sync: Track last completed fetch/checkout

Save the latest time any project is fetched and checked out. This will
be used to detect partial checkouts.

Bug: b/286126621
Change-Id: I53b264dc70ba168d506076dbd693ef79a696b61d
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/380514
Commit-Queue: Gavin Mak <gavinmak@google.com>
Reviewed-by: Joanna Wang <jojwang@google.com>
Tested-by: Gavin Mak <gavinmak@google.com>

3 files changed, 148 insertions, 17 deletions

diff --git a/main.py b/main.py
index 90aba144..4c5f1043 100755
--- a/main.py
+++ b/main.py
@@ -427,7 +427,8 @@ class _Repo(object):
                 if not ok:
                     exception_name = type(e).__name__
                     git_trace2_event_log.ErrorEvent(
-                        f"RepoExitError:{exception_name}")
+                        f"RepoExitError:{exception_name}"
+                    )
                 raise
 
         try:
diff --git a/subcmds/sync.py b/subcmds/sync.py
index a2cc1f89..5f8bc2f0 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -737,6 +737,7 @@ later is required to fix a server side protocol bug.
                     start = result.start
                     finish = result.finish
                     self._fetch_times.Set(project, finish - start)
+                    self._local_sync_state.SetFetchTime(project)
                     self.event_log.AddSync(
                         project,
                         event_log.TASK_SYNC_NETWORK,
@@ -807,6 +808,7 @@ later is required to fix a server side protocol bug.
         sync_event.set()
         pm.end()
         self._fetch_times.Save()
+        self._local_sync_state.Save()
 
         if not self.outer_client.manifest.IsArchive:
             self._GCProjects(projects, opt, err_event)
@@ -949,7 +951,9 @@ later is required to fix a server side protocol bug.
                 )
                 # Check for any errors before running any more tasks.
                 # ...we'll let existing jobs finish, though.
-                if not success:
+                if success:
+                    self._local_sync_state.SetCheckoutTime(project)
+                else:
                     ret = False
                     err_results.append(
                         project.RelPath(local=opt.this_manifest_only)
@@ -961,21 +965,19 @@ later is required to fix a server side protocol bug.
                 pm.update(msg=project.name)
             return ret
 
-        return (
-            self.ExecuteInParallel(
-                opt.jobs_checkout,
-                functools.partial(
-                    self._CheckoutOne, opt.detach_head, opt.force_sync
-                ),
-                all_projects,
-                callback=_ProcessResults,
-                output=Progress(
-                    "Checking out", len(all_projects), quiet=opt.quiet
-                ),
-            )
-            and not err_results
+        proc_res = self.ExecuteInParallel(
+            opt.jobs_checkout,
+            functools.partial(
+                self._CheckoutOne, opt.detach_head, opt.force_sync
+            ),
+            all_projects,
+            callback=_ProcessResults,
+            output=Progress("Checking out", len(all_projects), quiet=opt.quiet),
         )
 
+        self._local_sync_state.Save()
+        return proc_res and not err_results
+
     @staticmethod
     def _GetPreciousObjectsState(project: Project, opt):
         """Get the preciousObjects state for the project.
@@ -1684,6 +1686,7 @@ later is required to fix a server side protocol bug.
         )
 
         self._fetch_times = _FetchTimes(manifest)
+        self._local_sync_state = _LocalSyncState(manifest)
         if not opt.local_only:
             with multiprocessing.Manager() as manager:
                 with ssh.ProxyManager(manager) as ssh_proxy:
@@ -1898,12 +1901,64 @@ class _FetchTimes(object):
             platform_utils.remove(self._path, missing_ok=True)
 
