mercurial/templatefilters.py

rebase: allow collapsing branches in place (issue3111)

We allow rebase plus collapse, but not collapse only? I imagine people would
rebase first then collapse once they are sure the rebase is correct and it is
the right time to finish it.

I was reluctant to submit this patch for reasons detailed below, but it
improves rebase --collapse usefulness so much it is worth the ugliness.

The fix is ugly because we should be fixing the collapse code path rather than
the merge. Collapsing by merging changesets repeatedly is inefficient compared
to what commit --amend does: commitctx(), update, strip. The problem with the
latter is, to generate the synthetic changeset, copy records are gathered with
copies.pathcopies(). copies.pathcopies() is still implemented with merging in
mind and discards information like file replaced by the copy of another,
criss-cross copies and so forth. I believe this information should not be lost,
even if we decide not to interpret it fully later, at merge time.

The second issue with improving rebase --collapse is the option should not be
there to begin with. Rebasing and collapsing are orthogonal and a dedicated
command would probably enable a better, simpler ui. We should avoid advertizing
rebase --collapse, but with this fix it becomes the best shipped solution to
collapse changesets.

And for the record, available techniques are:
- revert + commit + strip: lose copies
- mq/qfold: repeated patching() (mostly correct, fragile)
- rebase: repeated merges (mostly correct, fragile)
- collapse: revert + tag rewriting wizardry, lose copies
- histedit: repeated patching() (mostly correct, fragile)
- amend: copies.pathcopies() + commitctx() + update + strip

# template-filters.py - common template expansion filters
#
# Copyright 2005-2008 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import cgi, re, os, time, urllib
import encoding, node, util
import hbisect

def addbreaks(text):
    """:addbreaks: Any text. Add an XHTML "<br />" tag before the end of
    every line except the last.
    """
    return text.replace('\n', '<br/>\n')

agescales = [("year", 3600 * 24 * 365),
             ("month", 3600 * 24 * 30),
             ("week", 3600 * 24 * 7),
             ("day", 3600 * 24),
             ("hour", 3600),
             ("minute", 60),
             ("second", 1)]

def age(date):
    """:age: Date. Returns a human-readable date/time difference between the
    given date/time and the current date/time.
    """

    def plural(t, c):
        if c == 1:
            return t
        return t + "s"
    def fmt(t, c):
        return "%d %s" % (c, plural(t, c))

    now = time.time()
    then = date[0]
    future = False
    if then > now:
        future = True
        delta = max(1, int(then - now))
        if delta > agescales[0][1] * 30:
            return 'in the distant future'
    else:
        delta = max(1, int(now - then))
        if delta > agescales[0][1] * 2:
            return util.shortdate(date)

    for t, s in agescales:
        n = delta // s
        if n >= 2 or s == 1:
            if future:
                return '%s from now' % fmt(t, n)
            return '%s ago' % fmt(t, n)

def basename(path):
    """:basename: Any text. Treats the text as a path, and returns the last
    component of the path after splitting by the path separator
    (ignoring trailing separators). For example, "foo/bar/baz" becomes
    "baz" and "foo/bar//" becomes "bar".
    """
    return os.path.basename(path)

def datefilter(text):
    """:date: Date. Returns a date in a Unix date format, including the
    timezone: "Mon Sep 04 15:13:13 2006 0700".
    """
    return util.datestr(text)

def domain(author):
    """:domain: Any text. Finds the first string that looks like an email
    address, and extracts just the domain component. Example: ``User
    <[e-mail]>`` becomes ``example.com``.
    """
    f = author.find('@')
    if f == -1:
        return ''
    author = author[f + 1:]
    f = author.find('>')
    if f >= 0:
        author = author[:f]
    return author

def email(text):
    """:email: Any text. Extracts the first string that looks like an email
    address. Example: ``User <[e-mail]>`` becomes
    ``[e-mail]``.
    """
    return util.email(text)

def escape(text):
    """:escape: Any text. Replaces the special XML/XHTML characters "&", "<"
    and ">" with XML entities.
    """
    return cgi.escape(text, True)

para_re = None
space_re = None

def fill(text, width):
    '''fill many paragraphs.'''
    global para_re, space_re
    if para_re is None:
        para_re = re.compile('(\n\n|\n\\s*[-*]\\s*)', re.M)
        space_re = re.compile(r'  +')

