--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/cm/ext/diff.py Mon Nov 23 15:14:29 2009 +0100
@@ -0,0 +1,271 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2004-2009 Edgewall Software
+# Copyright (C) 2004-2006 Christopher Lenz <cmlenz@gmx.de>
+# All rights reserved.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at http://trac.edgewall.org/wiki/TracLicense.
+#
+# This software consists of voluntary contributions made by many
+# individuals. For the exact contribution history, see the revision
+# history and logs, available at http://trac.edgewall.org/log/.
+#
+# Author: Christopher Lenz <cmlenz@gmx.de>
+
+from trac.util.html import escape, Markup
+from trac.util.text import expandtabs
+
+from difflib import SequenceMatcher
+import re
+
+__all__ = ['get_diff_options', 'hdf_diff', 'diff_blocks', 'unified_diff']
+
+
+def _get_change_extent(str1, str2):
+ """
+ Determines the extent of differences between two strings. Returns a tuple
+ containing the offset at which the changes start, and the negative offset
+ at which the changes end. If the two strings have neither a common prefix
+ nor a common suffix, (0, 0) is returned.
+ """
+ start = 0
+ limit = min(len(str1), len(str2))
+ while start < limit and str1[start] == str2[start]:
+ start += 1
+ end = -1
+ limit = limit - start
+ while -end <= limit and str1[end] == str2[end]:
+ end -= 1
+ return (start, end + 1)
+
+def _get_opcodes(fromlines, tolines, ignore_blank_lines=False,
+ ignore_case=False, ignore_space_changes=False):
+ """
+ Generator built on top of SequenceMatcher.get_opcodes().
+
+ This function detects line changes that should be ignored and emits them
+ as tagged as 'equal', possibly joined with the preceding and/or following
+ 'equal' block.
+ """
+
+ def is_ignorable(tag, fromlines, tolines):
+ if tag == 'delete' and ignore_blank_lines:
+ if ''.join(fromlines) == '':
+ return True
+ elif tag == 'insert' and ignore_blank_lines:
+ if ''.join(tolines) == '':
+ return True
+ elif tag == 'replace' and (ignore_case or ignore_space_changes):
+ if len(fromlines) != len(tolines):
+ return False
+ def f(str):
+ if ignore_case:
+ str = str.lower()
+ if ignore_space_changes:
+ str = ' '.join(str.split())
+ return str
+ for i in range(len(fromlines)):
+ if f(fromlines[i]) != f(tolines[i]):
+ return False
+ return True
+
+ matcher = SequenceMatcher(None, fromlines, tolines)
+ previous = None
+ for tag, i1, i2, j1, j2 in matcher.get_opcodes():
+ if tag == 'equal':
+ if previous:
+ previous = (tag, previous[1], i2, previous[3], j2)
+ else:
+ previous = (tag, i1, i2, j1, j2)
+ else:
+ if is_ignorable(tag, fromlines[i1:i2], tolines[j1:j2]):
+ if previous:
+ previous = 'equal', previous[1], i2, previous[3], j2
+ else:
+ previous = 'equal', i1, i2, j1, j2
+ continue
+ if previous:
+ yield previous
+ yield tag, i1, i2, j1, j2
+ previous = None
+
+ if previous:
+ yield previous
+
+def _group_opcodes(opcodes, n=3):
+ """
+ Python 2.2 doesn't have SequenceMatcher.get_grouped_opcodes(), so let's
+ provide equivalent here. The opcodes parameter can be any iterable or
+ sequence.
+
+ This function can also be used to generate full-context diffs by passing
+ None for the parameter n.
+ """
+ # Full context produces all the opcodes
+ if n is None:
+ yield list(opcodes)
+ return
+
+ # Otherwise we leave at most n lines with the tag 'equal' before and after
+ # every change
+ nn = n + n
+ group = []
+ for idx, (tag, i1, i2, j1, j2) in enumerate(opcodes):
+ if idx == 0 and tag == 'equal': # Fixup leading unchanged block
+ i1, j1 = max(i1, i2 - n), max(j1, j2 - n)
+ elif tag == 'equal' and i2 - i1 > nn:
+ group.append((tag, i1, min(i2, i1 + n), j1, min(j2, j1 + n)))
+ yield group
+ group = []
+ i1, j1 = max(i1, i2 - n), max(j1, j2 - n)
+ group.append((tag, i1, i2, j1 ,j2))
+
+ if group and not (len(group) == 1 and group[0][0] == 'equal'):
+ if group[-1][0] == 'equal': # Fixup trailing unchanged block
+ tag, i1, i2, j1, j2 = group[-1]
+ group[-1] = tag, i1, min(i2, i1 + n), j1, min(j2, j1 + n)
+ yield group
+
+def hdf_diff(*args, **kwargs):
+ return diff_blocks(*args, **kwargs)
+
+def diff_blocks(fromlines, tolines, context=None, tabwidth=8,
+ ignore_blank_lines=0, ignore_case=0, ignore_space_changes=0):
+ """Return an array that is adequate for adding to the data dictionary
+
+ See the diff_div.html template.
