tree b0df5bba90af21e8699173858b9aeefff47268d1
parent 55f5efa5681fe7456d0c7adbee324dbeff2a283e
author Stefan Sperling <ssperling@sysmocom.de> 1543932449 +0100
committer Stefan Sperling <ssperling@sysmocom.de> 1544179806 +0100

store a timestamp of the last location update seen from a subscriber

Timestamps are stored in the HLR DB in the new 'last_lu_seen' column
of the 'subscriber' table, in UTC and in granularity of seconds.

At present, osmo-hlr only records these timestamps but otherwise
makes no use of them. Because the timestamps are stored in a
human-readable form, they may already provide value to external
processes which need this information. For example:

  sqlite> select imsi,last_lu_seen from subscriber;
  901990000000001|2018-12-04 14:17:12

I didn't bother adding additional tests because the code added
with this commit is already being exercised by several calls
to db_subscr_lu() in db_test.c.

This change requires a HLR DB schema update. Existing databases
won't be upgraded automatically. However, osmo-hlr will refuse
to operate with databases which are not upgraded.

Change-Id: Ibeb49d45aec18451a260a6654b8c51b8fc3bec50
Related: OS#2838