[evolution] Add e_client_cache_is_backend_dead().

[Matthew Barnes <mbarnes src gnome org>]

commit 2c195f2266a51cce9499e3bb968d0a7a0ce90091
Author: Matthew Barnes <mbarnes redhat com>
Date:   Wed Feb 20 15:30:17 2013 -0500

    Add e_client_cache_is_backend_dead().
    
    Returns TRUE if an EClient instance for the given source and extension
    name was recently discarded after having emitted a "backend-died" signal,
    and a replacement EClient instance has not yet been created.

 doc/reference/libeutil/libeutil-sections.txt |    1 +
 e-util/e-client-cache.c                      |   48 ++++++++++++++++++++++++++
 e-util/e-client-cache.h                      |    3 ++
 3 files changed, 52 insertions(+), 0 deletions(-)
---
diff --git a/doc/reference/libeutil/libeutil-sections.txt b/doc/reference/libeutil/libeutil-sections.txt
index 7f092b0..3a4d5dd 100644
--- a/doc/reference/libeutil/libeutil-sections.txt
+++ b/doc/reference/libeutil/libeutil-sections.txt
@@ -1260,6 +1260,7 @@ e_client_cache_get_client_sync
 e_client_cache_get_client
 e_client_cache_get_client_finish
 e_client_cache_ref_cached_client
+e_client_cache_is_backend_dead
 <SUBSECTION Standard>
 E_CLIENT_CACHE
 E_IS_CLIENT_CACHE
diff --git a/e-util/e-client-cache.c b/e-util/e-client-cache.c
index 3709104..779ae9f 100644
--- a/e-util/e-client-cache.c
+++ b/e-util/e-client-cache.c
@@ -62,6 +62,7 @@ struct _ClientData {
        GWeakRef cache;
        EClient *client;
        GQueue connecting;
+       gboolean dead_backend;
        gulong backend_died_handler_id;
        gulong backend_error_handler_id;
        gulong notify_handler_id;
@@ -411,6 +412,14 @@ client_cache_backend_died_cb (EClient *client,
 
                g_object_unref (cache);
        }
+
+       /* Discard the EClient and tag the backend as
+        * dead until we create a replacement EClient. */
+       g_mutex_lock (&client_data->lock);
+       g_clear_object (&client_data->client);
+       client_data->dead_backend = TRUE;
+       g_mutex_unlock (&client_data->lock);
+
 }
 
 static void
@@ -495,7 +504,11 @@ client_cache_process_results (ClientData *client_data,
        if (client != NULL) {
                EClientCache *cache;
 
+               /* Make sure we're not leaking a reference. */
+               g_warn_if_fail (client_data->client == NULL);
+
                client_data->client = g_object_ref (client);
+               client_data->dead_backend = FALSE;
 
                cache = g_weak_ref_get (&client_data->cache);
 
@@ -1202,3 +1215,38 @@ e_client_cache_ref_cached_client (EClientCache *cache,
 
        return client;
 }
+
+/**
+ * e_client_cache_is_backend_dead:
+ * @cache: an #EClientCache
+ * @source: an #ESource
+ * @extension_name: an extension name
+ *
+ * Returns %TRUE if an #EClient instance for @source and @extension_name
+ * was recently discarded after having emitted a #EClient::backend-died
+ * signal, and a replacement #EClient instance has not yet been created.
+ *
+ * Returns: whether the backend for @source and @extension_name died
+ **/
+gboolean
+e_client_cache_is_backend_dead (EClientCache *cache,
+                                ESource *source,
+                                const gchar *extension_name)
+{
+       ClientData *client_data;
+       gboolean dead_backend = FALSE;
+
+       g_return_val_if_fail (E_IS_CLIENT_CACHE (cache), FALSE);
+       g_return_val_if_fail (E_IS_SOURCE (source), FALSE);
+       g_return_val_if_fail (extension_name != NULL, FALSE);
+
+       client_data = client_ht_lookup (cache, source, extension_name);
+
+       if (client_data != NULL) {
+               dead_backend = client_data->dead_backend;
+               client_data_unref (client_data);
+       }
+
+       return dead_backend;
+}
+
diff --git a/e-util/e-client-cache.h b/e-util/e-client-cache.h
index 89a70c6..9c92b09 100644
--- a/e-util/e-client-cache.h
+++ b/e-util/e-client-cache.h
@@ -102,6 +102,9 @@ EClient *   e_client_cache_ref_cached_client
                                                (EClientCache *cache,
                                                 ESource *source,
                                                 const gchar *extension_name);
+gboolean       e_client_cache_is_backend_dead  (EClientCache *cache,
+                                                ESource *source,
+                                                const gchar *extension_name);
 
 G_END_DECLS