 
+class _LocalSyncState(object):
+    _LAST_FETCH = "last_fetch"
+    _LAST_CHECKOUT = "last_checkout"
+
+    def __init__(self, manifest):
+        self._path = os.path.join(manifest.repodir, ".repo_localsyncstate.json")
+        self._time = time.time()
+        self._state = None
+        self._Load()
+
+    def SetFetchTime(self, project):
+        self._Set(project, self._LAST_FETCH)
+
+    def SetCheckoutTime(self, project):
+        self._Set(project, self._LAST_CHECKOUT)
+
+    def GetFetchTime(self, project):
+        return self._Get(project, self._LAST_FETCH)
+
+    def GetCheckoutTime(self, project):
+        return self._Get(project, self._LAST_CHECKOUT)
+
+    def _Get(self, project, key):
+        self._Load()
+        p = project.relpath
+        if p not in self._state:
+            return
+        return self._state[p].get(key)
+
+    def _Set(self, project, key):
+        p = project.relpath
+        if p not in self._state:
+            self._state[p] = {}
+        self._state[p][key] = self._time
+
+    def _Load(self):
+        if self._state is None:
+            try:
+                with open(self._path) as f:
+                    self._state = json.load(f)
+            except (IOError, ValueError):
+                platform_utils.remove(self._path, missing_ok=True)
+                self._state = {}
+
+    def Save(self):
+        if not self._state:
+            return
+        try:
+            with open(self._path, "w") as f:
+                json.dump(self._state, f, indent=2)
+        except (IOError, TypeError):
+            platform_utils.remove(self._path, missing_ok=True)
+
+
 # This is a replacement for xmlrpc.client.Transport using urllib2
 # and supporting persistent-http[s]. It cannot change hosts from
 # request to request like the normal transport, the real url
 # is passed during initialization.
-
-
 class PersistentTransport(xmlrpc.client.Transport):
     def __init__(self, orig_host):
         self.orig_host = orig_host
diff --git a/tests/test_subcmds_sync.py b/tests/test_subcmds_sync.py
index 5c8e606e..057478ef 100644
--- a/tests/test_subcmds_sync.py
+++ b/tests/test_subcmds_sync.py
@@ -14,6 +14,8 @@
 """Unittests for the subcmds/sync.py module."""
 
 import os
+import shutil
+import tempfile
 import unittest
 from unittest import mock
 
@@ -104,6 +106,79 @@ def test_cli_jobs(argv, jobs_manifest, jobs, jobs_net, jobs_check):
             assert opts.jobs_checkout == jobs_check
 
 
+class LocalSyncState(unittest.TestCase):
+    """Tests for _LocalSyncState."""
+
+    _TIME = 10
+
+    def setUp(self):
+        """Common setup."""
+        self.repodir = tempfile.mkdtemp(".repo")
+        self.manifest = mock.MagicMock(
+            repodir=self.repodir,
+        )
+        self.state = self._new_state()
+
+    def tearDown(self):
+        """Common teardown."""
+        shutil.rmtree(self.repodir)
+
+    def _new_state(self):
+        with mock.patch("time.time", return_value=self._TIME):
+            return sync._LocalSyncState(self.manifest)
+
+    def test_set(self):
+        """Times are set."""
+        p = mock.MagicMock(relpath="projA")
+        self.state.SetFetchTime(p)
+        self.state.SetCheckoutTime(p)
+        self.assertEqual(self.state.GetFetchTime(p), self._TIME)
+        self.assertEqual(self.state.GetCheckoutTime(p), self._TIME)
+
+    def test_update(self):
+        """Times are updated."""
+        with open(self.state._path, "w") as f:
+            f.write(
+                """
+            {
+              "projB": {
+                "last_fetch": 5,
+                "last_checkout": 7
+              }
+            }
+            """
+            )
+
+        # Initialize state to read from the new file.
+        self.state = self._new_state()
+        projA = mock.MagicMock(relpath="projA")
+        projB = mock.MagicMock(relpath="projB")
+        self.assertEqual(self.state.GetFetchTime(projA), None)
+        self.assertEqual(self.state.GetFetchTime(projB), 5)
+        self.assertEqual(self.state.GetCheckoutTime(projB), 7)
+
+        self.state.SetFetchTime(projA)
+        self.state.SetFetchTime(projB)
+        self.assertEqual(self.state.GetFetchTime(projA), self._TIME)
+        self.assertEqual(self.state.GetFetchTime(projB), self._TIME)
+        self.assertEqual(self.state.GetCheckoutTime(projB), 7)
+
+    def test_save_to_file(self):
+        """Data is saved under repodir."""
+        p = mock.MagicMock(relpath="projA")
+        self.state.SetFetchTime(p)
+        self.state.Save()
+        self.assertEqual(
+            os.listdir(self.repodir), [".repo_localsyncstate.json"]
+        )
+
+    def test_nonexistent_project(self):
+        """Unsaved projects don't have data."""
+        p = mock.MagicMock(relpath="projC")
+        self.assertEqual(self.state.GetFetchTime(p), None)
+        self.assertEqual(self.state.GetCheckoutTime(p), None)
+
+
 class GetPreciousObjectsState(unittest.TestCase):
     """Tests for _GetPreciousObjectsState."""