From 4c9597cff07443042f51c2330a050b7ee5bc9bcb Mon Sep 17 00:00:00 2001
From: Eugene Crosser <crosser@average.org>
Date: Fri, 15 Apr 2022 00:17:55 +0200
Subject: [PATCH] Initial version of zmq based architecture

---
 gps303.conf         |   5 ++
 gps303/collector.py | 144 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 149 insertions(+)
 create mode 100644 gps303/collector.py

diff --git a/gps303.conf b/gps303.conf
index 3a90e3b..cdad9c7 100644
--- a/gps303.conf
+++ b/gps303.conf
@@ -1,3 +1,8 @@
+[collector]
+port = 4303
+publishurl = ipc:///tmp/collected
+listenurl = ipc:///responses
+
 [daemon]
 port = 4303
 dbfn = gps303.sqlite
diff --git a/gps303/collector.py b/gps303/collector.py
new file mode 100644
index 0000000..d8ca86c
--- /dev/null
+++ b/gps303/collector.py
@@ -0,0 +1,144 @@
+from getopt import getopt
+from logging import getLogger, StreamHandler, DEBUG, INFO
+from logging.handlers import SysLogHandler
+from socket import socket, AF_INET, SOCK_STREAM, SOL_SOCKET, SO_REUSEADDR
+from time import time
+import sys
+import zmq
+
+from .config import readconfig
+from .GT06mod import handle_packet, make_response, LOGIN, set_config
+
+CONF = "/etc/gps303.conf"
+
+log = getLogger("gps303/collector")
+
+
+class Bcast:
+    def __init__(self, imei, msg):
+        self.as_bytes = imei.encode() + msg.encode()
+
+
+class Zmsg:
+    def __init__(self, msg):
+        self.imei = msg[:16].decode()
+        self.payload = msg[16:]
+
+
+class Client:
+    def __init__(self, clntsock, clntaddr):
+        self.clntsock = clntsock
+        self.clntaddr = clntaddr
+        self.buffer = b""
+        self.imei = None
+
+    def close(self):
+        self.clntsock.close()
+
+    def recv(self):
+        packet = self.clntsock.recv(4096)
+        if not packet:
+            return None
+        when = time()
+        self.buffer += packet
+        # implement framing properly
+        msg = handle_packet(packet, self.clntaddr, when)
+        self.buffer = self.buffer[len(packet):]
+        if isinstance(msg, LOGIN):
+            self.imei = msg.imei
+        return msg
+
+    def send(self, buffer):
+        self.clntsock.send(buffer)
+
+
+class Clients:
+    def __init__(self):
+        self.by_fd = {}
+        self.by_imei = {}
+
+    def add(self, clntsock, clntaddr):
+        fd = clntsock.fileno()
+        self.by_fd[fd] = Client(clntsock, clntaddr)
+        return fd
+
+    def stop(self, fd):
+        clnt = by_fd[fd]
+        clnt.close()
+        if clnt.imei:
+            del self.by_imei[clnt.imei]
+        del self.by_fd[fd]
+
+    def recv(self, fd):
+        clnt = by_fd[fd]
+        msg = clnt.recv()
+        if isinstance(msg, LOGIN):
+            self.by_imei[clnt.imei] = clnt
+        return clnt.imei, msg
+
+    def response(self, zmsg):
+        if zmsg.imei in self.by_imei:
+            clnt = self.by_imei[zmsg.imei].send(zmsg.payload)
+
+
+def runserver(opts, conf):
+    zctx = zmq.Context()
+    zpub = zctx.socket(zmq.PUB)
+    zpub.bind(conf.get("collector", "publishurl"))
+    zsub = zctx.socket(zmq.SUB)
+    zsub.connect(conf.get("collector", "listenurl"))
+    tcpl = socket(AF_INET, SOCK_STREAM)
+    tcpl.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
+    tcpl.bind(("", conf.getint("collector", "port")))
+    tcpl.listen(5)
+    tcpfd = tcpl.fileno()
+    poller = zmq.Poller()
+    poller.register(zsub, flags=zmq.POLLIN)
+    poller.register(tcpfd, flags=zmq.POLLIN)
+    clients = Clients()
+    try:
+        while True:
+            tosend = []
+            topoll = []
+            tostop = []
+            events = poller.poll(10)
+            for sk, fl in events:
+                if sk is zsub:
+                    while True:
+                        try:
+                            msg = zsub.recv(zmq.NOBLOCK)
+                            tosend.append(Zmsg(msg))
+                        except zmq.Again:
+                            break
+                elif sk == tcpfd:
+                    clntsock, clntaddr = ctlsock.accept()
+                    topoll.append((clntsock, clntaddr))
+                else:
+                    imei, msg = clients.recv(sk)
+                    zpub.send(Bcast(imei, msg).as_bytes)
+                    if msg is None or isinstance(msg, HIBERNATION):
+                        tostop.append(sk)
+            # poll queue consumed, make changes now
+            for fd in tostop:
+                clients.stop(fd)
+                pollset.unregister(fd)
+            for zmsg in tosend:
+                clients.response(zmsg)
+            for clntsock, clntaddr in topoll:
+                fd = clients.add(clntsock, clntaddr)
+                pollset.register(fd)
+    except KeyboardInterrupt:
+        pass
+
+
+if __name__.endswith("__main__"):
+    opts, _ = getopt(sys.argv[1:], "c:d")
+    opts = dict(opts)
+    conf = readconfig(opts["-c"] if "-c" in opts else CONF)
+    if sys.stdout.isatty():
+        log.addHandler(StreamHandler(sys.stderr))
+    else:
+        log.addHandler(SysLogHandler(address="/dev/log"))
+    log.setLevel(DEBUG if "-d" in opts else INFO)
+    log.info("starting with options: %s", opts)
+    runserver(opts, conf)
-- 
2.43.0