libsysprof-profile: add scaffolding for base objects

The goal here is to have a fairly small exposed API surface for profiling
similar to libsysprof-analyze where implementation details are hidden.

 SysprofProfiler - Where you setup your recording
 SysprofInstrument - What you add to a profiler to extract data
 SysprofRecording - Represents an active recording w/ instruments

src/libsysprof-profile/sysprof-profiler.c

@@ -0,0 +1,140 @@
+/* sysprof-profiler.c
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include "sysprof-profiler.h"
+
+struct _SysprofProfiler
+{
+  GObject parent_instance;
+  GPtrArray *instruments;
+};
+
+enum {
+  PROP_0,
+  N_PROPS
+};
+
+G_DEFINE_FINAL_TYPE (SysprofProfiler, sysprof_profiler, G_TYPE_OBJECT)
+
+static void
+sysprof_profiler_finalize (GObject *object)
+{
+  G_OBJECT_CLASS (sysprof_profiler_parent_class)->finalize (object);
+}
+
+static void
+sysprof_profiler_get_property (GObject    *object,
+                               guint       prop_id,
+                               GValue     *value,
+                               GParamSpec *pspec)
+{
+  switch (prop_id)
+    {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
+
+static void
+sysprof_profiler_set_property (GObject      *object,
+                               guint         prop_id,
+                               const GValue *value,
+                               GParamSpec   *pspec)
+{
+  switch (prop_id)
+    {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
+
+static void
+sysprof_profiler_class_init (SysprofProfilerClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->finalize = sysprof_profiler_finalize;
+  object_class->get_property = sysprof_profiler_get_property;
+  object_class->set_property = sysprof_profiler_set_property;
+}
+
+static void
+sysprof_profiler_init (SysprofProfiler *self)
+{
+  self->instruments = g_ptr_array_new_with_free_func (g_object_unref);
+}
+
+SysprofProfiler *
+sysprof_profiler_new (void)
+{
+  return g_object_new (SYSPROF_TYPE_PROFILER, NULL);
+}
+
+void
+sysprof_profiler_add_instrument (SysprofProfiler   *self,
+                                 SysprofInstrument *instrument)
+{
+  g_return_if_fail (SYSPROF_IS_PROFILER (self));
+  g_return_if_fail (SYSPROF_IS_INSTRUMENT (instrument));
+
+  g_ptr_array_add (self->instruments, g_object_ref (instrument));
+}
+
+void
+sysprof_profiler_record_async (SysprofProfiler     *self,
+                               GCancellable        *cancellable,
+                               GAsyncReadyCallback  callback,
+                               gpointer             user_data)
+{
+  g_autoptr(GTask) task = NULL;
+
+  g_return_if_fail (SYSPROF_IS_PROFILER (self));
+  g_return_if_fail (!cancellable || G_IS_CANCELLABLE (cancellable));
+
+  task = g_task_new (self, cancellable, callback, user_data);
+  g_task_set_source_tag (task, sysprof_profiler_record_async);
+
+
+}
+
+/**
+ * sysprof_profiler_record_finish:
+ * @self: a #SysprofProfiler
+ * @result: a #GAsyncResult
+ * @error: a location for a #GError
+ *
+ * Completes an asynchronous request to start recording.
+ *
+ * Returns: (transfer full): an active #SysprofRecording if successful;
+ *   otherwise %NULL and @error is set.
+ */
+SysprofRecording *
+sysprof_profiler_record_finish (SysprofProfiler  *self,
+                                GAsyncResult     *result,
+                                GError          **error)
+{
+  g_return_val_if_fail (SYSPROF_IS_PROFILER (self), NULL);
+  g_return_val_if_fail (G_IS_TASK (result), NULL);
+  g_return_val_if_fail (g_task_is_valid (result, self), NULL);
+
+  return g_task_propagate_pointer (G_TASK (result), error);
+}