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

diff --git a/Makefile-tests.am b/Makefile-tests.am
index 6a52faebe3032ea8f314d5322e54dac4ab8eeb88..c21867070644004098a36b4c128d8375e4df560a 100644 (file)
--- a/Makefile-tests.am
+++ b/Makefile-tests.am
@@ -212,7 +212,7 @@ endif
 _installed_or_uninstalled_test_programs = tests/test-varint tests/test-ot-unix-utils tests/test-bsdiff tests/test-mutable-tree \
        tests/test-keyfile-utils tests/test-ot-opt-utils tests/test-ot-tool-util \
        tests/test-gpg-verify-result tests/test-checksum tests/test-lzma tests/test-rollsum \
-       tests/test-basic-c tests/test-sysroot-c tests/test-pull-c
+       tests/test-basic-c tests/test-sysroot-c tests/test-pull-c tests/test-repo
 
 if ENABLE_EXPERIMENTAL_API
 test_programs += \
@@ -282,6 +282,9 @@ tests_test_sysroot_c_LDADD = $(TESTS_LDADD)
 tests_test_pull_c_CFLAGS = $(TESTS_CFLAGS)
 tests_test_pull_c_LDADD = $(TESTS_LDADD)
 
+tests_test_repo_CFLAGS = $(TESTS_CFLAGS)
+tests_test_repo_LDADD = $(TESTS_LDADD)
+
 tests_test_ot_unix_utils_CFLAGS = $(TESTS_CFLAGS)
 tests_test_ot_unix_utils_LDADD = $(TESTS_LDADD)
 

diff --git a/apidoc/ostree-sections.txt b/apidoc/ostree-sections.txt
index 547e1509b62fa89c2df9fc71826483227ee348b1..e5ce157cc7b527bba6ff8548235543453b221eac 100644 (file)
--- a/apidoc/ostree-sections.txt
+++ b/apidoc/ostree-sections.txt
@@ -287,6 +287,7 @@ ostree_repo_get_path
 ostree_repo_get_mode
 ostree_repo_get_config
 ostree_repo_get_dfd
+ostree_repo_hash
 ostree_repo_equal
 ostree_repo_copy_config
 ostree_repo_remote_add

diff --git a/src/libostree/libostree-devel.sym b/src/libostree/libostree-devel.sym
index a416b7c1ac8966fff3c70f3614ca190bd93019d1..1462a6471c96d1cb7f39a4dbb31f4e209da6e6d3 100644 (file)
--- a/src/libostree/libostree-devel.sym
+++ b/src/libostree/libostree-devel.sym
@@ -21,6 +21,7 @@
 LIBOSTREE_2017.12 {
 global:
   ostree_repo_equal;
+  ostree_repo_hash;
 } LIBOSTREE_2017.11;
 
 

diff --git a/src/libostree/ostree-repo.c b/src/libostree/ostree-repo.c
index b1d88e489ffec6f9e34f5ad6cb97cfbb56fe8295..7554bc4496cbc869bbbda7ad643fa1f74bde9a81 100644 (file)
--- a/src/libostree/ostree-repo.c
+++ b/src/libostree/ostree-repo.c
@@ -2609,6 +2609,36 @@ ostree_repo_get_dfd (OstreeRepo  *self)
   return self->repo_dir_fd;
 }
 
+/**
+ * ostree_repo_hash:
+ * @self: an #OstreeRepo
+ *
+ * Calculate a hash value for the given open repository, suitable for use when
+ * putting it into a hash table. It is an error to call this on an #OstreeRepo
+ * which is not yet open, as a persistent hash value cannot be calculated until
+ * the repository is open and the inode of its root directory has been loaded.
+ *
+ * This function does no I/O.
+ *
+ * Returns: hash value for the #OstreeRepo
+ * Since: 2017.12
+ */
+guint
+ostree_repo_hash (OstreeRepo *self)
+{
+  g_return_val_if_fail (OSTREE_IS_REPO (self), 0);
+
+  /* We cannot hash non-open repositories, since their hash value would change
+   * once they’re opened, resulting in false lookup misses and the inability to
+   * remove them from a hash table. */
+  g_assert (self->repo_dir_fd >= 0);
+
+  /* device and inode numbers are distributed fairly uniformly, so we can’t
+   * do much better than just combining them. No need to rehash to even out
+   * the distribution. */
+  return (self->device ^ self->inode);
+}
+
 /**
  * ostree_repo_equal:
  * @a: an #OstreeRepo

diff --git a/src/libostree/ostree-repo.h b/src/libostree/ostree-repo.h
index a2a46d4b8b64877a9ab6d4b4c38194b494aee43c..a22c1adeb882d647e7410fae55e0759faaaf5721 100644 (file)
--- a/src/libostree/ostree-repo.h
+++ b/src/libostree/ostree-repo.h
@@ -123,6 +123,8 @@ GFile *       ostree_repo_get_path (OstreeRepo  *self);
 _OSTREE_PUBLIC
 int           ostree_repo_get_dfd (OstreeRepo  *self);
 
+_OSTREE_PUBLIC
+guint         ostree_repo_hash (OstreeRepo *self);
 _OSTREE_PUBLIC
 gboolean      ostree_repo_equal (OstreeRepo *a,
                                  OstreeRepo *b);

diff --git a/tests/.gitignore b/tests/.gitignore
index 9bec67a36dbcf2faaa70def9ee77e47f0ea9fc55..e56a8393d9068c6998a745927297ad94f9643515 100644 (file)
--- 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 (file)
index 0000000..217ca23
--- /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 ();
+}