Additional changes to enable processing of lastn operations with large numbers of parameters.

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/BaseHapiFhirResourceDaoObservation.java

@@ -38,7 +38,7 @@ public abstract class BaseHapiFhirResourceDaoObservation<T extends IBaseResource
 		if (theSearchParameterMap.getSort() == null) {
 			SortSpec effectiveDtm = new SortSpec("date").setOrder(SortOrderEnum.DESC);
 			SortSpec observationCode = new SortSpec(IndexConstants.CODE_SEARCH_PARAM).setOrder(SortOrderEnum.ASC).setChain(effectiveDtm);
-			theSearchParameterMap.setSort(new SortSpec(IndexConstants.SUBJECT_SEARCH_PARAM).setChain(observationCode));
+			theSearchParameterMap.setSort(new SortSpec(IndexConstants.SUBJECT_SEARCH_PARAM).setOrder(SortOrderEnum.ASC).setChain(observationCode));
 		}
 	}
 

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/SearchBuilder.java

@@ -351,16 +351,19 @@ public class SearchBuilder implements ISearchBuilder {
 					}
 				}
 				Integer myMaxObservationsPerCode = null;
-				String[] maxCountParams = theRequest.getParameters().get("max");
+//				String[] maxCountParams = theRequest.getParameters().get("max");
-				if (maxCountParams != null && maxCountParams.length > 0) {
+//				if (maxCountParams != null && maxCountParams.length > 0) {
-					myMaxObservationsPerCode = Integer.valueOf(maxCountParams[0]);
+//					myMaxObservationsPerCode = Integer.valueOf(maxCountParams[0]);
+				if(myParams.getLastNMax() != null) {
+					myMaxObservationsPerCode = myParams.getLastNMax();
 				} else {
 					throw new InvalidRequestException("Max parameter is required for $lastn operation");
 				}
 				List<String> lastnResourceIds = myIElasticsearchSvc.executeLastN(myParams, myMaxObservationsPerCode);
-				for (String lastnResourceId : lastnResourceIds) {
+//				for (String lastnResourceId : lastnResourceIds) {
-					pids.add(myIdHelperService.resolveResourcePersistentIds(myRequestPartitionId, myResourceName, lastnResourceId));
+//					pids.add(myIdHelperService.resolveResourcePersistentIds(myRequestPartitionId, myResourceName, lastnResourceId));
-				}
+//				}
+				pids = normalizeIdListForLastNInClause(lastnResourceIds);
 			}
 			if (pids.isEmpty()) {
 				// Will never match
@@ -411,6 +414,50 @@ public class SearchBuilder implements ISearchBuilder {
 		return query;
 	}
 
+	private List<ResourcePersistentId> normalizeIdListForLastNInClause(List<String> lastnResourceIds) {
+		List<ResourcePersistentId> retVal = new ArrayList<>();
+		for (String lastnResourceId : lastnResourceIds) {
+			retVal.add(new ResourcePersistentId(Long.parseLong(lastnResourceId)));
+		}
+
+		/*
+			The following is a workaround to a known issue involving Hibernate. If queries are used with "in" clauses with large and varying
+			numbers of parameters, this can overwhelm Hibernate's QueryPlanCache and deplete heap space. See the following link for more info:
+			https://stackoverflow.com/questions/31557076/spring-hibernate-query-plan-cache-memory-usage.
+
+			Normalizing the number of parameters in the "in" clause stabilizes the size of the QueryPlanCache, so long as the number of
+			arguments never exceeds the maximum specified below.
+		 */
+		int listSize = retVal.size();
+		if(listSize > 1 && listSize < 10) {
+			padIdListWithPlaceholders(retVal, 10);
+		} else if (listSize > 10 && listSize < 100) {
+			padIdListWithPlaceholders(retVal, 100);
+		} else if (listSize > 100 && listSize < 200) {
+			padIdListWithPlaceholders(retVal, 200);
+		} else if (listSize > 200 && listSize < 500) {
+			padIdListWithPlaceholders(retVal, 500);
+		} else if (listSize > 500 && listSize < 1000) {
+			padIdListWithPlaceholders(retVal, 1000);
+		} else if (listSize > 1000 && listSize < 500) {
+			padIdListWithPlaceholders(retVal, 5000);
+		} else if (listSize > 5000 && listSize < 10000) {
+			padIdListWithPlaceholders(retVal, 10000);
+		} else if (listSize > 10000 && listSize < 20000) {
+			padIdListWithPlaceholders(retVal, 20000);
+		}  else if (listSize > 20000 && listSize < 30000) {
+			padIdListWithPlaceholders(retVal, 30000);
+		}
+
+		return retVal;
+	}
+
+	private void padIdListWithPlaceholders(List<ResourcePersistentId> theIdList, int preferredListSize) {
+		while(theIdList.size() < preferredListSize) {
+			theIdList.add(new ResourcePersistentId(-1L));
+		}
+	}
+
 	/**
 	 * @return Returns {@literal true} if any search parameter sorts were found, or false if
 	 * no sorts were found, or only non-search parameters ones (e.g. _id, _lastUpdated)
@@ -1190,7 +1237,7 @@ public class SearchBuilder implements ISearchBuilder {
 
 			mySearchRuntimeDetails.setQueryStopwatch(new StopWatch());
 
-			Query<Long> hibernateQuery = (Query<Long>) query;
+				Query<Long> hibernateQuery = (Query<Long>) query;
 			hibernateQuery.setFetchSize(myFetchSize);
 			ScrollableResults scroll = hibernateQuery.scroll(ScrollMode.FORWARD_ONLY);
 			myResultsIterator = new ScrollableResultsIterator<>(scroll);

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/dstu3/FhirResourceDaoObservationDstu3.java

@@ -29,6 +29,8 @@ import ca.uhn.fhir.rest.api.CacheControlDirective;
 import ca.uhn.fhir.rest.api.Constants;
 import ca.uhn.fhir.rest.api.server.IBundleProvider;
 import ca.uhn.fhir.rest.api.server.RequestDetails;
+import ca.uhn.fhir.rest.param.ReferenceAndListParam;
+import ca.uhn.fhir.rest.param.TokenAndListParam;
 import org.hl7.fhir.instance.model.api.IBaseResource;
 import org.hl7.fhir.dstu3.model.Observation;
 import org.springframework.beans.factory.annotation.Autowired;

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/r5/FhirResourceDaoObservationR5.java

@@ -29,6 +29,8 @@ import ca.uhn.fhir.rest.api.CacheControlDirective;
 import ca.uhn.fhir.rest.api.Constants;
 import ca.uhn.fhir.rest.api.server.IBundleProvider;
 import ca.uhn.fhir.rest.api.server.RequestDetails;
+import ca.uhn.fhir.rest.param.ReferenceAndListParam;
+import ca.uhn.fhir.rest.param.TokenAndListParam;
 import org.hl7.fhir.instance.model.api.IBaseResource;
 import org.hl7.fhir.r5.model.Observation;
 import org.springframework.beans.factory.annotation.Autowired;

