n-api: implement async helper methods

Based on the async methods we had in abi-stable-node before the napi
feature landed in node/master. Changed this set of APIs to handle
error cases and removed a lot of the extra methods we had for setting
all the pieces of napi_work opting instead to pass all of those as
arguments to napi_create_async_work as none of those parameters are
optional except for the complete callback, anyway.

Renamed the napi_work struct to napi_async_work and replace the
struct itself with a class which can better encapsulate the object
lifetime and uv_work_t that we're trying to wrap anyway.

Added a napi_async_callback type for the async helper callbacks
instead of taking raw function pointers and make this callback take a
napi_env parameter as well as the void* data it was already taking.

Call the complete handler for the async work item with a napi_status
code translated from the uvlib error code.

The execute callback is required for napi_create_async_work, though
complete callback is still optional.

Also added some async unit tests for addons-napi based on the
addons/async_hello_world test.

PR-URL: https://github.com/nodejs/node/pull/12250
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: Hitesh Kanwathirtha <hiteshk@microsoft.com>

1 files changed, 27 insertions, 20 deletions

diff --git a/src/node_api_types.h b/src/node_api_types.h
index f439cce1f9..4bf1b82631 100644
--- a/src/node_api_types.h
+++ b/src/node_api_types.h
@@ -16,12 +16,7 @@ typedef struct napi_ref__ *napi_ref;
 typedef struct napi_handle_scope__ *napi_handle_scope;
 typedef struct napi_escapable_handle_scope__ *napi_escapable_handle_scope;
 typedef struct napi_callback_info__ *napi_callback_info;
-
-typedef napi_value (*napi_callback)(napi_env env,
-                                    napi_callback_info info);
-typedef void (*napi_finalize)(napi_env env,
-                              void* finalize_data,
-                              void* finalize_hint);
+typedef struct napi_async_work__ *napi_async_work;
 
 typedef enum {
   napi_default = 0,
@@ -34,20 +29,6 @@ typedef enum {
   napi_static = 1 << 10,
 } napi_property_attributes;
 
-typedef struct {
-  // One of utf8name or name should be NULL.
-  const char* utf8name;
-  napi_value name;
-
-  napi_callback method;
-  napi_callback getter;
-  napi_callback setter;
-  napi_value value;
-
-  napi_property_attributes attributes;
-  void* data;
-} napi_property_descriptor;
-
 typedef enum {
   // ES6 types (corresponds to typeof)
   napi_undefined,
@@ -85,9 +66,35 @@ typedef enum {
   napi_array_expected,
   napi_generic_failure,
   napi_pending_exception,
+  napi_cancelled,
   napi_status_last
 } napi_status;
 
+typedef napi_value (*napi_callback)(napi_env env,
+                                    napi_callback_info info);
+typedef void (*napi_finalize)(napi_env env,
+                              void* finalize_data,
+                              void* finalize_hint);
+typedef void (*napi_async_execute_callback)(napi_env env,
+                                            void* data);
+typedef void (*napi_async_complete_callback)(napi_env env,
+                                             napi_status status,
+                                             void* data);
+
+typedef struct {
+  // One of utf8name or name should be NULL.
+  const char* utf8name;
+  napi_value name;
+
+  napi_callback method;
+  napi_callback getter;
+  napi_callback setter;
+  napi_value value;
+
+  napi_property_attributes attributes;
+  void* data;
+} napi_property_descriptor;
+
 typedef struct {
   const char* error_message;
   void* engine_reserved;