Add EClientCache.

New class to help reduce code duplication and centralize some EClient
handling policies.

Benefits:

- EClient instances can be shared across the entire application.

- Centralized rebroadcasting of "backend-died" and "backend-error"
  signals emitted from cached EClient instances.

- Automatic cache invalidation when backends crash.  The EClient
  is discarded, and a new instance is created on the next request.

1 files changed, 106 insertions, 0 deletions

diff --git a/e-util/e-client-cache.h b/e-util/e-client-cache.h
new file mode 100644
index 0000000000..d4e3799161
--- /dev/null
+++ b/e-util/e-client-cache.h
@@ -0,0 +1,106 @@
+/*
+ * e-client-cache.h
+ *
+ * This program 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) version 3.
+ *
+ * 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with the program; if not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+#if !defined (__E_UTIL_H_INSIDE__) && !defined (LIBEUTIL_COMPILATION)
+#error "Only <e-util/e-util.h> should be included directly."
+#endif
+
+#ifndef E_CLIENT_CACHE_H
+#define E_CLIENT_CACHE_H
+
+#include <e-util/e-alert.h>
+#include <libedataserver/libedataserver.h>
+
+/* Standard GObject macros */
+#define E_TYPE_CLIENT_CACHE \
+	(e_client_cache_get_type ())
+#define E_CLIENT_CACHE(obj) \
+	(G_TYPE_CHECK_INSTANCE_CAST \
+	((obj), E_TYPE_CLIENT_CACHE, EClientCache))
+#define E_CLIENT_CACHE_CLASS(cls) \
+	(G_TYPE_CHECK_CLASS_CAST \
+	((cls), E_TYPE_CLIENT_CACHE, EClientCacheClass))
+#define E_IS_CLIENT_CACHE(obj) \
+	(G_TYPE_CHECK_INSTANCE_TYPE \
+	((obj), E_TYPE_CLIENT_CACHE))
+#define E_IS_CLIENT_CACHE_CLASS(cls) \
+	(G_TYPE_CHECK_CLASS_TYPE \
+	((cls), E_TYPE_CLIENT_CACHE))
+#define E_CLIENT_CACHE_GET_CLASS(obj) \
+	(G_TYPE_INSTANCE_GET_CLASS \
+	((obj), E_TYPE_CLIENT_CACHE, EClientCacheClass))
+
+G_BEGIN_DECLS
+
+typedef struct _EClientCache EClientCache;
+typedef struct _EClientCacheClass EClientCacheClass;
+typedef struct _EClientCachePrivate EClientCachePrivate;
+
+/**
+ * EClientCache:
+ *
+ * Contains only private data that should be read and manipulated using the
+ * functions below.
+ **/
+struct _EClientCache {
+	GObject parent;
+	EClientCachePrivate *priv;
+};
+
+struct _EClientCacheClass {
+	GObjectClass parent_class;
+
+	/* Signals */
+	void		(*backend_died)		(EClientCache *cache,
+						 EClient *client,
+						 EAlert *alert);
+	void		(*backend_error)	(EClientCache *cache,
+						 EClient *client,
+						 EAlert *alert);
+	void		(*client_created)	(EClientCache *cache,
+						 EClient *client);
+};
+
+GType		e_client_cache_get_type		(void) G_GNUC_CONST;
+EClientCache *	e_client_cache_new		(ESourceRegistry *registry);
+ESourceRegistry *
+		e_client_cache_ref_registry	(EClientCache *cache);
+EClient *	e_client_cache_get_client_sync	(EClientCache *cache,
+						 ESource *source,
+						 const gchar *extension_name,
+						 GCancellable *cancellable,
+						 GError **error);
+void		e_client_cache_get_client	(EClientCache *cache,
+						 ESource *source,
+						 const gchar *extension_name,
+						 GCancellable *cancellable,
+						 GAsyncReadyCallback callback,
+						 gpointer user_data);
+EClient *	e_client_cache_get_client_finish
+						(EClientCache *cache,
+						 GAsyncResult *result,
+						 GError **error);
+EClient *	e_client_cache_ref_cached_client
+						(EClientCache *cache,
+						 ESource *source,
+						 const gchar *extension_name);
+
+G_END_DECLS
+
+#endif /* E_CLIENT_CACHE_H */
+