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/provider/dstu3/BaseJpaResourceProviderObservationDstu3.java

@@ -3,19 +3,17 @@ package ca.uhn.fhir.jpa.provider.dstu3;
 import ca.uhn.fhir.jpa.api.dao.IFhirResourceDaoObservation;
 import ca.uhn.fhir.jpa.model.util.JpaConstants;
 import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
-import ca.uhn.fhir.model.api.Include;
 import ca.uhn.fhir.model.api.annotation.Description;
 import ca.uhn.fhir.model.valueset.BundleTypeEnum;
 import ca.uhn.fhir.rest.annotation.*;
-import ca.uhn.fhir.rest.api.SearchTotalModeEnum;
+import ca.uhn.fhir.rest.api.Constants;
 import ca.uhn.fhir.rest.api.SortOrderEnum;
 import ca.uhn.fhir.rest.api.SortSpec;
-import ca.uhn.fhir.rest.api.SummaryEnum;
 import ca.uhn.fhir.rest.api.server.IBundleProvider;
 import ca.uhn.fhir.rest.param.*;
 import org.hl7.fhir.dstu3.model.Observation;
-
+import org.hl7.fhir.dstu3.model.UnsignedIntType;
-import java.util.Set;
+import org.hl7.fhir.instance.model.api.IPrimitiveType;
 
 /*
  * #%L
@@ -50,17 +48,9 @@ public class BaseJpaResourceProviderObservationDstu3 extends JpaResourceProvider
 
 		ca.uhn.fhir.rest.api.server.RequestDetails theRequestDetails,
 
-		@Description(shortDefinition="Search the contents of the resource's data using a filter")
+		@Description(formalDefinition = "Results from this method are returned across multiple pages. This parameter controls the size of those pages.")
-		@OperationParam(name=ca.uhn.fhir.rest.api.Constants.PARAM_FILTER)
+		@OperationParam(name = Constants.PARAM_COUNT)
-			StringAndListParam theFtFilter,
+			UnsignedIntType theCount,
-
-		@Description(shortDefinition="Search the contents of the resource's data using a fulltext search")
-		@OperationParam(name=ca.uhn.fhir.rest.api.Constants.PARAM_CONTENT)
-			StringAndListParam theFtContent,
-
-		@Description(shortDefinition="Search the contents of the resource's narrative using a fulltext search")
-		@OperationParam(name=ca.uhn.fhir.rest.api.Constants.PARAM_TEXT)
-			StringAndListParam theFtText,
 
 		@Description(shortDefinition="The classification of the type of observation")
 		@OperationParam(name="category")
@@ -70,10 +60,6 @@ public class BaseJpaResourceProviderObservationDstu3 extends JpaResourceProvider
 		@OperationParam(name="code")
 			TokenAndListParam theCode,
 
-		@Description(shortDefinition="Obtained date/time. If the obtained element is a period, a date that falls in the period")
-		@OperationParam(name="date")
-			DateRangeParam theDate,
-
 		@Description(shortDefinition="The subject that the observation is about (if patient)")
 		@OperationParam(name="patient")
 			ReferenceAndListParam thePatient,
@@ -82,69 +68,31 @@ public class BaseJpaResourceProviderObservationDstu3 extends JpaResourceProvider
 		@OperationParam(name="subject" )
 			ReferenceAndListParam theSubject,
 
-		@IncludeParam(reverse=true)
+		@Description(shortDefinition="The maximum number of observations to return for each observation code")
-			Set<Include> theRevIncludes,
+		@OperationParam(name = "max", typeName = "integer", min = 0, max = 1)
-		@Description(shortDefinition="Only return resources which were last updated as specified by the given range")
+			IPrimitiveType<Integer> theMax,
-		@OperationParam(name="_lastUpdated")
-			DateRangeParam theLastUpdated,
-
-		@IncludeParam(allow= {
-			"Observation:based-on",
-			"Observation:derived-from",
-			"Observation:device",
-			"Observation:encounter",
-			"Observation:focus",
-			"Observation:has-member",
-			"Observation:part-of",
-			"Observation:patient",
-			"Observation:performer",
-			"Observation:specimen",
-			"Observation:subject",
-			"*"
-		})
-			Set<Include> theIncludes,
 
 		@Sort
-			SortSpec theSort,
+			SortSpec theSort
-
-		@ca.uhn.fhir.rest.annotation.Count
-			Integer theCount,
-
-		SummaryEnum theSummaryMode,
-
-		SearchTotalModeEnum theSearchTotalMode
 
 	) {
 		startRequest(theServletRequest);
 		try {
 			SearchParameterMap paramMap = new SearchParameterMap();
-			paramMap.add(ca.uhn.fhir.rest.api.Constants.PARAM_FILTER, theFtFilter);
+			paramMap.add(Observation.SP_CATEGORY, theCategory);
-			paramMap.add(ca.uhn.fhir.rest.api.Constants.PARAM_CONTENT, theFtContent);
+			paramMap.add(Observation.SP_CODE, theCode);
-			paramMap.add(ca.uhn.fhir.rest.api.Constants.PARAM_TEXT, theFtText);
+			paramMap.add(Observation.SP_PATIENT, thePatient);
-			paramMap.add("category", theCategory);
+			paramMap.add(Observation.SP_SUBJECT, theSubject);
-			paramMap.add("code", theCode);
+			paramMap.setLastNMax(theMax.getValue());
-			paramMap.add("date", theDate);
+			if (theCount != null) {
-			paramMap.add("patient", thePatient);
+				paramMap.setCount(theCount.getValue());
-			paramMap.add("subject", theSubject);
-			paramMap.setRevIncludes(theRevIncludes);
-			paramMap.setLastUpdated(theLastUpdated);
-			paramMap.setIncludes(theIncludes);
-			paramMap.setLastN(true);
-			if (theSort == null) {
-				SortSpec effectiveDtm = new SortSpec("date").setOrder(SortOrderEnum.DESC);
-				SortSpec observationCode = new SortSpec("code").setOrder(SortOrderEnum.ASC).setChain(effectiveDtm);
-				if (thePatient != null && theSubject == null) {
-					theSort = new SortSpec("patient").setChain(observationCode);
-				} else {
-					theSort = new SortSpec("subject").setChain(observationCode);
-				}
 			}
-			paramMap.setSort(theSort);
-			paramMap.setCount(theCount);
-			paramMap.setSummaryMode(theSummaryMode);
-			paramMap.setSearchTotalMode(theSearchTotalMode);
 
-			return ((IFhirResourceDaoObservation<org.hl7.fhir.dstu3.model.Observation>) getDao()).observationsLastN(paramMap, theRequestDetails, theServletResponse);
+			if (theSort != null) {
+				paramMap.setSort(theSort);
+			}
+
+			return ((IFhirResourceDaoObservation<Observation>) getDao()).observationsLastN(paramMap, theRequestDetails, theServletResponse);
 		} finally {
 			endRequest(theServletRequest);
 		}

