view doc/gendoc.py @ 42377:0546ead39a7e stable

manifest: avoid corruption by dropping removed files with pure (issue5801)

Previously, removed files would simply be marked by overwriting the first byte
with NUL and dropping their entry in `self.position`.  But no effort was made to
ignore them when compacting the dictionary into text form.  This allowed them to
slip into the manifest revision, since the code seems to be trying to minimize
the string operations by copying as large a chunk as possible.  As part of this,
compact() walks the existing text based on entries in the `positions` list, and
consumed everything up to the next position entry.   This typically resulted in
a ValueError complaining about unsorted manifest entries.

Sometimes it seems that files do get dropped in large repos- it seems to
correspond to there being a new entry that would take the same slot.  A much
more trivial problem is that if the only changes were removals, `_compact()`
didn't even run because `__delitem__` doesn't add anything to `self.extradata`.
Now there's an explicit variable to flag this, both to allow `_compact()` to
run, and to avoid searching the manifest in cases where there are no removals.

In practice, this behavior was mostly obscured by the check in fastdelta() which
takes a different path that explicitly drops removed files if there are fewer
than 1000 changes.  However, timeless has a repo where after rebasing tens of
commits, a totally different path[1] is taken that bypasses the change count
check and hits this problem.

[1] https://www.mercurial-scm.org/repo/hg/file/2338bdea4474/mercurial/manifest.py#l1511

#!/usr/bin/env python
"""usage: %s DOC ...

where DOC is the name of a document
"""

from __future__ import absolute_import

import os
import sys
import textwrap

try:
    import msvcrt
    msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
    msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)
except ImportError:
    pass

# This script is executed during installs and may not have C extensions
# available. Relax C module requirements.
os.environ[r'HGMODULEPOLICY'] = r'allow'
# import from the live mercurial repo
sys.path.insert(0, r"..")
from mercurial import demandimport; demandimport.enable()
# Load util so that the locale path is set by i18n.setdatapath() before
# calling _().
from mercurial import util
util.datapath
from mercurial import (
    commands,
    encoding,
    extensions,
    help,
    minirst,
    pycompat,
    ui as uimod,
)
from mercurial.i18n import (
    gettext,
    _,
)

table = commands.table
globalopts = commands.globalopts
helptable = help.helptable
loaddoc = help.loaddoc

def get_desc(docstr):
    if not docstr:
        return b"", b""
    # sanitize
    docstr = docstr.strip(b"\n")
    docstr = docstr.rstrip()
    shortdesc = docstr.splitlines()[0].strip()

    i = docstr.find(b"\n")
    if i != -1:
        desc = docstr[i + 2:]
    else:
        desc = shortdesc

    desc = textwrap.dedent(desc.decode('latin1')).encode('latin1')

    return (shortdesc, desc)

def get_opts(opts):
    for opt in opts:
        if len(opt) == 5:
            shortopt, longopt, default, desc, optlabel = opt
        else:
            shortopt, longopt, default, desc = opt
            optlabel = _(b"VALUE")
        allopts = []
        if shortopt:
            allopts.append(b"-%s" % shortopt)
        if longopt:
            allopts.append(b"--%s" % longopt)
        if isinstance(default, list):
            allopts[-1] += b" <%s[+]>" % optlabel
        elif (default is not None) and not isinstance(default, bool):
            allopts[-1] += b" <%s>" % optlabel
        if b'\n' in desc:
            # only remove line breaks and indentation
            desc = b' '.join(l.lstrip() for l in desc.split(b'\n'))
        desc += default and _(b" (default: %s)") % bytes(default) or b""
        yield (b", ".join(allopts), desc)

def get_cmd(cmd, cmdtable):
    d = {}
    attr = cmdtable[cmd]
    cmds = cmd.lstrip(b"^").split(b"|")

    d[b'cmd'] = cmds[0]
    d[b'aliases'] = cmd.split(b"|")[1:]
    d[b'desc'] = get_desc(gettext(pycompat.getdoc(attr[0])))
    d[b'opts'] = list(get_opts(attr[1]))

    s = b'hg ' + cmds[0]
    if len(attr) > 2:
        if not attr[2].startswith(b'hg'):
            s += b' ' + attr[2]
        else:
            s = attr[2]
    d[b'synopsis'] = s.strip()

    return d

def showdoc(ui):
    # print options
    ui.write(minirst.section(_(b"Options")))
    multioccur = False
    for optstr, desc in get_opts(globalopts):
        ui.write(b"%s\n    %s\n\n" % (optstr, desc))
        if optstr.endswith(b"[+]>"):
            multioccur = True
    if multioccur:
        ui.write(_(b"\n[+] marked option can be specified multiple times\n"))
        ui.write(b"\n")

