[libgit2-glib] Add ggit_repository_get_ahead_behind

[Ignacio Casal Quinteiro <icq src gnome org>]

commit cf677660c659f78855c898797f330927f0bc7ec3
Author: Ignacio Casal Quinteiro <icq gnome org>
Date:   Tue Mar 26 15:26:09 2013 +0100

    Add ggit_repository_get_ahead_behind

 libgit2-glib/ggit-repository.c |   45 ++++++++++++++++++++++++++++++++++++++++
 libgit2-glib/ggit-repository.h |    7 ++++++
 2 files changed, 52 insertions(+), 0 deletions(-)
---
diff --git a/libgit2-glib/ggit-repository.c b/libgit2-glib/ggit-repository.c
index 5f6ecf9..0e79150 100644
--- a/libgit2-glib/ggit-repository.c
+++ b/libgit2-glib/ggit-repository.c
@@ -30,6 +30,7 @@
 #include <git2/submodule.h>
 #include <git2/revparse.h>
 #include <git2/stash.h>
+#include <git2/graph.h>
 
 #include "ggit-error.h"
 #include "ggit-oid.h"
@@ -1853,4 +1854,48 @@ ggit_repository_stash_foreach (GgitRepository     *repository,
        return TRUE;
 }
 
+/**
+ * ggit_repository_get_ahead_behind:
+ * @repository: a #GgitRepository.
+ * @local: the commit for local.
+ * @upstream: the commit for upstream.
+ * @ahead: number of unique from commits in @upstream.
+ * @behind: number of unique from commits in @local.
+ * @error: a #GError for error reporting, or %NULL.
+ *
+ * Count the number of unique commits between two commit objects.
+ *
+ * There is no need for branches containing the commits to have any
+ * upstream relationship, but it helps to think of one as a branch and
+ * the other as its upstream, the @ahead and @behind values will be
+ * what git would report for the branches.
+ */
+void
+ggit_repository_get_ahead_behind (GgitRepository  *repository,
+                                  GgitOId         *local,
+                                  GgitOId         *upstream,
+                                  gsize           *ahead,
+                                  gsize           *behind,
+                                  GError         **error)
+{
+       gint ret;
+
+       g_return_if_fail (GGIT_IS_REPOSITORY (repository));
+       g_return_if_fail (local != NULL);
+       g_return_if_fail (upstream != NULL);
+       g_return_if_fail (ahead != NULL);
+       g_return_if_fail (behind != NULL);
+       g_return_if_fail (error == NULL || *error == NULL);
+
+       ret = git_graph_ahead_behind (ahead, behind,
+                                     _ggit_native_get (repository),
+                                     _ggit_oid_get_oid (local),
+                                     _ggit_oid_get_oid (upstream));
+
+       if (ret != GIT_OK)
+       {
+               _ggit_error_set (error, ret);
+       }
+}
+
 /* ex:set ts=8 noet: */
diff --git a/libgit2-glib/ggit-repository.h b/libgit2-glib/ggit-repository.h
index a7ad460..06fbc54 100644
--- a/libgit2-glib/ggit-repository.h
+++ b/libgit2-glib/ggit-repository.h
@@ -234,6 +234,13 @@ gboolean            ggit_repository_stash_foreach     (GgitRepository        *re
                                                        gpointer               user_data,
                                                        GError               **error);
 
+void                ggit_repository_get_ahead_behind  (GgitRepository        *repository,
+                                                       GgitOId               *local,
+                                                       GgitOId               *upstream,
+                                                       gsize                 *ahead,
+                                                       gsize                 *behind,
+                                                       GError               **error);
+
 G_END_DECLS
 
 #endif /* __GGIT_REPOSITORY_H__ */