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/provider/r4/BaseJpaResourceProviderObservationR4.java

@@ -3,20 +3,17 @@ package ca.uhn.fhir.jpa.provider.r4;
 import ca.uhn.fhir.jpa.api.dao.IFhirResourceDaoObservation;
 import ca.uhn.fhir.jpa.model.util.JpaConstants;
 import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
-import ca.uhn.fhir.model.api.Include;
 import ca.uhn.fhir.model.api.annotation.Description;
 import ca.uhn.fhir.model.valueset.BundleTypeEnum;
 import ca.uhn.fhir.rest.annotation.*;
-import ca.uhn.fhir.rest.api.SearchTotalModeEnum;
+import ca.uhn.fhir.rest.api.Constants;
 import ca.uhn.fhir.rest.api.SortOrderEnum;
 import ca.uhn.fhir.rest.api.SortSpec;
-import ca.uhn.fhir.rest.api.SummaryEnum;
 import ca.uhn.fhir.rest.api.server.IBundleProvider;
 import ca.uhn.fhir.rest.param.*;
+import org.hl7.fhir.instance.model.api.IPrimitiveType;
 import org.hl7.fhir.r4.model.*;
 
-import java.util.Set;
-
 /*
  * #%L
  * HAPI FHIR JPA Server
@@ -50,17 +47,9 @@ public class BaseJpaResourceProviderObservationR4 extends JpaResourceProviderR4<
 
 		ca.uhn.fhir.rest.api.server.RequestDetails theRequestDetails,
 
-		@Description(shortDefinition="Search the contents of the resource's data using a filter")
+		@Description(formalDefinition = "Results from this method are returned across multiple pages. This parameter controls the size of those pages.")
-		@OperationParam(name=ca.uhn.fhir.rest.api.Constants.PARAM_FILTER)
+		@OperationParam(name = Constants.PARAM_COUNT)
-			StringAndListParam theFtFilter,
+			UnsignedIntType theCount,
-
-		@Description(shortDefinition="Search the contents of the resource's data using a fulltext search")
-		@OperationParam(name=ca.uhn.fhir.rest.api.Constants.PARAM_CONTENT)
-			StringAndListParam theFtContent,
-
-		@Description(shortDefinition="Search the contents of the resource's narrative using a fulltext search")
-		@OperationParam(name=ca.uhn.fhir.rest.api.Constants.PARAM_TEXT)
-			StringAndListParam theFtText,
 
 		@Description(shortDefinition="The classification of the type of observation")
 		@OperationParam(name="category")
@@ -70,10 +59,6 @@ public class BaseJpaResourceProviderObservationR4 extends JpaResourceProviderR4<
 		@OperationParam(name="code")
 			TokenAndListParam theCode,
 
-		@Description(shortDefinition="Obtained date/time. If the obtained element is a period, a date that falls in the period")
-		@OperationParam(name="date")
-			DateRangeParam theDate,
-
 		@Description(shortDefinition="The subject that the observation is about (if patient)")
 		@OperationParam(name="patient")
 			ReferenceAndListParam thePatient,
@@ -82,67 +67,29 @@ public class BaseJpaResourceProviderObservationR4 extends JpaResourceProviderR4<
 		@OperationParam(name="subject" )
 			ReferenceAndListParam theSubject,
 
-		@IncludeParam(reverse=true)
+		@Description(shortDefinition="The maximum number of observations to return for each observation code")
-			Set<Include> theRevIncludes,
+		@OperationParam(name = "max", typeName = "integer", min = 0, max = 1)
-		@Description(shortDefinition="Only return resources which were last updated as specified by the given range")
+			IPrimitiveType<Integer> theMax,
-		@OperationParam(name="_lastUpdated")
-			DateRangeParam theLastUpdated,
-
-		@IncludeParam(allow= {
-			"Observation:based-on",
-			"Observation:derived-from",
-			"Observation:device",
-			"Observation:encounter",
-			"Observation:focus",
-			"Observation:has-member",
-			"Observation:part-of",
-			"Observation:patient",
-			"Observation:performer",
-			"Observation:specimen",
-			"Observation:subject",
-			"*"
-		})
-			Set<Include> theIncludes,
 
 		@Sort
-			SortSpec theSort,
+			SortSpec theSort
-
-		@ca.uhn.fhir.rest.annotation.Count
-			Integer theCount,
-
-		SummaryEnum theSummaryMode,
-
-		SearchTotalModeEnum theSearchTotalMode
 
 		) {
 		startRequest(theServletRequest);
 		try {
 			SearchParameterMap paramMap = new SearchParameterMap();
-			paramMap.add(ca.uhn.fhir.rest.api.Constants.PARAM_FILTER, theFtFilter);
-			paramMap.add(ca.uhn.fhir.rest.api.Constants.PARAM_CONTENT, theFtContent);
-			paramMap.add(ca.uhn.fhir.rest.api.Constants.PARAM_TEXT, theFtText);
 			paramMap.add("category", theCategory);
 			paramMap.add("code", theCode);
-			paramMap.add("date", theDate);
 			paramMap.add("patient", thePatient);
 			paramMap.add("subject", theSubject);
-			paramMap.setRevIncludes(theRevIncludes);
+			paramMap.setLastNMax(theMax.getValue());
-			paramMap.setLastUpdated(theLastUpdated);
+			if (theCount != null) {
-			paramMap.setIncludes(theIncludes);
+				paramMap.setCount(theCount.getValue());
-/*			paramMap.setLastN(true);
+			}
-			if (theSort == null) {
+
-				SortSpec effectiveDtm = new SortSpec("date").setOrder(SortOrderEnum.DESC);
+			if (theSort != null) {
-				SortSpec observationCode = new SortSpec("code").setOrder(SortOrderEnum.ASC).setChain(effectiveDtm);
+				paramMap.setSort(theSort);
-				if (thePatient != null && theSubject == null) {
+			}
-					theSort = new SortSpec("patient").setChain(observationCode);
-				} else {
-					theSort = new SortSpec("subject").setChain(observationCode);
-				}
-			} */
-			paramMap.setSort(theSort);
-			paramMap.setCount(theCount);
-			paramMap.setSummaryMode(theSummaryMode);
-			paramMap.setSearchTotalMode(theSearchTotalMode);
 
 			return ((IFhirResourceDaoObservation<Observation>) getDao()).observationsLastN(paramMap, theRequestDetails, theServletResponse);
 		} finally {

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/provider/r5/BaseJpaResourceProviderObservationR5.java