    def findparas():
        start = 0
        while True:
            m = para_re.search(text, start)
            if not m:
                uctext = unicode(text[start:], encoding.encoding)
                w = len(uctext)
                while 0 < w and uctext[w - 1].isspace():
                    w -= 1
                yield (uctext[:w].encode(encoding.encoding),
                       uctext[w:].encode(encoding.encoding))
                break
            yield text[start:m.start(0)], m.group(1)
            start = m.end(1)

    return "".join([space_re.sub(' ', util.wrap(para, width=width)) + rest
                    for para, rest in findparas()])

def fill68(text):
    """:fill68: Any text. Wraps the text to fit in 68 columns."""
    return fill(text, 68)

def fill76(text):
    """:fill76: Any text. Wraps the text to fit in 76 columns."""
    return fill(text, 76)

def firstline(text):
    """:firstline: Any text. Returns the first line of text."""
    try:
        return text.splitlines(True)[0].rstrip('\r\n')
    except IndexError:
        return ''

def hexfilter(text):
    """:hex: Any text. Convert a binary Mercurial node identifier into
    its long hexadecimal representation.
    """
    return node.hex(text)

def hgdate(text):
    """:hgdate: Date. Returns the date as a pair of numbers: "1157407993
    25200" (Unix timestamp, timezone offset).
    """
    return "%d %d" % text

def isodate(text):
    """:isodate: Date. Returns the date in ISO 8601 format: "2009-08-18 13:00
    +0200".
    """
    return util.datestr(text, '%Y-%m-%d %H:%M %1%2')

def isodatesec(text):
    """:isodatesec: Date. Returns the date in ISO 8601 format, including
    seconds: "2009-08-18 13:00:13 +0200". See also the rfc3339date
    filter.
    """
    return util.datestr(text, '%Y-%m-%d %H:%M:%S %1%2')

def indent(text, prefix):
    '''indent each non-empty line of text after first with prefix.'''
    lines = text.splitlines()
    num_lines = len(lines)
    endswithnewline = text[-1:] == '\n'
    def indenter():
        for i in xrange(num_lines):
            l = lines[i]
            if i and l.strip():
                yield prefix
            yield l
            if i < num_lines - 1 or endswithnewline:
                yield '\n'
    return "".join(indenter())

def json(obj):
    if obj is None or obj is False or obj is True:
        return {None: 'null', False: 'false', True: 'true'}[obj]
    elif isinstance(obj, int) or isinstance(obj, float):
        return str(obj)
    elif isinstance(obj, str):
        u = unicode(obj, encoding.encoding, 'replace')
        return '"%s"' % jsonescape(u)
    elif isinstance(obj, unicode):
        return '"%s"' % jsonescape(obj)
    elif util.safehasattr(obj, 'keys'):
        out = []
        for k, v in obj.iteritems():
            s = '%s: %s' % (json(k), json(v))
            out.append(s)
        return '{' + ', '.join(out) + '}'
    elif util.safehasattr(obj, '__iter__'):
        out = []
        for i in obj:
            out.append(json(i))
        return '[' + ', '.join(out) + ']'
    else:
        raise TypeError('cannot encode type %s' % obj.__class__.__name__)

def _uescape(c):
    if ord(c) < 0x80:
        return c
    else:
        return '\\u%04x' % ord(c)

_escapes = [
    ('\\', '\\\\'), ('"', '\\"'), ('\t', '\\t'), ('\n', '\\n'),
    ('\r', '\\r'), ('\f', '\\f'), ('\b', '\\b'),
]

def jsonescape(s):
    for k, v in _escapes:
        s = s.replace(k, v)
    return ''.join(_uescape(c) for c in s)

def localdate(text):
    """:localdate: Date. Converts a date to local date."""
    return (text[0], util.makedate()[1])

def nonempty(str):
    """:nonempty: Any text. Returns '(none)' if the string is empty."""
    return str or "(none)"

def obfuscate(text):
    """:obfuscate: Any text. Returns the input text rendered as a sequence of
    XML entities.
    """
    text = unicode(text, encoding.encoding, 'replace')
    return ''.join(['&#%d;' % ord(c) for c in text])

def permissions(flags):
    if "l" in flags:
        return "lrwxrwxrwx"
    if "x" in flags:
        return "-rwxr-xr-x"
    return "-rw-r--r--"

def person(author):
    """:person: Any text. Returns the name before an email address,
    interpreting it as per RFC 5322.

