Diff for "RevlogSyncFlushProposal"

Differences between revisions 1 and 6 (spanning 5 versions)

Compressing revlog delta chunks reusing the zlib stream

Current revlog format compresses delta chunks separately from each other. The idea is using the same compression object for a snapshot and its delta chunks, simply sync-flushing the zlib stream for each chunk.

Test results

Mercurial crew (http://hg.intevation.org/mercurial/crew) - 10395 revisions
	total size (kb)	relative size (plain == 1)	00manifest.d size (kb)	00manifest.d relative size (plain == 1)
plain	25708	1.00	8632	1.00
zlibstream applied	18400	0.72	4104	0.48
plain, shrinked manifest	21740	0.85	4668	0.54
zlibstream applied, shrinked manifest	16856	0.66	2560	0.30

Linux kernel (http://www.kernel.org/hg/index.cgi/linux-2.6/) - 181609 revisions
	total size (kb)	relative size (plain == 1)	00manifest.d size (kb)	00manifest.d relative size (plain == 1)
plain	1418724	1.00	895624	1.00
zlibstream applied	1343864	0.95	874396	0.98
plain, shrinked manifest	752248	0.53	231112	0.26
zlibstream applied, shrinked manifest	681380	0.48	211912	0.24

Patch queue

The code currently doesn't properly sets and checks the requires file, and the changes on revlog chunks take effect immediately on any new revisions: take care when running this on existing repositories!

http://bitbucket.org/wbruna/hg-zlibstream/

Mailing list threads

http://www.selenic.com/pipermail/mercurial-devel/2010-February/018564.html

-  ⇤ ← Revision 1 as of 2010-02-09 17:47:42 → 
  Size: 1043
  Editor: WagnerBruna
  Comment:
+   ← Revision 6 as of 2010-02-17 02:00:17 → ⇥
  Size: 1885
  Editor: WagnerBruna
  Comment: linux-2.6 test results
-Deletions are marked like this.
+Additions are marked like this.
 Line 1:
+## page was renamed from RevlogCompression
-Line 3:
+Line 4:
-Current revlog format compresses delta chunks separately from each other. The idea is to use the same compression object for a snapshot chunk and its delta chunks, simply sync-flushing the zlib stream for each chunk.
+Current revlog format compresses delta chunks separately from each other. The idea is using the same compression object for a snapshot and its delta chunks, simply sync-flushing the zlib stream for each chunk.
-Line 8:
+Line 9:
-||                 || total size (kb) || relative size <<BR>> (plain == 1) || 00manifest.d size || 00manifest.d relative size <<BR>> (plain == 1) ||
|| plain           || 25708           || 1.00                       || 8632k             || 1.00 ||
+||                 || total size (kb) || relative size <<BR>> (plain == 1) || 00manifest.d size (kb) || 00manifest.d relative size <<BR>> (plain == 1) ||
|| plain           || 25708           || 1.00                       || 8632             || 1.00 ||
-Line 13:
+Line 14:
+||<-5> ||
||<-5>  Linux kernel (http://www.kernel.org/hg/index.cgi/linux-2.6/) - 181609 revisions ||
||                 || total size (kb) || relative size <<BR>> (plain == 1) || 00manifest.d size (kb) || 00manifest.d relative size <<BR>> (plain == 1) ||
|| plain           ||       1418724     ||   1.00                     ||     895624         || 1.00 ||
|| zlibstream applied ||  1343864   || 0.95 || 874396 || 0.98  ||
|| plain,<<BR>>shrinked manifest || 752248 || 0.53  || 231112 || 0.26 ||
|| zlibstream applied,<<BR>>shrinked manifest || 681380 ||  0.48  || 211912  || 0.24  ||
-Line 18:
+Line 25:
-http://bitbucket.org/wbruna/hg-zlibstream/
+<!> The code currently doesn't properly sets and checks the requires file, and the changes on revlog chunks take effect immediately on any new revisions: take care when running this on existing repositories!

http://bitbucket.org/wbruna/hg-zlibstream/