@@ -3,20 +3,18 @@ package ca.uhn.fhir.jpa.provider.r5;
 import ca.uhn.fhir.jpa.api.dao.IFhirResourceDaoObservation;
 import ca.uhn.fhir.jpa.model.util.JpaConstants;
 import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
-import ca.uhn.fhir.model.api.Include;
 import ca.uhn.fhir.model.api.annotation.Description;
 import ca.uhn.fhir.model.valueset.BundleTypeEnum;
 import ca.uhn.fhir.rest.annotation.*;
-import ca.uhn.fhir.rest.api.SearchTotalModeEnum;
+import ca.uhn.fhir.rest.api.Constants;
 import ca.uhn.fhir.rest.api.SortOrderEnum;
 import ca.uhn.fhir.rest.api.SortSpec;
-import ca.uhn.fhir.rest.api.SummaryEnum;
 import ca.uhn.fhir.rest.api.server.IBundleProvider;
 import ca.uhn.fhir.rest.param.*;
+import org.hl7.fhir.instance.model.api.IPrimitiveType;
+import org.hl7.fhir.r5.model.UnsignedIntType;
 import org.hl7.fhir.r5.model.Observation;
 
-import java.util.Set;
-
 /*
  * #%L
  * HAPI FHIR JPA Server
@@ -50,17 +48,9 @@ public class BaseJpaResourceProviderObservationR5 extends JpaResourceProviderR5<
 
 		ca.uhn.fhir.rest.api.server.RequestDetails theRequestDetails,
 
-		@Description(shortDefinition="Search the contents of the resource's data using a filter")
+		@Description(formalDefinition = "Results from this method are returned across multiple pages. This parameter controls the size of those pages.")
-		@OperationParam(name=ca.uhn.fhir.rest.api.Constants.PARAM_FILTER)
+		@OperationParam(name = Constants.PARAM_COUNT)
-			StringAndListParam theFtFilter,
+			UnsignedIntType theCount,
-
-		@Description(shortDefinition="Search the contents of the resource's data using a fulltext search")
-		@OperationParam(name=ca.uhn.fhir.rest.api.Constants.PARAM_CONTENT)
-			StringAndListParam theFtContent,
-
-		@Description(shortDefinition="Search the contents of the resource's narrative using a fulltext search")
-		@OperationParam(name=ca.uhn.fhir.rest.api.Constants.PARAM_TEXT)
-			StringAndListParam theFtText,
 
 		@Description(shortDefinition="The classification of the type of observation")
 		@OperationParam(name="category")
@@ -70,10 +60,6 @@ public class BaseJpaResourceProviderObservationR5 extends JpaResourceProviderR5<
 		@OperationParam(name="code")
 			TokenAndListParam theCode,
 
-		@Description(shortDefinition="Obtained date/time. If the obtained element is a period, a date that falls in the period")
-		@OperationParam(name="date")
-			DateRangeParam theDate,
-
 		@Description(shortDefinition="The subject that the observation is about (if patient)")
 		@OperationParam(name="patient")
 			ReferenceAndListParam thePatient,
@@ -82,69 +68,31 @@ public class BaseJpaResourceProviderObservationR5 extends JpaResourceProviderR5<
 		@OperationParam(name="subject" )
 			ReferenceAndListParam theSubject,
 
-		@IncludeParam(reverse=true)
+		@Description(shortDefinition="The maximum number of observations to return for each observation code")
-			Set<Include> theRevIncludes,
+		@OperationParam(name = "max", typeName = "integer", min = 0, max = 1)
-		@Description(shortDefinition="Only return resources which were last updated as specified by the given range")
+			IPrimitiveType<Integer> theMax,
-		@OperationParam(name="_lastUpdated")
-			DateRangeParam theLastUpdated,
-
-		@IncludeParam(allow= {
-			"Observation:based-on",
-			"Observation:derived-from",
-			"Observation:device",
-			"Observation:encounter",
-			"Observation:focus",
-			"Observation:has-member",
-			"Observation:part-of",
-			"Observation:patient",
-			"Observation:performer",
-			"Observation:specimen",
-			"Observation:subject",
-			"*"
-		})
-			Set<Include> theIncludes,
 
 		@Sort
-			SortSpec theSort,
+			SortSpec theSort
-
-		@ca.uhn.fhir.rest.annotation.Count
-			Integer theCount,
-
-		SummaryEnum theSummaryMode,
-
-		SearchTotalModeEnum theSearchTotalMode
 
 	) {
 		startRequest(theServletRequest);
 		try {
 			SearchParameterMap paramMap = new SearchParameterMap();
-			paramMap.add(ca.uhn.fhir.rest.api.Constants.PARAM_FILTER, theFtFilter);
-			paramMap.add(ca.uhn.fhir.rest.api.Constants.PARAM_CONTENT, theFtContent);
-			paramMap.add(ca.uhn.fhir.rest.api.Constants.PARAM_TEXT, theFtText);
 			paramMap.add("category", theCategory);
 			paramMap.add("code", theCode);
-			paramMap.add("date", theDate);
 			paramMap.add("patient", thePatient);
 			paramMap.add("subject", theSubject);
-			paramMap.setRevIncludes(theRevIncludes);
+			paramMap.setLastNMax(theMax.getValue());
-			paramMap.setLastUpdated(theLastUpdated);
+			if (theCount != null) {
-			paramMap.setIncludes(theIncludes);
+				paramMap.setCount(theCount.getValue());
-			paramMap.setLastN(true);
-			if (theSort == null) {
-				SortSpec effectiveDtm = new SortSpec("date").setOrder(SortOrderEnum.DESC);
-				SortSpec observationCode = new SortSpec("code").setOrder(SortOrderEnum.ASC).setChain(effectiveDtm);
-				if (thePatient != null && theSubject == null) {
-					theSort = new SortSpec("patient").setChain(observationCode);
-				} else {
-					theSort = new SortSpec("subject").setChain(observationCode);
-				}
 			}
-			paramMap.setSort(theSort);
-			paramMap.setCount(theCount);
-			paramMap.setSummaryMode(theSummaryMode);
-			paramMap.setSearchTotalMode(theSearchTotalMode);
 
-			return ((IFhirResourceDaoObservation<org.hl7.fhir.r5.model.Observation>) getDao()).observationsLastN(paramMap, theRequestDetails, theServletResponse);
+			if (theSort != null) {
+				paramMap.setSort(theSort);
+			}
+
+			return ((IFhirResourceDaoObservation<Observation>) getDao()).observationsLastN(paramMap, theRequestDetails, theServletResponse);
 		} finally {
 			endRequest(theServletRequest);
 		}

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

@@ -2,6 +2,7 @@ package ca.uhn.fhir.jpa.search.lastn;
 
 import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
 import ca.uhn.fhir.model.api.IQueryParameterType;
+import ca.uhn.fhir.model.dstu2.resource.Observation;
 import ca.uhn.fhir.rest.param.ReferenceParam;
 import ca.uhn.fhir.rest.param.TokenParam;
 import ca.uhn.fhir.jpa.search.lastn.json.CodeJson;
@@ -42,6 +43,7 @@ import org.shadehapi.elasticsearch.search.sort.SortOrder;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.function.Function;
 
 import static org.apache.commons.lang3.StringUtils.isBlank;
 
