[evolution-data-server] ECollectionBackend: Add a read-only "proxy-resolver" property.

[Matthew Barnes <mbarnes src gnome org>]

commit 5183c508b8961ed3c5dcbb2640e433213f906164
Author: Matthew Barnes <mbarnes redhat com>
Date:   Wed Oct 9 20:11:05 2013 -0400

    ECollectionBackend: Add a read-only "proxy-resolver" property.
    
    Tracks a GProxyResolver for the backend, which is actually another
    ESource with an ESourceProxy extension (if applicable to the backend).
    
    New functions:
    
      e_collection_backend_ref_proxy_resolver().

 .../reference/libebackend/libebackend-sections.txt |    1 +
 libebackend/e-collection-backend.c                 |  142 +++++++++++++++++++-
 libebackend/e-collection-backend.h                 |    3 +
 3 files changed, 144 insertions(+), 2 deletions(-)
---
diff --git a/docs/reference/libebackend/libebackend-sections.txt 
b/docs/reference/libebackend/libebackend-sections.txt
index 189f002..9b951a8 100644
--- a/docs/reference/libebackend/libebackend-sections.txt
+++ b/docs/reference/libebackend/libebackend-sections.txt
@@ -126,6 +126,7 @@ EBackendFactoryPrivate
 <TITLE>ECollectionBackend</TITLE>
 ECollectionBackend
 e_collection_backend_new_child
+e_collection_backend_ref_proxy_resolver
 e_collection_backend_ref_server
 e_collection_backend_get_cache_dir
 e_collection_backend_dup_resource_id
diff --git a/libebackend/e-collection-backend.c b/libebackend/e-collection-backend.c
index 2baa6a4..41c521f 100644
--- a/libebackend/e-collection-backend.c
+++ b/libebackend/e-collection-backend.c
@@ -59,8 +59,13 @@ struct _ECollectionBackendPrivate {
        GHashTable *children;
        GMutex children_lock;
 
+       GMutex property_lock;
+       GProxyResolver *proxy_resolver;
        gchar *cache_dir;
 
+       ESource *authentication_source;
+       gulong auth_source_changed_handler_id;
+
        /* Resource ID -> ESource */
        GHashTable *unclaimed_resources;
        GMutex unclaimed_resources_lock;
@@ -71,6 +76,7 @@ struct _ECollectionBackendPrivate {
 
 enum {
        PROP_0,
+       PROP_PROXY_RESOLVER,
        PROP_SERVER
 };
 
@@ -490,6 +496,73 @@ collection_backend_populate_idle_cb (gpointer user_data)
 }
 
 static void
+collection_backend_update_proxy_resolver (ECollectionBackend *backend)
+{
+       GProxyResolver *proxy_resolver = NULL;
+       ESourceAuthentication *extension;
+       ESource *source = NULL;
+       gboolean notify = FALSE;
+       gchar *uid;
+
+       extension = e_source_get_extension (
+               backend->priv->authentication_source,
+               E_SOURCE_EXTENSION_AUTHENTICATION);
+
+       uid = e_source_authentication_dup_proxy_uid (extension);
+       if (uid != NULL) {
+               ESourceRegistryServer *server;
+
+               server = e_collection_backend_ref_server (backend);
+               source = e_source_registry_server_ref_source (server, uid);
+               g_object_unref (server);
+               g_free (uid);
+       }
+
+       if (source != NULL) {
+               proxy_resolver = G_PROXY_RESOLVER (source);
+               if (!g_proxy_resolver_is_supported (proxy_resolver))
+                       proxy_resolver = NULL;
+       }
+
+       g_mutex_lock (&backend->priv->property_lock);
+
+       /* Emitting a "notify" signal unnecessarily might have
+        * unwanted side effects like cancelling a SoupMessage.
+        * Only emit if we now have a different GProxyResolver. */
+
+       if (proxy_resolver != backend->priv->proxy_resolver) {
+               g_clear_object (&backend->priv->proxy_resolver);
+               backend->priv->proxy_resolver = proxy_resolver;
+
+               if (proxy_resolver != NULL)
+                       g_object_ref (proxy_resolver);
+
+               notify = TRUE;
+       }
+
+       g_mutex_unlock (&backend->priv->property_lock);
+
+       if (notify)
+               g_object_notify (G_OBJECT (backend), "proxy-resolver");
+
+       g_clear_object (&source);
+}
+
+static void
+collection_backend_auth_source_changed_cb (ESource *authentication_source,
+                                           GWeakRef *backend_weak_ref)
+{
+       ECollectionBackend *backend;
+
+       backend = g_weak_ref_get (backend_weak_ref);
+
+       if (backend != NULL) {
+               collection_backend_update_proxy_resolver (backend);
+               g_object_unref (backend);
+       }
+}
+
+static void
 collection_backend_set_server (ECollectionBackend *backend,
                                ESourceRegistryServer *server)
 {
@@ -555,6 +628,9 @@ collection_backend_dispose (GObject *object)
        g_hash_table_remove_all (priv->children);
        g_mutex_unlock (&priv->children_lock);
 
+       g_clear_object (&priv->proxy_resolver);
+       g_clear_object (&priv->authentication_source);
+
        g_mutex_lock (&priv->unclaimed_resources_lock);
        g_hash_table_remove_all (priv->unclaimed_resources);
        g_mutex_unlock (&priv->unclaimed_resources_lock);
@@ -573,6 +649,8 @@ collection_backend_finalize (GObject *object)
        g_hash_table_destroy (priv->children);
        g_mutex_clear (&priv->children_lock);
 
