Alwas show initial context on html diffs.

rhodecode/lib/diffs.py

@@ -1,524 +1,523 b''
 # -*- coding: utf-8 -*-
 """
     rhodecode.lib.diffs
     ~~~~~~~~~~~~~~~~~~~
 
     Set of diffing helpers, previously part of vcs
 
 
     :created_on: Dec 4, 2011
     :author: marcink
     :copyright: (C) 2010-2012 Marcin Kuzminski <[e-mail]>
     :original copyright: 2007-2008 by Armin Ronacher
     :license: GPLv3, see COPYING for more details.
 """
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import re
 import difflib
 import markupsafe
 from itertools import tee, imap
 
 from pylons.i18n.translation import _
 
 from rhodecode.lib.vcs.exceptions import VCSError
 from rhodecode.lib.vcs.nodes import FileNode, SubModuleNode
 from rhodecode.lib.helpers import escape
 from rhodecode.lib.utils import EmptyChangeset
 
 
 def wrap_to_table(str_):
     return '''<table class="code-difftable">
                 <tr class="line no-comment">
                 <td class="lineno new"></td>
                 <td class="code no-comment"><pre>%s</pre></td>
                 </tr>
               </table>''' % str_
 
 
 def wrapped_diff(filenode_old, filenode_new, cut_off_limit=None,
                 ignore_whitespace=True, line_context=3,
                 enable_comments=False):
     """
     returns a wrapped diff into a table, checks for cut_off_limit and presents
     proper message
     """
 
     if filenode_old is None:
         filenode_old = FileNode(filenode_new.path, '', EmptyChangeset())
 
     if filenode_old.is_binary or filenode_new.is_binary:
         diff = wrap_to_table(_('binary file'))
         stats = (0, 0)
         size = 0
 
     elif cut_off_limit != -1 and (cut_off_limit is None or
     (filenode_old.size < cut_off_limit and filenode_new.size < cut_off_limit)):
 
         f_gitdiff = get_gitdiff(filenode_old, filenode_new,
                                 ignore_whitespace=ignore_whitespace,
                                 context=line_context)
         diff_processor = DiffProcessor(f_gitdiff, format='gitdiff')
 
         diff = diff_processor.as_html(enable_comments=enable_comments)
         stats = diff_processor.stat()
         size = len(diff or '')
     else:
         diff = wrap_to_table(_('Changeset was too big and was cut off, use '
                                'diff menu to display this diff'))
         stats = (0, 0)
         size = 0
     if not diff:
         submodules = filter(lambda o: isinstance(o, SubModuleNode),
                             [filenode_new, filenode_old])
         if submodules:
             diff = wrap_to_table(escape('Submodule %r' % submodules[0]))
         else:
             diff = wrap_to_table(_('No changes detected'))
 
     cs1 = filenode_old.changeset.raw_id
     cs2 = filenode_new.changeset.raw_id
 
     return size, cs1, cs2, diff, stats
 
 
 def get_gitdiff(filenode_old, filenode_new, ignore_whitespace=True, context=3):
     """
     Returns git style diff between given ``filenode_old`` and ``filenode_new``.
 
     :param ignore_whitespace: ignore whitespaces in diff
     """
     # make sure we pass in default context
     context = context or 3
     submodules = filter(lambda o: isinstance(o, SubModuleNode),
                         [filenode_new, filenode_old])
     if submodules:
         return ''
 
     for filenode in (filenode_old, filenode_new):
         if not isinstance(filenode, FileNode):
             raise VCSError("Given object should be FileNode object, not %s"
                 % filenode.__class__)
 
     repo = filenode_new.changeset.repository
     old_raw_id = getattr(filenode_old.changeset, 'raw_id', repo.EMPTY_CHANGESET)
     new_raw_id = getattr(filenode_new.changeset, 'raw_id', repo.EMPTY_CHANGESET)
 
     vcs_gitdiff = repo.get_diff(old_raw_id, new_raw_id, filenode_new.path,
                                  ignore_whitespace, context)
     return vcs_gitdiff
 
