Merge branch 'avoid-resource-allocation' into 'main'

resource: Add g_resource[s]_has_children and avoid a pointless allocation

See merge request GNOME/glib!4245

.gitlab-ci.yml

@@ -11,11 +11,11 @@ cache:
     - _ccache/
 
 variables:
-  FEDORA_IMAGE: "registry.gitlab.gnome.org/gnome/glib/fedora:v39.2"
+  FEDORA_IMAGE: "registry.gitlab.gnome.org/gnome/glib/fedora:v39.3"
   COVERITY_IMAGE: "registry.gitlab.gnome.org/gnome/glib/coverity:v7"
-  DEBIAN_IMAGE: "registry.gitlab.gnome.org/gnome/glib/debian-stable:v20"
-  ALPINE_IMAGE: "registry.gitlab.gnome.org/gnome/glib/alpine:v4"
-  MINGW_IMAGE: "registry.gitlab.gnome.org/gnome/glib/mingw:v39.2"
+  DEBIAN_IMAGE: "registry.gitlab.gnome.org/gnome/glib/debian-stable:v21"
+  ALPINE_IMAGE: "registry.gitlab.gnome.org/gnome/glib/alpine:v5"
+  MINGW_IMAGE: "registry.gitlab.gnome.org/gnome/glib/mingw:v39.3"
   GOBJECT_INTROSPECTION_TAG: "1.80.1"
   MESON_TEST_TIMEOUT_MULTIPLIER: 4
   G_MESSAGES_DEBUG: all
@@ -584,6 +584,8 @@ vs2017-x64:
     - win32-ps
   needs: []
   variables:
+    GIT_SUBMODULE_STRATEGY: recursive
+    GIT_SUBMODULE_DEPTH: 1
     PYTHONUTF8: "1"
   script:
     # FIXME: These should use --wrap-mode=nodownload but the Windows CI machines
@@ -615,6 +617,8 @@ vs2017-x64-static:
     - win32-ps
   needs: []
   variables:
+    GIT_SUBMODULE_STRATEGY: recursive
+    GIT_SUBMODULE_DEPTH: 1
     PYTHONUTF8: "1"
   script:
     # FIXME: These should use --wrap-mode=nodownload but the Windows CI machines

.gitlab-ci/mingw.Dockerfile

@@ -1,4 +1,4 @@
-FROM registry.gitlab.gnome.org/gnome/glib/fedora:v39.2
+FROM registry.gitlab.gnome.org/gnome/glib/fedora:v39.3
 
 USER root
 

.gitmodules

@@ -1,5 +1,5 @@
 [submodule "subprojects/gvdb"]
 	path = subprojects/gvdb
 	url = ../../GNOME/gvdb.git
-	branch = 0854af0fdb6d527a8d1999835ac2c5059976c210
+	branch = 2b42fc75f09dbe1cd1057580b5782b08f2dcb400
 	shallow = true

gio/gresource.c

@@ -923,6 +923,44 @@ g_resource_get_info (GResource             *resource,
   return do_lookup (resource, path, lookup_flags, size, flags, NULL, NULL, error);
 }
 
+static inline const char *
+ensure_slash_suffix (const char  *path,
+                     char        *local_str,
+                     gsize        len,
+                     char       **free_path)
+{
+  gsize path_len;
+
+  path_len = strlen (path);
+
+  if G_UNLIKELY (path[path_len-1] != '/')
+    {
+      if (path_len < len - 2)
+        {
+          /*
+           * We got a path that does not have a trailing /. It is not the
+           * ideal use of this API as we require trailing / for our lookup
+           * into gvdb. Some degenerate application configurations can hit
+           * this code path quite a bit, so we try to avoid using the
+           * g_strconcat()/g_free().
+           */
+          memcpy (local_str, path, path_len);
+          local_str[path_len] = '/';
+          local_str[path_len+1] = 0;
+          return local_str;
+        }
+      else
+        {
+          *free_path = g_strconcat (path, "/", NULL);
+          return *free_path;
+        }
+    }
+  else
+    {
+      return path;
+    }
+}
+
 /**
  * g_resource_enumerate_children:
  * @resource: A #GResource
@@ -949,17 +987,14 @@ g_resource_enumerate_children (GResource             *resource,
                                GResourceLookupFlags   lookup_flags,
                                GError               **error)
 {
-  gchar local_str[256];
-  const gchar *path_with_slash;
-  gchar **children;
-  gchar *free_path = NULL;
-  gsize path_len;
-
-  /*
-   * Size of 256 is arbitrarily chosen based on being large enough
+  /* Size of 256 is arbitrarily chosen based on being large enough
    * for pretty much everything we come across, but not cumbersome
    * on the stack. It also matches common cacheline sizes.
    */
+  gchar local_str[256];
+  const char *path_with_slash;
+  char *free_path = NULL;
+  gchar **children;
 
