libostree: Make OstreeRemote a public and internal API

Previously it was static to ostree-repo.c. Make it usable throughout
libostree so it can be used by an upcoming commit, but also expose the
typedef and reference counting functions so that opaque OstreeRemote
pointers can be used by user code, in anticipation of exposing more of
its API publicly in future.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Closes: #832
Approved by: cgwalters

src/libostree/ostree-remote.c

@@ -0,0 +1,144 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright © 2011 Colin Walters <walters@verbum.org>
+ * Copyright © 2015 Red Hat, Inc.
+ * Copyright © 2017 Endless Mobile, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Authors:
+ *  - Colin Walters <walters@verbum.org>
+ *  - Philip Withnall <withnall@endlessm.com>
+ */
+
+#include "config.h"
+
+#include <gio/gio.h>
+#include <glib.h>
+#include <glib-object.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "ostree-remote.h"
+#include "ostree-remote-private.h"
+#include "ot-keyfile-utils.h"
+
+/**
+ * SECTION:remote
+ *
+ * The #OstreeRemote structure represents the configuration for a single remote
+ * repository. Currently, all configuration is handled internally, and
+ * #OstreeRemote objects are represented by their textual name handle, or by an
+ * opaque pointer (which can be reference counted if needed).
+ *
+ * #OstreeRemote provides configuration for accessing a remote, but does not
+ * provide the results of accessing a remote, such as information about what
+ * refs are currently on a remote, or the commits they currently point to. Use
+ * #OstreeRepo in combination with an #OstreeRemote to query that information.
+ *
+ * Since: 2017.6
+ */
+
+OstreeRemote *
+ostree_remote_new (void)
+{
+  OstreeRemote *remote;
+
+  remote = g_slice_new0 (OstreeRemote);
+  remote->ref_count = 1;
+  remote->options = g_key_file_new ();
+
+  return remote;
+}
+
+OstreeRemote *
+ostree_remote_new_from_keyfile (GKeyFile    *keyfile,
+                                const gchar *group)
+{
+  g_autoptr(GMatchInfo) match = NULL;
+  OstreeRemote *remote;
+
+  static gsize regex_initialized;
+  static GRegex *regex;
+
+  if (g_once_init_enter (&regex_initialized))
+    {
+      regex = g_regex_new ("^remote \"(.+)\"$", 0, 0, NULL);
+      g_assert (regex);
+      g_once_init_leave (&regex_initialized, 1);
+    }
+
+  /* Sanity check */
+  g_return_val_if_fail (g_key_file_has_group (keyfile, group), NULL);
+
+  /* If group name doesn't fit the pattern, fail. */
+  if (!g_regex_match (regex, group, 0, &match))
+    return NULL;
+
+  remote = ostree_remote_new ();
+  remote->name = g_match_info_fetch (match, 1);
+  remote->group = g_strdup (group);
+  remote->keyring = g_strdup_printf ("%s.trustedkeys.gpg", remote->name);
+
+  ot_keyfile_copy_group (keyfile, remote->options, group);
+
+  return remote;
+}
+
+/**
+ * ostree_remote_ref:
+ * @remote: an #OstreeRemote
+ *
+ * Increase the reference count on the given @remote.
+ *
+ * Returns: (transfer full): a copy of @remote, for convenience
+ * Since: 2017.6
+ */
+OstreeRemote *
+ostree_remote_ref (OstreeRemote *remote)
+{
+  gint refcount;
+  g_return_val_if_fail (remote != NULL, NULL);
+  refcount = g_atomic_int_add (&remote->ref_count, 1);
+  g_assert (refcount > 0);
+  return remote;
+}
+
+/**
+ * ostree_remote_unref:
+ * @remote: (transfer full): an #OstreeRemote
+ *
+ * Decrease the reference count on the given @remote and free it if the
+ * reference count reaches 0.
+ *
+ * Since: 2017.6
+ */
+void
+ostree_remote_unref (OstreeRemote *remote)
+{
+  g_return_if_fail (remote != NULL);
+  g_return_if_fail (remote->ref_count > 0);
+
+  if (g_atomic_int_dec_and_test (&remote->ref_count))
+    {
+      g_clear_pointer (&remote->name, g_free);
+      g_clear_pointer (&remote->group, g_free);
+      g_clear_pointer (&remote->keyring, g_free);
+      g_clear_object (&remote->file);
+      g_clear_pointer (&remote->options, g_key_file_free);
+      g_slice_free (OstreeRemote, remote);
+    }
+}