Refactor Separation of embedding logic through the DocumentTransformer

separated common logic
process optimization

Author: youngmoneee

spring-ai-core/src/main/java/org/springframework/ai/transformer/DocumentEmbeddingTransformer.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2023 - 2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.ai.transformer;
+
+import java.util.List;
+import org.springframework.ai.document.Document;
+import org.springframework.ai.document.DocumentTransformer;
+import org.springframework.ai.embedding.EmbeddingModel;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Schedulers;
+
+/**
+ * DocumentEmbeddingTransformer injects embedding values into each Document using the
+ * EmbeddingModel if the Document does not already have embedding data.
+ *
+ * @author youngmon
+ * @since 1.0.0
+ */
+public class DocumentEmbeddingTransformer implements DocumentTransformer {
+
+	private final EmbeddingModel embeddingModel;
+
+	public DocumentEmbeddingTransformer(EmbeddingModel embeddingModel) {
+		this.embeddingModel = embeddingModel;
+	}
+
+	/**
+	 * Embedding values are generated using the embedding model provided through the
+	 * constructor and then injected into each Document object.
+	 * @param documents to process.
+	 * @return processed documents
+	 */
+	@Override
+	public List<Document> apply(List<Document> documents) {
+		return Flux.fromIterable(documents).flatMap(document -> {
+			if (document.getEmbedding() == null || document.getEmbedding().length == 0)
+				return Mono
+					.zip(Mono.just(document), Mono.fromCallable(() -> embeddingModel.embed(document)), (doc, embed) -> {
+						doc.setEmbedding(embed);
+						return doc;
+					})
+					.subscribeOn(Schedulers.boundedElastic());
+			return Mono.just(document);
+		}).collectList().block();
+	}
+
+}