wireproto: add streams to frame-based protocol
Previously, the frame-based protocol was just a series of frames,
with each frame associated with a request ID.
In order to scale the protocol, we'll want to enable the use of
compression. While it is possible to enable compression at the
socket/pipe level, this has its disadvantages. The big one is it
undermines the point of frames being standalone, atomic units that
can be read and written: if you add compression above the framing
protocol, you are back to having a stream-based protocol as opposed
to something frame-based.
So in order to preserve frames, compression needs to occur at
the frame payload level.
Compressing each frame's payload individually will limit compression
ratios because the window size of the compressor will be limited
by the max frame size, which is 32-64kb as currently defined. It
will also add CPU overhead, as it is more efficient for compressors
to operate on fewer, larger blocks of data than more, smaller blocks.
So compressing each frame independently is out.
This means we need to compress each frame's payload as if it is part
of a larger stream.
The simplest approach is to have 1 stream per connection. This
could certainly work. However, it has disadvantages (documented below).
We could also have 1 stream per RPC/command invocation. (This is the
model HTTP/2 goes with.) This also has disadvantages.
The main disadvantage to one global stream is that it has the very
real potential to create CPU bottlenecks doing compression. Networks
are only getting faster and the performance of single CPU cores has
been relatively flat. Newer compression formats like zstandard offer
better CPU cycle efficiency than predecessors like zlib. But it still
all too common to saturate your CPU with compression overhead long
before you saturate the network pipe.
The main disadvantage with streams per request is that you can't
reap the benefits of the compression context for multiple requests.
For example, if you send 1000 RPC requests (or HTTP/2 requests for
that matter), the response to each would have its own compression
context. The overall size of the raw responses would be larger because
compression contexts wouldn't be able to reference data from another
request or response.
The approach for streams as implemented in this commit is to support
N streams per connection and for streams to potentially span requests
and responses. As explained by the added internals docs, this
facilitates servers and clients delegating independent streams and
compression to independent threads / CPU cores. This helps alleviate
the CPU bottleneck of compression. This design also allows compression
contexts to be reused across requests/responses. This can result in
improved compression ratios and less overhead for compressors and
decompressors having to build new contexts.
Another feature that was defined was the ability for individual frames
within a stream to declare whether that individual frame's payload
uses the content encoding (read: compression) defined by the stream.
The idea here is that some servers may serve data from a combination
of caches and dynamic resolution. Data coming from caches may be
pre-compressed. We want to facilitate servers being able to essentially
stream bytes from caches to the wire with minimal overhead. Being
able to mix and match with frames are compressed within a stream
enables these types of advanced server functionality.
This commit defines the new streams mechanism. Basic code for
supporting streams in frames has been added. But that code is
seriously lacking and doesn't fully conform to the defined protocol.
For example, we don't close any streams. And support for content
encoding within streams is not yet implemented. The change was
rather invasive and I didn't think it would be reasonable to implement
the entire feature in a single commit.
For the record, I would have loved to reuse an existing multiplexing
protocol to build the new wire protocol on top of. However, I couldn't
find a protocol that offers the performance and scaling characteristics
that I desired. Namely, it should support multiple compression
contexts to facilitate scaling out to multiple CPU cores and
compression contexts should be able to live longer than single RPC
requests. HTTP/2 *almost* fits the bill. But the semantics of HTTP
message exchange state that streams can only live for a single
request-response. We /could/ tunnel on top of HTTP/2 streams and
frames with HEADER and DATA frames. But there's no guarantee that
HTTP/2 libraries and proxies would allow us to use HTTP/2 streams
and frames without the HTTP message exchange semantics defined in
RFC 7540 Section 8. Other RPC protocols like gRPC tunnel are built
on top of HTTP/2 and thus preserve its semantics of stream per
RPC invocation. Even QUIC does this. We could attempt to invent a
higher-level stream that spans HTTP/2 streams. But this would be
violating HTTP/2 because there is no guarantee that HTTP/2 streams
are routed to the same server. The best we can do - which is what
this protocol does - is shoehorn all request and response data into
a single HTTP message and create streams within. At that point, we've
defined a Content-Type in HTTP parlance. It just so happens our
media type can also work as a standalone, stream-based protocol,
without leaning on HTTP or similar protocol.
