sync: add retry to fetch operations

Add retries with exponential backoff and jitter to the fetch
operations. By default don't change behavior and enable
behind the new flag '--fetch-retries'.

Bug: https://crbug.com/1061473

Change-Id: I492710843985d00f81cbe3402dc56f2d21a45b35
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/261576
Reviewed-by: Mike Frysinger <vapier@google.com>
Tested-by: George Engelbrecht <engeg@google.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/subcmds/sync.py b/subcmds/sync.py
index de6deecb..efd39616 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -265,6 +265,9 @@ later is required to fix a server side protocol bug.
     p.add_option('--optimized-fetch',
                  dest='optimized_fetch', action='store_true',
                  help='only fetch projects fixed to sha1 if revision does not exist locally')
+    p.add_option('--retry-fetches',
+                 default=0, action='store', type='int',
+                 help='number of times to retry fetches on transient errors')
     p.add_option('--prune', dest='prune', action='store_true',
                  help='delete refs that no longer exist on the remote')
     if show_smart:
@@ -342,6 +345,7 @@ later is required to fix a server side protocol bug.
             clone_bundle=opt.clone_bundle,
             tags=opt.tags, archive=self.manifest.IsArchive,
             optimized_fetch=opt.optimized_fetch,
+            retry_fetches=opt.retry_fetches,
             prune=opt.prune,
             clone_filter=clone_filter)
         self._fetch_times.Set(project, time.time() - start)
@@ -777,6 +781,7 @@ later is required to fix a server side protocol bug.
                                     current_branch_only=opt.current_branch_only,
                                     tags=opt.tags,
                                     optimized_fetch=opt.optimized_fetch,
+                                    retry_fetches=opt.retry_fetches,
                                     submodules=self.manifest.HasSubmodules,
                                     clone_filter=self.manifest.CloneFilter)
       finish = time.time()