   if (*path == 0)
     {
@@ -970,35 +1005,10 @@ g_resource_enumerate_children (GResource             *resource,
       return NULL;
     }
 
-  path_len = strlen (path);
-
-  if G_UNLIKELY (path[path_len-1] != '/')
-    {
-      if (path_len < sizeof (local_str) - 2)
-        {
-          /*
-           * We got a path that does not have a trailing /. It is not the
-           * ideal use of this API as we require trailing / for our lookup
-           * into gvdb. Some degenerate application configurations can hit
-           * this code path quite a bit, so we try to avoid using the
-           * g_strconcat()/g_free().
-           */
-          memcpy (local_str, path, path_len);
-          local_str[path_len] = '/';
-          local_str[path_len+1] = 0;
-          path_with_slash = local_str;
-        }
-      else
-        {
-          path_with_slash = free_path = g_strconcat (path, "/", NULL);
-        }
-    }
-  else
-    {
-      path_with_slash = path;
-    }
+  path_with_slash = ensure_slash_suffix (path, local_str, sizeof (local_str), &free_path);
 
   children = gvdb_table_list (resource->table, path_with_slash);
+
   g_free (free_path);
 
   if (children == NULL)
@@ -1013,6 +1023,43 @@ g_resource_enumerate_children (GResource             *resource,
   return children;
 }
 
+/**
+ * g_resource_has_children:
+ * @resource: A #GResource
+ * @path: A pathname inside the resource
+ *
+ * Returns whether the specified @path in the resource
+ * has children.
+ *
+ * Returns: %TRUE if @path has children
+ *
+ * Since: 2.84
+ */
+gboolean
+g_resource_has_children (GResource  *resource,
+                         const char *path)
+{
+  /* Size of 256 is arbitrarily chosen based on being large enough
+   * for pretty much everything we come across, but not cumbersome
+   * on the stack. It also matches common cacheline sizes.
+   */
+  char local_str[256];
+  const char *path_with_slash;
+  guint n;
+  char *freeme = NULL;
+
+  if (*path == 0)
+    return FALSE;
+
+  path_with_slash = ensure_slash_suffix (path, local_str, sizeof (local_str), &freeme);
+
+  n = gvdb_table_n_children (resource->table, path_with_slash);
+
+  g_free (freeme);
+
+  return n > 0;
+}
+
 static GRWLock resources_lock;
 static GList *registered_resources;
 
@@ -1291,6 +1338,39 @@ g_resources_enumerate_children (const gchar           *path,
     }
 }
 
+/**
+ * g_resources_has_children:
+ * @path: A pathname
+ *
+ * Returns whether the specified @path in the set of
+ * globally registered resources has children.
+ *
+ * Returns: %TRUE if @patch has children
+ *
+ * Since: 2.84
+ */
+gboolean
+g_resources_has_children (const char *path)
+{
+  register_lazy_static_resources ();
+
+  g_rw_lock_reader_lock (&resources_lock);
+
+  for (GList *l = registered_resources; l != NULL; l = l->next)
+    {
+      GResource *r = l->data;
+
+      if (g_resource_has_children (r, path))
+        {
+          g_rw_lock_reader_unlock (&resources_lock);
+          return TRUE;
+        }
+    }
+
+  g_rw_lock_reader_unlock (&resources_lock);
+  return FALSE;
+}
+
 /**
  * g_resources_get_info:
  * @path: A pathname inside the resource

gio/gresource.h

@@ -119,6 +119,12 @@ gboolean      g_resources_get_info           (const char            *path,
 					      guint32               *flags,
 					      GError               **error);
 
