~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005-2010 Aaron Bentley, Canonical Ltd

# <aaron.bentley@utoronto.ca>

#

# 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 2 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, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

import re

binary_files_re = 'Binary files (.*) and (.*) differ\n'

class BinaryFiles(Exception):

    def __init__(self, orig_name, mod_name):

        self.orig_name = orig_name

        self.mod_name = mod_name

        Exception.__init__(self, 'Binary files section encountered.')

class PatchSyntax(Exception):

    def __init__(self, msg):

        Exception.__init__(self, msg)

class MalformedPatchHeader(PatchSyntax):

    def __init__(self, desc, line):

        self.desc = desc

        self.line = line

        msg = "Malformed patch header.  %s\n%r" % (self.desc, self.line)

        PatchSyntax.__init__(self, msg)

class MalformedHunkHeader(PatchSyntax):

    def __init__(self, desc, line):

        self.desc = desc

        self.line = line

        msg = "Malformed hunk header.  %s\n%r" % (self.desc, self.line)

        PatchSyntax.__init__(self, msg)

class MalformedLine(PatchSyntax):

    def __init__(self, desc, line):

        self.desc = desc

        self.line = line

        msg = "Malformed line.  %s\n%s" % (self.desc, self.line)

        PatchSyntax.__init__(self, msg)

class PatchConflict(Exception):

    def __init__(self, line_no, orig_line, patch_line):

        orig = orig_line.rstrip('\n')

        patch = str(patch_line).rstrip('\n')

        msg = 'Text contents mismatch at line %d.  Original has "%s",'\

            ' but patch says it should be "%s"' % (line_no, orig, patch)

        Exception.__init__(self, msg)

def get_patch_names(iter_lines):

    try:

        line = iter_lines.next()

        match = re.match(binary_files_re, line)

        if match is not None:

            raise BinaryFiles(match.group(1), match.group(2))

        if not line.startswith("--- "):

            raise MalformedPatchHeader("No orig name", line)

        else:

            orig_name = line[4:].rstrip("\n")

    except StopIteration:

        raise MalformedPatchHeader("No orig line", "")

    try:

        line = iter_lines.next()

        if not line.startswith("+++ "):

            raise PatchSyntax("No mod name")

        else:

            mod_name = line[4:].rstrip("\n")

    except StopIteration:

        raise MalformedPatchHeader("No mod line", "")

    return (orig_name, mod_name)

def parse_range(textrange):

    """Parse a patch range, handling the "1" special-case

    :param textrange: The text to parse

    :type textrange: str

    :return: the position and range, as a tuple

    :rtype: (int, int)

    """

    tmp = textrange.split(',')

    if len(tmp) == 1:

        pos = tmp[0]

        range = "1"

    else:

        (pos, range) = tmp

    pos = int(pos)

    range = int(range)

    return (pos, range)

def hunk_from_header(line):

    import re

    matches = re.match(r'\@\@ ([^@]*) \@\@( (.*))?\n', line)

    if matches is None:

        raise MalformedHunkHeader("Does not match format.", line)

    try:

        (orig, mod) = matches.group(1).split(" ")

    except (ValueError, IndexError), e:

        raise MalformedHunkHeader(str(e), line)

    if not orig.startswith('-') or not mod.startswith('+'):

        raise MalformedHunkHeader("Positions don't start with + or -.", line)

    try:

        (orig_pos, orig_range) = parse_range(orig[1:])

        (mod_pos, mod_range) = parse_range(mod[1:])

    except (ValueError, IndexError), e:

        raise MalformedHunkHeader(str(e), line)

    if mod_range < 0 or orig_range < 0:

        raise MalformedHunkHeader("Hunk range is negative", line)

    tail = matches.group(3)

    return Hunk(orig_pos, orig_range, mod_pos, mod_range, tail)

class HunkLine:

    def __init__(self, contents):

        self.contents = contents

    def get_str(self, leadchar):

        if self.contents == "\n" and leadchar == " " and False:

            return "\n"

        if not self.contents.endswith('\n'):

            terminator = '\n' + NO_NL

        else:

            terminator = ''

        return leadchar + self.contents + terminator

class ContextLine(HunkLine):

    def __init__(self, contents):

        HunkLine.__init__(self, contents)

    def __str__(self):

        return self.get_str(" ")

class InsertLine(HunkLine):

    def __init__(self, contents):

        HunkLine.__init__(self, contents)

    def __str__(self):

        return self.get_str("+")

class RemoveLine(HunkLine):

    def __init__(self, contents):