 
 class DiffProcessor(object):
     """
     Give it a unified diff and it returns a list of the files that were
     mentioned in the diff together with a dict of meta information that
     can be used to render it in a HTML template.
     """
     _chunk_re = re.compile(r'@@ -(\d+)(?:,(\d+))? \+(\d+)(?:,(\d+))? @@(.*)')
 
     def __init__(self, diff, differ='diff', format='udiff'):
         """
         :param diff:   a text in diff format or generator
         :param format: format of diff passed, `udiff` or `gitdiff`
         """
         if isinstance(diff, basestring):
             diff = [diff]
 
         self.__udiff = diff
         self.__format = format
         self.adds = 0
         self.removes = 0
 
         if isinstance(self.__udiff, basestring):
             self.lines = iter(self.__udiff.splitlines(1))
 
         elif self.__format == 'gitdiff':
             udiff_copy = self.copy_iterator()
             self.lines = imap(self.escaper, self._parse_gitdiff(udiff_copy))
         else:
             udiff_copy = self.copy_iterator()
             self.lines = imap(self.escaper, udiff_copy)
 
         # Select a differ.
         if differ == 'difflib':
             self.differ = self._highlight_line_difflib
         else:
             self.differ = self._highlight_line_udiff
 
     def escaper(self, string):
         return markupsafe.escape(string)
 
     def copy_iterator(self):
         """
         make a fresh copy of generator, we should not iterate thru
         an original as it's needed for repeating operations on
         this instance of DiffProcessor
         """
         self.__udiff, iterator_copy = tee(self.__udiff)
         return iterator_copy
 
     def _extract_rev(self, line1, line2):
         """
         Extract the filename and revision hint from a line.
         """
 
         try:
             if line1.startswith('--- ') and line2.startswith('+++ '):
                 l1 = line1[4:].split(None, 1)
                 old_filename = (l1[0].replace('a/', '', 1)
                                 if len(l1) >= 1 else None)
                 old_rev = l1[1] if len(l1) == 2 else 'old'
 
                 l2 = line2[4:].split(None, 1)
                 new_filename = (l2[0].replace('b/', '', 1)
                                 if len(l1) >= 1 else None)
                 new_rev = l2[1] if len(l2) == 2 else 'new'
 
                 filename = (old_filename
                             if old_filename != '/dev/null' else new_filename)
 
                 return filename, new_rev, old_rev
         except (ValueError, IndexError):
             pass
 
         return None, None, None
 
     def _parse_gitdiff(self, diffiterator):
         def line_decoder(l):
             if l.startswith('+') and not l.startswith('+++'):
                 self.adds += 1
             elif l.startswith('-') and not l.startswith('---'):
                 self.removes += 1
             return l.decode('utf8', 'replace')
 
         output = list(diffiterator)
         size = len(output)
 
         if size == 2:
             l = []
             l.extend([output[0]])
             l.extend(output[1].splitlines(1))
             return map(line_decoder, l)
         elif size == 1:
             return  map(line_decoder, output[0].splitlines(1))
         elif size == 0:
             return []
 
         raise Exception('wrong size of diff %s' % size)
 
     def _highlight_line_difflib(self, line, next_):
         """
         Highlight inline changes in both lines.
         """
 
         if line['action'] == 'del':
             old, new = line, next_
         else:
             old, new = next_, line
 
         oldwords = re.split(r'(\W)', old['line'])
         newwords = re.split(r'(\W)', new['line'])
 
         sequence = difflib.SequenceMatcher(None, oldwords, newwords)
 
         oldfragments, newfragments = [], []
         for tag, i1, i2, j1, j2 in sequence.get_opcodes():
             oldfrag = ''.join(oldwords[i1:i2])
             newfrag = ''.join(newwords[j1:j2])
             if tag != 'equal':
                 if oldfrag:
                     oldfrag = '<del>%s</del>' % oldfrag
                 if newfrag:
                     newfrag = '<ins>%s</ins>' % newfrag
             oldfragments.append(oldfrag)
             newfragments.append(newfrag)
 
         old['line'] = "".join(oldfragments)
         new['line'] = "".join(newfragments)
 