Differential Revision: https://phab.mercurial-scm.org/D2907
# help.py - help data for mercurial
#
# Copyright 2006 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import itertools
import os
import textwrap
from .i18n import (
_,
gettext,
)
from . import (
cmdutil,
encoding,
error,
extensions,
fancyopts,
filemerge,
fileset,
minirst,
pycompat,
revset,
templatefilters,
templatefuncs,
templatekw,
util,
)
from .hgweb import (
webcommands,
)
_exclkeywords = {
"(ADVANCED)",
"(DEPRECATED)",
"(EXPERIMENTAL)",
# i18n: "(ADVANCED)" is a keyword, must be translated consistently
_("(ADVANCED)"),
# i18n: "(DEPRECATED)" is a keyword, must be translated consistently
_("(DEPRECATED)"),
# i18n: "(EXPERIMENTAL)" is a keyword, must be translated consistently
_("(EXPERIMENTAL)"),
}
def listexts(header, exts, indent=1, showdeprecated=False):
'''return a text listing of the given extensions'''
rst = []
if exts:
for name, desc in sorted(exts.iteritems()):
if not showdeprecated and any(w in desc for w in _exclkeywords):
continue
rst.append('%s:%s: %s\n' % (' ' * indent, name, desc))
if rst:
rst.insert(0, '\n%s\n\n' % header)
return rst
def extshelp(ui):
rst = loaddoc('extensions')(ui).splitlines(True)
rst.extend(listexts(
_('enabled extensions:'), extensions.enabled(), showdeprecated=True))
rst.extend(listexts(_('disabled extensions:'), extensions.disabled(),
showdeprecated=ui.verbose))
doc = ''.join(rst)
return doc
def optrst(header, options, verbose):
data = []
multioccur = False
for option in options:
if len(option) == 5:
shortopt, longopt, default, desc, optlabel = option
else:
shortopt, longopt, default, desc = option
optlabel = _("VALUE") # default label
if not verbose and any(w in desc for w in _exclkeywords):
continue
so = ''
if shortopt:
so = '-' + shortopt
lo = '--' + longopt
if isinstance(default, fancyopts.customopt):
default = default.getdefaultvalue()
if default and not callable(default):
# default is of unknown type, and in Python 2 we abused
# the %s-shows-repr property to handle integers etc. To
# match that behavior on Python 3, we do str(default) and
# then convert it to bytes.
desc += _(" (default: %s)") % pycompat.bytestr(default)
if isinstance(default, list):
lo += " %s [+]" % optlabel
multioccur = True
elif (default is not None) and not isinstance(default, bool):
lo += " %s" % optlabel
data.append((so, lo, desc))
if multioccur:
header += (_(" ([+] can be repeated)"))
rst = ['\n%s:\n\n' % header]
rst.extend(minirst.maketable(data, 1))
return ''.join(rst)
def indicateomitted(rst, omitted, notomitted=None):
rst.append('\n\n.. container:: omitted\n\n %s\n\n' % omitted)
if notomitted:
rst.append('\n\n.. container:: notomitted\n\n %s\n\n' % notomitted)
def filtercmd(ui, cmd, kw, doc):
if not ui.debugflag and cmd.startswith("debug") and kw != "debug":
return True
if not ui.verbose and doc and any(w in doc for w in _exclkeywords):
return True
return False
def topicmatch(ui, commands, kw):
"""Return help topics matching kw.
Returns {'section': [(name, summary), ...], ...} where section is
one of topics, commands, extensions, or extensioncommands.
"""
kw = encoding.lower(kw)
def lowercontains(container):
return kw in encoding.lower(container) # translated in helptable
results = {'topics': [],
'commands': [],
'extensions': [],
'extensioncommands': [],
}
for names, header, doc in helptable:
