view tests/test-relink.t @ 31553:56acc4250900

scmutil: add a simple key-value file helper

The purpose of the added class is to serve purposes like save files of shelve
or state files of shelve, rebase and histedit. Keys of these files can be
alphanumeric and start with letters, while values must not contain newlines.

In light of Mercurial's reluctancy to use Python's json module, this tries
to provide a reasonable alternative for a non-nested named data.
Comparing to current approach of storing state in plain text files, where
semantic meaning of lines of text is only determined by their oreder,
simple key-value file allows for reordering lines and thus helps handle
optional values.

Initial use-case I see for this is obs-shelve's shelve files. Later we
can possibly migrate state files to this approach.

The test is in a new file beause I did not figure out where to put it
within existing test suite. If you give me a better idea, I will gladly
follow it.

#require hardlink

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "relink=" >> $HGRCPATH

  $ fix_path() {
  >     tr '\\' /
  > }

  $ cat > arelinked.py <<EOF
  > import sys, os
  > from mercurial import util
  > path1, path2 = sys.argv[1:3]
  > if util.samefile(path1, path2):
  >     print '%s == %s' % (path1, path2)
  > else:
  >     print '%s != %s' % (path1, path2)
  > EOF


create source repository

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ echo b > b
  $ hg ci -Am addfile
  adding a
  adding b
  $ cat "$TESTDIR/binfile.bin" >> a
  $ cat "$TESTDIR/binfile.bin" >> b
  $ hg ci -Am changefiles

make another commit to create files larger than 1 KB to test
formatting of final byte count

  $ cat "$TESTDIR/binfile.bin" >> a
  $ cat "$TESTDIR/binfile.bin" >> b
  $ hg ci -m anotherchange

don't sit forever trying to double-lock the source repo

  $ hg relink .
  relinking $TESTTMP/repo/.hg/store to $TESTTMP/repo/.hg/store (glob)
  there is nothing to relink


Test files are read in binary mode

  $ $PYTHON -c "file('.hg/store/data/dummy.i', 'wb').write('a\r\nb\n')"
  $ cd ..


clone and pull to break links

  $ hg clone --pull -r0 repo clone
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd clone
  $ hg pull -q
  $ echo b >> b
  $ hg ci -m changeb
  created new head
  $ $PYTHON -c "file('.hg/store/data/dummy.i', 'wb').write('a\nb\r\n')"


relink

  $ hg relink --debug --config progress.debug=true | fix_path
  relinking $TESTTMP/repo/.hg/store to $TESTTMP/clone/.hg/store
  tip has 2 files, estimated total number of files: 3
  collecting: 00changelog.i 1/3 files (33.33%)
  collecting: 00manifest.i 2/3 files (66.67%)
  collecting: a.i 3/3 files (100.00%)
  collecting: b.i 4/3 files (133.33%)
  collecting: dummy.i 5/3 files (166.67%)
  collected 5 candidate storage files
  not linkable: 00changelog.i
  not linkable: 00manifest.i
  pruning: data/a.i 3/5 files (60.00%)
  not linkable: data/b.i
  pruning: data/dummy.i 5/5 files (100.00%)
  pruned down to 2 probably relinkable files
  relinking: data/a.i 1/2 files (50.00%)
  not linkable: data/dummy.i
  relinked 1 files (1.36 KB reclaimed)
  $ cd ..


check hardlinks

  $ python arelinked.py repo/.hg/store/data/a.i clone/.hg/store/data/a.i
  repo/.hg/store/data/a.i == clone/.hg/store/data/a.i
  $ python arelinked.py repo/.hg/store/data/b.i clone/.hg/store/data/b.i
  repo/.hg/store/data/b.i != clone/.hg/store/data/b.i