Add servlet for cron job to remove expired participants #85
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jzwang8
requested review from
kmh287,
tcwanggoogle,
dhruvi618 and
TcgVanguardTroll
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| List<Entity> results = datastore.prepare(query).asList(FetchOptions.Builder.withDefaults()); | ||
| List<Participant> participants = | ||
| results.stream().map(p -> getParticipantFromEntity(p)).collect(Collectors.toList()); |
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nit: p -> getParticipantFromEntity(p) can instead be a method reference this::getParticipantFromEntity
| public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException { | ||
| System.out.println("Remove expired participants"); | ||
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| List<Participant> unmatchedParticipants = participantDatastore.getUnmatchedParticipants(); | ||
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| // Check if match exists and not returned yet | ||
| for (Participant participant : unmatchedParticipants) { | ||
| if (isExpired(participant)) { | ||
| participantDatastore.removeParticipant(participant.getUsername()); | ||
| return; | ||
| } | ||
| } | ||
| response.setStatus(HttpServletResponse.SC_OK); |
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Continuing from the other PR:
I think you may be able to delete a batch of entries at once, which would be helpful if we could query datastore for unmatched AND endTimeAvailable. Or else we'd have to loop through the list of unmatchedParticipants and create another list of the ones who are unmatched and expired. I couldn't find detailed documentation about that operation, though. And I was hesitant to try out querying by endTimeAvailable since I had so much trouble doing that last time--I wanted to see if the cron job works before optimizing the query.
I agree that the query is sufficient for now. But at this step, it would still make sense to delete all of the expired participants in one delete operation instead of one transaction per participant.
https://cloud.google.com/appengine/docs/standard/java/javadoc/com/google/appengine/api/datastore/DatastoreService.html#delete-java.lang.Iterable-
Files changed:
(Same as PR #84 except this one includes only the correct files)