@@ -200,21 +202,64 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 	@Override
 	public List<String> executeLastN(SearchParameterMap theSearchParameterMap, Integer theMaxObservationsPerCode) {
 		String[] topHitsInclude = {OBSERVATION_IDENTIFIER_FIELD_NAME};
-		SearchRequest myLastNRequest = buildObservationsSearchRequest(theSearchParameterMap, createCompositeAggregationBuilder(theMaxObservationsPerCode, topHitsInclude));
 		try {
-			SearchResponse lastnResponse = executeSearchRequest(myLastNRequest);
+			List<SearchResponse> responses = buildAndExecuteSearch(theSearchParameterMap, theMaxObservationsPerCode, topHitsInclude);
-			return buildObservationIdList(lastnResponse);
+			List<String> observationIds = new ArrayList<>();
+			for (SearchResponse response : responses) {
+//				observationIds.addAll(buildObservationIdList(response));
+				observationIds.addAll(buildObservationList(response, t -> t.getIdentifier(), theSearchParameterMap));
+			}
+			return observationIds;
 		} catch (IOException theE) {
 			throw new InvalidRequestException("Unable to execute LastN request", theE);
 		}
 	}
 
+	private List<SearchResponse> buildAndExecuteSearch(SearchParameterMap theSearchParameterMap, Integer theMaxObservationsPerCode, String[] topHitsInclude) {
+		List<SearchResponse> responses = new ArrayList<>();
+		if (theSearchParameterMap.containsKey(IndexConstants.PATIENT_SEARCH_PARAM) || theSearchParameterMap.containsKey(IndexConstants.SUBJECT_SEARCH_PARAM)) {
+			ArrayList<String> subjectReferenceCriteria = new ArrayList<>();
+			List<List<IQueryParameterType>> patientParams = new ArrayList<>();
+			if (theSearchParameterMap.get(IndexConstants.PATIENT_SEARCH_PARAM) != null) {
+				patientParams.addAll(theSearchParameterMap.get(IndexConstants.PATIENT_SEARCH_PARAM));
+			}
+			if (theSearchParameterMap.get(IndexConstants.SUBJECT_SEARCH_PARAM) != null) {
+				patientParams.addAll(theSearchParameterMap.get(IndexConstants.SUBJECT_SEARCH_PARAM));
+			}
+			for (List<? extends IQueryParameterType> nextSubjectList : patientParams) {
+				subjectReferenceCriteria.addAll(getReferenceValues(nextSubjectList));
+			}
+			for (String subject : subjectReferenceCriteria) {
+				SearchRequest myLastNRequest = buildObservationsSearchRequest(subject, theSearchParameterMap, createCompositeAggregationBuilder(theMaxObservationsPerCode, topHitsInclude));
+				try {
+					SearchResponse lastnResponse = executeSearchRequest(myLastNRequest);
+					responses.add(lastnResponse);
+				} catch (IOException theE) {
+					throw new InvalidRequestException("Unable to execute LastN request", theE);
+				}
+			}
+		} else {
+			SearchRequest myLastNRequest = buildObservationsSearchRequest(theSearchParameterMap, createObservationCodeAggregationBuilder(theMaxObservationsPerCode, topHitsInclude));
+			try {
+				SearchResponse lastnResponse = executeSearchRequest(myLastNRequest);
+				responses.add(lastnResponse);
+			} catch (IOException theE) {
+				throw new InvalidRequestException("Unable to execute LastN request", theE);
+			}
+
+		}
+		return responses;
+	}
+
 	@VisibleForTesting
 	List<ObservationJson> executeLastNWithAllFields(SearchParameterMap theSearchParameterMap, Integer theMaxObservationsPerCode) {
-		SearchRequest myLastNRequest = buildObservationsSearchRequest(theSearchParameterMap, createCompositeAggregationBuilder(theMaxObservationsPerCode, null));
 		try {
-			SearchResponse lastnResponse = executeSearchRequest(myLastNRequest);
+			List<SearchResponse> responses = buildAndExecuteSearch(theSearchParameterMap, theMaxObservationsPerCode, null);
-			return buildObservationDocumentList(lastnResponse);
+			List<ObservationJson> observationDocuments = new ArrayList<>();
+			for (SearchResponse response : responses) {
+				observationDocuments.addAll(buildObservationList(response, t -> t, theSearchParameterMap));
+			}
+			return observationDocuments;
 		} catch (IOException theE) {
 			throw new InvalidRequestException("Unable to execute LastN request", theE);
 		}
@@ -227,8 +272,7 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 		return buildCodeResult(codeSearchResponse);
 	}
 
-	@VisibleForTesting
+	private SearchRequest buildObservationCodesSearchRequest(int theMaxResultSetSize) {
-	SearchRequest buildObservationCodesSearchRequest(int theMaxResultSetSize) {
 		SearchRequest searchRequest = new SearchRequest(IndexConstants.CODE_INDEX);
 		SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
 		// Query
@@ -239,27 +283,30 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 	}
 
 	private CompositeAggregationBuilder createCompositeAggregationBuilder(int theMaxNumberObservationsPerCode, String[] theTopHitsInclude) {
+		CompositeValuesSourceBuilder<?> subjectValuesBuilder = new TermsValuesSourceBuilder("subject").field("subject");
+		List<CompositeValuesSourceBuilder<?>> compositeAggSubjectSources = new ArrayList();
+		compositeAggSubjectSources.add(subjectValuesBuilder);
+		CompositeAggregationBuilder compositeAggregationSubjectBuilder = new CompositeAggregationBuilder(GROUP_BY_SUBJECT, compositeAggSubjectSources);
+		compositeAggregationSubjectBuilder.subAggregation(createObservationCodeAggregationBuilder(theMaxNumberObservationsPerCode, theTopHitsInclude));
+		compositeAggregationSubjectBuilder.size(10000);
+
+		return compositeAggregationSubjectBuilder;
+	}
+
+	private TermsAggregationBuilder createObservationCodeAggregationBuilder(int theMaxNumberObservationsPerCode, String[] theTopHitsInclude) {
 		TermsAggregationBuilder observationCodeAggregationBuilder = new TermsAggregationBuilder(GROUP_BY_CODE, ValueType.STRING).field("codeconceptid");
 		// Top Hits Aggregation
 		observationCodeAggregationBuilder.subAggregation(AggregationBuilders.topHits("most_recent_effective")
 			.sort("effectivedtm", SortOrder.DESC)
 			.fetchSource(theTopHitsInclude, null).size(theMaxNumberObservationsPerCode));
 		observationCodeAggregationBuilder.size(10000);
-		CompositeValuesSourceBuilder<?> subjectValuesBuilder = new TermsValuesSourceBuilder("subject").field("subject");
+		return observationCodeAggregationBuilder;
-		List<CompositeValuesSourceBuilder<?>> compositeAggSubjectSources = new ArrayList();
-		compositeAggSubjectSources.add(subjectValuesBuilder);
-		CompositeAggregationBuilder compositeAggregationSubjectBuilder = new CompositeAggregationBuilder(GROUP_BY_SUBJECT, compositeAggSubjectSources);
-		compositeAggregationSubjectBuilder.subAggregation(observationCodeAggregationBuilder);
-		compositeAggregationSubjectBuilder.size(10000);
-
-		return compositeAggregationSubjectBuilder;
 	}
 
