hgext/beautifygraph.py

hidden: add support to explicitly access hidden changesets via HTTP

We now detect hidden access request and validate them while handling HTTP
wireprotocol command. This changeset only introduces server support. Client
support is added in a subsequent changeset.

The mechanism we use for the HTTP wireprotocol is the same as the one used to
lift filtering for hgweb. The use of the global `access-hidden` parameter in
the http url is a simple and effective approach that

* works around the lack of global parameters in wire protocol v1,
* reuses the mechanism used for hgweb (that does not use the wireproto), and
* can be safely ignored by older client (fitting the best effort contract).

The feature is still experimental, so we can easily update the implementation
details in the future. However, landing a first implementation now will help
test the feature in the wild and iterate on alternative implementations if
deemed necessary.

# -*- coding: UTF-8 -*-
# beautifygraph.py - improve graph output by using Unicode characters
#
# Copyright 2018 John Stiles <[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.

'''beautify log -G output by using Unicode characters (EXPERIMENTAL)

   A terminal with UTF-8 support and monospace narrow text are required.
'''


from mercurial.i18n import _
from mercurial import (
    encoding,
    extensions,
    graphmod,
    templatekw,
)

# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b'ships-with-hg-core'


def prettyedge(before, edge, after):
    if edge == b'~':
        return b'\xE2\x95\xA7'  # U+2567 ╧
    if edge == b'/':
        return b'\xE2\x95\xB1'  # U+2571 ╱
    if edge == b'-':
        return b'\xE2\x94\x80'  # U+2500 ─
    if edge == b'|':
        return b'\xE2\x94\x82'  # U+2502 │
    if edge == b':':
        return b'\xE2\x94\x86'  # U+2506 ┆
    if edge == b'\\':
        return b'\xE2\x95\xB2'  # U+2572 ╲
    if edge == b'+':
        if before == b' ' and not after == b' ':
            return b'\xE2\x94\x9C'  # U+251C ├
        if after == b' ' and not before == b' ':
            return b'\xE2\x94\xA4'  # U+2524 ┤
        return b'\xE2\x94\xBC'  # U+253C ┼
    return edge


def convertedges(line):
    line = b' %s ' % line
    pretty = []
    for idx in range(len(line) - 2):
        pretty.append(
            prettyedge(
                line[idx : idx + 1],
                line[idx + 1 : idx + 2],
                line[idx + 2 : idx + 3],
            )
        )
    return b''.join(pretty)


def getprettygraphnode(orig, *args, **kwargs):
    node = orig(*args, **kwargs)
    if node == b'o':
        return b'\xE2\x97\x8B'  # U+25CB ○
    if node == b'@':
        return b'\xE2\x97\x89'  # U+25C9 ◉
    if node == b'%':
        return b'\xE2\x97\x8D'  # U+25CE ◎
    if node == b'*':
        return b'\xE2\x88\x97'  # U+2217 ∗
    if node == b'x':
        return b'\xE2\x97\x8C'  # U+25CC ◌
    if node == b'_':
        return b'\xE2\x95\xA4'  # U+2564 ╤
    return node


def outputprettygraph(orig, ui, graph, *args, **kwargs):
    (edges, text) = zip(*graph)
    graph = zip([convertedges(e) for e in edges], text)
    return orig(ui, graph, *args, **kwargs)


def extsetup(ui):
    if ui.plain(b'graph'):
        return

    if encoding.encoding != b'UTF-8':
        ui.warn(_(b'beautifygraph: unsupported encoding, UTF-8 required\n'))
        return

    if 'A' in encoding._wide:
        ui.warn(
            _(
                b'beautifygraph: unsupported terminal settings, '
                b'monospace narrow text required\n'
            )
        )
        return

    extensions.wrapfunction(graphmod, b'outputgraph', outputprettygraph)
    extensions.wrapfunction(templatekw, b'getgraphnode', getprettygraphnode)