    >>> person('foo@bar')
    'foo'
    >>> person('Foo Bar <foo@bar>')
    'Foo Bar'
    >>> person('"Foo Bar" <foo@bar>')
    'Foo Bar'
    >>> person('"Foo \"buz\" Bar" <foo@bar>')
    'Foo "buz" Bar'
    >>> # The following are invalid, but do exist in real-life
    ...
    >>> person('Foo "buz" Bar <foo@bar>')
    'Foo "buz" Bar'
    >>> person('"Foo Bar <foo@bar>')
    'Foo Bar'
    """
    if '@' not in author:
        return author
    f = author.find('<')
    if f != -1:
        return author[:f].strip(' "').replace('\\"', '"')
    f = author.find('@')
    return author[:f].replace('.', ' ')

def rfc3339date(text):
    """:rfc3339date: Date. Returns a date using the Internet date format
    specified in RFC 3339: "2009-08-18T13:00:13+02:00".
    """
    return util.datestr(text, "%Y-%m-%dT%H:%M:%S%1:%2")

def rfc822date(text):
    """:rfc822date: Date. Returns a date using the same format used in email
    headers: "Tue, 18 Aug 2009 13:00:13 +0200".
    """
    return util.datestr(text, "%a, %d %b %Y %H:%M:%S %1%2")

def short(text):
    """:short: Changeset hash. Returns the short form of a changeset hash,
    i.e. a 12 hexadecimal digit string.
    """
    return text[:12]

def shortbisect(text):
    """:shortbisect: Any text. Treats `text` as a bisection status, and
    returns a single-character representing the status (G: good, B: bad,
    S: skipped, U: untested, I: ignored). Returns single space if `text`
    is not a valid bisection status.
    """
    return hbisect.shortlabel(text) or ' '

def shortdate(text):
    """:shortdate: Date. Returns a date like "2006-09-18"."""
    return util.shortdate(text)

def stringescape(text):
    return text.encode('string_escape')

def stringify(thing):
    """:stringify: Any type. Turns the value into text by converting values into
    text and concatenating them.
    """
    if util.safehasattr(thing, '__iter__') and not isinstance(thing, str):
        return "".join([stringify(t) for t in thing if t is not None])
    return str(thing)

def strip(text):
    """:strip: Any text. Strips all leading and trailing whitespace."""
    return text.strip()

def stripdir(text):
    """:stripdir: Treat the text as path and strip a directory level, if
    possible. For example, "foo" and "foo/bar" becomes "foo".
    """
    dir = os.path.dirname(text)
    if dir == "":
        return os.path.basename(text)
    else:
        return dir

def tabindent(text):
    """:tabindent: Any text. Returns the text, with every line except the
    first starting with a tab character.
    """
    return indent(text, '\t')

def urlescape(text):
    """:urlescape: Any text. Escapes all "special" characters. For example,
    "foo bar" becomes "foo%20bar".
    """
    return urllib.quote(text)

def userfilter(text):
    """:user: Any text. Returns a short representation of a user name or email
    address."""
    return util.shortuser(text)

def emailuser(text):
    """:emailuser: Any text. Returns the user portion of an email address."""
    return util.emailuser(text)

def xmlescape(text):
    text = (text
            .replace('&', '&amp;')
            .replace('<', '&lt;')
            .replace('>', '&gt;')
            .replace('"', '&quot;')
            .replace("'", '&#39;')) # &apos; invalid in HTML
    return re.sub('[\x00-\x08\x0B\x0C\x0E-\x1F]', ' ', text)

filters = {
    "addbreaks": addbreaks,
    "age": age,
    "basename": basename,
    "date": datefilter,
    "domain": domain,
    "email": email,
    "escape": escape,
    "fill68": fill68,
    "fill76": fill76,
    "firstline": firstline,
    "hex": hexfilter,
    "hgdate": hgdate,
    "isodate": isodate,
    "isodatesec": isodatesec,
    "json": json,
    "jsonescape": jsonescape,
    "localdate": localdate,
    "nonempty": nonempty,
    "obfuscate": obfuscate,
    "permissions": permissions,
    "person": person,
    "rfc3339date": rfc3339date,
    "rfc822date": rfc822date,
    "short": short,
    "shortbisect": shortbisect,
    "shortdate": shortdate,
    "stringescape": stringescape,
    "stringify": stringify,
    "strip": strip,
    "stripdir": stripdir,
    "tabindent": tabindent,
    "urlescape": urlescape,
    "user": userfilter,
    "emailuser": emailuser,
    "xmlescape": xmlescape,
}

# tell hggettext to extract docstrings from these functions:
i18nfunctions = filters.values()