     def _highlight_line_udiff(self, line, next_):
         """
         Highlight inline changes in both lines.
         """
         start = 0
         limit = min(len(line['line']), len(next_['line']))
         while start < limit and line['line'][start] == next_['line'][start]:
             start += 1
         end = -1
         limit -= start
         while -end <= limit and line['line'][end] == next_['line'][end]:
             end -= 1
         end += 1
         if start or end:
             def do(l):
                 last = end + len(l['line'])
                 if l['action'] == 'add':
                     tag = 'ins'
                 else:
                     tag = 'del'
                 l['line'] = '%s<%s>%s</%s>%s' % (
                     l['line'][:start],
                     tag,
                     l['line'][start:last],
                     tag,
                     l['line'][last:]
                 )
             do(line)
             do(next_)
 
     def _parse_udiff(self):
         """
         Parse the diff an return data for the template.
         """
         lineiter = self.lines
         files = []
         try:
             line = lineiter.next()
-            # skip first context
-            skipfirst = True
             while 1:
                 # continue until we found the old file
                 if not line.startswith('--- '):
                     line = lineiter.next()
                     continue
 
                 chunks = []
                 filename, old_rev, new_rev = \
                     self._extract_rev(line, lineiter.next())
                 files.append({
                     'filename':         filename,
                     'old_revision':     old_rev,
                     'new_revision':     new_rev,
                     'chunks':           chunks
                 })
 
                 line = lineiter.next()
                 while line:
                     match = self._chunk_re.match(line)
                     if not match:
                         break
 
                     lines = []
                     chunks.append(lines)
 
                     old_line, old_end, new_line, new_end = \
                         [int(x or 1) for x in match.groups()[:-1]]
                     old_line -= 1
                     new_line -= 1
-                    context = len(match.groups()) == 5
+                    gr = match.groups()
+                    context = len(gr) == 5
                     old_end += old_line
                     new_end += new_line
 
                     if context:
-                        if not skipfirst:
+                        # skip context only if it's first line
+                        if int(gr[0]) > 1:
                             lines.append({
                                 'old_lineno': '...',
                                 'new_lineno': '...',
                                 'action':     'context',
                                 'line':       line,
                             })
-                        else:
-                            skipfirst = False
 
                     line = lineiter.next()
+
                     while old_line < old_end or new_line < new_end:
                         if line:
                             command, line = line[0], line[1:]
                         else:
                             command = ' '
                         affects_old = affects_new = False
 
                         # ignore those if we don't expect them
                         if command in '#@':
                             continue
                         elif command == '+':
                             affects_new = True
                             action = 'add'
                         elif command == '-':
                             affects_old = True
                             action = 'del'
                         else:
                             affects_old = affects_new = True
                             action = 'unmod'
 
                         old_line += affects_old
                         new_line += affects_new
                         lines.append({
                             'old_lineno':   affects_old and old_line or '',
                             'new_lineno':   affects_new and new_line or '',
                             'action':       action,
                             'line':         line
                         })
                         line = lineiter.next()
 
         except StopIteration:
             pass
 
         # highlight inline changes
         for _ in files:
             for chunk in chunks:
                 lineiter = iter(chunk)
                 #first = True
                 try:
                     while 1:
                         line = lineiter.next()
                         if line['action'] != 'unmod':
                             nextline = lineiter.next()
                             if nextline['action'] == 'unmod' or \
                                nextline['action'] == line['action']:
                                 continue
                             self.differ(line, nextline)
                 except StopIteration:
                     pass
 
         return files
 
     def prepare(self):
         """
         Prepare the passed udiff for HTML rendering. It'l return a list
         of dicts
         """
         return self._parse_udiff()
 
     def _safe_id(self, idstring):
         """Make a string safe for including in an id attribute.
 
         The HTML spec says that id attributes 'must begin with
         a letter ([A-Za-z]) and may be followed by any number
         of letters, digits ([0-9]), hyphens ("-"), underscores
         ("_"), colons (":"), and periods (".")'. These regexps
         are slightly over-zealous, in that they remove colons
         and periods unnecessarily.
 
