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
#!/usr/bin/env python3
#
# checkseclevel - checking section title levels in each online help document
from __future__ import absolute_import
import optparse
import os
import sys
# import from the live mercurial repo
os.environ['HGMODULEPOLICY'] = 'py'
sys.path.insert(0, "..")
from mercurial import demandimport
demandimport.enable()
from mercurial import (
commands,
extensions,
help,
minirst,
ui as uimod,
)
table = commands.table
helptable = help.helptable
level2mark = [b'"', b'=', b'-', b'.', b'#']
reservedmarks = [b'"']
mark2level = {}
for m, l in zip(level2mark, range(len(level2mark))):
if m not in reservedmarks:
mark2level[m] = l
initlevel_topic = 0
initlevel_cmd = 1
initlevel_ext = 1
initlevel_ext_cmd = 3
def showavailables(ui, initlevel):
avail = ' available marks and order of them in this help: %s\n' % (
', '.join(['%r' % (m * 4) for m in level2mark[initlevel + 1 :]])
)
ui.warn(avail.encode('utf-8'))
def checkseclevel(ui, doc, name, initlevel):
ui.notenoi18n('checking "%s"\n' % name)
if not isinstance(doc, bytes):
doc = doc.encode('utf-8')
blocks, pruned = minirst.parse(doc, 0, ['verbose'])
errorcnt = 0
curlevel = initlevel
for block in blocks:
if block[b'type'] != b'section':
continue
mark = block[b'underline']
title = block[b'lines'][0]
if (mark not in mark2level) or (mark2level[mark] <= initlevel):
ui.warn(
(
'invalid section mark %r for "%s" of %s\n'
% (mark * 4, title, name)
).encode('utf-8')
)
showavailables(ui, initlevel)
errorcnt += 1
continue
nextlevel = mark2level[mark]
if curlevel < nextlevel and curlevel + 1 != nextlevel:
ui.warnnoi18n(
'gap of section level at "%s" of %s\n' % (title, name)
)
showavailables(ui, initlevel)
errorcnt += 1
continue
ui.notenoi18n(
'appropriate section level for "%s %s"\n'
% (mark * (nextlevel * 2), title)
)
curlevel = nextlevel
return errorcnt
def checkcmdtable(ui, cmdtable, namefmt, initlevel):
errorcnt = 0
for k, entry in cmdtable.items():
name = k.split(b"|")[0].lstrip(b"^")
if not entry[0].__doc__:
ui.notenoi18n(
'skip checking %s: no help document\n' % (namefmt % name)
)
continue
errorcnt += checkseclevel(
ui, entry[0].__doc__, namefmt % name, initlevel
)
return errorcnt
def checkhghelps(ui):
errorcnt = 0
for h in helptable:
names, sec, doc = h[0:3]
if callable(doc):
doc = doc(ui)
errorcnt += checkseclevel(
ui, doc, '%s help topic' % names[0], initlevel_topic
)
errorcnt += checkcmdtable(ui, table, '%s command', initlevel_cmd)
for name in sorted(
list(extensions.enabled()) + list(extensions.disabled())
):
mod = extensions.load(ui, name, None)
if not mod.__doc__:
ui.notenoi18n(
'skip checking %s extension: no help document\n' % name
)
continue
errorcnt += checkseclevel(
ui, mod.__doc__, '%s extension' % name, initlevel_ext
)
cmdtable = getattr(mod, 'cmdtable', None)
if cmdtable:
errorcnt += checkcmdtable(
ui,
cmdtable,
'%%s command of %s extension' % name,
initlevel_ext_cmd,
)
return errorcnt
def checkfile(ui, filename, initlevel):
if filename == '-':
filename = 'stdin'
doc = sys.stdin.read()
else:
with open(filename) as fp:
doc = fp.read()
ui.notenoi18n(
'checking input from %s with initlevel %d\n' % (filename, initlevel)
)
return checkseclevel(ui, doc, 'input from %s' % filename, initlevel)
def main():
optparser = optparse.OptionParser(
"""%prog [options]
This checks all help documents of Mercurial (topics, commands,
extensions and commands of them), if no file is specified by --file
option.
"""
)
optparser.add_option(
"-v", "--verbose", help="enable additional output", action="store_true"
)
optparser.add_option(
"-d", "--debug", help="debug mode", action="store_true"
)
optparser.add_option(
"-f",
"--file",
help="filename to read in (or '-' for stdin)",
action="store",
default="",
)
optparser.add_option(
"-t",
"--topic",
help="parse file as help topic",
action="store_const",
dest="initlevel",
const=0,
)
optparser.add_option(
"-c",
"--command",
help="parse file as help of core command",
action="store_const",
dest="initlevel",
const=1,
)
optparser.add_option(
"-e",
"--extension",
help="parse file as help of extension",
action="store_const",
dest="initlevel",
const=1,
)
optparser.add_option(
"-C",
"--extension-command",
help="parse file as help of extension command",
action="store_const",
dest="initlevel",
const=3,
)
optparser.add_option(
"-l",
"--initlevel",
help="set initial section level manually",
action="store",
type="int",
default=0,
)
(options, args) = optparser.parse_args()
ui = uimod.ui.load()
ui.setconfig(b'ui', b'verbose', options.verbose, b'--verbose')
ui.setconfig(b'ui', b'debug', options.debug, b'--debug')
if options.file:
if checkfile(ui, options.file, options.initlevel):
sys.exit(1)
else:
if checkhghelps(ui):
sys.exit(1)
if __name__ == "__main__":
main()