HSEARCH-3460 Introduce SPIs for explicit index refresh

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/work/execution/impl/ElasticsearchIndexWorkspace.java

@@ -58,4 +58,10 @@ public CompletableFuture<?> purge() {
 	public CompletableFuture<?> flush() {
 		return orchestrator.submit( builderFactory.flush().index( indexName ).build() );
 	}
+
+	@Override
+	public CompletableFuture<?> refresh() {
+		// TODO HSEARCH-3460
+		throw new UnsupportedOperationException( "Not implemented yet" );
+	}
 }

backend/lucene/src/main/java/org/hibernate/search/backend/lucene/work/execution/impl/LuceneIndexWorkspace.java

@@ -46,6 +46,12 @@ public CompletableFuture<?> flush() {
 		return doSubmit( factory.flush() );
 	}
 
+	@Override
+	public CompletableFuture<?> refresh() {
+		// TODO HSEARCH-3460
+		throw new UnsupportedOperationException( "Not implemented yet" );
+	}
+
 	private CompletableFuture<?> doSubmit(LuceneWriteWork<?> work) {
 		Collection<LuceneWriteWorkOrchestrator> orchestrators = indexManagerContext.getAllWriteOrchestrators();
 		CompletableFuture<?>[] futures = new CompletableFuture[orchestrators.size()];
@@ -59,6 +65,5 @@ private CompletableFuture<?> doSubmit(LuceneWriteWork<?> work) {
 			++i;
 		}
 		return CompletableFuture.allOf( futures );
-
 	}
 }

engine/src/main/java/org/hibernate/search/engine/backend/work/execution/spi/IndexWorkspace.java

@@ -19,4 +19,6 @@ public interface IndexWorkspace {
 
 	CompletableFuture<?> flush();
 
+	CompletableFuture<?> refresh();
+
 }

mapper/pojo-base/src/main/java/org/hibernate/search/mapper/pojo/work/impl/PojoScopeWorkspaceImpl.java

@@ -42,6 +42,11 @@ public CompletableFuture<?> flush() {
 		return doOperationOnTypes( IndexWorkspace::flush );
 	}
 
+	@Override
+	public CompletableFuture<?> refresh() {
+		return doOperationOnTypes( IndexWorkspace::refresh );
+	}
+
 	private CompletableFuture<?> doOperationOnTypes(Function<IndexWorkspace, CompletableFuture<?>> operation) {
 		CompletableFuture<?>[] futures = new CompletableFuture<?>[delegates.size()];
 		int typeCounter = 0;

mapper/pojo-base/src/main/java/org/hibernate/search/mapper/pojo/work/spi/PojoScopeWorkspace.java

@@ -16,4 +16,6 @@ public interface PojoScopeWorkspace {
 
 	CompletableFuture<?> flush();
 
+	CompletableFuture<?> refresh();
+
 }

util/internal/integrationtest/common/src/main/java/org/hibernate/search/util/impl/integrationtest/common/rule/BackendMock.java

@@ -363,6 +363,14 @@ public IndexScopeWorkCallListContext flush(CompletableFuture<?> future) {
 			return indexScopeWork( StubIndexScopeWork.Type.FLUSH, future );
 		}
 
+		public IndexScopeWorkCallListContext refresh() {
+			return indexScopeWork( StubIndexScopeWork.Type.REFRESH );
+		}
+
+		public IndexScopeWorkCallListContext refresh(CompletableFuture<?> future) {
+			return indexScopeWork( StubIndexScopeWork.Type.REFRESH, future );
+		}
+
 		public IndexScopeWorkCallListContext indexScopeWork(StubIndexScopeWork.Type type) {
 			return indexScopeWork( type, CompletableFuture.completedFuture( null ) );
 		}

util/internal/integrationtest/common/src/main/java/org/hibernate/search/util/impl/integrationtest/common/stub/backend/index/StubIndexScopeWork.java

@@ -9,7 +9,7 @@
 public final class StubIndexScopeWork {
 
 	public enum Type {
-		MERGE_SEGMENTS, PURGE, FLUSH
+		MERGE_SEGMENTS, PURGE, FLUSH, REFRESH
 	}
 
 	public static Builder builder(Type type) {

util/internal/integrationtest/common/src/main/java/org/hibernate/search/util/impl/integrationtest/common/stub/backend/index/impl/StubIndexWorkspace.java

@@ -46,4 +46,10 @@ public CompletableFuture<?> flush() {
 		StubIndexScopeWork work = StubIndexScopeWork.builder( StubIndexScopeWork.Type.FLUSH ).build();
 		return behavior.executeIndexScopeWork( Collections.singleton( indexName ), work );
 	}
+
+	@Override
+	public CompletableFuture<?> refresh() {
+		StubIndexScopeWork work = StubIndexScopeWork.builder( StubIndexScopeWork.Type.REFRESH ).build();
+		return behavior.executeIndexScopeWork( Collections.singleton( indexName ), work );
+	}
 }