-	private SearchResponse executeSearchRequest(SearchRequest searchRequest) throws IOException {
+	public SearchResponse executeSearchRequest(SearchRequest searchRequest) throws IOException {
 		return myRestHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
 	}
 
-
 	private List<String> buildObservationIdList(SearchResponse theSearchResponse) throws IOException {
 		List<String> theObservationList = new ArrayList<>();
 		for (ParsedComposite.ParsedBucket subjectBucket : getSubjectBuckets(theSearchResponse)) {
@@ -288,12 +335,43 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 		return theObservationList;
 	}
 
+	private <T> List<T> buildObservationList(SearchResponse theSearchResponse, Function<ObservationJson,T> setValue, SearchParameterMap theSearchParameterMap) throws IOException {
+		List<T> theObservationList = new ArrayList<>();
+		if (theSearchParameterMap.containsKey(IndexConstants.PATIENT_SEARCH_PARAM) || theSearchParameterMap.containsKey(IndexConstants.SUBJECT_SEARCH_PARAM)) {
+			for (ParsedComposite.ParsedBucket subjectBucket : getSubjectBuckets(theSearchResponse)) {
+				for (Terms.Bucket observationCodeBucket : getObservationCodeBuckets(subjectBucket)) {
+					for (SearchHit lastNMatch : getLastNMatches(observationCodeBucket)) {
+						String indexedObservation = lastNMatch.getSourceAsString();
+						ObservationJson observationJson = objectMapper.readValue(indexedObservation, ObservationJson.class);
+						theObservationList.add(setValue.apply(observationJson));
+					}
+				}
+			}
+		} else {
+			for (Terms.Bucket observationCodeBucket : getObservationCodeBuckets(theSearchResponse)) {
+				for (SearchHit lastNMatch : getLastNMatches(observationCodeBucket)) {
+					String indexedObservation = lastNMatch.getSourceAsString();
+					ObservationJson observationJson = objectMapper.readValue(indexedObservation, ObservationJson.class);
+					theObservationList.add(setValue.apply(observationJson));
+				}
+			}
+		}
+
+		return theObservationList;
+	}
+
 	private List<ParsedComposite.ParsedBucket> getSubjectBuckets(SearchResponse theSearchResponse) {
 		Aggregations responseAggregations = theSearchResponse.getAggregations();
 		ParsedComposite aggregatedSubjects = responseAggregations.get(GROUP_BY_SUBJECT);
 		return aggregatedSubjects.getBuckets();
 	}
 
+	private List<? extends Terms.Bucket> getObservationCodeBuckets(SearchResponse theSearchResponse) {
+		Aggregations responseAggregations = theSearchResponse.getAggregations();
+		ParsedTerms aggregatedObservationCodes = responseAggregations.get(GROUP_BY_CODE);
+		return aggregatedObservationCodes.getBuckets();
+	}
+
 	private List<? extends Terms.Bucket> getObservationCodeBuckets(ParsedComposite.ParsedBucket theSubjectBucket) {
 		Aggregations observationCodeAggregations = theSubjectBucket.getAggregations();
 		ParsedTerms aggregatedObservationCodes = observationCodeAggregations.get(GROUP_BY_CODE);
@@ -338,6 +416,24 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 		return searchRequest;
 	}
 
+	private SearchRequest buildObservationsSearchRequest(String theSubjectParam, SearchParameterMap theSearchParameterMap, AggregationBuilder theAggregationBuilder) {
+		SearchRequest searchRequest = new SearchRequest(IndexConstants.OBSERVATION_INDEX);
+		SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
+		// Query
+		BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
+		boolQueryBuilder.must(QueryBuilders.termQuery("subject", theSubjectParam));
+		addCategoriesCriteria(boolQueryBuilder, theSearchParameterMap);
+		addObservationCodeCriteria(boolQueryBuilder, theSearchParameterMap);
+		searchSourceBuilder.query(boolQueryBuilder);
+		searchSourceBuilder.size(0);
+
+		// Aggregation by order codes
+		searchSourceBuilder.aggregation(theAggregationBuilder);
+		searchRequest.source(searchSourceBuilder);
+
+		return searchRequest;
+	}
+
 	private Boolean searchParamsHaveLastNCriteria(SearchParameterMap theSearchParameterMap) {
 		return theSearchParameterMap != null &&
 			(theSearchParameterMap.containsKey(IndexConstants.PATIENT_SEARCH_PARAM) || theSearchParameterMap.containsKey(IndexConstants.SUBJECT_SEARCH_PARAM) ||
@@ -519,11 +615,12 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 		myRestHighLevelClient.deleteByQuery(deleteByQueryRequest, RequestOptions.DEFAULT);
 	}
 
-	public void deleteObservationIndex(String theObservationIdentifier) throws IOException {
+/*	public void deleteObservationIndex(String theObservationIdentifier) throws IOException {
 		DeleteByQueryRequest deleteByQueryRequest = new DeleteByQueryRequest(IndexConstants.OBSERVATION_DOCUMENT_TYPE);
 		BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
 		boolQueryBuilder.must(QueryBuilders.termsQuery(OBSERVATION_IDENTIFIER_FIELD_NAME, theObservationIdentifier));
 		deleteByQueryRequest.setQuery(boolQueryBuilder);
 		myRestHighLevelClient.deleteByQuery(deleteByQueryRequest, RequestOptions.DEFAULT);
 	}
+ */
 }

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/dao/r4/FhirResourceDaoR4SearchLastNIT.java

@@ -5,6 +5,7 @@ import ca.uhn.fhir.jpa.api.dao.*;
 import ca.uhn.fhir.jpa.api.config.DaoConfig;
 import ca.uhn.fhir.jpa.config.TestR4ConfigWithElasticsearchClient;
 import ca.uhn.fhir.jpa.dao.BaseJpaTest;
+import ca.uhn.fhir.jpa.rp.r4.ObservationResourceProvider;
 import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
 import ca.uhn.fhir.rest.param.*;
 import ca.uhn.fhir.rest.server.servlet.ServletRequestDetails;
@@ -57,6 +58,8 @@ public class FhirResourceDaoR4SearchLastNIT extends BaseJpaTest {
 		return myPlatformTransactionManager;
 	}
 
