posix: give checklink a fast path that cache the check file and is read only
util.checklink would create a symlink and remove it again. That would sometimes
happen multiple times. Write operations are relatively expensive and give disk
tear and noise for applications monitoring file system activity.
Instead of creating a symlink and deleting it again, just create it once and
leave it in .hg/cache/check-link . If the file exists, just verify that
os.islink reports true. We will assume that this check is as good as symlink
creation not failing.
Note: The symlink left in .hg/cache has to resolve to a file - otherwise 'make
dist' will fail ...
test-symlink-os-yes-fs-no.py does some monkey patching to simulate a platform
without symlink support. The slightly different testing method requires
additional monkeying.
initial
$ hg init test-a
$ cd test-a
$ cat >test.txt <<"EOF"
> 1
> 2
> 3
> EOF
$ hg add test.txt
$ hg commit -m "Initial"
clone
$ cd ..
$ hg clone test-a test-b
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
change test-a
$ cd test-a
$ cat >test.txt <<"EOF"
> one
> two
> three
> EOF
$ hg commit -m "Numbers as words"
change test-b
$ cd ../test-b
$ cat >test.txt <<"EOF"
> 1
> 2.5
> 3
> EOF
$ hg commit -m "2 -> 2.5"
now pull and merge from test-a
$ hg pull ../test-a
pulling from ../test-a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg merge
merging test.txt
warning: conflicts while merging test.txt! (edit, then use 'hg resolve --mark')
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
resolve conflict
$ cat >test.txt <<"EOF"
> one
> two-point-five
> three
> EOF
$ rm -f *.orig
$ hg resolve -m test.txt
(no more unresolved files)
$ hg commit -m "Merge 1"
change test-a again
$ cd ../test-a
$ cat >test.txt <<"EOF"
> one
> two-point-one
> three
> EOF
$ hg commit -m "two -> two-point-one"
pull and merge from test-a again
$ cd ../test-b
$ hg pull ../test-a
pulling from ../test-a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg merge --debug
searching for copies back to rev 1
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: 96b70246a118, local: 50c3a7e29886+, remote: 40d11a4173a8
preserving test.txt for resolve of test.txt
starting 4 threads for background file closing (?)
test.txt: versions differ -> m (premerge)
picked tool ':merge' for test.txt (binary False symlink False changedelete False)
merging test.txt
my test.txt@50c3a7e29886+ other test.txt@40d11a4173a8 ancestor test.txt@96b70246a118
test.txt: versions differ -> m (merge)
picked tool ':merge' for test.txt (binary False symlink False changedelete False)
my test.txt@50c3a7e29886+ other test.txt@40d11a4173a8 ancestor test.txt@96b70246a118
warning: conflicts while merging test.txt! (edit, then use 'hg resolve --mark')
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ cat test.txt
one
<<<<<<< working copy: 50c3a7e29886 - test: Merge 1
two-point-five
=======
two-point-one
>>>>>>> merge rev: 40d11a4173a8 - test: two -> two-point-one
three
$ hg debugindex test.txt
rev offset length ..... linkrev nodeid p1 p2 (re)
0 0 7 ..... 0 01365c4cca56 000000000000 000000000000 (re)
1 7 9 ..... 1 7b013192566a 01365c4cca56 000000000000 (re)
2 16 15 ..... 2 8fe46a3eb557 01365c4cca56 000000000000 (re)
3 31 2. ..... 3 fc3148072371 7b013192566a 8fe46a3eb557 (re)
4 5. 25 ..... 4 d40249267ae3 8fe46a3eb557 000000000000 (re)
$ hg log
changeset: 4:40d11a4173a8
tag: tip
parent: 2:96b70246a118
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: two -> two-point-one
changeset: 3:50c3a7e29886
parent: 1:d1e159716d41
parent: 2:96b70246a118
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Merge 1
changeset: 2:96b70246a118
parent: 0:b1832b9d912a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Numbers as words
changeset: 1:d1e159716d41
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2 -> 2.5
changeset: 0:b1832b9d912a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Initial
$ cd ..