         Whitespace is transformed into underscores, and then
         anything which is not a hyphen or a character that
         matches \w (alphanumerics and underscore) is removed.
 
         """
         # Transform all whitespace to underscore
         idstring = re.sub(r'\s', "_", '%s' % idstring)
         # Remove everything that is not a hyphen or a member of \w
         idstring = re.sub(r'(?!-)\W', "", idstring).lower()
         return idstring
 
     def raw_diff(self):
         """
         Returns raw string as udiff
         """
         udiff_copy = self.copy_iterator()
         if self.__format == 'gitdiff':
             udiff_copy = self._parse_gitdiff(udiff_copy)
         return u''.join(udiff_copy)
 
     def as_html(self, table_class='code-difftable', line_class='line',
                 new_lineno_class='lineno old', old_lineno_class='lineno new',
                 code_class='code', enable_comments=False):
         """
         Return udiff as html table with customized css classes
         """
         def _link_to_if(condition, label, url):
             """
             Generates a link if condition is meet or just the label if not.
             """
 
             if condition:
                 return '''<a href="%(url)s">%(label)s</a>''' % {
                     'url': url,
                     'label': label
                 }
             else:
                 return label
         diff_lines = self.prepare()
         _html_empty = True
         _html = []
         _html.append('''<table class="%(table_class)s">\n''' % {
             'table_class': table_class
         })
         for diff in diff_lines:
             for line in diff['chunks']:
                 _html_empty = False
                 for change in line:
                     _html.append('''<tr class="%(lc)s %(action)s">\n''' % {
                         'lc': line_class,
                         'action': change['action']
                     })
                     anchor_old_id = ''
                     anchor_new_id = ''
                     anchor_old = "%(filename)s_o%(oldline_no)s" % {
                         'filename': self._safe_id(diff['filename']),
                         'oldline_no': change['old_lineno']
                     }
                     anchor_new = "%(filename)s_n%(oldline_no)s" % {
                         'filename': self._safe_id(diff['filename']),
                         'oldline_no': change['new_lineno']
                     }
                     cond_old = (change['old_lineno'] != '...' and
                                 change['old_lineno'])
                     cond_new = (change['new_lineno'] != '...' and
                                 change['new_lineno'])
                     if cond_old:
                         anchor_old_id = 'id="%s"' % anchor_old
                     if cond_new:
                         anchor_new_id = 'id="%s"' % anchor_new
                     ###########################################################
                     # OLD LINE NUMBER
                     ###########################################################
                     _html.append('''\t<td %(a_id)s class="%(olc)s">''' % {
                         'a_id': anchor_old_id,
                         'olc': old_lineno_class
                     })
 
                     _html.append('''%(link)s''' % {
                         'link': _link_to_if(True, change['old_lineno'],
                                             '#%s' % anchor_old)
                     })
                     _html.append('''</td>\n''')
                     ###########################################################
                     # NEW LINE NUMBER
                     ###########################################################
 
                     _html.append('''\t<td %(a_id)s class="%(nlc)s">''' % {
                         'a_id': anchor_new_id,
                         'nlc': new_lineno_class
                     })
 
                     _html.append('''%(link)s''' % {
                         'link': _link_to_if(True, change['new_lineno'],
                                             '#%s' % anchor_new)
                     })
                     _html.append('''</td>\n''')
                     ###########################################################
                     # CODE
                     ###########################################################
                     comments = '' if enable_comments else 'no-comment'
                     _html.append('''\t<td class="%(cc)s %(inc)s">''' % {
                         'cc': code_class,
                         'inc': comments
                     })
                     _html.append('''\n\t\t<pre>%(code)s</pre>\n''' % {
                         'code': change['line']
                     })
                     _html.append('''\t</td>''')
                     _html.append('''\n</tr>\n''')
         _html.append('''</table>''')
         if _html_empty:
             return None
         return ''.join(_html)
 
     def stat(self):
         """
         Returns tuple of added, and removed lines for this instance
         """
         return self.adds, self.removes