Prepare to have dynamically chosen lookup backend

diff --git a/gps303/lookaside.py b/gps303/lookaside.py
index b42ce06f378a5ae10fe9a642475556ab577d6859..6924757ec344a7992b8b3aed510f536ecef2c66a 100644 (file)
--- a/gps303/lookaside.py
+++ b/gps303/lookaside.py
@@ -1,6 +1,7 @@
 """ Estimate coordinates from WIFI_POSITIONING and send back """
 
 from datetime import datetime, timezone
+from importlib import import_module
 from logging import getLogger
 from os import umask
 from struct import pack
@@ -8,17 +9,19 @@ import zmq
 
 from . import common
 from .gps303proto import parse_message, WIFI_POSITIONING
-from .opencellid import qry_cell
 from .zmsg import Bcast, Resp, topic
 
 log = getLogger("gps303/lookaside")
 
 
 def runserver(conf):
-    if conf.get("lookaside", "backend") != "opencellid":
+    if conf.get("lookaside", "backend") == "opencellid":
+        qry = import_module(".opencellid", __package__)
+    else:
         raise NotImplementedError(
             "Lookaside only implements opencellid backend"
         )
+    qry.init(conf)
     zctx = zmq.Context()
     zsub = zctx.socket(zmq.SUB)
     zsub.connect(conf.get("collector", "publishurl"))
@@ -37,9 +40,7 @@ def runserver(conf):
                 datetime.fromtimestamp(zmsg.when).astimezone(tz=timezone.utc),
                 msg,
             )
-            lat, lon = qry_cell(
-                conf["opencellid"]["dbfn"], msg.mcc, msg.gsm_cells
-            )
+            lat, lon = qry.lookup(msg.mcc, msg.gsm_cells, msg.wifi_aps)
             resp = Resp(
                 imei=zmsg.imei,
                 when=zmsg.when,  # not the current time, but the original!

diff --git a/gps303/mkgpx.py b/gps303/mkgpx.py
index f694b7ee80cd5c69de49805be79d1e18f2cf061b..061b54a26ead78440f4476f39329d7f3ff8aa1e0 100644 (file)
--- a/gps303/mkgpx.py
+++ b/gps303/mkgpx.py
@@ -3,8 +3,9 @@ from sqlite3 import connect
 import sys
 
 from .gps303proto import *
-from .opencellid import qry_cell
+from . import opencellid as ocid
 
+ocid.init({"opencellid": {"dbfn": sys.argv[2]}})
 db = connect(sys.argv[1])
 c = db.cursor()
 c.execute(
@@ -38,7 +39,7 @@ xmlns="http://www.topografix.com/GPX/1/1">
 for tstamp, packet in c:
     msg = parse_message(packet)
     if isinstance(msg, (WIFI_POSITIONING, WIFI_OFFLINE_POSITIONING)):
-        lat, lon = qry_cell(sys.argv[2], msg.mcc, msg.gsm_cells)
+        lat, lon = ocid.lookup(msg.mcc, msg.gsm_cells, msg.wifi_aps)
         if lat is None or lon is None:
             continue
     elif isinstance(msg, (GPS_POSITIONING, GPS_OFFLINE_POSITIONING)):

diff --git a/gps303/opencellid.py b/gps303/opencellid.py
index 436d559bd6ca4699e2fa97d041410d4318f9ae8d..0131dc0305bdb6a4e385f7392470c7aecf5bba52 100644 (file)
--- a/gps303/opencellid.py
+++ b/gps303/opencellid.py
@@ -1,58 +1,48 @@
 """
-Download csv for your carrier and your area from https://opencellid.org/
-$ sqlite3 <cell-database-file>
-sqlite> create table if not exists cells (
-  "radio" text,
-  "mcc" int,
-  "net" int,
-  "area" int,
-  "cell" int,
-  "unit" int,
-  "lon" int,
-  "lat" int,
-  "range" int,
-  "samples" int,
-  "changeable" int,
-  "created" int,
-  "updated" int,
-  "averageSignal" int
-);
-sqlite> .mode csv
-sqlite> .import <downloaded-file.csv> cells
-sqlite> create index if not exists cell_idx on cells (mcc, area, cell);
+Lookaside backend to query local opencellid database
 """
 
 from sqlite3 import connect
 
+__all__ = "init", "lookup"
 
