Automatically remove duplicate conditional creates in JPA

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

@@ -44,10 +44,7 @@ import ca.uhn.fhir.rest.server.interceptor.IServerInterceptor;
 import ca.uhn.fhir.rest.server.method.BaseMethodBinding;
 import ca.uhn.fhir.rest.server.method.BaseResourceReturningMethodBinding;
 import ca.uhn.fhir.rest.server.servlet.ServletRequestDetails;
-import ca.uhn.fhir.util.FhirTerser;
-import ca.uhn.fhir.util.ResourceReferenceInfo;
-import ca.uhn.fhir.util.StopWatch;
-import ca.uhn.fhir.util.UrlUtil;
+import ca.uhn.fhir.util.*;
 import com.google.common.collect.ArrayListMultimap;
 import org.apache.commons.lang3.Validate;
 import org.apache.http.NameValuePair;
@@ -98,6 +95,14 @@ public class TransactionProcessor<BUNDLE extends IBaseBundle, BUNDLEENTRY> {
 		String actionName = "Transaction";
 		BUNDLE response = processTransactionAsSubRequest((ServletRequestDetails) theRequestDetails, theRequest, actionName);
 
+		List<BUNDLEENTRY> entries = myVersionAdapter.getEntries(response);
+		for (int i = 0; i < entries.size(); i++) {
+			if (ElementUtil.isEmpty(entries.get(i))) {
+				entries.remove(i);
+				i--;
+			}
+		}
+
 		return response;
 	}
 
@@ -500,6 +505,42 @@ public class TransactionProcessor<BUNDLE extends IBaseBundle, BUNDLEENTRY> {
 			Set<ResourceTable> updatedEntities = new HashSet<>();
 			Map<String, Class<? extends IBaseResource>> conditionalRequestUrls = new HashMap<>();
 
+			/*
+			 * Look for duplicate conditional creates and consolidate them
+			 */
+			Map<String, String> ifNoneExistToUuid = new HashMap<>();
+			for (int index = 0, originalIndex = 0; index < theEntries.size(); index++, originalIndex++) {
+				BUNDLEENTRY nextReqEntry = theEntries.get(index);
+				String verb = myVersionAdapter.getEntryRequestVerb(nextReqEntry);
+				String entryUrl = myVersionAdapter.getFullUrl(nextReqEntry);
+				String requestUrl = myVersionAdapter.getEntryRequestUrl(nextReqEntry);
+				String ifNoneExist = myVersionAdapter.getEntryRequestIfNoneExist(nextReqEntry);
+				if ("POST".equals(verb)) {
+					if (isNotBlank(entryUrl) && isNotBlank(requestUrl) && isNotBlank(ifNoneExist)) {
+						if (!entryUrl.equals(requestUrl)) {
+							String key = requestUrl + "|" + ifNoneExist; // just in case the ifNoneExist doesn't include the resource type
+							if (!ifNoneExistToUuid.containsKey(key)) {
+								ifNoneExistToUuid.put(key, entryUrl);
+							} else {
+								ourLog.info("Discarding transaction bundle entry {} as it contained a duplicate conditional create: {}", originalIndex, ifNoneExist);
+								theEntries.remove(index);
+								index--;
+								String existingUuid = ifNoneExistToUuid.get(key);
+								for (BUNDLEENTRY nextEntry : theEntries) {
+									IBaseResource nextResource = myVersionAdapter.getResource(nextEntry);
+									for (ResourceReferenceInfo nextReference : myContext.newTerser().getAllResourceReferences(nextResource)) {
+										if (entryUrl.equals(nextReference.getResourceReference().getReferenceElement().getValue())) {
+											nextReference.getResourceReference().setReference(existingUuid);
+										}
+									}
+								}
+							}
+						}
+					}
+				}
+			}
+
+
 			/*
 			 * Loop through the request and process any entries of type
 			 * PUT, POST or DELETE

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/dao/r4/FhirSystemDaoR4Test.java

@@ -38,6 +38,7 @@ import java.io.UnsupportedEncodingException;
 import java.math.BigDecimal;
 import java.nio.charset.StandardCharsets;
 import java.util.*;
+import java.util.stream.Collectors;
 
 import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
@@ -1044,6 +1045,66 @@ public class FhirSystemDaoR4Test extends BaseJpaR4SystemTest {
 
 	}
 
+	@Test
+	public void testTransactionWithDuplicateConditionalCreates() {
+		Bundle request = new Bundle();
+		request.setType(BundleType.TRANSACTION);
+
+		Practitioner p = new Practitioner();
+		p.setId(IdType.newRandomUuid());
+		p.addIdentifier().setSystem("http://foo").setValue("bar");
+		request.addEntry()
+			.setFullUrl(p.getId())
+			.setResource(p)
+			.getRequest()
+			.setMethod(HTTPVerb.POST)
+			.setUrl("Practitioner/")
+			.setIfNoneExist("Practitioner?identifier=http://foo|bar");
+
+		Observation o = new Observation();
+		o.setId(IdType.newRandomUuid());
+		o.getPerformerFirstRep().setReference(p.getId());
+		request.addEntry()
+			.setFullUrl(o.getId())
+			.setResource(o)
+			.getRequest()
+			.setMethod(HTTPVerb.POST)
+			.setUrl("Observation/");
+
+		p = new Practitioner();
+		p.setId(IdType.newRandomUuid());
+		p.addIdentifier().setSystem("http://foo").setValue("bar");
+		request.addEntry()
+			.setFullUrl(p.getId())
+			.setResource(p)
+			.getRequest()
+			.setMethod(HTTPVerb.POST)
+			.setUrl("Practitioner/")
+			.setIfNoneExist("Practitioner?identifier=http://foo|bar");
+
+		o = new Observation();
+		o.setId(IdType.newRandomUuid());
+		o.getPerformerFirstRep().setReference(p.getId());
+		request.addEntry()
+			.setFullUrl(o.getId())
+			.setResource(o)
+			.getRequest()
+			.setMethod(HTTPVerb.POST)
+			.setUrl("Observation/");
+
+		Bundle response = mySystemDao.transaction(null, request);
+
+		ourLog.info("Response:\n{}", myFhirCtx.newJsonParser().setPrettyPrint(true).encodeResourceToString(response));
+
+		List<String> responseTypes = response
+			.getEntry()
+			.stream()
+			.map(t -> new IdType(t.getResponse().getLocation()).getResourceType())
+			.collect(Collectors.toList());
+		assertThat(responseTypes.toString(), responseTypes, contains("Practitioner", "Observation", "Observation"));
+	}
+
+
 	@Test
 	public void testTransactionCreateInlineMatchUrlWithTwoMatches() {
 		String methodName = "testTransactionCreateInlineMatchUrlWithTwoMatches";

src/changes/changes.xml

@@ -52,6 +52,12 @@
 				The JPA query builder has been optimized to take better advantage of SQL IN (..) expressions
 				when performing token searches with multiple OR values.
 			</action>
+			<action type="add">
+				The JPA server transaction processor will now automatically detect if the request
+				Bundle contains multiple entries having identical conditional create operations, and
+				collapse these into a single operation. This is done as a convenience, since many
+				conversion algorithms can accidentally generate such duplicates.
+			</action>
 		</release>
 		<release version="3.7.0" date="2019-02-06" description="Gale">
 			<action type="add">