[gnome-software: 21/25] gs-odrs-provider: Make HTTP code in fetch_reviews_for_app_async() async

[Philip Withnall <pwithnall src gnome org>]

commit 3d93b683d8a192a1a3ef8cd068dbf2405050543d
Author: Philip Withnall <pwithnall endlessos org>
Date:   Fri Feb 25 15:31:56 2022 +0000

    gs-odrs-provider: Make HTTP code in fetch_reviews_for_app_async() async
    
    It previously wasn’t, which would cause blocking.
    
    A nice side effect of this is that now the parsing is stream-based,
    which avoids having to allocate large heap buffers for the downloaded
    data before it’s parsed.
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>
    
    Helps: #1658

 lib/gs-odrs-provider.c | 139 ++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 102 insertions(+), 37 deletions(-)
---
diff --git a/lib/gs-odrs-provider.c b/lib/gs-odrs-provider.c
index 8cc87375b..3c6ca084f 100644
--- a/lib/gs-odrs-provider.c
+++ b/lib/gs-odrs-provider.c
@@ -652,10 +652,34 @@ gs_odrs_provider_get_compat_ids (GsApp *app)
        return g_steal_pointer (&json_node);
 }
 
+static void open_input_stream_cb (GObject      *source_object,
+                                  GAsyncResult *result,
+                                  gpointer      user_data);
+static void parse_reviews_cb (GObject      *source_object,
+                              GAsyncResult *result,
+                              gpointer      user_data);
 static void set_reviews_on_app (GsOdrsProvider *self,
                                 GsApp          *app,
                                 GPtrArray      *reviews);
 
+typedef struct {
+       GsApp *app;  /* (not nullable) (owned) */
+       gchar *cache_filename;  /* (not nullable) (owned) */
+       SoupMessage *message;  /* (nullable) (owned) */
+} FetchReviewsForAppData;
+
+static void
+fetch_reviews_for_app_data_free (FetchReviewsForAppData *data)
+{
+       g_clear_object (&data->app);
+       g_free (data->cache_filename);
+       g_clear_object (&data->message);
+
+       g_free (data);
+}
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (FetchReviewsForAppData, fetch_reviews_for_app_data_free)
+
 static void
 gs_odrs_provider_fetch_reviews_for_app_async (GsOdrsProvider      *self,
                                               GsApp               *app,
@@ -665,12 +689,9 @@ gs_odrs_provider_fetch_reviews_for_app_async (GsOdrsProvider      *self,
 {
        JsonNode *json_compat_ids;
        const gchar *version;
-       guint status_code;
-       gconstpointer downloaded_data;
-       gsize downloaded_data_length;
        g_autofree gchar *cachefn_basename = NULL;
        g_autofree gchar *cachefn = NULL;
-       g_autofree gchar *data = NULL;
+       g_autofree gchar *request_body = NULL;
        g_autofree gchar *uri = NULL;
        g_autoptr(GFile) cachefn_file = NULL;
        g_autoptr(GPtrArray) reviews = NULL;
@@ -683,11 +704,17 @@ gs_odrs_provider_fetch_reviews_for_app_async (GsOdrsProvider      *self,
        g_autoptr(GBytes) bytes = NULL;
 #endif
        g_autoptr(GTask) task = NULL;
+       FetchReviewsForAppData *data;
+       g_autoptr(FetchReviewsForAppData) data_owned = NULL;
        g_autoptr(GError) local_error = NULL;
 
        task = g_task_new (self, cancellable, callback, user_data);
        g_task_set_source_tag (task, gs_odrs_provider_fetch_reviews_for_app_async);
 
+       data = data_owned = g_new0 (FetchReviewsForAppData, 1);
+       data->app = g_object_ref (app);
+       g_task_set_task_data (task, g_steal_pointer (&data_owned), (GDestroyNotify) 
fetch_reviews_for_app_data_free);
+
        /* look in the cache */
        cachefn_basename = g_strdup_printf ("%s.json", gs_app_get_id (app));
        cachefn = gs_utils_get_cache_filename ("odrs",
@@ -700,6 +727,7 @@ gs_odrs_provider_fetch_reviews_for_app_async (GsOdrsProvider      *self,
                return;
        }
 
+       data->cache_filename = g_strdup (cachefn);
        cachefn_file = g_file_new_for_path (cachefn);
        if (gs_utils_get_file_age (cachefn_file) < self->max_cache_age_secs) {
                g_debug ("got review data for %s from %s",
@@ -758,47 +786,50 @@ gs_odrs_provider_fetch_reviews_for_app_async (GsOdrsProvider      *self,
        json_generator = json_generator_new ();
        json_generator_set_pretty (json_generator, TRUE);
        json_generator_set_root (json_generator, json_root);
-       data = json_generator_to_data (json_generator, NULL);
+       request_body = json_generator_to_data (json_generator, NULL);
 
