From: Eugene Crosser <crosser@average.org>
Date: Fri, 6 May 2022 23:50:49 +0000 (+0200)
Subject: WIP on baclog fetcher
X-Git-Tag: 0.01~3
X-Git-Url: http://www.average.org/gitweb/?p=loctrkd.git;a=commitdiff_plain;h=96538346bd332d76d2cac5d6a0ef2b4e4a40de30

WIP on baclog fetcher
---

diff --git a/gps303/backlog.py b/gps303/backlog.py
new file mode 100644
index 0000000..39dfcbc
--- /dev/null
+++ b/gps303/backlog.py
@@ -0,0 +1,26 @@
+""" Get backlog from evstore """
+
+from .opencellid import qry_cell
+from .evstore import initdb, fetch
+from .gps303proto import GPS_POSITIONING, WIFI_POSITIONING, parse_message
+from .zmsg import LocEvt
+
+OCDB = None
+
+def blinit(evdb, ocdb):
+    global OCDB
+    OCDB = ocdb
+    initdb(evdb)
+
+def backlog(imei, backlog):
+    result = []
+    for packet in fetch(imei, (GPS_POSITIONING.PROTO, WIFI_POSITIONING.PROTO), backlog):
+        msg = parse_message(packet)
+        if isinstance(msg, GPS_POSITIONING):
+            result.append(LocEvt(devtime=msg.devtime, lon=msg.longitude,
+                lat=msg.latitude, is_gps=True, imei=imei))
+        elif isinstance(msg, WIFI_POSITIONING):
+            lat, lon = qry_cell(OCDB, msg.mcc, msg.gsm_cells)
+            result.append(LocEvt(devtime=msg.devtime, lon=lon,
+                lat=lat, is_gps=False, imei=imei))
+    return reversed(result)
diff --git a/gps303/evstore.py b/gps303/evstore.py
index 70a3ac6..c10ecb1 100644
--- a/gps303/evstore.py
+++ b/gps303/evstore.py
@@ -2,7 +2,7 @@
 
 from sqlite3 import connect
 
-__all__ = "initdb", "stow"
+__all__ = "fetch", "initdb", "stow"
 
 DB = None
 
@@ -43,3 +43,15 @@ def stow(**kwargs):
         parms,
     )
     DB.commit()
+
+def fetch(imei, protos, backlog):
+    assert DB is not None
+    protosel = ", ".join(["?" for _ in range(len(protos))])
+    cur = DB.cursor()
+    cur.execute(f"""select packet from events
+                    where proto in ({protosel}) and imei = ?
+                    order by tstamp desc limit ?""",
+                protos + (imei, backlog))
+    result = [row[0] for row in cur]
+    cur.close()
+    return result
diff --git a/gps303/wsgateway.py b/gps303/wsgateway.py
index f9f5c6a..7756fe9 100644
--- a/gps303/wsgateway.py
+++ b/gps303/wsgateway.py
@@ -17,6 +17,7 @@ from wsproto.utilities import RemoteProtocolError
 import zmq
 
 from . import common
+from .backlog import blinit, backlog
 from .zmsg import LocEvt
 
 log = getLogger("gps303/wsgateway")
@@ -196,14 +197,7 @@ class Clients:
 
     def recv(self, fd):
         clnt = self.by_fd[fd]
-        msgs = clnt.recv()
-        if msgs is None:
-            return None
-        result = []
-        for msg in msgs:
-            log.debug("Received: %s", msg)
-            result.append(msg)
-        return result
+        return clnt.recv()
 
     def send(self, msg):
         towrite = set()
@@ -230,6 +224,7 @@ class Clients:
 def runserver(conf):
     global htmlfile
 
+    blinit(conf.get("storage", "dbfn"), conf.get("opencellid", "dbfn"))
     htmlfile = conf.get("wsgateway", "htmlfile")
     zctx = zmq.Context()
     zsub = zctx.socket(zmq.SUB)
@@ -280,6 +275,10 @@ def runserver(conf):
                     else:
                         for msg in received:
                             log.debug("Received from %d: %s", sk, msg)
+                            if msg.get("type", None) == "subscribe":
+                                imei = msg.get("imei")
+                                if imei:
+                                    tosend.extend(backlog(imei[0], 5))
                         towrite.add(sk)
                 elif fl & zmq.POLLOUT:
                     log.debug("Write now open for fd %d", sk)