# Old extensions may use a str as doc.
if (sum(map(lowercontains, names))
or lowercontains(header)
or (callable(doc) and lowercontains(doc(ui)))):
results['topics'].append((names[0], header))
for cmd, entry in commands.table.iteritems():
if len(entry) == 3:
summary = entry[2]
else:
summary = ''
# translate docs *before* searching there
docs = _(pycompat.getdoc(entry[0])) or ''
if kw in cmd or lowercontains(summary) or lowercontains(docs):
doclines = docs.splitlines()
if doclines:
summary = doclines[0]
cmdname = cmdutil.parsealiases(cmd)[0]
if filtercmd(ui, cmdname, kw, docs):
continue
results['commands'].append((cmdname, summary))
for name, docs in itertools.chain(
extensions.enabled(False).iteritems(),
extensions.disabled().iteritems()):
if not docs:
continue
name = name.rpartition('.')[-1]
if lowercontains(name) or lowercontains(docs):
# extension docs are already translated
results['extensions'].append((name, docs.splitlines()[0]))
try:
mod = extensions.load(ui, name, '')
except ImportError:
# debug message would be printed in extensions.load()
continue
for cmd, entry in getattr(mod, 'cmdtable', {}).iteritems():
if kw in cmd or (len(entry) > 2 and lowercontains(entry[2])):
cmdname = cmdutil.parsealiases(cmd)[0]
cmddoc = pycompat.getdoc(entry[0])
if cmddoc:
cmddoc = gettext(cmddoc).splitlines()[0]
else:
cmddoc = _('(no help text available)')
if filtercmd(ui, cmdname, kw, cmddoc):
continue
results['extensioncommands'].append((cmdname, cmddoc))
return results
def loaddoc(topic, subdir=None):
"""Return a delayed loader for help/topic.txt."""
def loader(ui):
docdir = os.path.join(util.datapath, 'help')
if subdir:
docdir = os.path.join(docdir, subdir)
path = os.path.join(docdir, topic + ".txt")
doc = gettext(util.readfile(path))
for rewriter in helphooks.get(topic, []):
doc = rewriter(ui, topic, doc)
return doc
return loader
internalstable = sorted([
(['bundle2'], _('Bundle2'),
loaddoc('bundle2', subdir='internals')),
(['bundles'], _('Bundles'),
loaddoc('bundles', subdir='internals')),
(['censor'], _('Censor'),
loaddoc('censor', subdir='internals')),
(['changegroups'], _('Changegroups'),
loaddoc('changegroups', subdir='internals')),
(['config'], _('Config Registrar'),
loaddoc('config', subdir='internals')),
(['requirements'], _('Repository Requirements'),
loaddoc('requirements', subdir='internals')),
(['revlogs'], _('Revision Logs'),
loaddoc('revlogs', subdir='internals')),
(['wireprotocol'], _('Wire Protocol'),
loaddoc('wireprotocol', subdir='internals')),
])
def internalshelp(ui):
"""Generate the index for the "internals" topic."""
lines = ['To access a subtopic, use "hg help internals.{subtopic-name}"\n',
'\n']
for names, header, doc in internalstable:
lines.append(' :%s: %s\n' % (names[0], header))
return ''.join(lines)
helptable = sorted([
(['bundlespec'], _("Bundle File Formats"), loaddoc('bundlespec')),
(['color'], _("Colorizing Outputs"), loaddoc('color')),
(["config", "hgrc"], _("Configuration Files"), loaddoc('config')),
(["dates"], _("Date Formats"), loaddoc('dates')),
(["flags"], _("Command-line flags"), loaddoc('flags')),
(["patterns"], _("File Name Patterns"), loaddoc('patterns')),
(['environment', 'env'], _('Environment Variables'),
loaddoc('environment')),
(['revisions', 'revs', 'revsets', 'revset', 'multirevs', 'mrevs'],
_('Specifying Revisions'), loaddoc('revisions')),
(['filesets', 'fileset'], _("Specifying File Sets"), loaddoc('filesets')),
(['diffs'], _('Diff Formats'), loaddoc('diffs')),
(['merge-tools', 'mergetools', 'mergetool'], _('Merge Tools'),
loaddoc('merge-tools')),
(['templating', 'templates', 'template', 'style'], _('Template Usage'),
loaddoc('templates')),
(['urls'], _('URL Paths'), loaddoc('urls')),
(["extensions"], _("Using Additional Features"), extshelp),
(["subrepos", "subrepo"], _("Subrepositories"), loaddoc('subrepos')),
(["hgweb"], _("Configuring hgweb"), loaddoc('hgweb')),
(["glossary"], _("Glossary"), loaddoc('glossary')),
(["hgignore", "ignore"], _("Syntax for Mercurial Ignore Files"),
loaddoc('hgignore')),
(["phases"], _("Working with Phases"), loaddoc('phases')),
(['scripting'], _('Using Mercurial from scripts and automation'),
loaddoc('scripting')),
(['internals'], _("Technical implementation topics"),
internalshelp),
(['pager'], _("Pager Support"), loaddoc('pager')),
])
# Maps topics with sub-topics to a list of their sub-topics.
subtopics = {
'internals': internalstable,
}
# Map topics to lists of callable taking the current topic help and
# returning the updated version
helphooks = {}
def addtopichook(topic, rewriter):
helphooks.setdefault(topic, []).append(rewriter)
def makeitemsdoc(ui, topic, doc, marker, items, dedent=False):
"""Extract docstring from the items key to function mapping, build a
single documentation block and use it to overwrite the marker in doc.