        uri = g_strdup_printf ("%s/fetch", self->review_server);
        g_debug ("Updating ODRS cache for %s from %s to %s; request %s", gs_app_get_id (app),
-                uri, cachefn, data);
+                uri, cachefn, request_body);
        msg = soup_message_new (SOUP_METHOD_POST, uri);
+       data->message = g_object_ref (msg);
+
 #if SOUP_CHECK_VERSION(3, 0, 0)
        g_odrs_provider_set_message_request_body (msg, "application/json; charset=utf-8",
-                                                 data, strlen (data));
-       bytes = soup_session_send_and_read (self->session, msg, cancellable, &local_error);
-       if (bytes == NULL) {
-               g_task_return_error (task, g_steal_pointer (&local_error));
-               return;
-       }
-
-       downloaded_data = g_bytes_get_data (bytes, &downloaded_data_length);
-       status_code = soup_message_get_status (msg);
+                                                 request_body, strlen (request_body));
+       soup_session_send_async (self->session, msg, G_PRIORITY_DEFAULT,
+                                cancellable, open_input_stream_cb, g_steal_pointer (&task));
 #else
        soup_message_set_request (msg, "application/json; charset=utf-8",
-                                 SOUP_MEMORY_COPY, data, strlen (data));
-       status_code = soup_session_send_message (self->session, msg);
-       downloaded_data = msg->response_body ? msg->response_body->data : NULL;
-       downloaded_data_length = msg->response_body ? msg->response_body->length : 0;
+                                 SOUP_MEMORY_COPY, request_body, strlen (request_body));
+       soup_session_send_async (self->session, msg, cancellable,
+                                open_input_stream_cb, g_steal_pointer (&task));
 #endif
-       if (status_code != SOUP_STATUS_OK) {
-               g_autoptr(GInputStream) input_stream = g_memory_input_stream_new_from_data (downloaded_data, 
downloaded_data_length, NULL);
-               if (!gs_odrs_provider_parse_success (input_stream, &local_error)) {
-                       g_task_return_error (task, g_steal_pointer (&local_error));
-                       return;
-               }
+}
 
-               /* not sure what to do here */
-               g_task_return_new_error (task,
-                                        GS_ODRS_PROVIDER_ERROR,
-                                        GS_ODRS_PROVIDER_ERROR_DOWNLOADING,
-                                        "status code invalid");
-               return;
-       }
+static void
+open_input_stream_cb (GObject      *source_object,
+                      GAsyncResult *result,
+                      gpointer      user_data)
+{
+       SoupSession *soup_session = SOUP_SESSION (source_object);
+       g_autoptr(GTask) task = g_steal_pointer (&user_data);
+       FetchReviewsForAppData *data = g_task_get_task_data (task);
+       GCancellable *cancellable = g_task_get_cancellable (task);
+       g_autoptr(GInputStream) input_stream = NULL;
+       guint status_code;
+       g_autoptr(JsonParser) json_parser = NULL;
+       g_autoptr(GError) local_error = NULL;
 
-       /* nothing */
-       if (downloaded_data == NULL) {
+#if SOUP_CHECK_VERSION(3, 0, 0)
+       input_stream = soup_session_send_finish (soup_session, result, &local_error);
+       status_code = soup_message_get_status (data->message);
+#else
+       input_stream = soup_session_send_finish (soup_session, result, &local_error);
+       status_code = data->message->status_code;
+#endif
+
+       if (input_stream == NULL) {
                if (!g_network_monitor_get_network_available (g_network_monitor_get_default ()))
                        g_task_return_new_error (task,
                                                 GS_ODRS_PROVIDER_ERROR,
@@ -812,9 +843,39 @@ gs_odrs_provider_fetch_reviews_for_app_async (GsOdrsProvider      *self,
                return;
        }
 
+       if (status_code != SOUP_STATUS_OK) {
+               if (!gs_odrs_provider_parse_success (input_stream, &local_error)) {
+                       g_task_return_error (task, g_steal_pointer (&local_error));
+                       return;
+               }
+
+               /* not sure what to do here */
+               g_task_return_new_error (task,
+                                        GS_ODRS_PROVIDER_ERROR,
+                                        GS_ODRS_PROVIDER_ERROR_DOWNLOADING,
+                                        "status code invalid");
+               return;
+       }
+
        /* parse the data and find the array of ratings */
        json_parser = json_parser_new_immutable ();
-       if (!json_parser_load_from_data (json_parser, downloaded_data, downloaded_data_length, &local_error)) 
{
+       json_parser_load_from_stream_async (json_parser, input_stream, cancellable, parse_reviews_cb, 
g_steal_pointer (&task));
+}
+
+static void
+parse_reviews_cb (GObject      *source_object,
+                  GAsyncResult *result,
+                  gpointer      user_data)
+{
+       JsonParser *json_parser = JSON_PARSER (source_object);
+       g_autoptr(GTask) task = g_steal_pointer (&user_data);
+       GsOdrsProvider *self = g_task_get_source_object (task);
+       FetchReviewsForAppData *data = g_task_get_task_data (task);
+       g_autoptr(GPtrArray) reviews = NULL;
+       g_autoptr(JsonGenerator) cache_generator = NULL;
+       g_autoptr(GError) local_error = NULL;
+
+       if (!json_parser_load_from_stream_finish (json_parser, result, &local_error)) {
                g_task_return_new_error (task,
                                         GS_ODRS_PROVIDER_ERROR,
                                         GS_ODRS_PROVIDER_ERROR_PARSING_DATA,
@@ -829,12 +890,16 @@ gs_odrs_provider_fetch_reviews_for_app_async (GsOdrsProvider      *self,
        }
 
        /* save to the cache */
-       if (!g_file_set_contents (cachefn, downloaded_data, downloaded_data_length, &local_error)) {
+       cache_generator = json_generator_new ();
+       json_generator_set_pretty (cache_generator, FALSE);
+       json_generator_set_root (cache_generator, json_parser_get_root (json_parser));
+
+       if (!json_generator_to_file (cache_generator, data->cache_filename, &local_error)) {
                g_task_return_error (task, g_steal_pointer (&local_error));
                return;
        }
 
-       set_reviews_on_app (self, app, reviews);
+       set_reviews_on_app (self, data->app, reviews);
 
        /* success */
        g_task_return_pointer (task, g_steal_pointer (&reviews), (GDestroyNotify) g_ptr_array_unref);