    # print cmds
    ui.write(minirst.section(_(b"Commands")))
    commandprinter(ui, table, minirst.subsection)

    # print help topics
    # The config help topic is included in the hgrc.5 man page.
    helpprinter(ui, helptable, minirst.section, exclude=[b'config'])

    ui.write(minirst.section(_(b"Extensions")))
    ui.write(_(b"This section contains help for extensions that are "
               b"distributed together with Mercurial. Help for other "
               b"extensions is available in the help system."))
    ui.write((b"\n\n"
              b".. contents::\n"
              b"   :class: htmlonly\n"
              b"   :local:\n"
              b"   :depth: 1\n\n"))

    for extensionname in sorted(allextensionnames()):
        mod = extensions.load(ui, extensionname, None)
        ui.write(minirst.subsection(extensionname))
        ui.write(b"%s\n\n" % gettext(pycompat.getdoc(mod)))
        cmdtable = getattr(mod, 'cmdtable', None)
        if cmdtable:
            ui.write(minirst.subsubsection(_(b'Commands')))
            commandprinter(ui, cmdtable, minirst.subsubsubsection)

def showtopic(ui, topic):
    extrahelptable = [
        ([b"common"], b'', loaddoc(b'common'), help.TOPIC_CATEGORY_MISC),
        ([b"hg.1"], b'', loaddoc(b'hg.1'), help.TOPIC_CATEGORY_CONFIG),
        ([b"hg-ssh.8"], b'', loaddoc(b'hg-ssh.8'), help.TOPIC_CATEGORY_CONFIG),
        ([b"hgignore.5"], b'', loaddoc(b'hgignore.5'),
         help.TOPIC_CATEGORY_CONFIG),
        ([b"hgrc.5"], b'', loaddoc(b'hgrc.5'), help.TOPIC_CATEGORY_CONFIG),
        ([b"hgignore.5.gendoc"], b'', loaddoc(b'hgignore'),
         help.TOPIC_CATEGORY_CONFIG),
        ([b"hgrc.5.gendoc"], b'', loaddoc(b'config'),
         help.TOPIC_CATEGORY_CONFIG),
    ]
    helpprinter(ui, helptable + extrahelptable, None, include=[topic])

def helpprinter(ui, helptable, sectionfunc, include=[], exclude=[]):
    for h in helptable:
        names, sec, doc = h[0:3]
        if exclude and names[0] in exclude:
            continue
        if include and names[0] not in include:
            continue
        for name in names:
            ui.write(b".. _%s:\n" % name)
        ui.write(b"\n")
        if sectionfunc:
            ui.write(sectionfunc(sec))
        if callable(doc):
            doc = doc(ui)
        ui.write(doc)
        ui.write(b"\n")

def commandprinter(ui, cmdtable, sectionfunc):
    h = {}
    for c, attr in cmdtable.items():
        f = c.split(b"|")[0]
        f = f.lstrip(b"^")
        h[f] = c
    cmds = h.keys()

    for f in sorted(cmds):
        if f.startswith(b"debug"):
            continue
        d = get_cmd(h[f], cmdtable)
        ui.write(sectionfunc(d[b'cmd']))
        # short description
        ui.write(d[b'desc'][0])
        # synopsis
        ui.write(b"::\n\n")
        synopsislines = d[b'synopsis'].splitlines()
        for line in synopsislines:
            # some commands (such as rebase) have a multi-line
            # synopsis
            ui.write(b"   %s\n" % line)
        ui.write(b'\n')
        # description
        ui.write(b"%s\n\n" % d[b'desc'][1])
        # options
        opt_output = list(d[b'opts'])
        if opt_output:
            opts_len = max([len(line[0]) for line in opt_output])
            ui.write(_(b"Options:\n\n"))
            multioccur = False
            for optstr, desc in opt_output:
                if desc:
                    s = b"%-*s  %s" % (opts_len, optstr, desc)
                else:
                    s = optstr
                ui.write(b"%s\n" % s)
                if optstr.endswith(b"[+]>"):
                    multioccur = True
            if multioccur:
                ui.write(_(b"\n[+] marked option can be specified"
                           b" multiple times\n"))
            ui.write(b"\n")
        # aliases
        if d[b'aliases']:
            ui.write(_(b"    aliases: %s\n\n") % b" ".join(d[b'aliases']))


def allextensionnames():
    return set(extensions.enabled().keys()) | set(extensions.disabled().keys())

if __name__ == "__main__":
    doc = b'hg.1.gendoc'
    if len(sys.argv) > 1:
        doc = encoding.strtolocal(sys.argv[1])

    ui = uimod.ui.load()
    if doc == b'hg.1.gendoc':
        showdoc(ui)
    else:
        showtopic(ui, encoding.strtolocal(sys.argv[1]))