"""
entries = []
for name in sorted(items):
text = (pycompat.getdoc(items[name]) or '').rstrip()
if (not text
or not ui.verbose and any(w in text for w in _exclkeywords)):
continue
text = gettext(text)
if dedent:
# Abuse latin1 to use textwrap.dedent() on bytes.
text = textwrap.dedent(text.decode('latin1')).encode('latin1')
lines = text.splitlines()
doclines = [(lines[0])]
for l in lines[1:]:
# Stop once we find some Python doctest
if l.strip().startswith('>>>'):
break
if dedent:
doclines.append(l.rstrip())
else:
doclines.append(' ' + l.strip())
entries.append('\n'.join(doclines))
entries = '\n\n'.join(entries)
return doc.replace(marker, entries)
def addtopicsymbols(topic, marker, symbols, dedent=False):
def add(ui, topic, doc):
return makeitemsdoc(ui, topic, doc, marker, symbols, dedent=dedent)
addtopichook(topic, add)
addtopicsymbols('bundlespec', '.. bundlecompressionmarker',
util.bundlecompressiontopics())
addtopicsymbols('filesets', '.. predicatesmarker', fileset.symbols)
addtopicsymbols('merge-tools', '.. internaltoolsmarker',
filemerge.internalsdoc)
addtopicsymbols('revisions', '.. predicatesmarker', revset.symbols)
addtopicsymbols('templates', '.. keywordsmarker', templatekw.keywords)
addtopicsymbols('templates', '.. filtersmarker', templatefilters.filters)
addtopicsymbols('templates', '.. functionsmarker', templatefuncs.funcs)
addtopicsymbols('hgweb', '.. webcommandsmarker', webcommands.commands,
dedent=True)
def help_(ui, commands, name, unknowncmd=False, full=True, subtopic=None,
**opts):
'''
Generate the help for 'name' as unformatted restructured text. If
'name' is None, describe the commands available.
'''
opts = pycompat.byteskwargs(opts)
def helpcmd(name, subtopic=None):
try:
aliases, entry = cmdutil.findcmd(name, commands.table,
strict=unknowncmd)
except error.AmbiguousCommand as inst:
# py3k fix: except vars can't be used outside the scope of the
# except block, nor can be used inside a lambda. python issue4617
prefix = inst.args[0]
select = lambda c: cmdutil.parsealiases(c)[0].startswith(prefix)
rst = helplist(select)
return rst
rst = []
# check if it's an invalid alias and display its error if it is
if getattr(entry[0], 'badalias', None):
rst.append(entry[0].badalias + '\n')
if entry[0].unknowncmd:
try:
rst.extend(helpextcmd(entry[0].cmdname))
except error.UnknownCommand:
pass
return rst
# synopsis
if len(entry) > 2:
if entry[2].startswith('hg'):
rst.append("%s\n" % entry[2])
else:
rst.append('hg %s %s\n' % (aliases[0], entry[2]))
else:
rst.append('hg %s\n' % aliases[0])
# aliases
if full and not ui.quiet and len(aliases) > 1:
rst.append(_("\naliases: %s\n") % ', '.join(aliases[1:]))
rst.append('\n')
# description
doc = gettext(pycompat.getdoc(entry[0]))
if not doc:
doc = _("(no help text available)")
if util.safehasattr(entry[0], 'definition'): # aliased command
source = entry[0].source
if entry[0].definition.startswith('!'): # shell alias
doc = (_('shell alias for: %s\n\n%s\n\ndefined by: %s\n') %
(entry[0].definition[1:], doc, source))
else:
doc = (_('alias for: hg %s\n\n%s\n\ndefined by: %s\n') %
