view hgext/highlight/highlight.py @ 42200:69921d02daaf

peer: introduce a limitedarguments attributes

When set to True, it signal that the peer cannot receive too larges arguments
and that algorithm must adapt. This should only be True for http peer that does
not support argument passed as "post".

This will be useful to unlock better discovery performance in the next
changesets.

I am using a dedicated argument because this is not really a usual
"capabilities" things. An alternative approach would be to adds a
"large-arguments" to all peer, but the http peers. That seemed a bit too hacky
to me.

# highlight.py - highlight extension implementation file
#
#  Copyright 2007-2009 Adam Hupp <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
#
# The original module was split in an interface and an implementation
# file to defer pygments loading and speedup extension setup.

from __future__ import absolute_import

from mercurial import demandimport
demandimport.IGNORES.update(['pkgutil', 'pkg_resources', '__main__'])

from mercurial import (
    encoding,
)

from mercurial.utils import (
    stringutil,
)

with demandimport.deactivated():
    import pygments
    import pygments.formatters
    import pygments.lexers
    import pygments.plugin
    import pygments.util

    for unused in pygments.plugin.find_plugin_lexers():
        pass

highlight = pygments.highlight
ClassNotFound = pygments.util.ClassNotFound
guess_lexer = pygments.lexers.guess_lexer
guess_lexer_for_filename = pygments.lexers.guess_lexer_for_filename
TextLexer = pygments.lexers.TextLexer
HtmlFormatter = pygments.formatters.HtmlFormatter

SYNTAX_CSS = ('\n<link rel="stylesheet" href="{url}highlightcss" '
              'type="text/css" />')

def pygmentize(field, fctx, style, tmpl, guessfilenameonly=False):

    # append a <link ...> to the syntax highlighting css
    tmpl.load('header')
    old_header = tmpl.cache['header']
    if SYNTAX_CSS not in old_header:
        new_header = old_header + SYNTAX_CSS
        tmpl.cache['header'] = new_header

    text = fctx.data()
    if stringutil.binary(text):
        return

    # str.splitlines() != unicode.splitlines() because "reasons"
    for c in "\x0c\x1c\x1d\x1e":
        if c in text:
            text = text.replace(c, '')

    # Pygments is best used with Unicode strings:
    # <http://pygments.org/docs/unicode/>
    text = text.decode(encoding.encoding, 'replace')

    # To get multi-line strings right, we can't format line-by-line
    try:
        lexer = guess_lexer_for_filename(fctx.path(), text[:1024],
                                         stripnl=False)
    except (ClassNotFound, ValueError):
        # guess_lexer will return a lexer if *any* lexer matches. There is
        # no way to specify a minimum match score. This can give a high rate of
        # false positives on files with an unknown filename pattern.
        if guessfilenameonly:
            return

        try:
            lexer = guess_lexer(text[:1024], stripnl=False)
        except (ClassNotFound, ValueError):
            # Don't highlight unknown files
            return

    # Don't highlight text files
    if isinstance(lexer, TextLexer):
        return

    formatter = HtmlFormatter(nowrap=True, style=style)

    colorized = highlight(text, lexer, formatter)
    coloriter = (s.encode(encoding.encoding, 'replace')
                 for s in colorized.splitlines())

    tmpl._filters['colorize'] = lambda x: next(coloriter)

    oldl = tmpl.cache[field]
    newl = oldl.replace('line|escape', 'line|colorize')
    tmpl.cache[field] = newl