revlog: use an explicit config option to enable mmap usage for index
We replace the `experimental.mmapindexthreshold` with two options:
The `storage.revlog.mmap.index` is a boolean option to enable or disable the
feature. The `storage.revlog.mmap.index:size-threshold` is a bytes option that
control when we will be using mmap instead of plain reading.
Test encode/decode filters
$ hg init repo
$ cd repo
$ 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 ..