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[PATCH 4/4] archive: ignore blob objects when checking reachability

From
Jeff King <peff@peff.net>
Date
Jun 5, 2013, 22:40 UTC
Message-ID
<20130605224038.GD15607@sigill.intra.peff.net>
In-Reply-To
<20130605223551.GF8664@sigill.intra.peff.net>

We cannot create an archive from a blob object, so we would not expect anyone to provide one to us. And if they do, we will fail anyway just after the reachability check. We can therefore optimize our reachability check to ignore blobs completely, and not even create a "struct blob" for them.

Depending on the repository size and the exact place we find the reachable object in the traversal, this can save 20-25%, a we can avoid many lookups in the object hash.

The downside of this is that a blob provided to a remote archive process will fail with "no such object" rather than "object is not a tree" (we could organize the code to retain the old message, but since we no longer know whether the blob is reachable or not, we would potentially be leaking information about the existence of unreachable objects).

Signed-off-by: Jeff King <peff@peff.net>
---
 archive.c | 1 +
 1 file changed, 1 insertion(+)
diff --git a/archive.c b/archive.c
index 4d77624..98691cd 100644
--- a/archive.c
+++ b/archive.c
@@ -290,6 +290,7 @@ static int object_is_reachable(const unsigned char *sha1)
 	save_commit_buffer = 0;
 	init_revisions(&data.revs, NULL);
 	setup_revisions(ARRAY_SIZE(argv) - 1, argv, &data.revs, NULL);
+	data.revs.blob_objects = 0;
 	if (prepare_revision_walk(&data.revs))
 		return 0;
 
-- 
1.8.3.rc2.14.g7eee6b3
Previous: Jeff KingNext: Michael Haggerty
Message 19 of 30 in “[BUG] git archive broken in 1.7.8.1”
  1. Albert Astals CidJan 10, 2012
  2. Carlos Martín NietoJan 10, 2012
  3. Albert Astals CidJan 10, 2012
  4. Carlos Martín NietoJan 10, 2012
  5. Jeff KingJan 10, 2012
  6. archive: re-allow HEAD:Documentation on a remote invocationCarlos Martín Nieto, Jan 11, 2012
  7. Jeff KingJan 11, 2012
  8. 1/2 get_sha1_with_context: report features used in resolutionJeff King, Jan 11, 2012
  9. Junio C HamanoJan 12, 2012
  10. Jeff KingJan 12, 2012
  11. 2/2 archive: loosen restrictions on remote object lookupJeff King, Jan 11, 2012
  12. Ian HarveyMay 29, 2013
  13. Jeff KingJun 5, 2013
  14. 0/4 real reachability checks for upload-archiveJeff King, Jun 5, 2013
  15. 1/4 clear parsed flag when we free tree buffersJeff King, Jun 5, 2013
  16. Junio C HamanoJun 6, 2013
  17. 2/4 upload-archive: restrict remote objects with reachability checkJeff King, Jun 5, 2013
  18. 3/4 list-objects: optimize "revs->blob_objects = 0" caseJeff King, Jun 5, 2013
  19. 4/4 archive: ignore blob objects when checking reachabilityJeff King, Jun 5, 2013
  20. Michael HaggertyJun 6, 2013
  21. Eric SunshineJun 7, 2013
  22. Junio C HamanoJun 6, 2013
  23. Junio C HamanoJan 12, 2012
  24. Jeff KingJan 12, 2012
  25. Jeff KingJan 12, 2012
  26. Junio C HamanoJan 12, 2012
  27. Jeff KingJan 12, 2012
  28. Junio C HamanoJan 12, 2012
  29. Allan WindJan 10, 2012
  30. Carlos Martín NietoJan 11, 2012

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