view tests/test-mq-qdiff.t @ 16120:47ee41fcf42b

largefiles: optimize update speed by only updating changed largefiles Historically, during 'hg update', every largefile in the working copy was hashed (which is a very expensive operation on big files) and any largefiles that did not have a hash that matched their standin were updated. This patch optimizes 'hg update' by keeping track of what standins have changed between the old and new revisions, and only updating the largefiles that have changed. This saves a lot of time by avoiding the unecessary calculation of a list of sha1 hashes for big files. With this patch, the time 'hg update' takes to complete is a function of how many largefiles need to be updated and what their size is. Performance tests on a repository with about 80 largefiles ranging from a few MB to about 97 MB are shown below. The tests show how long it takes to run 'hg update' with no changes actually being updated. Mercurial 2.1 release: $ time hg update 0 files updated, 0 files merged, 0 files removed, 0 files unresolved getting changed largefiles 0 largefiles updated, 0 removed real 0m10.045s user 0m9.367s sys 0m0.674s With this patch: $ time hg update 0 files updated, 0 files merged, 0 files removed, 0 files unresolved real 0m0.965s user 0m0.845s sys 0m0.115s The same repsoitory, without the largefiles extension enabled: $ time hg update 0 files updated, 0 files merged, 0 files removed, 0 files unresolved real 0m0.799s user 0m0.684s sys 0m0.111s So before the patch, 'hg update' with no changes was approximately 9.25s slower with largefiles enabled. With this patch, it is approximately 0.165s slower.
author Na'Tosha Bard <natosha@unity3d.com>
date Mon, 13 Feb 2012 18:37:07 +0100
parents 2e8f4b82c551
children f2719b387380
line wrap: on
line source

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH
  $ echo "[mq]" >> $HGRCPATH
  $ echo "git=keep" >> $HGRCPATH

  $ hg init a
  $ cd a

  $ echo 'base' > base
  $ hg ci -Ambase
  adding base

  $ hg qnew -mmqbase mqbase

  $ echo 'patched' > base
  $ hg qrefresh

qdiff:

  $ hg qdiff
  diff -r d20a80d4def3 base
  --- a/base	Thu Jan 01 00:00:00 1970 +0000
  +++ b/base* (glob)
  @@ -1,1 +1,1 @@
  -base
  +patched

qdiff dirname:

  $ hg qdiff --nodates .
  diff -r d20a80d4def3 base
  --- a/base
  +++ b/base
  @@ -1,1 +1,1 @@
  -base
  +patched

qdiff filename:

  $ hg qdiff --nodates base
  diff -r d20a80d4def3 base
  --- a/base
  +++ b/base
  @@ -1,1 +1,1 @@
  -base
  +patched

  $ hg revert -a

  $ hg qpop
  popping mqbase
  patch queue now empty

  $ hg qdelete mqbase

  $ printf '1\n2\n3\n4\nhello world\ngoodbye world\n7\n8\n9\n' > lines
  $ hg ci -Amlines -d '2 0'
  adding lines

  $ hg qnew -mmqbase2 mqbase2
  $ printf '\n\n1\n2\n3\n4\nhello  world\n     goodbye world\n7\n8\n9\n' > lines

  $ hg qdiff --nodates -U 1
  diff -r b0c220e1cf43 lines
  --- a/lines
  +++ b/lines
  @@ -1,1 +1,3 @@
  +
  +
   1
  @@ -4,4 +6,4 @@
   4
  -hello world
  -goodbye world
  +hello  world
  +     goodbye world
   7

  $ hg qdiff --nodates -b
  diff -r b0c220e1cf43 lines
  --- a/lines
  +++ b/lines
  @@ -1,9 +1,11 @@
  +
  +
   1
   2
   3
   4
   hello world
  -goodbye world
  +     goodbye world
   7
   8
   9

  $ hg qdiff --nodates -U 1 -B
  diff -r b0c220e1cf43 lines
  --- a/lines
  +++ b/lines
  @@ -4,4 +4,4 @@
   4
  -hello world
  -goodbye world
  +hello  world
  +     goodbye world
   7

  $ hg qdiff --nodates -w
  diff -r b0c220e1cf43 lines
  --- a/lines
  +++ b/lines
  @@ -1,3 +1,5 @@
  +
  +
   1
   2
   3

  $ hg qdiff --nodates --reverse
  diff -r b0c220e1cf43 lines
  --- a/lines
  +++ b/lines
  @@ -1,11 +1,9 @@
  -
  -
   1
   2
   3
   4
  -hello  world
  -     goodbye world
  +hello world
  +goodbye world
   7
   8
   9

qdiff preserve existing git flag:

  $ hg qrefresh --git
  $ echo a >> lines
  $ hg qdiff
  diff --git a/lines b/lines
  --- a/lines
  +++ b/lines
  @@ -1,9 +1,12 @@
  +
  +
   1
   2
   3
   4
  -hello world
  -goodbye world
  +hello  world
  +     goodbye world
   7
   8
   9
  +a

  $ hg qdiff --stat
   lines |  7 +++++--
   1 files changed, 5 insertions(+), 2 deletions(-)
  $ hg qrefresh

qdiff when file deleted (but not removed) in working dir:

  $ hg qnew deleted-file
  $ echo a > newfile
  $ hg add newfile
  $ hg qrefresh
  $ rm newfile
  $ hg qdiff