Handle null returns from search cache methods

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/search/SearchCoordinatorSvcImpl.java

@@ -209,11 +209,7 @@ public class SearchCoordinatorSvcImpl implements ISearchCoordinatorSvc {
 
 			search = mySearchCacheSvc
 				.fetchByUuid(theUuid)
-				.orElseThrow(() -> {
+				.orElseThrow(() -> newResourceGoneException(theUuid));
-					ourLog.trace("Client requested unknown paging ID[{}]", theUuid);
-					String msg = myContext.getLocalizer().getMessage(PageMethodBinding.class, "unknownSearchId", theUuid);
-					return new ResourceGoneException(msg);
-				});
 
 			verifySearchHasntFailedOrThrowInternalErrorException(search);
 			if (search.getStatus() == SearchStatusEnum.FINISHED) {
@@ -252,12 +248,22 @@ public class SearchCoordinatorSvcImpl implements ISearchCoordinatorSvc {
 		ourLog.trace("Finished looping");
 
 		List<Long> pids = mySearchResultCacheSvc.fetchResultPids(search, theFrom, theTo);
+		if (pids == null) {
+			throw newResourceGoneException(theUuid);
+		}
 
 		ourLog.trace("Fetched {} results", pids.size());
 
 		return pids;
 	}
 
+	@Nonnull
+	private ResourceGoneException newResourceGoneException(String theUuid) {
+		ourLog.trace("Client requested unknown paging ID[{}]", theUuid);
+		String msg = myContext.getLocalizer().getMessage(PageMethodBinding.class, "unknownSearchId", theUuid);
+		return new ResourceGoneException(msg);
+	}
+
 
 	private void populateBundleProvider(PersistedJpaBundleProvider theRetVal) {
 		theRetVal.setContext(myContext);
@@ -1101,14 +1107,21 @@ public class SearchCoordinatorSvcImpl implements ISearchCoordinatorSvc {
 				txTemplate.afterPropertiesSet();
 				txTemplate.execute(t -> {
 					List<Long> previouslyAddedResourcePids = mySearchResultCacheSvc.fetchAllResultPids(getSearch());
+					if (previouslyAddedResourcePids == null) {
+						throw newResourceGoneException(getSearch().getUuid());
+					}
+
 					ourLog.debug("Have {} previously added IDs in search: {}", previouslyAddedResourcePids.size(), getSearch().getUuid());
 					setPreviouslyAddedResourcePids(previouslyAddedResourcePids);
 					return null;
 				});
 			} catch (Throwable e) {
 				ourLog.error("Failure processing search", e);
-				getSearch().setFailureMessage(e.toString());
+				getSearch().setFailureMessage(e.getMessage());
 				getSearch().setStatus(SearchStatusEnum.FAILED);
+				if (e instanceof BaseServerResponseException) {
+					getSearch().setFailureCode(((BaseServerResponseException) e).getStatusCode());
+				}
 
 				saveSearch();
 				return null;

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/search/cache/ISearchResultCacheSvc.java

@@ -22,6 +22,7 @@ package ca.uhn.fhir.jpa.search.cache;
 
 import ca.uhn.fhir.jpa.entity.Search;
 
+import javax.annotation.Nullable;
 import java.util.List;
 
 public interface ISearchResultCacheSvc {
@@ -38,14 +39,20 @@ public interface ISearchResultCacheSvc {
 	 * @param theSearch The search to fetch IDs for
 	 * @param theFrom   The starting index (inclusive)
 	 * @param theTo     The ending index (exclusive)
-	 * @return A list of resource PIDs
+	 * @return A list of resource PIDs, or <code>null</code> if the results no longer exist (this should only happen if the results
+	 * have been removed from the cache for some reason, such as expiry or manual purge)
 	 */
+	@Nullable
 	List<Long> fetchResultPids(Search theSearch, int theFrom, int theTo);
 
 	/**
 	 * Fetch all result PIDs for a given search with no particular order required
-	 * @param theSearch
+	 *
-	 * @return
+	 * @param theSearch The search object
+	 * @return A list of resource PIDs, or <code>null</code> if the results no longer exist (this should only happen if the results
+	 * have been removed from the cache for some reason, such as expiry or manual purge)
 	 */
+	@Nullable
 	List<Long> fetchAllResultPids(Search theSearch);
+
 }

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/search/SearchCoordinatorSvcImplTest.java

@@ -469,6 +469,62 @@ public class SearchCoordinatorSvcImplTest {
 		assertEquals("109", resources.get(99).getIdElement().getValueAsString());
 	}
 
+	/**
+	 * Simulate results being removed from the search result cache but not the search cache
+	 */
+	@Test
+	public void testFetchResultsReturnsNull() {
+
+		Search search = new Search();
+		search.setStatus(SearchStatusEnum.FINISHED);
+		search.setNumFound(100);
+		search.setTotalCount(100);
+		when(mySearchCacheSvc.fetchByUuid(eq("0000-1111"))).thenReturn(Optional.of(search));
+
+		when(mySearchResultCacheSvc.fetchResultPids(any(), anyInt(), anyInt())).thenReturn(null);
+
+		try {
+			mySvc.getResources("0000-1111", 0, 10, null);
+			fail();
+		}  catch (ResourceGoneException e) {
+			assertEquals("Search ID \"0000-1111\" does not exist and may have expired", e.getMessage());
+		}
+
+	}
+
+	/**
+	 * Simulate results being removed from the search result cache but not the search cache
+	 */
+	@Test
+	public void testFetchAllResultsReturnsNull() {
+
+		when(myDaoRegistry.getResourceDao(anyString())).thenReturn(myCallingDao);
+		when(myCallingDao.getContext()).thenReturn(ourCtx);
+
+		Search search = new Search();
+		search.setUuid("0000-1111");
+		search.setResourceType("Patient");
+		search.setStatus(SearchStatusEnum.PASSCMPLET);
+		search.setNumFound(5);
+		search.setSearchParameterMap(new SearchParameterMap());
+		when(mySearchCacheSvc.fetchByUuid(eq("0000-1111"))).thenReturn(Optional.of(search));
+
+		when(mySearchCacheSvc.tryToMarkSearchAsInProgress(any())).thenAnswer(t->{
+			search.setStatus(SearchStatusEnum.LOADING);
+			return Optional.of(search);
+		});
+
+		when(mySearchResultCacheSvc.fetchAllResultPids(any())).thenReturn(null);
+
+		try {
+			mySvc.getResources("0000-1111", 0, 10, null);
+			fail();
+		}  catch (ResourceGoneException e) {
+			assertEquals("Search ID \"0000-1111\" does not exist and may have expired", e.getMessage());
+		}
+
+	}
+
 	public static class FailAfterNIterator extends BaseIterator<Long> implements IResultIterator {
 
 		private int myCount;

hapi-fhir-jpaserver-model/src/main/java/ca/uhn/fhir/jpa/model/search/SearchStatusEnum.java

@@ -39,6 +39,10 @@ public enum SearchStatusEnum {
 	/**
 	 * The search failed and will not continue
 	 */
-	FAILED
+	FAILED,
+	/**
+	 * The search has been expired and will be expunged shortly
+	 */
+	GONE
 
 }