annotate mercurial/templatefilters.py @ 18988:5bae936764bb

parsers: a C implementation of the new ancestors algorithm

The performance of both the old and new Python ancestor algorithms
depends on the number of revs they need to traverse.  Although the
new algorithm performs far better than the old when revs are
numerically and topologically close, both algorithms become slow
under other circumstances, taking up to 1.8 seconds to give answers
in a Linux kernel repo.

This C implementation of the new algorithm is a fairly straightforward
transliteration.  The only corner case of interest is that it raises
an OverflowError if the number of GCA candidates found during the
first pass is greater than 24, to avoid the dual perils of fixnum
overflow and trying to allocate too much memory.  (If this exception
is raised, the Python implementation is used instead.)

Performance numbers are good: in a Linux kernel repo, time for "hg
debugancestors" on two distant revs (24bf01de7537 and c2a8808f5943)
is as follows:

  Old Python: 0.36 sec
  New Python: 0.42 sec
  New C: 0.02 sec

For a case where the new algorithm should perform well:

  Old Python: 1.84 sec
  New Python: 0.07 sec
  New C: measures as zero when using --time

(This commit includes a paranoid cross-check to ensure that the
Python and C implementations give identical answers. The above
performance numbers were measured with that check disabled.)

# 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.

from i18n import _
import cgi, re, os, time, urllib
import encoding, node, util, error
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, and filters out NUL characters.
    """
    return cgi.escape(text.replace('\0', ''), 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 (util.parsedate(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,
}

def websub(text, websubtable):
    """:websub: Any text. Only applies to hgweb. Applies the regular
    expression replacements defined in the websub section.
    """
    if websubtable:
        for regexp, format in websubtable:
            text = regexp.sub(format, text)
    return text

def fillfunc(context, mapping, args):
    if not (1 <= len(args) <= 2):
        raise error.ParseError(_("fill expects one or two arguments"))

    text = stringify(args[0][0](context, mapping, args[0][1]))
    width = 76
    if len(args) == 2:
        try:
            width = int(stringify(args[1][0](context, mapping, args[1][1])))
        except ValueError:
            raise error.ParseError(_("fill expects an integer width"))

    return fill(text, width)

def datefunc(context, mapping, args):
    if not (1 <= len(args) <= 2):
        raise error.ParseError(_("date expects one or two arguments"))

    date = args[0][0](context, mapping, args[0][1])
    if len(args) == 2:
        fmt = stringify(args[1][0](context, mapping, args[1][1]))
        return util.datestr(date, fmt)
    return util.datestr(date)

funcs = {
    "fill": fillfunc,
    "date": datefunc,
}

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