+	ObservationResourceProvider observationRp = new ObservationResourceProvider();
+
 	private final String observationCd0 = "code0";
 	private final String observationCd1 = "code1";
 	private final String observationCd2 = "code2";
@@ -101,6 +104,8 @@ public class FhirResourceDaoR4SearchLastNIT extends BaseJpaTest {
 			dataLoaded = true;
 		}
 
+		observationRp.setDao(myObservationDao);
+
 	}
 
 	private void createObservationsForPatient(IIdType thePatientId) {
@@ -138,9 +143,13 @@ public class FhirResourceDaoR4SearchLastNIT extends BaseJpaTest {
 	}
 
 	@Test
-	public void testLastNNoParams() {
+	public void testLastNAllPatients() {
 
 		SearchParameterMap params = new SearchParameterMap();
+		ReferenceParam subjectParam1 = new ReferenceParam("Patient", "", patient0Id.getValue());
+		ReferenceParam subjectParam2 = new ReferenceParam("Patient", "", patient1Id.getValue());
+		ReferenceParam subjectParam3 = new ReferenceParam("Patient", "", patient2Id.getValue());
+		params.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam1, subjectParam2, subjectParam3));
 
 		List<String> sortedPatients = new ArrayList<>();
 		sortedPatients.add(patient0Id.getValue());
@@ -155,14 +164,39 @@ public class FhirResourceDaoR4SearchLastNIT extends BaseJpaTest {
 		executeTestCase(params, sortedPatients, sortedObservationCodes, null,90);
 	}
 
+	@Test
+	public void testLastNNoPatients() {
+
+		SearchParameterMap params = new SearchParameterMap();
+		params.setLastNMax(1);
+
+		List<String> sortedPatients = new ArrayList<>();
+
+		List<String> sortedObservationCodes = new ArrayList<>();
+		sortedObservationCodes.add(observationCd0);
+		sortedObservationCodes.add(observationCd1);
+		sortedObservationCodes.add(observationCd2);
+
+//		executeTestCase(params, sortedPatients, sortedObservationCodes, null,3);
+		params.setLastN(true);
+		Map<String, String[]> requestParameters = new HashMap<>();
+		when(mySrd.getParameters()).thenReturn(requestParameters);
+
+		List<String> actual = toUnqualifiedVersionlessIdValues(myObservationDao.observationsLastN(params, mockSrd(),null));
+
+		assertEquals(3, actual.size());
+	}
+
 	private void executeTestCase(SearchParameterMap params, List<String> sortedPatients, List<String> sortedObservationCodes, List<String> theCategories, int expectedObservationCount) {
 		List<String> actual;
 		params.setLastN(true);
 
 		Map<String, String[]> requestParameters = new HashMap<>();
-		String[] maxParam = new String[1];
+//		String[] maxParam = new String[1];
-		maxParam[0] = "100";
+//		maxParam[0] = "100";
-		requestParameters.put("max", maxParam);
+//		requestParameters.put("max", maxParam);
+		params.setLastNMax(100);
+
 		when(mySrd.getParameters()).thenReturn(requestParameters);
 
 		actual = toUnqualifiedVersionlessIdValues(myObservationDao.observationsLastN(params, mockSrd(),null));
@@ -297,6 +331,11 @@ public class FhirResourceDaoR4SearchLastNIT extends BaseJpaTest {
 
 		// One category parameter.
 		SearchParameterMap params = new SearchParameterMap();
+		ReferenceParam subjectParam1 = new ReferenceParam("Patient", "", patient0Id.getValue());
+		ReferenceParam subjectParam2 = new ReferenceParam("Patient", "", patient1Id.getValue());
+		ReferenceParam subjectParam3 = new ReferenceParam("Patient", "", patient2Id.getValue());
+		params.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam1, subjectParam2, subjectParam3));
+
 		TokenParam categoryParam = new TokenParam(categorySystem, categoryCd0);
 		params.add(Observation.SP_CATEGORY, buildTokenAndListParam(categoryParam));
 		List<String> myCategories = new ArrayList<>();
@@ -315,6 +354,7 @@ public class FhirResourceDaoR4SearchLastNIT extends BaseJpaTest {
 
 		// Another category parameter.
 		params = new SearchParameterMap();
+		params.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam1, subjectParam2, subjectParam3));
 		categoryParam = new TokenParam(categorySystem, categoryCd2);
 		params.add(Observation.SP_CATEGORY, buildTokenAndListParam(categoryParam));
 		myCategories = new ArrayList<>();
@@ -333,6 +373,11 @@ public class FhirResourceDaoR4SearchLastNIT extends BaseJpaTest {
 
 		// Two category parameters.
 		SearchParameterMap params = new SearchParameterMap();
+		ReferenceParam subjectParam1 = new ReferenceParam("Patient", "", patient0Id.getValue());
+		ReferenceParam subjectParam2 = new ReferenceParam("Patient", "", patient1Id.getValue());
+		ReferenceParam subjectParam3 = new ReferenceParam("Patient", "", patient2Id.getValue());
+		params.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam1, subjectParam2, subjectParam3));
+
 		TokenParam categoryParam1 = new TokenParam(categorySystem, categoryCd0);
 		TokenParam categoryParam2 = new TokenParam(categorySystem, categoryCd1);
 		params.add(Observation.SP_CATEGORY, buildTokenAndListParam(categoryParam1, categoryParam2));
@@ -357,6 +402,11 @@ public class FhirResourceDaoR4SearchLastNIT extends BaseJpaTest {
 
 		// One code parameter.
 		SearchParameterMap params = new SearchParameterMap();
+		ReferenceParam subjectParam1 = new ReferenceParam("Patient", "", patient0Id.getValue());
+		ReferenceParam subjectParam2 = new ReferenceParam("Patient", "", patient1Id.getValue());
+		ReferenceParam subjectParam3 = new ReferenceParam("Patient", "", patient2Id.getValue());
+		params.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam1, subjectParam2, subjectParam3));
+
 		TokenParam code = new TokenParam(codeSystem, observationCd0);
 		params.add(Observation.SP_CODE, buildTokenAndListParam(code));
 		List<String> sortedObservationCodes = new ArrayList<>();
@@ -371,6 +421,7 @@ public class FhirResourceDaoR4SearchLastNIT extends BaseJpaTest {
 
 		// Another code parameter.
 		params = new SearchParameterMap();
+		params.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam1, subjectParam2, subjectParam3));
 		code = new TokenParam(codeSystem, observationCd2);
 		params.add(Observation.SP_CODE, buildTokenAndListParam(code));
 		sortedObservationCodes = new ArrayList<>();
@@ -385,6 +436,11 @@ public class FhirResourceDaoR4SearchLastNIT extends BaseJpaTest {
 
