mercurial/formatter.py

revset-limit: use boolean testing instead of `len(revs) < 1`

I'm not sure why we wrote it that way. But smartsets have faster/lazier non-zero
testing than length computation.

# 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

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 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")

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 != "":
        raise util.Abort(_("custom templates not yet supported"))
    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)