[epiphany/wip/sync: 52/83] sync: Add EphySynchronizable interface that all synced objects need to implement

[Gabriel Ivașcu <gabrielivascu src gnome org>]

commit 2e4e66e46f974dfb23be93938a1e6c81ed230051
Author: Gabriel Ivascu <ivascu gabriel59 gmail com>
Date:   Wed Mar 15 17:32:43 2017 +0200

    sync: Add EphySynchronizable interface that all synced objects need to implement

 src/Makefile.am                |    2 +
 src/sync/ephy-synchronizable.c |  119 ++++++++++++++++++++++++++++++++++++++++
 src/sync/ephy-synchronizable.h |   54 ++++++++++++++++++
 3 files changed, 175 insertions(+), 0 deletions(-)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index aab514a..478f7b6 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -76,6 +76,8 @@ libephymain_la_SOURCES = \
 
 if ENABLE_SYNC
 libephymain_la_SOURCES += \
+       sync/ephy-synchronizable.c              \
+       sync/ephy-synchronizable.h              \
        sync/ephy-sync-crypto.c                 \
        sync/ephy-sync-crypto.h                 \
        sync/ephy-sync-secret.c                 \
diff --git a/src/sync/ephy-synchronizable.c b/src/sync/ephy-synchronizable.c
new file mode 100644
index 0000000..b959f16
--- /dev/null
+++ b/src/sync/ephy-synchronizable.c
@@ -0,0 +1,119 @@
+/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/*
+ *  Copyright © 2017 Gabriel Ivascu <ivascu gabriel59 gmail com>
+ *
+ *  This file is part of Epiphany.
+ *
+ *  Epiphany 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.
+ *
+ *  Epiphany 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 Epiphany.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "config.h"
+#include "ephy-synchronizable.h"
+
+G_DEFINE_INTERFACE (EphySynchronizable, ephy_synchronizable, JSON_TYPE_SERIALIZABLE);
+
+enum {
+  PROP_0,
+  PROP_ID,
+  LAST_PROP
+};
+
+static void
+ephy_synchronizable_default_init (EphySynchronizableInterface *iface)
+{
+  iface->get_id = ephy_synchronizable_get_id;
+  iface->to_bso = ephy_synchronizable_to_bso;
+
+  g_object_interface_install_property (iface,
+                                       g_param_spec_string ("id",
+                                                            "ID",
+                                                            "The record's id",
+                                                            "112233445566",
+                                                            G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | 
G_PARAM_STATIC_STRINGS));
+}
+
+/**
+ * ephy_synchronizable_get_id:
+ * @synchronizable: an #EphySynchronizable
+ *
+ * Returns @synchronizable's id.
+ *
+ * Return value: (transfer none): @synchronizable's id
+ **/
+const char *
+ephy_synchronizable_get_id (EphySynchronizable *synchronizable)
+{
+  EphySynchronizableInterface *iface;
+
+  g_return_val_if_fail (EPHY_IS_SYNCHRONIZABLE (synchronizable), NULL);
+
+  iface = EPHY_SYNCHRONIZABLE_GET_IFACE (synchronizable);
+  return iface->get_id (synchronizable);
+}
+
+/**
+ * ephy_synchronizable_to_bso:
+ * @synchronizable: an #EphySynchronizable
+ * @error: return location for a #GError, or %NULL
+ *
+ * Converts an #EphySynchronizable into its string representation
+ * of a Basic Storage Object from the client's point of view
+ * (i.e. the %modified field is missing). Check the BSO format documentation
+ * (https://docs.services.mozilla.com/storage/apis-1.5.html#basic-storage-object)
+ * for more details.
+ *
+ * Return value: (transfer full): @synchronizable's BSO's string representation
+ **/
+char *
+ephy_synchronizable_to_bso (EphySynchronizable  *synchronizable,
+                            GError             **error)
+{
+  EphySynchronizableInterface *iface;
+
+  g_return_val_if_fail (EPHY_IS_SYNCHRONIZABLE (synchronizable), NULL);
+
+  iface = EPHY_SYNCHRONIZABLE_GET_IFACE (synchronizable);
+  return iface->to_bso (synchronizable, error);
+}
+
+/**
+ * ephy_synchronizable_from_bso:
+ * @bso: an #JsonObject holding the JSON representation of a Basic Storage Object
+ * @gtype: the #GType of object to construct
+ * @error: return location for a #GError, or %NULL
+ *
+ * Converts a JSON representation of a Basic Storage Object
+ * from the server's point of view (i.e. the %modified field is present)
+ * into an object of type @gtype. Check the BSO format documentation
+ * (https://docs.services.mozilla.com/storage/apis-1.5.html#basic-storage-object)
+ * for more details.
+ *
+ * Note: The @gtype must be a sub-type of #EphySynchronizable (i.e. must
+ * implement the #EphySynchronizable interface). It is up to the caller to cast
+ * the returned #GObject to the type of @gtype.
+ *
+ *  Return value: (transfer full): a #GObject or %NULL
+ **/
+GObject *
+ephy_synchronizable_from_bso (JsonObject  *bso,
+                              GType        gtype,
+                              GError     **error)
+{
+  g_return_val_if_fail (bso, NULL);
+
+  /* TODO: Implement this. */
+
+  return NULL;
+}
diff --git a/src/sync/ephy-synchronizable.h b/src/sync/ephy-synchronizable.h
new file mode 100644
index 0000000..6263d4e
--- /dev/null
+++ b/src/sync/ephy-synchronizable.h
@@ -0,0 +1,54 @@
+/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/*
+ *  Copyright © 2017 Gabriel Ivascu <ivascu gabriel59 gmail com>
+ *
+ *  This file is part of Epiphany.
+ *
+ *  Epiphany 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.
+ *
+ *  Epiphany 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 Epiphany.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <glib-object.h>
+#include <json-glib/json-glib.h>
+
+G_BEGIN_DECLS
+
+#define EPHY_TYPE_SYNCHRONIZABLE (ephy_synchronizable_get_type ())
+
+/* FIXME: This needs to be defined manually for json-glib < 1.2.4
+ * G_DEFINE_AUTOPTR_CLEANUP_FUNC (JsonSerializable, g_object_unref)
+ */
+
+G_DECLARE_INTERFACE (EphySynchronizable, ephy_synchronizable, EPHY, SYNCHRONIZABLE, JsonSerializable)
+
+struct _EphySynchronizableInterface {
+  GTypeInterface parent_iface;
+
+  const char * (*get_id)  (EphySynchronizable  *synchronizable);
+
+  char *       (*to_bso)  (EphySynchronizable  *synchronizable,
+                           GError             **error);
+};
+
+const char          *ephy_synchronizable_get_id   (EphySynchronizable  *synchronizable);
+char                *ephy_synchronizable_to_bso   (EphySynchronizable  *synchronizable,
+                                                   GError             **error);
+/* This can't be an interface method because we lack the EphySynchronizable object.
+ * Think of it as more of an utility function. */
+GObject             *ephy_synchronizable_from_bso (JsonObject          *bso,
+                                                   GType                gtype,
+                                                   GError             **error);
+
+G_END_DECLS