+       g_mutex_clear (&priv->property_lock);
+
        g_hash_table_destroy (priv->unclaimed_resources);
        g_mutex_clear (&priv->unclaimed_resources_lock);
 
@@ -597,6 +675,7 @@ collection_backend_constructed (GObject *object)
        G_OBJECT_CLASS (e_collection_backend_parent_class)->
                constructed (object);
 
+       server = e_collection_backend_ref_server (backend);
        source = e_backend_get_source (E_BACKEND (backend));
 
        /* Determine the backend's cache directory. */
@@ -607,6 +686,23 @@ collection_backend_constructed (GObject *object)
                user_cache_dir, "sources", collection_uid, NULL);
        g_mkdir_with_parents (backend->priv->cache_dir, 0700);
 
+       /* Track the proxy resolver for this backend. */
+       backend->priv->authentication_source =
+               e_source_registry_server_find_extension (
+               server, source, E_SOURCE_EXTENSION_AUTHENTICATION);
+       if (backend->priv->authentication_source != NULL) {
+               gulong handler_id;
+
+               handler_id = g_signal_connect_data (
+                       backend->priv->authentication_source, "changed",
+                       G_CALLBACK (collection_backend_auth_source_changed_cb),
+                       e_weak_ref_new (backend),
+                       (GClosureNotify) e_weak_ref_free, 0);
+               backend->priv->auth_source_changed_handler_id = handler_id;
+
+               collection_backend_update_proxy_resolver (backend);
+       }
+
        /* This requires the cache directory to be set. */
        collection_backend_load_resources (backend);
 
@@ -625,8 +721,6 @@ collection_backend_constructed (GObject *object)
         * from the server, which may trigger our own "child-added"
         * and "child-removed" signals. */
 
-       server = e_collection_backend_ref_server (backend);
-
        handler_id = g_signal_connect (
                server, "source-added",
                G_CALLBACK (collection_backend_source_added_cb), backend);
@@ -908,6 +1002,17 @@ e_collection_backend_class_init (ECollectionBackendClass *class)
 
        g_object_class_install_property (
                object_class,
+               PROP_PROXY_RESOLVER,
+               g_param_spec_object (
+                       "proxy-resolver",
+                       "Proxy Resolver",
+                       "The proxy resolver for this backend",
+                       G_TYPE_PROXY_RESOLVER,
+                       G_PARAM_READABLE |
+                       G_PARAM_STATIC_STRINGS));
+
+       g_object_class_install_property (
+               object_class,
                PROP_SERVER,
                g_param_spec_object (
                        "server",
@@ -984,6 +1089,7 @@ e_collection_backend_init (ECollectionBackend *backend)
        backend->priv = E_COLLECTION_BACKEND_GET_PRIVATE (backend);
        backend->priv->children = children;
        g_mutex_init (&backend->priv->children_lock);
+       g_mutex_init (&backend->priv->property_lock);
        backend->priv->unclaimed_resources = unclaimed_resources;
        g_mutex_init (&backend->priv->unclaimed_resources_lock);
 }
@@ -1040,6 +1146,38 @@ e_collection_backend_new_child (ECollectionBackend *backend,
 }
 
 /**
+ * e_collection_backend_ref_proxy_resolver:
+ * @backend: an #ECollectionBackend
+ *
+ * Returns the #GProxyResolver for @backend (if applicable), as indicated
+ * by the #ESourceAuthentication:proxy-uid of @backend's #EBackend:source
+ * or one of its ancestors.
+ *
+ * The returned #GProxyResolver is referenced for thread-safety and must
+ * be unreferenced with g_object_unref() when finished with it.
+ *
+ * Returns: a #GProxyResolver, or %NULL
+ *
+ * Since: 3.12
+ **/
+GProxyResolver *
+e_collection_backend_ref_proxy_resolver (ECollectionBackend *backend)
+{
+       GProxyResolver *proxy_resolver = NULL;
+
+       g_return_val_if_fail (E_IS_COLLECTION_BACKEND (backend), NULL);
+
+       g_mutex_lock (&backend->priv->property_lock);
+
+       if (backend->priv->proxy_resolver != NULL)
+               proxy_resolver = g_object_ref (backend->priv->proxy_resolver);
+
+       g_mutex_unlock (&backend->priv->property_lock);
+
+       return proxy_resolver;
+}
+
+/**
  * e_collection_backend_ref_server:
  * @backend: an #ECollectionBackend
  *
diff --git a/libebackend/e-collection-backend.h b/libebackend/e-collection-backend.h
index 1ebcd7f..2054571 100644
--- a/libebackend/e-collection-backend.h
+++ b/libebackend/e-collection-backend.h
@@ -113,6 +113,9 @@ struct _ECollectionBackendClass {
 GType          e_collection_backend_get_type   (void) G_GNUC_CONST;
 ESource *      e_collection_backend_new_child  (ECollectionBackend *backend,
                                                 const gchar *resource_id);
+GProxyResolver *
+               e_collection_backend_ref_proxy_resolver
+                                               (ECollectionBackend *backend);
 struct _ESourceRegistryServer *
                e_collection_backend_ref_server (ECollectionBackend *backend);
 const gchar *  e_collection_backend_get_cache_dir