encoding: fix trim() to be O(n) instead of O(n^2)
`encoding.trim()` iterated over the possible lengths smaller than the
input and created a slice for each. It then calculated the column
width of the result, which is of course O(n), so the overall algorithm
was O(n). This patch rewrites it to iterate over the unicode
characters, keeping track of the length so far. Also, the old
algorithm started from the end of the string, which made it much worse
when the input is large and the limit is small (such as the typical 72
we pass to it).
You can time it by running something like this:
```
time python3 -c 'from mercurial.utils import stringutil; print(stringutil.ellipsis(b"0123456789" * 1000, 5))'
```
That drops from 4.05 s to 83 ms with this patch (and most of that is
of course startup time).
Differential Revision: https://phab.mercurial-scm.org/D12089
Create a repository:
#if no-extraextensions
$ hg config
chgserver.idletimeout=60
devel.all-warnings=true
devel.default-date=0 0
extensions.fsmonitor= (fsmonitor !)
format.exp-rc-dirstate-v2=1 (dirstate-v2 !)
largefiles.usercache=$TESTTMP/.cache/largefiles
lfs.usercache=$TESTTMP/.cache/lfs
ui.slash=True
ui.interactive=False
ui.detailed-exit-code=True
ui.merge=internal:merge
ui.mergemarkers=detailed
ui.promptecho=True
ui.ssh=* (glob)
ui.timeout.warn=15
web.address=localhost
web\.ipv6=(?:True|False) (re)
web.server-header=testing stub value
#endif
$ hg init t
$ cd t
Prepare a changeset:
$ echo a > a
$ hg add a
$ hg status
A a
Writes to stdio succeed and fail appropriately
#if devfull
$ hg status 2>/dev/full
A a
$ hg status >/dev/full
abort: No space left on device* (glob)
[255]
#endif
#if devfull
$ hg status >/dev/full 2>&1
[255]
$ hg status ENOENT 2>/dev/full
[255]
#endif
On Python 3, stdio may be None:
$ hg debuguiprompt --config ui.interactive=true 0<&-
abort: Bad file descriptor (no-rhg !)
abort: response expected (rhg !)
[255]
$ hg version -q 0<&-
Mercurial Distributed SCM * (glob)
#if py3 no-rhg
$ hg version -q 1>&-
abort: Bad file descriptor
[255]
#else
$ hg version -q 1>&-
#endif
$ hg unknown -q 1>&-
hg: unknown command 'unknown'
(did you mean debugknown?)
[10]
$ hg version -q 2>&-
Mercurial Distributed SCM * (glob)
$ hg unknown -q 2>&-
[10]
$ hg commit -m test
This command is ancient:
$ hg history
changeset: 0:acb14030fe0a
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: test
Verify that updating to revision 0 via commands.update() works properly
$ cat <<EOF > update_to_rev0.py
> from mercurial import commands, hg, ui as uimod
> myui = uimod.ui.load()
> repo = hg.repository(myui, path=b'.')
> commands.update(myui, repo, rev=b"0")
> EOF
$ hg up null
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ "$PYTHON" ./update_to_rev0.py
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg identify -n
0
Poke around at hashes:
$ hg manifest --debug
b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 644 a
$ hg cat a
a
Verify should succeed:
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
Repository root:
$ hg root
$TESTTMP/t
$ hg log -l1 -T '{reporoot}\n'
$TESTTMP/t
$ hg root -Tjson | sed 's|\\\\|\\|g'
[
{
"hgpath": "$TESTTMP/t/.hg",
"reporoot": "$TESTTMP/t",
"storepath": "$TESTTMP/t/.hg/store"
}
]
At the end...
$ cd ..
Status message redirection:
$ hg init empty
status messages are sent to stdout by default:
$ hg outgoing -R t empty -Tjson 2>/dev/null
comparing with empty
searching for changes
[
{
"bookmarks": [],
"branch": "default",
"date": [0, 0],
"desc": "test",
"node": "acb14030fe0a21b60322c440ad2d20cf7685a376",
"parents": ["0000000000000000000000000000000000000000"],
"phase": "draft",
"rev": 0,
"tags": ["tip"],
"user": "test"
}
]
which can be configured to send to stderr, so the output wouldn't be
interleaved:
$ cat <<'EOF' >> "$HGRCPATH"
> [ui]
> message-output = stderr
> EOF
$ hg outgoing -R t empty -Tjson 2>/dev/null
[
{
"bookmarks": [],
"branch": "default",
"date": [0, 0],
"desc": "test",
"node": "acb14030fe0a21b60322c440ad2d20cf7685a376",
"parents": ["0000000000000000000000000000000000000000"],
"phase": "draft",
"rev": 0,
"tags": ["tip"],
"user": "test"
}
]
$ hg outgoing -R t empty -Tjson >/dev/null
comparing with empty
searching for changes
this option should be turned off by HGPLAIN= since it may break scripting use:
$ HGPLAIN= hg outgoing -R t empty -Tjson 2>/dev/null
comparing with empty
searching for changes
[
{
"bookmarks": [],
"branch": "default",
"date": [0, 0],
"desc": "test",
"node": "acb14030fe0a21b60322c440ad2d20cf7685a376",
"parents": ["0000000000000000000000000000000000000000"],
"phase": "draft",
"rev": 0,
"tags": ["tip"],
"user": "test"
}
]
but still overridden by --config:
$ HGPLAIN= hg outgoing -R t empty -Tjson --config ui.message-output=stderr \
> 2>/dev/null
[
{
"bookmarks": [],
"branch": "default",
"date": [0, 0],
"desc": "test",
"node": "acb14030fe0a21b60322c440ad2d20cf7685a376",
"parents": ["0000000000000000000000000000000000000000"],
"phase": "draft",
"rev": 0,
"tags": ["tip"],
"user": "test"
}
]
Invalid ui.message-output option:
$ hg log -R t --config ui.message-output=bad
abort: invalid ui.message-output destination: bad
[255]
Underlying message streams should be updated when ui.fout/ferr are set:
$ cat <<'EOF' > capui.py
> from mercurial import pycompat, registrar
> cmdtable = {}
> command = registrar.command(cmdtable)
> @command(b'capui', norepo=True)
> def capui(ui):
> out = ui.fout
> ui.fout = pycompat.bytesio()
> ui.status(b'status\n')
> ui.ferr = pycompat.bytesio()
> ui.warn(b'warn\n')
> out.write(b'stdout: %s' % ui.fout.getvalue())
> out.write(b'stderr: %s' % ui.ferr.getvalue())
> EOF
$ hg --config extensions.capui=capui.py --config ui.message-output=stdio capui
stdout: status
stderr: warn