rust-nodemap: accounting for dead blocks
By the very append-only nature of the `NodeTree`, inserting
new blocks has the effect of making some of the older ones
useless as they become unreachable.
Therefore some automatic housekeeping will need to be provided.
This is standard procedure in the word of databases, under names
such as "repack" or "vacuum".
The new `masked_readonly_blocks()` will provide callers with
useful information to decide if the nodetree is ripe for
repacking, but all the `NodeTree` can provide is how many
blocks have been masked in the currently mutable part. Analysing
the readonly part would be way too long to do it for each
transaction and defeat the whole purpose of nodemap persistence.
Serializing callers (from the Python layer) will get this figure
before each extraction and maintain an aggregate counter of
unreachable blocks separately.
Note: at this point, the most efficient repacking is just to restart
afresh with a full rescan.
Differential Revision: https://phab.mercurial-scm.org/D8097
$ testparseutil="$TESTDIR"/../contrib/testparseutil.py
Internal test by doctest
$ "$PYTHON" -m doctest "$testparseutil"
Tests for embedded python script
Typical cases
$ "$PYTHON" "$testparseutil" -v pyembedded <<NO_CHECK_EOF
> >>> for f in [1, 2, 3]:
> ... foo = 1
> >>> foo = 2
> $ echo "doctest is terminated by command, empty line, or comment"
> >>> foo = 31
> expected output of doctest fragment
> >>> foo = 32
>
> >>> foo = 33
>
> >>> foo = 34
> comment
> >>> foo = 35
>
> $ "\$PYTHON" <<EOF
> > foo = 4
> >
> > EOF
> $ cat > foo.py <<EOF
> > foo = 5
> > EOF
> $ cat >> foo.py <<EOF
> > foo = 6 # appended
> > EOF
>
> NO_CHECK_EOF limit mark makes parsing ignore corresponded fragment
> (this is useful to use bad code intentionally)
>
> $ "\$PYTHON" <<NO_CHECK_EOF
> > foo = 7 # this should be ignored at detection
> > NO_CHECK_EOF
> $ cat > foo.py <<NO_CHECK_EOF
> > foo = 8 # this should be ignored at detection
> > NO_CHECK_EOF
>
> doctest fragment ended by EOF
>
> >>> foo = 9
> NO_CHECK_EOF
<stdin>:1: <anonymous> starts
|for f in [1, 2, 3]:
| foo = 1
|foo = 2
<stdin>:4: <anonymous> ends
<stdin>:5: <anonymous> starts
|foo = 31
|
|foo = 32
|
|foo = 33
<stdin>:10: <anonymous> ends
<stdin>:11: <anonymous> starts
|foo = 34
<stdin>:12: <anonymous> ends
<stdin>:13: <anonymous> starts
|foo = 35
<stdin>:14: <anonymous> ends
<stdin>:16: <anonymous> starts
|foo = 4
|
<stdin>:18: <anonymous> ends
<stdin>:20: foo.py starts
|foo = 5
<stdin>:21: foo.py ends
<stdin>:23: foo.py starts
|foo = 6 # appended
<stdin>:24: foo.py ends
<stdin>:38: <anonymous> starts
|foo = 9
<stdin>:39: <anonymous> ends
Invalid test script
(similar test for shell script and hgrc configuration is omitted,
because this tests common base class of them)
$ "$PYTHON" "$testparseutil" -v pyembedded <<NO_CHECK_EOF > detected
> $ "\$PYTHON" <<EOF
> > foo = 1
>
> $ "\$PYTHON" <<EOF
> > foo = 2
> $ cat > bar.py <<EOF
> > bar = 2 # this fragment will be detected as expected
> > EOF
>
> $ cat > foo.py <<EOF
> > foo = 3
> NO_CHECK_EOF
<stdin>:3: unexpected line for "heredoc python invocation"
<stdin>:6: unexpected line for "heredoc python invocation"
<stdin>:11: unexpected end of file for "heredoc .py file"
[1]
$ cat detected
<stdin>:7: bar.py starts
|bar = 2 # this fragment will be detected as expected
<stdin>:8: bar.py ends
Tests for embedded shell script
$ "$PYTHON" "$testparseutil" -v shembedded <<NO_CHECK_EOF
> $ cat > foo.sh <<EOF
> > foo = 1
> >
> > foo = 2
> > EOF
> $ cat >> foo.sh <<EOF
> > foo = 3 # appended
> > EOF
>
> NO_CHECK_EOF limit mark makes parsing ignore corresponded fragment
> (this is useful to use bad code intentionally)
>
> $ cat > foo.sh <<NO_CHECK_EOF
> > # this should be ignored at detection
> > foo = 4
> > NO_CHECK_EOF
>
> NO_CHECK_EOF
<stdin>:2: foo.sh starts
|foo = 1
|
|foo = 2
<stdin>:5: foo.sh ends
<stdin>:7: foo.sh starts
|foo = 3 # appended
<stdin>:8: foo.sh ends
Tests for embedded hgrc configuration
$ "$PYTHON" "$testparseutil" -v hgrcembedded <<NO_CHECK_EOF
> $ cat > .hg/hgrc <<EOF
> > [ui]
> > verbose = true
> >
> > # end of local configuration
> > EOF
>
> $ cat > \$HGRCPATH <<EOF
> > [extensions]
> > rebase =
> > # end of global configuration
> > EOF
>
> $ cat >> \$HGRCPATH <<EOF
> > # appended
> > [extensions]
> > rebase =!
> > EOF
>
> NO_CHECK_EOF limit mark makes parsing ignore corresponded fragment
> (this is useful to use bad code intentionally)
>
> $ cat > .hg/hgrc <<NO_CHECK_EOF
> > # this local configuration should be ignored at detection
> > [ui]
> > username = foo bar
> > NO_CHECK_EOF
>
> $ cat > \$HGRCPATH <<NO_CHECK_EOF
> > # this global configuration should be ignored at detection
> > [extensions]
> > foobar =
> > NO_CHECK_EOF
> NO_CHECK_EOF
<stdin>:2: .hg/hgrc starts
|[ui]
|verbose = true
|
|# end of local configuration
<stdin>:6: .hg/hgrc ends
<stdin>:9: $HGRCPATH starts
|[extensions]
|rebase =
|# end of global configuration
<stdin>:12: $HGRCPATH ends
<stdin>:15: $HGRCPATH starts
|# appended
|[extensions]
|rebase =!
<stdin>:18: $HGRCPATH ends