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[PATCH v2 7/7] t5326: test propagating hashcache values

From
Taylor Blau <me@ttaylorr.com>
Date
Sep 14, 2021, 22:06 UTC
Message-ID
<fdf71432b32ef47b23b79ddfc3db8de8734ef7a5.1631657157.git.me@ttaylorr.com>
In-Reply-To
<cover.1631657157.git.me@ttaylorr.com>

Now that we both can propagate values from the hashcache, and respect the configuration to enable the hashcache at all, test that both of these function correctly by hardening their behavior with a test.

Like the hash-cache in classic single-pack bitmaps, this helps more proportionally the more up-to-date your bitmap coverage is. When our bitmap coverage is out-of-date with the ref tips, we spend more time proportionally traversing, and all of that traversal gets the name-hash filled in.

But for the up-to-date bitmaps, this helps quite a bit. These numbers are on git.git, with `pack.threads=1` to help see the difference reflected in the overall runtime.

    Test                            origin/tb/multi-pack-bitmaps   HEAD
    -------------------------------------------------------------------------------------
    5326.4: simulated clone         1.87(1.80+0.07)                1.46(1.42+0.03) -21.9%
    5326.5: simulated fetch         2.66(2.61+0.04)                1.47(1.43+0.04) -44.7%
    5326.6: pack to file (bitmap)   2.74(2.62+0.12)                1.89(1.82+0.07) -31.0%
Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 t/t5326-multi-pack-bitmaps.sh | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
diff --git a/t/t5326-multi-pack-bitmaps.sh b/t/t5326-multi-pack-bitmaps.sh
index 4ad7c2c969..24148ca35b 100755
--- a/t/t5326-multi-pack-bitmaps.sh
+++ b/t/t5326-multi-pack-bitmaps.sh
@@ -283,4 +283,36 @@ test_expect_success 'pack.preferBitmapTips' '
 	)
 '
 
+test_expect_success 'hash-cache values are propagated from pack bitmaps' '
+	rm -fr repo &&
+	git init repo &&
+	test_when_finished "rm -fr repo" &&
+	(
+		cd repo &&
+
+		git config pack.writeBitmapHashCache true &&
+
+		test_commit base &&
+		test_commit base2 &&
+		git repack -adb &&
+
+		test-tool bitmap dump-hashes >pack.raw &&
+		test_file_not_empty pack.raw &&
+		sort pack.raw >pack.hashes &&
+
+		test_commit new &&
+		git repack &&
+		git multi-pack-index write --bitmap &&
+
+		test-tool bitmap dump-hashes >midx.raw &&
+		sort midx.raw >midx.hashes &&
+
+		# ensure that every namehash in the pack bitmap can be found in
+		# the midx bitmap (i.e., that there are no oid-namehash pairs
+		# unique to the pack bitmap).
+		comm -23 pack.hashes midx.hashes >dropped.hashes &&
+		test_must_be_empty dropped.hashes
+	)
+'
+
 test_done
-- 
2.33.0.96.g73915697e6
Previous: Taylor BlauNext: Jeff King
Message 44 of 55 in “pack-bitmap: permute existing namehash values”
  1. 0/4 pack-bitmap: permute existing namehash valuesTaylor Blau, Sep 7, 2021
  2. 1/4 t/helper/test-bitmap.c: add 'dump-hashes' modeTaylor Blau, Sep 7, 2021
  3. Ævar Arnfjörð BjarmasonSep 8, 2021
  4. Taylor BlauSep 8, 2021
  5. 2/4 pack-bitmap.c: propagate namehash values from existing bitmapsTaylor Blau, Sep 7, 2021
  6. 3/4 midx.c: respect 'pack.writeBitmapHashcache' when writing bitmapsTaylor Blau, Sep 7, 2021
  7. Ævar Arnfjörð BjarmasonSep 8, 2021
  8. Taylor BlauSep 8, 2021
  9. Ævar Arnfjörð BjarmasonSep 9, 2021
  10. Ævar Arnfjörð BjarmasonSep 9, 2021
  11. Taylor BlauSep 9, 2021
  12. Ævar Arnfjörð BjarmasonSep 9, 2021
  13. Taylor BlauSep 9, 2021
  14. Taylor BlauSep 9, 2021
  15. Junio C HamanoSep 13, 2021
  16. Taylor BlauSep 14, 2021
  17. 4/4 t5326: test propagating hashcache valuesTaylor Blau, Sep 7, 2021
  18. Ævar Arnfjörð BjarmasonSep 8, 2021
  19. Taylor BlauSep 8, 2021
  20. Ævar Arnfjörð BjarmasonSep 17, 2021
  21. Taylor BlauSep 17, 2021
  22. Ævar Arnfjörð BjarmasonSep 17, 2021
  23. Junio C HamanoSep 13, 2021
  24. Taylor BlauSep 14, 2021
  25. Junio C HamanoSep 14, 2021
  26. Taylor BlauSep 14, 2021
  27. Taylor BlauSep 14, 2021
  28. Jeff KingSep 14, 2021
  29. Taylor BlauSep 14, 2021
  30. Jeff KingSep 14, 2021
  31. Junio C HamanoSep 14, 2021
  32. 0/7 pack-bitmap: permute existing namehash valuesTaylor Blau, Sep 14, 2021
  33. 1/7 t/helper/test-bitmap.c: add 'dump-hashes' modeTaylor Blau, Sep 14, 2021
  34. 2/7 pack-bitmap.c: propagate namehash values from existing bitmapsTaylor Blau, Sep 14, 2021
  35. 3/7 midx.c: respect 'pack.writeBitmapHashcache' when writing bitmapsTaylor Blau, Sep 14, 2021
  36. 4/7 p5326: create missing 'perf-tag' tagTaylor Blau, Sep 14, 2021
  37. Jeff KingSep 16, 2021
  38. Taylor BlauSep 17, 2021
  39. 5/7 p5326: don't set core.multiPackIndex unnecessarilyTaylor Blau, Sep 14, 2021
  40. Jeff KingSep 16, 2021
  41. 6/7 p5326: generate pack bitmaps before writing the MIDX bitmapTaylor Blau, Sep 14, 2021
  42. Jeff KingSep 16, 2021
  43. Taylor BlauSep 17, 2021
  44. 7/7 t5326: test propagating hashcache valuesTaylor Blau, Sep 14, 2021
  45. Jeff KingSep 16, 2021
  46. Jeff KingSep 16, 2021
  47. 0/7 pack-bitmap: permute existing namehash valuesTaylor Blau, Sep 17, 2021
  48. 1/7 t/helper/test-bitmap.c: add 'dump-hashes' modeTaylor Blau, Sep 17, 2021
  49. 2/7 pack-bitmap.c: propagate namehash values from existing bitmapsTaylor Blau, Sep 17, 2021
  50. 3/7 midx.c: respect 'pack.writeBitmapHashcache' when writing bitmapsTaylor Blau, Sep 17, 2021
  51. 4/7 p5326: create missing 'perf-tag' tagTaylor Blau, Sep 17, 2021
  52. 5/7 p5326: don't set core.multiPackIndex unnecessarilyTaylor Blau, Sep 17, 2021
  53. 6/7 p5326: generate pack bitmaps before writing the MIDX bitmapTaylor Blau, Sep 17, 2021
  54. 7/7 t5326: test propagating hashcache valuesTaylor Blau, Sep 17, 2021
  55. Jeff KingSep 17, 2021

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