reimplement backlog query again

[loctrkd.git] / gps303 / evstore.py

diff --git a/gps303/evstore.py b/gps303/evstore.py
index 76173624bed9069359f202f46d07e0eba3cc8491..a52a64c1e5ad468676349ad299e6fb14b174eceb 100644 (file)
--- a/gps303/evstore.py
+++ b/gps303/evstore.py
@@ -20,8 +20,10 @@ def initdb(dbname):
     global DB
     DB = connect(dbname)
     try:
-        DB.execute("""alter table events add column
-                is_incoming int not null default TRUE""")
+        DB.execute(
+            """alter table events add column
+                is_incoming int not null default TRUE"""
+        )
     except OperationalError:
         DB.execute(SCHEMA)
 
@@ -50,14 +52,22 @@ def stow(**kwargs):
     )
     DB.commit()
 
-def fetch(imei, protos, backlog):
+
+def fetch(imei, matchlist, backlog):
+    # matchlist is a list of tuples (is_incoming, proto)
+    # returns a list of tuples (is_incoming, timestamp, packet)
     assert DB is not None
-    protosel = ", ".join(["?" for _ in range(len(protos))])
+    selector = " or ".join(
+        (f"(is_incoming = ? and proto = ?)" for _ in range(len(matchlist)))
+    )
     cur = DB.cursor()
-    cur.execute(f"""select packet from events
-                    where proto in ({protosel}) and imei = ?
+    cur.execute(
+        f"""select is_incoming, tstamp, packet from events
+                    where ({selector}) and imei = ?
                     order by tstamp desc limit ?""",
-                protos + (imei, backlog))
-    result = [row[0] for row in cur]
+        tuple(item for sublist in matchlist for item in sublist)
+        + (imei, backlog),
+    )
+    result = list(cur)
     cur.close()
-    return result
+    return list(reversed(result))