view tests/test-symlinks.t @ 40393:229d23cdb203

exchangev2: support fetching shallow files history

This commit teaches the exchangev2 client code to handle fetching shallow
files data.

Only shallow fetching of files data is supported: shallow fetching of
changeset and manifest data is explicitly not yet supported.

Previously, we would fetch file revisions for changesets that were received
by the current pull operation. In the new model, we calculate the set of
"relevant" changesets given the pull depth and only fetch files data for
those changesets.

We also teach the "filesdata" command invocation to vary parameters as needed.

The implementation here is far from complete or optimal. Subsequent pulls will
end up re-fetching a lot of files data. But the application of this data should
mostly be a no-op on the client, so it isn't a big deal.

Depending on the order file revisions are fetched in, revisions could get
inserted with the wrong revision number relationships. I think the best way
to deal with this is to remove revision numbers from storage and to either
dynamically derive them (by reconstructing a DAG from nodes/parents) or remove
revision numbers from the file storage interface completely.

A missing API that we'll likely want to write pretty soon is "ensure files
for revision(s) are present." We can kind of cajole exchangev2.pull() to do
this. But it isn't very efficient. For example, in simple cases like
widening the store to obtain data for a single revision, it is probably
more efficient to walk the manifest and find exactly which file revisions
are missing and to make explicit requests for just their data. In more
advanced cases, asking the server for all files data may be more efficient,
even though it requires sending data the client already has. There is tons
of room for future experimentation here. And TBH I'm not sure what the
final state will be.

Anyway, this commit gets us pretty close to being able to have shallow
and narrow checkouts with exchangev2/sqlite storage. Close enough that a
minimal extension should be able to provide fill in the gaps until the code
in core stabilizes and there is a user-facing way to trigger the
narrow/shallow bits from `hg clone` without also implying using of the
narrow extension...

Differential Revision: https://phab.mercurial-scm.org/D5169

#require symlink

== tests added in 0.7 ==

  $ hg init test-symlinks-0.7; cd test-symlinks-0.7;
  $ touch foo; ln -s foo bar; ln -s nonexistent baz

import with add and addremove -- symlink walking should _not_ screwup.

  $ hg add
  adding bar
  adding baz
  adding foo
  $ hg forget bar baz foo
  $ hg addremove
  adding bar
  adding baz
  adding foo

commit -- the symlink should _not_ appear added to dir state

  $ hg commit -m 'initial'

  $ touch bomb

again, symlink should _not_ show up on dir state

  $ hg addremove
  adding bomb

Assert screamed here before, should go by without consequence

  $ hg commit -m 'is there a bug?'
  $ cd ..


== fifo & ignore ==

  $ hg init test; cd test;

  $ mkdir dir
  $ touch a.c dir/a.o dir/b.o

test what happens if we want to trick hg

  $ hg commit -A -m 0
  adding a.c
  adding dir/a.o
  adding dir/b.o
  $ echo "relglob:*.o" > .hgignore
  $ rm a.c
  $ rm dir/a.o
  $ rm dir/b.o
  $ mkdir dir/a.o
  $ ln -s nonexistent dir/b.o
  $ mkfifo a.c

it should show a.c, dir/a.o and dir/b.o deleted

  $ hg status
  M dir/b.o
  ! a.c
  ! dir/a.o
  ? .hgignore
  $ hg status a.c
  a.c: unsupported file type (type is fifo)
  ! a.c
  $ cd ..


== symlinks from outside the tree ==

test absolute path through symlink outside repo

  $ p=`pwd`
  $ hg init x
  $ ln -s x y
  $ cd x
  $ touch f
  $ hg add f
  $ hg status "$p"/y/f
  A f

try symlink outside repo to file inside

  $ ln -s x/f ../z

this should fail

  $ hg status ../z && { echo hg mistakenly exited with status 0; exit 1; } || :
  abort: ../z not under root '$TESTTMP/x'
  $ cd ..


