diff --git a/cache/include/tango_cache_client.h b/cache/include/tango_cache_client.h
index 1592b8e..c551e8f 100644
--- a/cache/include/tango_cache_client.h
+++ b/cache/include/tango_cache_client.h
@@ -150,6 +150,7 @@ struct tango_cache_ctx *tango_cache_update_start(struct tango_cache_instance *in
 int tango_cache_update_frag_data(struct tango_cache_ctx *ctx, const char *data, size_t size);
 int tango_cache_update_frag_evbuf(struct tango_cache_ctx *ctx, enum EVBUFFER_COPY_WAY way, struct evbuffer *evbuf);
 void tango_cache_update_end(struct tango_cache_ctx *ctx);
+//调用cancel后不会产生结果回调，认作传输失败
 void tango_cache_update_cancel(struct tango_cache_ctx *ctx);
 
 //获取对象key值；当CACHE_OBJECT_KEY_HASH_SWITCH=1开启对URL/文件名哈希时有用
diff --git a/cache/src/tango_cache_client.cpp b/cache/src/tango_cache_client.cpp
index 46eac9e..c04bb37 100644
--- a/cache/src/tango_cache_client.cpp
+++ b/cache/src/tango_cache_client.cpp
@@ -268,6 +268,7 @@ void tango_cache_update_cancel(struct tango_cache_ctx *ctx)
 		ctx->curl = NULL;
 	}
 	tango_cache_set_fail_state(ctx, CACHE_UPDATE_CANCELED);
+	//已经产生分段上传ID时，调用cancel删除
 	if(ctx->put.uploadID!=NULL && cache_cancel_upload_minio(ctx))
 	{
 		ctx->put.state = PUT_STATE_CANCEL;
diff --git a/cache/test/tango_cache_test.c b/cache/test/tango_cache_test.cpp
similarity index 100%
rename from cache/test/tango_cache_test.c
rename to cache/test/tango_cache_test.cpp