lib/repo: Add ostree_repo_hash() and tests

Add a hash function for OstreeRepo instances, which relies on the repo
being open, and hence being able to hash the device and inode of its
root directory.

Add unit tests for this and ostree_repo_equal().

Signed-off-by: Philip Withnall <withnall@endlessm.com>

https://github.com/ostreedev/ostree/issues/1191

Closes: #1205
Approved by: cgwalters

2 files changed, 169 insertions, 0 deletions

diff --git a/tests/.gitignore b/tests/.gitignore
index 9bec67a3..e56a8393 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -15,6 +15,7 @@ test-mutable-tree
 test-ot-opt-utils
 test-ot-tool-util
 test-ot-unix-utils
+test-repo
 test-repo-finder-avahi
 test-repo-finder-config
 test-repo-finder-mount
diff --git a/tests/test-repo.c b/tests/test-repo.c
new file mode 100644
index 00000000..217ca23c
--- /dev/null
+++ b/tests/test-repo.c
@@ -0,0 +1,168 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright © 2017 Endless Mobile, Inc.
+ *
+ * This library 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) any later version.
+ *
+ * This library 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 this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Authors:
+ *  - Philip Withnall <withnall@endlessm.com>
+ */
+
+#include "config.h"
+
+#include <gio/gio.h>
+#include <glib.h>
+#include <glib-object.h>
+#include <libglnx.h>
+#include <locale.h>
+
+#include "ostree-autocleanups.h"
+#include "ostree-types.h"
+
+/* Test fixture. Creates a temporary directory. */
+typedef struct
+{
+  GLnxTmpDir tmpdir;  /* (owned) */
+} Fixture;
+
+static void
+setup (Fixture       *fixture,
+       gconstpointer  test_data)
+{
+  g_autoptr(GError) error = NULL;
+
+  (void) glnx_mkdtemp ("test-repo-XXXXXX", 0700, &fixture->tmpdir, &error);
+  g_assert_no_error (error);
+
+  g_test_message ("Using temporary directory: %s", fixture->tmpdir.path);
+}
+
+static void
+teardown (Fixture       *fixture,
+          gconstpointer  test_data)
+{
+  /* Recursively remove the temporary directory. */
+  (void) glnx_tmpdir_delete (&fixture->tmpdir, NULL, NULL);
+}
+
+/* Test that the hash values for two #OstreeRepo instances pointing at the same
+ * repository are equal. We can’t test anything else, since hash collisions are
+ * always a possibility. */
+static void
+test_repo_hash (Fixture       *fixture,
+                gconstpointer  test_data)
+{
+  g_autoptr(GError) error = NULL;
+  g_autoptr(OstreeRepo) repo1 = ostree_repo_create_at (fixture->tmpdir.fd, ".",
+                                                       OSTREE_REPO_MODE_ARCHIVE_Z2,
+                                                       NULL,
+                                                       NULL, &error);
+  g_assert_no_error (error);
+
+  g_autoptr(OstreeRepo) repo2 = ostree_repo_open_at (fixture->tmpdir.fd, ".",
+                                                     NULL, &error);
+  g_assert_no_error (error);
+
+  g_assert_cmpuint (ostree_repo_hash (repo1), ==, ostree_repo_hash (repo2));
+}
+
+/* Test that trying to hash a closed repo results in an assertion failure. */
+static void
+test_repo_hash_closed (Fixture       *fixture,
+                       gconstpointer  test_data)
+{
+  if (g_test_subprocess ())
+    {
+      g_autoptr(GFile) repo_path = g_file_new_for_path (fixture->tmpdir.path);
+      g_autoptr(OstreeRepo) repo = ostree_repo_new (repo_path);
+
+      ostree_repo_hash (repo);
+
+      return;
+    }
+
+  g_test_trap_subprocess (NULL, 0, 0);
+  g_test_trap_assert_failed ();
+  g_test_trap_assert_stderr ("*ERROR*ostree_repo_hash: assertion failed:*");
+}
+
+/* Test that various repositories test equal (or not) with each other. */
+static void
+test_repo_equal (Fixture       *fixture,
+                 gconstpointer  test_data)
+{
+  g_autoptr(GError) error = NULL;
+
+  /* Create a few separate repos and some #OstreeRepo objects for them. */
+  glnx_ensure_dir (fixture->tmpdir.fd, "repo1", 0755, &error);
+  g_assert_no_error (error);
+  glnx_ensure_dir (fixture->tmpdir.fd, "repo2", 0755, &error);
+  g_assert_no_error (error);
+
+  g_autoptr(OstreeRepo) repo1 = ostree_repo_create_at (fixture->tmpdir.fd, "repo1",
+                                                       OSTREE_REPO_MODE_ARCHIVE_Z2,
+                                                       NULL,
+                                                       NULL, &error);
+  g_assert_no_error (error);
+
+  g_autoptr(OstreeRepo) repo1_alias = ostree_repo_open_at (fixture->tmpdir.fd, "repo1",
+                                                           NULL, &error);
+  g_assert_no_error (error);
+
+  g_autoptr(OstreeRepo) repo2 = ostree_repo_create_at (fixture->tmpdir.fd, "repo2",
+                                                       OSTREE_REPO_MODE_ARCHIVE_Z2,
+                                                       NULL,
+                                                       NULL, &error);
+  g_assert_no_error (error);
+
+  g_autoptr(GFile) closed_repo_path = g_file_new_for_path (fixture->tmpdir.path);
+  g_autoptr(OstreeRepo) closed_repo = ostree_repo_new (closed_repo_path);
+
+  /* Test various equalities. */
+  g_assert_true (ostree_repo_equal (repo1, repo1));
+  g_assert_true (ostree_repo_equal (repo1_alias, repo1_alias));
+  g_assert_true (ostree_repo_equal (repo1, repo1_alias));
+  g_assert_true (ostree_repo_equal (repo1_alias, repo1));
+  g_assert_true (ostree_repo_equal (repo2, repo2));
+  g_assert_false (ostree_repo_equal (repo1, repo2));
+  g_assert_false (ostree_repo_equal (repo1_alias, repo2));
+  g_assert_false (ostree_repo_equal (repo2, repo1));
+  g_assert_false (ostree_repo_equal (repo2, repo1_alias));
+  g_assert_false (ostree_repo_equal (repo1, closed_repo));
+  g_assert_false (ostree_repo_equal (repo1_alias, closed_repo));
+  g_assert_false (ostree_repo_equal (closed_repo, repo1));
+  g_assert_false (ostree_repo_equal (closed_repo, repo1_alias));
+  g_assert_false (ostree_repo_equal (repo2, closed_repo));
+  g_assert_false (ostree_repo_equal (closed_repo, repo2));
+  g_assert_false (ostree_repo_equal (closed_repo, closed_repo));
+}
+
+int
+main (int    argc,
+      char **argv)
+{
+  setlocale (LC_ALL, "");
+  g_test_init (&argc, &argv, NULL);
+
+  g_test_add ("/repo/hash", Fixture, NULL, setup,
+              test_repo_hash, teardown);
+  g_test_add ("/repo/hash/closed", Fixture, NULL, setup,
+              test_repo_hash_closed, teardown);
+  g_test_add ("/repo/equal", Fixture, NULL, setup,
+              test_repo_equal, teardown);
+
+  return g_test_run ();
+}