[folks] Add support to switch primary backend either by GConf or an env var

[Raul Gutierrez Segales <raulgs src gnome org>]

commit 467672197a8225a4c9b91e541e80afe53fdbbfd4
Author: Raul Gutierrez Segales <raul gutierrez segales collabora co uk>
Date:   Mon Mar 28 11:49:44 2011 +0100

    Add support to switch primary backend either by GConf or an env var

 configure.ac                     |    2 +
 folks/Makefile.am                |    3 ++
 folks/individual-aggregator.vala |   58 ++++++++++++++++++++++++++++++++-----
 3 files changed, 55 insertions(+), 8 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 6c51708..a12f8b4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -83,6 +83,7 @@ TP_GLIB_REQUIRED=0.13.1
 VALA_REQUIRED=0.11.6
 VALADOC_REQUIRED=0.2.1
 TRACKER_SPARQL_REQUIRED=0.10
+GCONF2_REQUIRED=2.31
 
 PKG_CHECK_MODULES([GLIB],
                   [glib-2.0 >= $GLIB_REQUIRED
@@ -90,6 +91,7 @@ PKG_CHECK_MODULES([GLIB],
 PKG_CHECK_MODULES([GMODULE], [gmodule-no-export-2.0])
 PKG_CHECK_MODULES([GIO], [gio-2.0 >= $GLIB_REQUIRED])
 PKG_CHECK_MODULES([DBUS_GLIB], [dbus-glib-1])
+PKG_CHECK_MODULES([GCONF2], [gconf-2.0 >= $GCONF2_REQUIRED])
 
 # FIXME: We depend on libgee < 0.7 because 0.7 breaks API. bgo#627746
 PKG_CHECK_MODULES([GEE], [gee-1.0 < 0.7])
diff --git a/folks/Makefile.am b/folks/Makefile.am
index 4700b6b..4013118 100644
--- a/folks/Makefile.am
+++ b/folks/Makefile.am
@@ -46,6 +46,7 @@ libfolks_la_VALAFLAGS = \
 	--pkg gmodule-2.0 \
 	--pkg gio-2.0 \
 	--pkg gee-1.0 \
+	--pkg gconf-2.0 \
 	--vapi folks.vapi \
 	-H folks.h \
 	$(NULL)
@@ -55,6 +56,7 @@ libfolks_la_CFLAGS = \
 	$(GLIB_CFLAGS) \
 	$(GMODULE_CFLAGS) \
 	$(GEE_CFLAGS) \
+	$(GCONF2_CFLAGS) \
 	$(NULL)
 
 libfolks_la_LIBADD = \
@@ -62,6 +64,7 @@ libfolks_la_LIBADD = \
 	$(GLIB_LIBS) \
 	$(GMODULE_LIBS) \
 	$(GEE_LIBS) \
+	$(GCONF2_LIBS) \
 	$(NULL)
 
 # The quoting here is unnecessary but harmless, and has the useful side-effect
diff --git a/folks/individual-aggregator.vala b/folks/individual-aggregator.vala
index 6c0bb78..c1f3ebf 100644
--- a/folks/individual-aggregator.vala
+++ b/folks/individual-aggregator.vala
@@ -63,6 +63,9 @@ public class Folks.IndividualAggregator : Object
   private HashTable<string, Individual> _link_map;
   private bool _linking_enabled = true;
   private bool _is_prepared = false;
+  private string _configured_writeable_store_type_id;
+  private static const string _FOLKS_CONFIG_KEY =
+    "/system/folks/backends/primary_store";
 
   /**
    * Whether { link IndividualAggregator.prepare} has successfully completed for
@@ -76,6 +79,23 @@ public class Folks.IndividualAggregator : Object
     }
 
   /**
+   * Our configured primary (writeable) store.
+   *
+   * Which one to use is decided (in order or precedence)
+   * by:
+   *
+   * - the FOLKS_WRITEABLE_STORE env var (mostly for debugging)
+   * - the GConf key set in _FOLKS_CONFIG_KEY (system set store)
+   * - going with the `key-file` store as the fall-back option
+   *
+   * @since UNRELEASED
+   */
+  public PersonaStore primary_store
+    {
+      get { return this._writeable_store; }
+    }
+
+  /**
    * A table mapping { link Individual.id}s to their { link Individual}s.
    *
    * This is the canonical set of { link Individual}s provided by this
@@ -142,6 +162,28 @@ public class Folks.IndividualAggregator : Object
 
       this._backends = new HashSet<Backend> ();
 
+      /* Check out the configured writeable store */
+      var store_type_id = Environment.get_variable ("FOLKS_WRITEABLE_STORE");
+      if (store_type_id != null)
+        {
+          this._configured_writeable_store_type_id = store_type_id;
+        }
+      else
+        {
+          this._configured_writeable_store_type_id = "key-file";
+          try
+            {
+              unowned GConf.Client client = GConf.Client.get_default ();
+              GConf.Value? val = client.get (this._FOLKS_CONFIG_KEY);
+              if (val != null)
+                this._configured_writeable_store_type_id = val.get_string ();
+            }
+          catch (GLib.Error e)
+            {
+              /* We ignore errors and go with the default store */
+            }
+        }
+
       var disable_linking = Environment.get_variable ("FOLKS_DISABLE_LINKING");
       if (disable_linking != null)
         disable_linking = disable_linking.strip ().down ();
@@ -214,9 +256,9 @@ public class Folks.IndividualAggregator : Object
     {
       var store_id = this._get_store_full_id (store.type_id, store.id);
 
-      /* FIXME: We hardcode the key-file backend's singleton PersonaStore as the
-       * only trusted and writeable PersonaStore for now. */
-      if (store.type_id == "key-file")
+      /* We use the configured PersonaStore as the only trusted and writeable
+       * PersonaStore. */
+      if (store.type_id == this._configured_writeable_store_type_id)
         {
           store.is_writeable = true;
           store.trust_level = PersonaStoreTrust.FULL;
@@ -665,10 +707,10 @@ public class Folks.IndividualAggregator : Object
 
   private void _trust_level_changed_cb (Object object, ParamSpec pspec)
     {
-      /* FIXME: For the moment, assert that only the key-file backend's
-       * singleton PersonaStore is trusted. */
+      /* Only our writeable_store can be fully trusted. */
       var store = (PersonaStore) object;
-      if (store.type_id == "key-file")
+      if (this._writeable_store != null &&
+          store.type_id == this._writeable_store.type_id)
         assert (store.trust_level == PersonaStoreTrust.FULL);
       else
         assert (store.trust_level != PersonaStoreTrust.FULL);
@@ -861,8 +903,8 @@ public class Folks.IndividualAggregator : Object
 
       /* Create a new persona in the writeable store which links together the
        * given personas */
-      /* FIXME: We hardcode this to use the key-file backend for now */
-      assert (this._writeable_store.type_id == "key-file");
+      assert (this._writeable_store.type_id ==
+          this._configured_writeable_store_type_id);
 
       /* `protocols_addrs_set` will be passed to the new Kf.Persona */
       var protocols_addrs_set =