 		// Two code parameters.
 		SearchParameterMap params = new SearchParameterMap();
+		ReferenceParam subjectParam1 = new ReferenceParam("Patient", "", patient0Id.getValue());
+		ReferenceParam subjectParam2 = new ReferenceParam("Patient", "", patient1Id.getValue());
+		ReferenceParam subjectParam3 = new ReferenceParam("Patient", "", patient2Id.getValue());
+		params.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam1, subjectParam2, subjectParam3));
+
 		TokenParam codeParam1 = new TokenParam(codeSystem, observationCd0);
 		TokenParam codeParam2 = new TokenParam(codeSystem, observationCd1);
 		params.add(Observation.SP_CODE, buildTokenAndListParam(codeParam1, codeParam2));

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/dao/r4/PersistObservationIndexedSearchParamLastNR4IT.java

@@ -79,6 +79,8 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 	private final String CODEFIRSTCODINGSYSTEM = "http://mycodes.org/fhir/observation-code";
 	private final String CODEFIRSTCODINGCODE = "test-code";
 
+	private ReferenceAndListParam multiSubjectParams = null;
+
 	@Test
 	public void testIndexObservationSingle() {
 		indexSingleObservation();
@@ -177,6 +179,8 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 
 		// Check that all observations were indexed.
 		SearchParameterMap searchParameterMap = new SearchParameterMap();
+		searchParameterMap.add(Observation.SP_SUBJECT, multiSubjectParams);
+		//searchParameterMap.
 		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 10);
 		assertEquals(100, observationIdsOnly.size());
 
@@ -223,10 +227,14 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 		categoryCodeableConcept2.setCoding(category2);
 		categoryConcepts2.add(categoryCodeableConcept2);
 
+		ReferenceOrListParam subjectParams = new ReferenceOrListParam();
 		for (int patientCount = 0; patientCount < 10; patientCount++) {
 
 			String subjectId = String.valueOf(patientCount);
 
+			ReferenceParam subjectParam = new ReferenceParam("Patient", "", subjectId);
+			subjectParams.addOr(subjectParam);
+
 			for (int entryCount = 0; entryCount < 10; entryCount++) {
 
 				Observation observation = new Observation();
@@ -254,6 +262,9 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 			}
 
 		}
+
+		multiSubjectParams = new ReferenceAndListParam().addAnd(subjectParams);
+
 	}
 
 	@Test
@@ -265,6 +276,7 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 		assertNotNull(observation);
 
 		SearchParameterMap searchParameterMap = new SearchParameterMap();
+		searchParameterMap.add(Observation.SP_SUBJECT, multiSubjectParams);
 		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 10);
 		assertEquals(100, observationIdsOnly.size());
 		assertTrue(observationIdsOnly.contains("55"));

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

@@ -56,23 +56,40 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 	}
 
 	@Test
-	public void testLastNNoCriteriaQuery() {
+	public void testLastNAllPatientsQuery() {
 
 		// execute Observation ID search (Composite Aggregation) last 3 observations for each patient
-		List<ObservationJson> observations = elasticsearchSvc.executeLastNWithAllFields(null, 3);
+		SearchParameterMap searchParameterMap = new SearchParameterMap();
+		ReferenceParam subjectParam = new ReferenceParam("Patient", "", "0");
+		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
+		subjectParam = new ReferenceParam("Patient", "", "1");
+		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
+		subjectParam = new ReferenceParam("Patient", "", "2");
+		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
+		subjectParam = new ReferenceParam("Patient", "", "3");
+		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
+		subjectParam = new ReferenceParam("Patient", "", "4");
+		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
+		subjectParam = new ReferenceParam("Patient", "", "5");
+		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
+		subjectParam = new ReferenceParam("Patient", "", "6");
+		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
+		subjectParam = new ReferenceParam("Patient", "", "7");
+		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
+		subjectParam = new ReferenceParam("Patient", "", "8");
+		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
+		subjectParam = new ReferenceParam("Patient", "", "9");
+		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
 
-		validateQueryResponse(observations);
+		List<ObservationJson> observations = elasticsearchSvc.executeLastNWithAllFields(searchParameterMap, 3);
 
-	}
+		assertEquals(60, observations.size());
-
-	private void validateQueryResponse(List<ObservationJson> observationIdsOnly) {
-		assertEquals(60, observationIdsOnly.size());
 
 		// Observation documents should be grouped by subject, then by observation code, and then sorted by effective date/time
 		// within each observation code. Verify the grouping by creating a nested Map.
 		Map<String, Map<String, List<Date>>> queriedPatientObservationMap = new HashMap<>();
 		ObservationJson previousObservationJson = null;
-		for (ObservationJson observationJson : observationIdsOnly) {
+		for (ObservationJson observationJson : observations) {
 			assertNotNull(observationJson.getIdentifier());
 			assertNotNull(observationJson.getSubject());
 			assertNotNull(observationJson.getCode_concept_id());
@@ -373,4 +390,19 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 
 	}
 
+	@Test
+	public void testLastNNoParamsQuery() {
+		SearchParameterMap searchParameterMap = new SearchParameterMap();
+		List<ObservationJson> observations = elasticsearchSvc.executeLastNWithAllFields(searchParameterMap, 1);
+
+		assertEquals(2, observations.size());
+
+		String observationCode1 = observations.get(0).getCode_coding_code_system_hash();
+		String observationCode2 = observations.get(1).getCode_coding_code_system_hash();
+
+		assertNotEquals(observationCode1, observationCode2);
+
+	}
+
+
 }

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/search/lastn/config/TestElasticsearchConfig.java

@@ -47,9 +47,9 @@ public class TestElasticsearchConfig {
 		return embeddedElastic;
 	}
 
-	@PreDestroy
+//	@PreDestroy
-	public void stop() {
+//	public void stop() {
-		embeddedElasticSearch().stop();
+//		embeddedElasticSearch().stop();
-	}
+//	}
 
 }

hapi-fhir-jpaserver-searchparam/src/main/java/ca/uhn/fhir/jpa/searchparam/SearchParameterMap.java

@@ -62,6 +62,7 @@ public class SearchParameterMap implements Serializable {
 	private SearchTotalModeEnum mySearchTotalMode;
 	private QuantityParam myNearDistanceParam;
 	private boolean myLastN;
+	private Integer myLastNMax;
 
 	/**
 	 * Constructor
@@ -322,6 +323,24 @@ public class SearchParameterMap implements Serializable {
 	}
 
 
+	/**
+	 * If set, tells the server the maximum number of observations to return for each
+	 * observation code in the result set of a lastn operation
+	 */
+	public Integer getLastNMax() {
+		return myLastNMax;
+	}
+
+	/**
+	 * If set, tells the server the maximum number of observations to return for each
+	 * observation code in the result set of a lastn operation
+	 */
+	public SearchParameterMap setLastNMax(Integer theLastNMax) {
+		myLastNMax = theLastNMax;
+		return this;
+	}
+
+
 	/**
 	 * This method creates a URL query string representation of the parameters in this
 	 * object, excluding the part before the parameters, e.g.