jenkins-bot has submitted this change and it was merged.
Change subject: Cherrypick: select and apply diffs between texts ......................................................................
Cherrypick: select and apply diffs between texts
Display diffs, allow their selection and apply approved diffs. Return text obtained by applying only approved diffs.
Change-Id: I11b5f36b2416f3f9a9209141d9df3fab483004b8 --- A pywikibot/diff.py 1 file changed, 337 insertions(+), 0 deletions(-)
Approvals: John Vandenberg: Looks good to me, approved jenkins-bot: Verified
diff --git a/pywikibot/diff.py b/pywikibot/diff.py new file mode 100644 index 0000000..490b0df --- /dev/null +++ b/pywikibot/diff.py @@ -0,0 +1,337 @@ +# -*- coding: utf-8 -*- +""" +User-interface related functions +""" +# +# (C) Pywikibot team, 2014 +# +# Distributed under the terms of the MIT license. +# +__version__ = '$Id$' + + +import difflib +import itertools + +import pywikibot + + +class Hunk(object): + """One change hunk between a and b. + + a and b: two sequences of lines. + grouped_opcode: list of 5-tuples describing how to turn a into b. + it has the same format as returned by difflib.get_opcodes(). + + Note: parts of this code are taken from by difflib.get_grouped_opcodes(). + + """ + + APPR = 1 + NOT_APPR = -1 + PENDING = 0 + + def __init__(self, a, b, grouped_opcode): + self.a = a + self.b = b + self.group = grouped_opcode + self.header = u'' + self.colors = { + '+': 'lightgreen', + '-': 'lightred', + } + + self.diff = list(self.create_diff()) + self.diff_plain_text = u''.join(self.diff) + self.diff_text = u''.join(self.format_diff()) + + first, last = self.group[0], self.group[-1] + self.a_rng = (first[1], last[2]) + self.b_rng = (first[3], last[4]) + + self.header = self.get_header() + self.diff_plain_text = u'%s\n%s' % (self.header, self.diff_plain_text) + self.diff_text = u'%s' % self.diff_text + + self.reviewed = self.PENDING + + def get_header(self): + """Provide header of unified diff.""" + + a_rng = difflib._format_range_unified(*self.a_rng) + b_rng = difflib._format_range_unified(*self.b_rng) + return '@@ -{} +{} @@{}'.format(a_rng, b_rng, '\n') + + def create_diff(self): + """Generator of diff text for this hunk, without formatting.""" + + # make sure each line ends with '\n' to prevent + # behaviour like http://bugs.python.org/issue2142 + def check_line(l): + if not l.endswith('\n'): + return l + '\n' + return l + + for tag, i1, i2, j1, j2 in self.group: + if tag == 'equal': + for line in self.a[i1:i2]: + yield ' ' + check_line(line) + if tag in ('delete'): + for line in self.a[i1:i2]: + yield '-' + check_line(line) + if tag in ('insert'): + for line in self.b[j1:j2]: + yield '+' + check_line(line) + if tag in ('replace'): + for line in difflib.ndiff(self.a[i1:i2], self.b[j1:j2]): + yield check_line(line) + + def format_diff(self): + """Color diff lines.""" + + diff = iter(self.diff) + + l1, l2 = '', next(diff) + for line in diff: + l1, l2 = l2, line + # do not show lines starting with '?'. + if l1.startswith('?'): + continue + if l2.startswith('?'): + yield self.color_line(l1, l2) + else: + yield self.color_line(l1) + + # handle last line + if not l2.startswith('?'): + yield self.color_line(l2) + + def color_line(self, line, line_ref=None): + """Color line characters. + + If line_ref is None, the whole line is colored. + If line_ref[i] is not blank, line[i] is colored. + Color depends if line starts with +/-. + + line: string + line_ref: string. + + """ + + color = line[0] + + if line_ref is None: + if color in self.colors: + colored_line = '\03{%s}%s\03{default}' % (self.colors[color], line) + return colored_line + else: + return line + + colored_line = u'' + state = 'Close' + for char, char_ref in itertools.izip_longest(line, line_ref.strip(), fillvalue=' '): + char_tagged = char + if state == 'Close': + if char_ref != ' ': + char_tagged = '\03{%s}%s' % (self.colors[color], char) + state = 'Open' + elif state == 'Open': + if char_ref == ' ': + char_tagged = '\03{default}%s' % char + state = 'Close' + colored_line += char_tagged + + if state == 'Open': + colored_line += '\03{default}' + + return colored_line + + def apply(self): + """Turn a into b for this hunk.""" + return self.b[self.b_rng[0]:self.b_rng[1]] + + def __str__(self): + return u''.join(self.diff_plain_text) + + def __repr__(self): + """Return a reconstructable representation.""" + # TODO + return '%s(a, b, %s)' \ + % (self.__class__.