+ """
+
+ type_map = {'replace': 'mod', 'delete': 'rem', 'insert': 'add',
+ 'equal': 'unmod'}
+
+ space_re = re.compile(' ( +)|^ ')
+ def htmlify(match):
+ div, mod = divmod(len(match.group(0)), 2)
+ return div * ' ' + mod * ' '
+
+ def markup_intraline_changes(opcodes):
+ for tag, i1, i2, j1, j2 in opcodes:
+ if tag == 'replace' and i2 - i1 == j2 - j1:
+ for i in range(i2 - i1):
+ fromline, toline = fromlines[i1 + i], tolines[j1 + i]
+ (start, end) = _get_change_extent(fromline, toline)
+ if start != 0 or end != 0:
+ last = end+len(fromline)
+ fromlines[i1+i] = fromline[:start] + '\0' + fromline[start:last] + \
+ '\1' + fromline[last:]
+ last = end+len(toline)
+ tolines[j1+i] = toline[:start] + '\0' + toline[start:last] + \
+ '\1' + toline[last:]
+ yield tag, i1, i2, j1, j2
+
+ changes = []
+ opcodes = _get_opcodes(fromlines, tolines, ignore_blank_lines, ignore_case,
+ ignore_space_changes)
+ for group in _group_opcodes(opcodes, context):
+ blocks = []
+ last_tag = None
+ for tag, i1, i2, j1, j2 in markup_intraline_changes(group):
+ if tag != last_tag:
+ blocks.append({'type': type_map[tag],
+ 'base': {'offset': i1, 'lines': []},
+ 'changed': {'offset': j1, 'lines': []}})
+ if tag == 'equal':
+ for line in fromlines[i1:i2]:
+ line = line.expandtabs(tabwidth)
+ line = space_re.sub(htmlify, escape(line, quotes=False))
+ blocks[-1]['base']['lines'].append(Markup(unicode(line)))
+ for line in tolines[j1:j2]:
+ line = line.expandtabs(tabwidth)
+ line = space_re.sub(htmlify, escape(line, quotes=False))
+ blocks[-1]['changed']['lines'].append(Markup(unicode(line)))
+ else:
+ if tag in ('replace', 'delete'):
+ for line in fromlines[i1:i2]:
+ line = expandtabs(line, tabwidth, '\0\1')
+ line = escape(line, quotes=False)
+ line = '<del>'.join([space_re.sub(htmlify, seg)
+ for seg in line.split('\0')])
+ line = line.replace('\1', '</del>')
+ blocks[-1]['base']['lines'].append(
+ Markup(unicode(line)))
+ if tag in ('replace', 'insert'):
+ for line in tolines[j1:j2]:
+ line = expandtabs(line, tabwidth, '\0\1')
+ line = escape(line, quotes=False)
+ line = '<ins>'.join([space_re.sub(htmlify, seg)
+ for seg in line.split('\0')])
+ line = line.replace('\1', '</ins>')
+ blocks[-1]['changed']['lines'].append(
+ Markup(unicode(line)))
+ changes.append(blocks)
+ return changes
+
+def unified_diff(fromlines, tolines, context=None, ignore_blank_lines=0,
+ ignore_case=0, ignore_space_changes=0):
+ opcodes = _get_opcodes(fromlines, tolines, ignore_blank_lines, ignore_case,
+ ignore_space_changes)
+ for group in _group_opcodes(opcodes, context):
+ i1, i2, j1, j2 = group[0][1], group[-1][2], group[0][3], group[-1][4]
+ if i1 == 0 and i2 == 0:
+ i1, i2 = -1, -1 # support for 'A'dd changes
+ yield '@@ -%d,%d +%d,%d @@' % (i1 + 1, i2 - i1, j1 + 1, j2 - j1)
+ for tag, i1, i2, j1, j2 in group:
+ if tag == 'equal':
+ for line in fromlines[i1:i2]:
+ yield ' ' + line
+ else:
+ if tag in ('replace', 'delete'):
+ for line in fromlines[i1:i2]:
+ yield '-' + line
+ if tag in ('replace', 'insert'):
+ for line in tolines[j1:j2]:
+ yield '+' + line
+
+def get_diff_options(req):
+ options_data = {}
+ data = {'options': options_data}
+
+ def get_bool_option(name, default=0):
+ pref = int(req.session.get('diff_' + name, default))
+ arg = int(req.args.has_key(name))
+ if req.args.has_key('update') and arg != pref:
+ req.session['diff_' + name] = arg
+ else:
+ arg = pref
+ return arg
+
+ pref = req.session.get('diff_style', 'inline')
+ style = req.args.get('style', pref)
+ if req.args.has_key('update') and style != pref:
+ req.session['diff_style'] = style
+ data['style'] = style
+
+ pref = int(req.session.get('diff_contextlines', 2))
+ try:
+ arg = int(req.args.get('contextlines', pref))
+ except ValueError:
+ arg = -1
+ if req.args.has_key('update') and arg != pref:
+ req.session['diff_contextlines'] = arg
+ options = ['-U%d' % arg]
+ options_data['contextlines'] = arg
+
+ arg = get_bool_option('ignoreblanklines')
+ if arg:
+ options.append('-B')
+ options_data['ignoreblanklines'] = arg
+
+ arg = get_bool_option('ignorecase')
+ if arg:
+ options.append('-i')
+ options_data['ignorecase'] = arg
+
+ arg = get_bool_option('ignorewhitespace')
+ if arg:
+ options.append('-b')
+ options_data['ignorewhitespace'] = arg
+
+ return (style, options, data)