view tests/test-fix-metadata.t @ 49275:c6a3243567b6

chg: replace mercurial.util.recvfds() by simpler pure Python implementation

On Python 3, we have socket.socket.recvmsg(). This makes it possible to receive
FDs in pure Python code. The new code behaves like the previous
implementations, except that it’s more strict about the format of the ancillary
data. This works because we know in which format the FDs are passed.

Because the code is (and always has been) specific to chg (payload is 1 byte,
number of passed FDs is limited) and we now have only one implementation and
the code is very short, I decided to stop exposing a function in
mercurial.util.

Note on terminology: The SCM_RIGHTS mechanism is used to share open file
descriptions to another process over a socket. The sending side passes an array
of file descriptors and the receiving side receives an array of file
descriptors. The file descriptors are different in general on both sides but
refer to the same open file descriptions. The two terms are often conflated,
even in the official documentation. That’s why I used “FD” above, which could
mean both “file descriptor” and “file description”.

A python hook for "hg fix" that prints out the number of files and revisions
that were affected, along with which fixer tools were applied. Also checks how
many times it sees a specific key generated by one of the fixer tools defined
below.

  $ cat >> $TESTTMP/postfixhook.py <<EOF
  > import collections
  > def file(ui, repo, rev=None, path=b'', metadata=None, **kwargs):
  >   ui.status(b'fixed %s in revision %d using %s\n' %
  >             (path, rev, b', '.join(metadata.keys())))
  > def summarize(ui, repo, replacements=None, wdirwritten=False,
  >               metadata=None, **kwargs):
  >     counts = collections.defaultdict(int)
  >     keys = 0
  >     for fixername, metadatalist in metadata.items():
  >         for metadata in metadatalist:
  >             if metadata is None:
  >                 continue
  >             counts[fixername] += 1
  >             if 'key' in metadata:
  >                 keys += 1
  >     ui.status(b'saw "key" %d times\n' % (keys,))
  >     for name, count in sorted(counts.items()):
  >         ui.status(b'fixed %d files with %s\n' % (count, name))
  >     if replacements:
  >         ui.status(b'fixed %d revisions\n' % (len(replacements),))
  >     if wdirwritten:
  >         ui.status(b'fixed the working copy\n')
  > EOF

Some mock output for fixer tools that demonstrate what could go wrong with
expecting the metadata output format.

  $ printf 'new content\n' > $TESTTMP/missing
  $ printf 'not valid json\0new content\n' > $TESTTMP/invalid
  $ printf '{"key": "value"}\0new content\n' > $TESTTMP/valid

Configure some fixer tools based on the output defined above, and enable the
hooks defined above. Disable parallelism to make output of the parallel file
processing phase stable.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > fix =
  > [fix]
  > metadatafalse:command=cat $TESTTMP/missing
  > metadatafalse:pattern=metadatafalse
  > metadatafalse:metadata=false
  > missing:command=cat $TESTTMP/missing
  > missing:pattern=missing
  > missing:metadata=true
  > invalid:command=cat $TESTTMP/invalid
  > invalid:pattern=invalid
  > invalid:metadata=true
  > valid:command=cat $TESTTMP/valid
  > valid:pattern=valid
  > valid:metadata=true
  > [hooks]
  > postfixfile = python:$TESTTMP/postfixhook.py:file
  > postfix = python:$TESTTMP/postfixhook.py:summarize
  > [worker]
  > enabled=false
  > EOF

See what happens when we execute each of the fixer tools. Some print warnings,
some write back to the file.

  $ hg init repo
  $ cd repo

  $ printf "old content\n" > metadatafalse
  $ printf "old content\n" > invalid
  $ printf "old content\n" > missing
  $ printf "old content\n" > valid
  $ hg add -q

  $ hg fix -w
  ignored invalid output from fixer tool: invalid
  fixed metadatafalse in revision 2147483647 using metadatafalse
  ignored invalid output from fixer tool: missing
  fixed valid in revision 2147483647 using valid
  saw "key" 1 times
  fixed 1 files with valid
  fixed the working copy

  $ cat metadatafalse
  new content
  $ cat missing
  old content
  $ cat invalid
  old content
  $ cat valid
  new content

  $ cd ..