(entry[0].definition, doc, source))
doc = doc.splitlines(True)
if ui.quiet or not full:
rst.append(doc[0])
else:
rst.extend(doc)
rst.append('\n')
# check if this command shadows a non-trivial (multi-line)
# extension help text
try:
mod = extensions.find(name)
doc = gettext(pycompat.getdoc(mod)) or ''
if '\n' in doc.strip():
msg = _("(use 'hg help -e %s' to show help for "
"the %s extension)") % (name, name)
rst.append('\n%s\n' % msg)
except KeyError:
pass
# options
if not ui.quiet and entry[1]:
rst.append(optrst(_("options"), entry[1], ui.verbose))
if ui.verbose:
rst.append(optrst(_("global options"),
commands.globalopts, ui.verbose))
if not ui.verbose:
if not full:
rst.append(_("\n(use 'hg %s -h' to show more help)\n")
% name)
elif not ui.quiet:
rst.append(_('\n(some details hidden, use --verbose '
'to show complete help)'))
return rst
def helplist(select=None, **opts):
# list of commands
if name == "shortlist":
header = _('basic commands:\n\n')
elif name == "debug":
header = _('debug commands (internal and unsupported):\n\n')
else:
header = _('list of commands:\n\n')
h = {}
cmds = {}
for c, e in commands.table.iteritems():
fs = cmdutil.parsealiases(c)
f = fs[0]
p = ''
if c.startswith("^"):
p = '^'
if select and not select(p + f):
continue
if (not select and name != 'shortlist' and
e[0].__module__ != commands.__name__):
continue
if name == "shortlist" and not p:
continue
doc = pycompat.getdoc(e[0])
if filtercmd(ui, f, name, doc):
continue
doc = gettext(doc)
if not doc:
doc = _("(no help text available)")
h[f] = doc.splitlines()[0].rstrip()
cmds[f] = '|'.join(fs)
rst = []
if not h:
if not ui.quiet:
rst.append(_('no commands defined\n'))
return rst
if not ui.quiet:
rst.append(header)
fns = sorted(h)
for f in fns:
if ui.verbose:
commacmds = cmds[f].replace("|",", ")
rst.append(" :%s: %s\n" % (commacmds, h[f]))
else:
rst.append(' :%s: %s\n' % (f, h[f]))
ex = opts.get
anyopts = (ex(r'keyword') or not (ex(r'command') or ex(r'extension')))
if not name and anyopts:
exts = listexts(_('enabled extensions:'), extensions.enabled())
if exts:
rst.append('\n')
rst.extend(exts)
rst.append(_("\nadditional help topics:\n\n"))
topics = []
for names, header, doc in helptable:
topics.append((names[0], header))
for t, desc in topics:
rst.append(" :%s: %s\n" % (t, desc))
if ui.quiet:
pass
elif ui.verbose:
rst.append('\n%s\n' % optrst(_("global options"),
commands.globalopts, ui.verbose))
if name == 'shortlist':
rst.append(_("\n(use 'hg help' for the full list "
"of commands)\n"))
else:
if name == 'shortlist':
rst.append(_("\n(use 'hg help' for the full list of commands "
"or 'hg -v' for details)\n"))
elif name and not full:
rst.append(_("\n(use 'hg help %s' to show the full help "
"text)\n") % name)
elif name and cmds and name in cmds.keys():
rst.append(_("\n(use 'hg help -v -e %s' to show built-in "
"aliases and global options)\n") % name)
else:
rst.append(_("\n(use 'hg help -v%s' to show built-in aliases "
"and global options)\n")
% (name and " " + name or ""))
return rst
def helptopic(name, subtopic=None):