-def qry_cell(dbname, mcc, gsm_cells):
-    with connect(dbname) as ldb:
-        lc = ldb.cursor()
-        lc.execute("""attach database ":memory:" as mem""")
-        lc.execute("create table mem.seen (locac int, cellid int, signal int)")
-        lc.executemany(
-            """insert into mem.seen (locac, cellid, signal)
-                            values (?, ?, ?)""",
-            gsm_cells,
-        )
-        lc.execute(
-            """select c.lat, c.lon, s.signal
-                      from main.cells c, mem.seen s
-                      where c.mcc = ?
-                      and c.area = s.locac
-                      and c.cell = s.cellid""",
-            (mcc,),
-        )
-        data = list(lc.fetchall())
-        if not data:
-            return None, None
-        sumsig = sum([1 / sig for _, _, sig in data])
-        nsigs = [1 / sig / sumsig for _, _, sig in data]
-        avlat = sum([lat * nsig for (lat, _, _), nsig in zip(data, nsigs)])
-        avlon = sum([lon * nsig for (_, lon, _), nsig in zip(data, nsigs)])
-        # lc.execute("drop table mem.seen")
-        lc.close()
-        return avlat, avlon
+ldb = None
+
+
+def init(conf):
+    global ldb
+    ldb = connect(conf["opencellid"]["dbfn"])
+
+
+def lookup(mcc, gsm_cells, _):
+    lc = ldb.cursor()
+    lc.execute("""attach database ":memory:" as mem""")
+    lc.execute("create table mem.seen (locac int, cellid int, signal int)")
+    lc.executemany(
+        """insert into mem.seen (locac, cellid, signal)
+                        values (?, ?, ?)""",
+        gsm_cells,
+    )
+    ldb.commit()
+    lc.execute(
+        """select c.lat, c.lon, s.signal
+                  from main.cells c, mem.seen s
+                  where c.mcc = ?
+                  and c.area = s.locac
+                  and c.cell = s.cellid""",
+        (mcc,),
+    )
+    data = list(lc.fetchall())
+    if not data:
+        return None, None
+    sumsig = sum([1 / sig for _, _, sig in data])
+    nsigs = [1 / sig / sumsig for _, _, sig in data]
+    avlat = sum([lat * nsig for (lat, _, _), nsig in zip(data, nsigs)])
+    avlon = sum([lon * nsig for (_, lon, _), nsig in zip(data, nsigs)])
+    # lc.execute("drop table mem.seen")
+    lc.execute("""detach database mem""")
+    lc.close()
+    return avlat, avlon
 
 
 if __name__.endswith("__main__"):
@@ -63,13 +53,14 @@ if __name__.endswith("__main__"):
     db = connect(sys.argv[1])
     c = db.cursor()
     c.execute(
-        """select select tstamp, packet from events
+        """select tstamp, packet from events
             where proto in (?, ?)""",
         (WIFI_POSITIONING.PROTO, WIFI_OFFLINE_POSITIONING.PROTO),
     )
-    for timestamp, imei, clntaddr, proto, payload in c:
+    init({"opencellid": {"dbfn": sys.argv[2]}})
+    for timestamp, packet in c:
         obj = parse_message(packet)
-        avlat, avlon = qry_cell(sys.argv[2], obj.mcc, obj.gsm_cells)
+        avlat, avlon = lookup(obj.mcc, obj.gsm_cells, obj.wifi_aps)
         print(
             "{} {:+#010.8g},{:+#010.8g}".format(
                 datetime.fromtimestamp(timestamp), avlat, avlon