From fa625a73882abbbf6f521a9d19eb84217dc99f68 Mon Sep 17 00:00:00 2001
From: Simon Sapin <simon.sapin@exyr.org>
Date: Thu, 19 Mar 2020 18:26:49 +0100
Subject: [PATCH] Index tasks by git tree hash instead of parent commits hashes
---
etc/taskcluster/decisionlib.py | 23 ++++++-----------------
1 file changed, 6 insertions(+), 17 deletions(-)
diff --git a/etc/taskcluster/decisionlib.py b/etc/taskcluster/decisionlib.py
index 2ac0d4569b4..34cc634e5c2 100644
--- a/etc/taskcluster/decisionlib.py
+++ b/etc/taskcluster/decisionlib.py
@@ -65,23 +65,12 @@ class Config:
def task_id(self):
- if hasattr(self, "_task_id"):
- return self._task_id
- # If the head commit is a merge, we want to generate a unique task id which incorporates
- # the merge parents rather that the actual sha of the merge commit. This ensures that tasks
- # can be reused if the tree is in an identical state. Otherwise, if the head commit is
- # not a merge, we can rely on the head commit sha for that purpose.
- raw_commit = subprocess.check_output(["git", "cat-file", "commit", "HEAD"])
- parent_commits = [
- value.decode("utf8")
- for line in raw_commit.split(b"\n")
- for key, _, value in [line.partition(b" ")]
- if key == b"parent"
- ]
- if len(parent_commits) > 1:
- self._task_id = "-".join(parent_commits) # pragma: no cover
- else:
- self._task_id = self.git_sha # pragma: no cover
+ if not hasattr(self, "_task_id"):
+ # Use the SHA-1 hash of the git "tree" object rather than the commit.
+ # A `@bors-servo retry` command creates a new merge commit with a different commit hash
+ # but with the same tree hash.
+ output = subprocess.check_output(["git", "show", "-s", "--format=%T", "HEAD"])
+ self._task_id = output.decode("utf-8").strip()
return self._task_id
def git_sha_is_current_head(self):