+GIO_AVAILABLE_IN_2_84
+gboolean      g_resource_has_children        (GResource             *resource,
+                                              const char            *path);
+GIO_AVAILABLE_IN_2_84
+gboolean      g_resources_has_children       (const char            *path);
+
 
 GIO_AVAILABLE_IN_2_32
 void          g_static_resource_init          (GStaticResource *static_resource);

gio/gresourcefile.c

@@ -455,21 +455,14 @@ g_resource_file_query_info (GFile                *file,
   gboolean res;
   gsize size = 0;
   guint32 resource_flags = 0;
-  char **children;
   gboolean is_dir;
   char *base;
 
-  is_dir = FALSE;
-  children = g_resources_enumerate_children (resource->path, 0, NULL);
-  if (children != NULL)
-    {
-      g_strfreev (children);
-      is_dir = TRUE;
-    }
-
   /* root is always there */
   if (strcmp ("/", resource->path) == 0)
     is_dir = TRUE;
+  else
+    is_dir = g_resources_has_children (resource->path);
 
   if (!is_dir)
     {

gio/tests/resources.c

@@ -1046,6 +1046,31 @@ test_overlay (void)
   g_test_trap_assert_passed ();
 }
 
+static void
+test_resource_has_children (void)
+{
+  GResource *resource;
+  GError *error = NULL;
+
+  g_assert_true (g_resources_has_children ("/auto_loaded"));
+  g_assert_true (g_resources_has_children ("/auto_loaded/"));
+  g_assert_false (g_resources_has_children ("/auto_loaded/test1.txt"));
+  g_assert_false (g_resources_has_children ("/no/such/prefix"));
+  g_assert_false (g_resources_has_children (""));
+
+  resource = g_resource_load (g_test_get_filename (G_TEST_BUILT, "test.gresource", NULL), &error);
+  g_assert_nonnull (resource);
+  g_assert_no_error (error);
+
+  g_assert_true (g_resource_has_children (resource, "/a_prefix"));
+  g_assert_true (g_resource_has_children (resource, "/a_prefix/"));
+  g_assert_false (g_resource_has_children (resource, "/a_prefix/test2.txt"));
+  g_assert_false (g_resource_has_children (resource, "/no/such/prefix"));
+  g_assert_false (g_resource_has_children (resource, ""));
+
+  g_resource_unref (resource);
+}
+
 int
 main (int   argc,
       char *argv[])
@@ -1075,6 +1100,7 @@ main (int   argc,
   g_test_add_func ("/resource/64k", test_resource_64k);
   g_test_add_func ("/resource/overlay", test_overlay);
   g_test_add_func ("/resource/digits", test_resource_digits);
+  g_test_add_func ("/resource/has-children", test_resource_has_children);
 
   return g_test_run();
 }

meson.build

@@ -2239,7 +2239,7 @@ else
 endif
 
 # Import the gvdb sources as a subproject to avoid having the copylib in-tree
-subproject('gvdb')
+subproject('gvdb', default_options: {'tests': false})
 gvdb_dep = dependency('gvdb')
 
 libm = cc.find_library('m', required : false)

subprojects/gvdb

@@ -1 +1 @@
-Subproject commit 0854af0fdb6d527a8d1999835ac2c5059976c210
+Subproject commit 2b42fc75f09dbe1cd1057580b5782b08f2dcb400

subprojects/gvdb.wrap

@@ -1,7 +1,7 @@
 [wrap-git]
 directory=gvdb
 url=https://gitlab.gnome.org/GNOME/gvdb.git
-revision=0854af0fdb6d527a8d1999835ac2c5059976c210
+revision=2b42fc75f09dbe1cd1057580b5782b08f2dcb400
 depth=1
 
 [provide]