__name__, self.group) + + +class PatchManager(object): + """Apply patches to text_a to obtain a new text. + + If all hunks are approved, text_b will be obtained. + letter by letter. + + """ + + def __init__(self, text_a, text_b, n=0, by_letter=False): + """Constructor. + + text_a: string + text_b: string + n: int, line of context as defined in difflib.get_grouped_opcodes(). + by_letter: if text_a and text_b are single lines, comparison can be done + + """ + + if '\n' in text_a or '\n' in text_b: + self.a = text_a.splitlines(1) + self.b = text_b.splitlines(1) + else: + if by_letter: + self.a = text_a + self.b = text_b + else: + self.a = text_a.splitlines(1) + self.b = text_b.splitlines(1) + + # groups and hunk have same order (one hunk correspond to one group). + s = difflib.SequenceMatcher(None, self.a, self.b) + self.groups = list(s.get_grouped_opcodes(n)) + self.hunks = [Hunk(self.a, self.b, group) for group in self.groups] + # blocks are a superset of hunk, as include also parts not + # included in any hunk. + self.blocks = self.get_blocks() + + def get_blocks(self): + """Return list with blocks of indexes which compose a and, where applicable, b. + + Format of each block: + [-1, (i1, i2), (-1, -1)] -> block a[i1:i2] does not change from a to b + then is there is no corresponding hunk. + [hunk index, (i1, i2), (j1, j2)] -> block a[i1:i2] becomes b[j1:j2] + + """ + + blocks = [] + i2 = 0 + for hunk_idx, group in enumerate(self.groups): + + first, last = group[0], group[-1] + i1, prev_i2, i2 = first[1], i2, last[2] + + # there is a section of unchanged text before this hunk. + if prev_i2 < i1: + rng = (-1, (prev_i2, i1), (-1, -1)) + blocks.append(rng) + + rng = (hunk_idx, (first[1], last[2]), (first[3], last[4])) + blocks.append(rng) + + # there is a section of unchanged text at the end of a, b. + if i2 < len(self.a): + rng = (-1, (last[2], len(self.a)), (-1, -1)) + blocks.append(rng) + + return blocks + + def review_hunks(self): + "Review hunks." + + help_msg = ['y -> accept this hunk', + 'n -> do not accept this hunk', + 's -> do not accept this hunk and stop reviewing', + 'a -> accept this hunk and all other pending', + 'r -> review later', + 'h -> help', + ] + + question = 'Accept this hunk?' + answers = ['yes', 'no', 'stop', 'all', 'review', 'help'] + hotkeys = ['y', 'n', 's', 'a', 'r', 'h'] + actions = {'y': Hunk.APPR, + 'n': Hunk.NOT_APPR, + 's': Hunk.NOT_APPR, + 'a': Hunk.APPR, + 'r': Hunk.PENDING, + } + + pending = [h for h in self.hunks if h.reviewed == h.PENDING] + + while pending: + + hunk = pending.pop(0) + + pywikibot.output(hunk.header + hunk.diff_text) + choice = pywikibot.inputChoice(question, answers, hotkeys, default='r') + + if choice in actions.keys(): + hunk.reviewed = actions[choice] + if choice == 's': + while pending: + hunk = pending.pop(0) + hunk.reviewed = hunk.NOT_APPR + break + elif choice == 'a': + while pending: + hunk = pending.pop(0) + hunk.reviewed = hunk.APPR + break + elif choice == 'h': + pywikibot.output(u'\03{purple}%s\03{default}' % u'\n'.join(help_msg)) + pending.insert(0, hunk) + elif choice == 'r': + pending.append(hunk) + + return + + def apply(self): + """Apply changes. If there are undecided changes, ask to review.""" + + if any(h.reviewed == h.PENDING for h in self.hunks): + pywikibot.output("There are unreviewed hunks.\n" + "Please review them before proceeding.\n") + self.review_hunks() + + l_text = [] + for hunk_idx, (i1, i2), (j1, j2) in self.blocks: + # unchanged text. + if hunk_idx < 0: + l_text.extend(self.a[i1:i2]) + # changed text; check if hunk is approved. + else: + hunk = self.hunks[hunk_idx] + if hunk.reviewed == hunk.APPR: + l_text.extend(self.b[j1:j2]) + else: + l_text.extend(self.a[i1:i2]) + + # Make a sanity check in case all are approved. + if all(h.reviewed == h.APPR for h in self.hunks): + assert u''.join(l_text) == u''.join(self.b) + return l_text + + +def cherry_pick(oldtext, newtext, n=0, by_letter=False): + """Propose a list of changes for approval. + + Text with approved changes will be returned. + n: int, line of context as defined in difflib.get_grouped_opcodes(). + by_letter: if text_a and text_b are single lines, comparison can be done + + """ + + patch = PatchManager(oldtext, newtext, n=n, by_letter=by_letter) + pywikibot.output('\03{{lightpurple}}\n{:*^50}\03{{default}}\n'.format(' ALL CHANGES ')) + + for hunk in patch.hunks: + pywikibot.output(hunk.diff_text) + pywikibot.output('\03{{lightpurple}}\n{:*^50}\03{{default}}\n'.format(' REVIEW CHANGES ')) + + text_list = patch.apply() + pywikibot.output('\03{{lightpurple}}\n{:*^50}\03{{default}}\n'.format(' APPROVED CHANGES ')) + + if any(hunk.reviewed == hunk.APPR for hunk in patch.hunks): + for hunk in patch.hunks: + if hunk.reviewed == hunk.APPR: + pywikibot.output(hunk.diff_text) + else: + pywikibot.output('\03{{lightpurple}}{:^50}\03{{default}}'.format('None.')) + + text = ''.join(text_list) + + return text