changing-files: rework the way we store changed files in side-data
We need to store new data so this is a good opportunity to rework this fully.
1) We directly store the list of affected file in the side data:
* This avoid having to fetch and parse the `files` list in the revision in
addition to the sidedata. Making the data more self sufficient.
* This work around situation where that `files` field contains wrong
information, and open the way to other bug fixing (eg:
issue6219)
* The format (fixed initial index, sorted files) allow for fast lookup of
filename within the structure.
* This unify the storage of affected files and copies sources and destination,
limiting the number filename stored redundantly.
* This prepare for the fact we should drop the `files` as soon as we do any
change affecting the revision schema.
* This rely on compression to avoid a significant increase of the changelog.d.
More testing on this will be done before we freeze the final format.
2) We can store additional data:
* The new "merged" field,
* A future "salvaged" set recording files that might have been deleted but have
were still present in the final result.
Differential Revision: https://phab.mercurial-scm.org/D9090
Test encode/decode filters
$ hg init
$ cat > .hg/hgrc <<EOF
> [encode]
> not.gz = tr [:lower:] [:upper:]
> *.gz = gzip -d
> [decode]
> not.gz = tr [:upper:] [:lower:]
> *.gz = gzip
> EOF
$ echo "this is a test" | gzip > a.gz
$ echo "this is a test" > not.gz
$ hg add *
$ hg ci -m "test"
no changes
$ hg status
$ touch *
no changes
$ hg status
check contents in repo are encoded
$ hg debugdata a.gz 0
this is a test
$ hg debugdata not.gz 0
THIS IS A TEST
check committed content was decoded
$ gunzip < a.gz
this is a test
$ cat not.gz
this is a test
$ rm *
$ hg co -C
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
check decoding of our new working dir copy
$ gunzip < a.gz
this is a test
$ cat not.gz
this is a test
check hg cat operation
$ hg cat a.gz
this is a test
$ hg cat --decode a.gz | gunzip
this is a test
$ mkdir subdir
$ cd subdir
$ hg -R .. cat ../a.gz
this is a test
$ hg -R .. cat --decode ../a.gz | gunzip
this is a test
$ cd ..
check tempfile filter
$ hg cat a.gz --decode --config 'decode.*.gz=tempfile:gzip -c INFILE > OUTFILE' | gunzip
this is a test
$ hg cat a.gz --decode --config 'decode.*.gz=tempfile:sh -c "exit 1"'
abort: command '*' failed: exited with status 1 (glob)
[255]
$ cd ..