mercurial/formatter.py

import-checker: establish modern import convention

We introduce a new convention for declaring imports and enforce it via
the import checker script.

The new convention is only active when absolute imports are used, which is
currently nowhere. Keying off "from __future__ import absolute_import" to
engage the new import convention seems like the easiest solution. It is
also beneficial for Mercurial to use this mode because it means less work
and ambiguity for the importer and potentially better performance due to
fewer stat() system calls because the importer won't look for modules in
relative paths unless explicitly asked.

Once all files are converted to use absolute import, we can refactor
this code to again only have a single import convention and we can
require use of absolute import in the style checker.

The rules for the new convention are documented in the docstring of the
added function. Tests have been added to test-module-imports.t. Some
tests are sensitive to newlines and source column position, which makes
docstring testing difficult and/or impossible.

# formatter.py - generic output formatting for mercurial
#
# Copyright 2012 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 cPickle
from node import hex, short
from i18n import _
import encoding, util
import templater
import os

class baseformatter(object):
    def __init__(self, ui, topic, opts):
        self._ui = ui
        self._topic = topic
        self._style = opts.get("style")
        self._template = opts.get("template")
        self._item = None
        # function to convert node to string suitable for this output
        self.hexfunc = hex
    def __nonzero__(self):
        '''return False if we're not doing real templating so we can
        skip extra work'''
        return True
    def _showitem(self):
        '''show a formatted item once all data is collected'''
        pass
    def startitem(self):
        '''begin an item in the format list'''
        if self._item is not None:
            self._showitem()
        self._item = {}
    def data(self, **data):
        '''insert data into item that's not shown in default output'''
        self._item.update(data)
    def write(self, fields, deftext, *fielddata, **opts):
        '''do default text output while assigning data to item'''
        for k, v in zip(fields.split(), fielddata):
            self._item[k] = v
    def condwrite(self, cond, fields, deftext, *fielddata, **opts):
        '''do conditional write (primarily for plain formatter)'''
        for k, v in zip(fields.split(), fielddata):
            self._item[k] = v
    def plain(self, text, **opts):
        '''show raw text for non-templated mode'''
        pass
    def end(self):
        '''end output for the formatter'''
        if self._item is not None:
            self._showitem()

class plainformatter(baseformatter):
    '''the default text output scheme'''
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
        if ui.debugflag:
            self.hexfunc = hex
        else:
            self.hexfunc = short
    def __nonzero__(self):
        return False
    def startitem(self):
        pass
    def data(self, **data):
        pass
    def write(self, fields, deftext, *fielddata, **opts):
        self._ui.write(deftext % fielddata, **opts)
    def condwrite(self, cond, fields, deftext, *fielddata, **opts):
        '''do conditional write'''
        if cond:
            self._ui.write(deftext % fielddata, **opts)
    def plain(self, text, **opts):
        self._ui.write(text, **opts)
    def end(self):
        pass

class debugformatter(baseformatter):
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
        self._ui.write("%s = [\n" % self._topic)
    def _showitem(self):
        self._ui.write("    " + repr(self._item) + ",\n")
    def end(self):
        baseformatter.end(self)
        self._ui.write("]\n")

class pickleformatter(baseformatter):
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
        self._data = []
    def _showitem(self):
        self._data.append(self._item)
    def end(self):
        baseformatter.end(self)
        self._ui.write(cPickle.dumps(self._data))

def _jsonifyobj(v):
    if isinstance(v, tuple):
        return '[' + ', '.join(_jsonifyobj(e) for e in v) + ']'
    elif v is None:
        return 'null'
    elif v is True:
        return 'true'
    elif v is False:
        return 'false'
    elif isinstance(v, (int, float)):
        return str(v)
    else:
        return '"%s"' % encoding.jsonescape(v)

class jsonformatter(baseformatter):
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
        self._ui.write("[")
        self._ui._first = True
    def _showitem(self):
        if self._ui._first:
            self._ui._first = False
        else:
            self._ui.write(",")

        self._ui.write("\n {\n")
        first = True
        for k, v in sorted(self._item.items()):
            if first:
                first = False
            else:
                self._ui.write(",\n")
            self._ui.write('  "%s": %s' % (k, _jsonifyobj(v)))
        self._ui.write("\n }")
    def end(self):
        baseformatter.end(self)
        self._ui.write("\n]\n")

class templateformatter(baseformatter):
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
        self._topic = topic
        self._t = gettemplater(ui, topic, opts.get('template', ''))
    def _showitem(self):
        g = self._t(self._topic, **self._item)
        self._ui.write(templater.stringify(g))

def lookuptemplate(ui, topic, tmpl):
    # looks like a literal template?
    if '{' in tmpl:
        return tmpl, None

    # perhaps a stock style?
    if not os.path.split(tmpl)[0]:
        mapname = (templater.templatepath('map-cmdline.' + tmpl)
                   or templater.templatepath(tmpl))
        if mapname and os.path.isfile(mapname):
            return None, mapname

    # perhaps it's a reference to [templates]
    t = ui.config('templates', tmpl)
    if t:
        try:
            tmpl = templater.unquotestring(t)
        except SyntaxError:
            tmpl = t
        return tmpl, None

    if tmpl == 'list':
        ui.write(_("available styles: %s\n") % templater.stylelist())
        raise util.Abort(_("specify a template"))

    # perhaps it's a path to a map or a template
    if ('/' in tmpl or '\\' in tmpl) and os.path.isfile(tmpl):
        # is it a mapfile for a style?
        if os.path.basename(tmpl).startswith("map-"):
            return None, os.path.realpath(tmpl)
        tmpl = open(tmpl).read()
        return tmpl, None

    # constant string?
    return tmpl, None

def gettemplater(ui, topic, spec):
    tmpl, mapfile = lookuptemplate(ui, topic, spec)
    t = templater.templater(mapfile, {})
    if tmpl:
        t.cache[topic] = tmpl
    return t

def formatter(ui, topic, opts):
    template = opts.get("template", "")
    if template == "json":
        return jsonformatter(ui, topic, opts)
    elif template == "pickle":
        return pickleformatter(ui, topic, opts)
    elif template == "debug":
        return debugformatter(ui, topic, opts)
    elif template != "":
        return templateformatter(ui, topic, opts)
    elif ui.configbool('ui', 'formatdebug'):
        return debugformatter(ui, topic, opts)
    elif ui.configbool('ui', 'formatjson'):
        return jsonformatter(ui, topic, opts)
    return plainformatter(ui, topic, opts)