== cloning symlinks ==
  $ hg init clone; cd clone;

try cloning symlink in a subdir
1. commit a symlink

  $ mkdir -p a/b/c
  $ cd a/b/c
  $ ln -s /path/to/symlink/source demo
  $ cd ../../..
  $ hg stat
  ? a/b/c/demo
  $ hg commit -A -m 'add symlink in a/b/c subdir'
  adding a/b/c/demo

2. clone it

  $ cd ..
  $ hg clone clone clonedest
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved


== symlink and git diffs ==

git symlink diff

  $ cd clonedest
  $ hg diff --git -r null:tip
  diff --git a/a/b/c/demo b/a/b/c/demo
  new file mode 120000
  --- /dev/null
  +++ b/a/b/c/demo
  @@ -0,0 +1,1 @@
  +/path/to/symlink/source
  \ No newline at end of file
  $ hg export --git tip > ../sl.diff

import git symlink diff

  $ hg rm a/b/c/demo
  $ hg commit -m'remove link'
  $ hg import ../sl.diff
  applying ../sl.diff
  $ hg diff --git -r 1:tip
  diff --git a/a/b/c/demo b/a/b/c/demo
  new file mode 120000
  --- /dev/null
  +++ b/a/b/c/demo
  @@ -0,0 +1,1 @@
  +/path/to/symlink/source
  \ No newline at end of file

== symlinks and addremove ==

directory moved and symlinked

  $ mkdir foo
  $ touch foo/a
  $ hg ci -Ama
  adding foo/a
  $ mv foo bar
  $ ln -s bar foo
  $ hg status
  ! foo/a
  ? bar/a
  ? foo

now addremove should remove old files

  $ hg addremove
  adding bar/a
  adding foo
  removing foo/a

commit and update back

  $ hg ci -mb
  $ hg up '.^'
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg up tip
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ cd ..

== root of repository is symlinked ==

  $ hg init root
  $ ln -s root link
  $ cd root
  $ echo foo > foo
  $ hg status
  ? foo
  $ hg status ../link
  ? foo
  $ hg add foo
  $ hg cp foo "$TESTTMP/link/bar"
  foo has not been committed yet, so no copy data will be stored for bar.
  $ cd ..


  $ hg init b
  $ cd b
  $ ln -s nothing dangling
  $ hg commit -m 'commit symlink without adding' dangling
  abort: dangling: file not tracked!
  [255]
  $ hg add dangling
  $ hg commit -m 'add symlink'

  $ hg tip -v
  changeset:   0:cabd88b706fc
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       dangling
  description:
  add symlink
  
  
  $ hg manifest --debug
  2564acbe54bbbedfbf608479340b359f04597f80 644 @ dangling
  $ readlink.py dangling
  dangling -> nothing

  $ rm dangling
  $ ln -s void dangling
  $ hg commit -m 'change symlink'
  $ readlink.py dangling
  dangling -> void


modifying link

  $ rm dangling
  $ ln -s empty dangling
  $ readlink.py dangling
  dangling -> empty


reverting to rev 0:

  $ hg revert -r 0 -a
  reverting dangling
  $ readlink.py dangling
  dangling -> nothing


backups:

  $ readlink.py *.orig
  dangling.orig -> empty
  $ rm *.orig
  $ hg up -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

copies

  $ hg cp -v dangling dangling2
  copying dangling to dangling2
  $ hg st -Cmard
  A dangling2
    dangling
  $ readlink.py dangling dangling2
  dangling -> void
  dangling2 -> void


Issue995: hg copy -A incorrectly handles symbolic links

  $ hg up -C
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ mkdir dir
  $ ln -s dir dirlink
  $ hg ci -qAm 'add dirlink'
  $ mkdir newdir
  $ mv dir newdir/dir
  $ mv dirlink newdir/dirlink
  $ hg mv -A dirlink newdir/dirlink

  $ cd ..