GH-5724: Add purgeEmbeddings method to ChromaVectorStore

vector-stores/spring-ai-chroma-store/src/main/java/org/springframework/ai/chroma/vectorstore/ChromaVectorStore.java

@@ -63,6 +63,8 @@
  */
 public class ChromaVectorStore extends AbstractObservationVectorStore implements InitializingBean {
 
+	private static final int DEFAULT_PURGE_BATCH_SIZE = 1000;
+
 	private final ChromaApi chromaApi;
 
 	private final String tenantName;
@@ -175,6 +177,44 @@ public void doDelete(List<String> idList) {
 				new DeleteEmbeddingsRequest(idList));
 	}
 
+	/**
+	 * Deletes all embeddings from the current collection while keeping the collection
+	 * itself intact. Embeddings are deleted in batches by repeatedly fetching the first
+	 * page of ids until the collection is empty.
+	 * <p>
+	 * Note: This method does not support concurrency control. Concurrent writes or
+	 * deletions may result in incomplete deletions or duplicate deletion attempts.
+	 * @return the number of embeddings requested for deletion
+	 * @since 2.0.0-SNAPSHOT
+	 */
+	public int purgeEmbeddings() {
+		int deleteCount = 0;
+		String collectionId = this.requireCollectionId();
+		try {
+			while (true) {
+				var response = this.chromaApi.getEmbeddings(this.tenantName, this.databaseName, collectionId,
+						new ChromaApi.GetEmbeddingsRequest(List.of(), Map.of(), DEFAULT_PURGE_BATCH_SIZE, 0,
+								List.of()));
+
+				if (response == null || CollectionUtils.isEmpty(response.ids())) {
+					return deleteCount;
+				}
+				List<String> ids = response.ids();
+				this.chromaApi.deleteEmbeddings(this.tenantName, this.databaseName, collectionId,
+						new DeleteEmbeddingsRequest(ids));
+				deleteCount += ids.size();
+
+				if (ids.size() < DEFAULT_PURGE_BATCH_SIZE) {
+					return deleteCount;
+				}
+			}
+		}
+		catch (Exception e) {
+			logger.error("Purge failed: {}", e.getMessage());
+			throw new IllegalStateException("Failed to purge chroma collection", e);
+		}
+	}
+
 	@Override
 	protected void doDelete(Filter.Expression expression) {
 		Assert.notNull(expression, "Filter expression must not be null");

vector-stores/spring-ai-chroma-store/src/test/java/org/springframework/ai/chroma/vectorstore/ChromaVectorStoreIT.java

@@ -272,6 +272,17 @@ public void searchThresholdTest() {
 		});
 	}
 
+	@Test
+	public void purgeEmbeddingsCollection() {
+		this.contextRunner.run(context -> {
+			VectorStore vectorStore = context.getBean(VectorStore.class);
+			vectorStore.add(this.documents);
+
+			int deletedCount = ((ChromaVectorStore) vectorStore).purgeEmbeddings();
+			assertThat(deletedCount).isEqualTo(this.documents.size());
+		});
+	}
+
 	@SpringBootConfiguration
 	public static class TestApplication {