-message cfg)
::ws/on-snd-message (partial on-snd-message cfg)
::ws/on-connect (partial on-connect cfg)
::ws/handler (partial handle-message cfg)
::profile-id profile-id
::session-id session-id)
(yws/upgrade req)
(respond)))))))