view tests/test-merge-prompt.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.

Test for
b5605d88dc27: Make ui.prompt repeat on "unrecognized response" again
 (issue897)

840e2b315c1f: Fix misleading error and prompts during update/merge
 (issue556)

  $ status() {
  >     echo "--- status ---"
  >     hg st -A file1 file2
  >     for file in file1 file2; do
  >         if [ -f $file ]; then
  >             echo "--- $file ---"
  >             cat $file
  >         else
  >             echo "*** $file does not exist"
  >         fi
  >     done
  > }

  $ hg init

  $ echo 1 > file1
  $ echo 2 > file2
  $ hg ci -Am 'added file1 and file2'
  adding file1
  adding file2

  $ hg rm file1
  $ echo changed >> file2
  $ hg ci -m 'removed file1, changed file2'

  $ hg co 0
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ echo changed >> file1
  $ hg rm file2
  $ hg ci -m 'changed file1, removed file2'
  created new head


Non-interactive merge:

  $ hg merge -y
   local changed file1 which remote deleted
  use (c)hanged version or (d)elete? c
  remote changed file2 which local deleted
  use (c)hanged version or leave (d)eleted? c
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ status
  --- status ---
  M file2
  C file1
  --- file1 ---
  1
  changed
  --- file2 ---
  2
  changed


Interactive merge:

  $ hg co -C
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg merge --config ui.interactive=true <<EOF
  > c
  > d
  > EOF
   local changed file1 which remote deleted
  use (c)hanged version or (d)elete? remote changed file2 which local deleted
  use (c)hanged version or leave (d)eleted? 0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ status
  --- status ---
  file2: * (glob)
  C file1
  --- file1 ---
  1
  changed
  *** file2 does not exist


Interactive merge with bad input:

  $ hg co -C
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg merge --config ui.interactive=true <<EOF
  > foo
  > bar
  > d
  > baz
  > c
  > EOF
   local changed file1 which remote deleted
  use (c)hanged version or (d)elete? unrecognized response
   local changed file1 which remote deleted
  use (c)hanged version or (d)elete? unrecognized response
   local changed file1 which remote deleted
  use (c)hanged version or (d)elete? remote changed file2 which local deleted
  use (c)hanged version or leave (d)eleted? unrecognized response
  remote changed file2 which local deleted
  use (c)hanged version or leave (d)eleted? 1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ status
  --- status ---
  M file2
  R file1
  *** file1 does not exist
  --- file2 ---
  2
  changed


Interactive merge with not enough input:

  $ hg co -C
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg merge --config ui.interactive=true <<EOF
  > d
  > EOF
   local changed file1 which remote deleted
  use (c)hanged version or (d)elete? remote changed file2 which local deleted
  use (c)hanged version or leave (d)eleted? abort: response expected
  [255]

  $ status
  --- status ---
  file2: * (glob)
  C file1
  --- file1 ---
  1
  changed
  *** file2 does not exist