From 6eff65f7b03bc66a479df0fd694250e1e0b7c5ae Mon Sep 17 00:00:00 2001
From: Eugene Crosser <crosser@average.org>
Date: Thu, 10 Nov 2022 23:17:36 +0100
Subject: [PATCH] Send backlog only the the ws client that requested

---
 loctrkd/wsgateway.py | 41 +++++++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/loctrkd/wsgateway.py b/loctrkd/wsgateway.py
index e568584..e94845e 100644
--- a/loctrkd/wsgateway.py
+++ b/loctrkd/wsgateway.py
@@ -209,16 +209,28 @@ class Clients:
         clnt.close()
         del self.by_fd[fd]
 
-    def recv(self, fd: int) -> Optional[List[Dict[str, Any]]]:
+    def recv(self, fd: int) -> Tuple[Client, Optional[List[Dict[str, Any]]]]:
         clnt = self.by_fd[fd]
-        return clnt.recv()
+        return (clnt, clnt.recv())
 
-    def send(self, msg: Dict[str, Any]) -> Set[int]:
+    def send(self, clnt: Optional[Client], msg: Dict[str, Any]) -> Set[int]:
         towrite = set()
-        for fd, clnt in self.by_fd.items():
-            if clnt.wants(msg["imei"]):
+        if clnt is None:
+            for fd, cl in self.by_fd.items():
+                if cl.wants(msg["imei"]):
+                    cl.send(msg)
+                    towrite.add(fd)
+        else:
+            fd = clnt.sock.fileno()
+            if self.by_fd.get(fd, None) == clnt:
                 clnt.send(msg)
                 towrite.add(fd)
+            else:
+                log.info(
+                    "Trying to send %s to client at %d, not in service",
+                    msg,
+                    fd,
+                )
         return towrite
 
     def write(self, towrite: Set[int]) -> Set[int]:
@@ -264,7 +276,7 @@ def runserver(conf: ConfigParser) -> None:
                 zsub.setsockopt(zmq.UNSUBSCRIBE, rtopic(imei))
             activesubs = neededsubs
             log.debug("Subscribed to: %s", activesubs)
-            tosend = []
+            tosend: List[Tuple[Optional[Client], Dict[str, Any]]] = []
             topoll = []
             tostop = []
             towrite = set()
@@ -277,14 +289,14 @@ def runserver(conf: ConfigParser) -> None:
                             msg = loads(zmsg.payload)
                             msg["imei"] = zmsg.imei
                             log.debug("Got %s, sending %s", zmsg, msg)
-                            tosend.append(msg)
+                            tosend.append((None, msg))
                         except zmq.Again:
                             break
                 elif sk == tcpfd:
                     clntsock, clntaddr = tcpl.accept()
                     topoll.append((clntsock, clntaddr))
                 elif fl & zmq.POLLIN:
-                    received = clients.recv(sk)
+                    clnt, received = clients.recv(sk)
                     if received is None:
                         log.debug("Client gone from fd %d", sk)
                         tostop.append(sk)
@@ -297,7 +309,12 @@ def runserver(conf: ConfigParser) -> None:
                                 imeis = cast(List[str], wsmsg.get("imei"))
                                 numback: int = wsmsg.get("backlog", 5)
                                 for imei in imeis:
-                                    tosend.extend(backlog(imei, numback))
+                                    tosend.extend(
+                                        [
+                                            (clnt, msg)
+                                            for msg in backlog(imei, numback)
+                                        ]
+                                    )
                         towrite.add(sk)
                 elif fl & zmq.POLLOUT:
                     log.debug("Write now open for fd %d", sk)
@@ -309,9 +326,9 @@ def runserver(conf: ConfigParser) -> None:
             for fd in tostop:
                 poller.unregister(fd)  # type: ignore
                 clients.stop(fd)
-            for wsmsg in tosend:
-                log.debug("Sending to the clients: %s", wsmsg)
-                towrite |= clients.send(wsmsg)
+            for towhom, wsmsg in tosend:
+                log.debug("Sending to the client %s: %s", towhom, wsmsg)
+                towrite |= clients.send(towhom, wsmsg)
             for clntsock, clntaddr in topoll:
                 fd = clients.add(clntsock, clntaddr)
                 poller.register(fd, flags=zmq.POLLIN)
-- 
2.39.2