# Look for sub-topic entry first.
header, doc = None, None
if subtopic and name in subtopics:
for names, header, doc in subtopics[name]:
if subtopic in names:
break
if not header:
for names, header, doc in helptable:
if name in names:
break
else:
raise error.UnknownCommand(name)
rst = [minirst.section(header)]
# description
if not doc:
rst.append(" %s\n" % _("(no help text available)"))
if callable(doc):
rst += [" %s\n" % l for l in doc(ui).splitlines()]
if not ui.verbose:
omitted = _('(some details hidden, use --verbose'
' to show complete help)')
indicateomitted(rst, omitted)
try:
cmdutil.findcmd(name, commands.table)
rst.append(_("\nuse 'hg help -c %s' to see help for "
"the %s command\n") % (name, name))
except error.UnknownCommand:
pass
return rst
def helpext(name, subtopic=None):
try:
mod = extensions.find(name)
doc = gettext(pycompat.getdoc(mod)) or _('no help text available')
except KeyError:
mod = None
doc = extensions.disabledext(name)
if not doc:
raise error.UnknownCommand(name)
if '\n' not in doc:
head, tail = doc, ""
else:
head, tail = doc.split('\n', 1)
rst = [_('%s extension - %s\n\n') % (name.rpartition('.')[-1], head)]
if tail:
rst.extend(tail.splitlines(True))
rst.append('\n')
if not ui.verbose:
omitted = _('(some details hidden, use --verbose'
' to show complete help)')
indicateomitted(rst, omitted)
if mod:
try:
ct = mod.cmdtable
except AttributeError:
ct = {}
modcmds = set([c.partition('|')[0] for c in ct])
rst.extend(helplist(modcmds.__contains__))
else:
rst.append(_("(use 'hg help extensions' for information on enabling"
" extensions)\n"))
return rst
def helpextcmd(name, subtopic=None):
cmd, ext, mod = extensions.disabledcmd(ui, name,
ui.configbool('ui', 'strict'))
doc = gettext(pycompat.getdoc(mod)).splitlines()[0]
rst = listexts(_("'%s' is provided by the following "
"extension:") % cmd, {ext: doc}, indent=4,
showdeprecated=True)
rst.append('\n')
rst.append(_("(use 'hg help extensions' for information on enabling "
"extensions)\n"))
return rst
rst = []
kw = opts.get('keyword')
if kw or name is None and any(opts[o] for o in opts):
matches = topicmatch(ui, commands, name or '')
helpareas = []
if opts.get('extension'):
helpareas += [('extensions', _('Extensions'))]
if opts.get('command'):
helpareas += [('commands', _('Commands'))]
if not helpareas:
helpareas = [('topics', _('Topics')),
('commands', _('Commands')),
('extensions', _('Extensions')),
('extensioncommands', _('Extension Commands'))]
for t, title in helpareas:
if matches[t]:
rst.append('%s:\n\n' % title)
rst.extend(minirst.maketable(sorted(matches[t]), 1))
rst.append('\n')
if not rst:
msg = _('no matches')
hint = _("try 'hg help' for a list of topics")
raise error.Abort(msg, hint=hint)
elif name and name != 'shortlist':
queries = []
if unknowncmd:
queries += [helpextcmd]
if opts.get('extension'):
queries += [helpext]
if opts.get('command'):
queries += [helpcmd]
if not queries:
queries = (helptopic, helpcmd, helpext, helpextcmd)
for f in queries:
try:
rst = f(name, subtopic)
break
except error.UnknownCommand:
pass
else:
if unknowncmd:
raise error.UnknownCommand(name)
else:
msg = _('no such help topic: %s') % name
hint = _("try 'hg help --keyword %s'") % name
raise error.Abort(msg, hint=hint)
else:
# program name
if not ui.quiet:
rst = [_("Mercurial Distributed SCM\n"), '\n']
rst.extend(helplist(None, **pycompat.strkwargs(opts)))
return ''.join(rst)
def formattedhelp(ui, commands, name, keep=None, unknowncmd=False, full=True,
**opts):
"""get help for a given topic (as a dotted name) as rendered rst
Either returns the rendered help text or raises an exception.
"""
if keep is None:
keep = []
else:
keep = list(keep) # make a copy so we can mutate this later
fullname = name
section = None
subtopic = None
if name and '.' in name:
name, remaining = name.split('.', 1)
remaining = encoding.lower(remaining)
if '.' in remaining:
subtopic, section = remaining.split('.', 1)
else:
if name in subtopics:
subtopic = remaining
else:
section = remaining
textwidth = ui.configint('ui', 'textwidth')
termwidth = ui.termwidth() - 2
if textwidth <= 0 or termwidth < textwidth:
textwidth = termwidth
text = help_(ui, commands, name,
subtopic=subtopic, unknowncmd=unknowncmd, full=full, **opts)
formatted, pruned = minirst.format(text, textwidth, keep=keep,
section=section)
# We could have been given a weird ".foo" section without a name
# to look for, or we could have simply failed to found "foo.bar"
# because bar isn't a section of foo
if section and not (formatted and name):
raise error.Abort(_("help section not found: %s") % fullname)
if 'verbose' in pruned:
keep.append('omitted')
else:
keep.append('notomitted')
formatted, pruned = minirst.format(text, textwidth, keep=keep,
section=section)
return formatted