        HunkLine.__init__(self, contents)

    def __str__(self):

        return self.get_str("-")

NO_NL = '\\ No newline at end of file\n'

__pychecker__="no-returnvalues"

def parse_line(line):

    if line.startswith("\n"):

        return ContextLine(line)

    elif line.startswith(" "):

        return ContextLine(line[1:])

    elif line.startswith("+"):

        return InsertLine(line[1:])

    elif line.startswith("-"):

        return RemoveLine(line[1:])

    else:

        raise MalformedLine("Unknown line type", line)

__pychecker__=""

class Hunk:

    def __init__(self, orig_pos, orig_range, mod_pos, mod_range, tail=None):

        self.orig_pos = orig_pos

        self.orig_range = orig_range

        self.mod_pos = mod_pos

        self.mod_range = mod_range

        self.tail = tail

        self.lines = []

    def get_header(self):

        if self.tail is None:

            tail_str = ''

        else:

            tail_str = ' ' + self.tail

        return "@@ -%s +%s @@%s\n" % (self.range_str(self.orig_pos,

                                                     self.orig_range),

                                      self.range_str(self.mod_pos,

                                                     self.mod_range),

                                      tail_str)

    def range_str(self, pos, range):

        """Return a file range, special-casing for 1-line files.

        :param pos: The position in the file

        :type pos: int

        :range: The range in the file

        :type range: int

        :return: a string in the format 1,4 except when range == pos == 1

        """

        if range == 1:

            return "%i" % pos

        else:

            return "%i,%i" % (pos, range)

    def __str__(self):

        lines = [self.get_header()]

        for line in self.lines:

            lines.append(str(line))

        return "".join(lines)

    def shift_to_mod(self, pos):

        if pos < self.orig_pos-1:

            return 0

        elif pos > self.orig_pos+self.orig_range:

            return self.mod_range - self.orig_range

        else:

            return self.shift_to_mod_lines(pos)

    def shift_to_mod_lines(self, pos):

        position = self.orig_pos-1

        shift = 0

        for line in self.lines:

            if isinstance(line, InsertLine):

                shift += 1

            elif isinstance(line, RemoveLine):

                if position == pos:

                    return None

                shift -= 1

                position += 1

            elif isinstance(line, ContextLine):

                position += 1

            if position > pos:

                break

        return shift

def iter_hunks(iter_lines, allow_dirty=False):

    '''

    :arg iter_lines: iterable of lines to parse for hunks

    :kwarg allow_dirty: If True, when we encounter something that is not

        a hunk header when we're looking for one, assume the rest of the lines

        are not part of the patch (comments or other junk).  Default False

    '''

    hunk = None

    for line in iter_lines:

        if line == "\n":

            if hunk is not None:

                yield hunk

                hunk = None

            continue

        if hunk is not None:

            yield hunk

        try:

            hunk = hunk_from_header(line)

        except MalformedHunkHeader:

            if allow_dirty:

                # If the line isn't a hunk header, then we've reached the end

                # of this patch and there's "junk" at the end.  Ignore the

                # rest of this patch.

                return

            raise

        orig_size = 0

        mod_size = 0

        while orig_size < hunk.orig_range or mod_size < hunk.mod_range:

            hunk_line = parse_line(iter_lines.next())

            hunk.lines.append(hunk_line)

            if isinstance(hunk_line, (RemoveLine, ContextLine)):

                orig_size += 1

            if isinstance(hunk_line, (InsertLine, ContextLine)):

                mod_size += 1

    if hunk is not None:

        yield hunk

class BinaryPatch(object):

    def __init__(self, oldname, newname):

        self.oldname = oldname

        self.newname = newname

    def __str__(self):

        return 'Binary files %s and %s differ\n' % (self.oldname, self.newname)

class Patch(BinaryPatch):

    def __init__(self, oldname, newname):

        BinaryPatch.__init__(self, oldname, newname)

        self.hunks = []

    def __str__(self):

        ret = self.get_header()

        ret += "".join([str(h) for h in self.hunks])

        return ret

    def get_header(self):

        return "--- %s\n+++ %s\n" % (self.oldname, self.newname)

    def stats_values(self):

        """Calculate the number of inserts and removes."""

        removes = 0

        inserts = 0

        for hunk in self.hunks:

            for line in hunk.lines:

                if isinstance(line, InsertLine):

                     inserts+=1;

                elif isinstance(line, RemoveLine):

                     removes+=1;

        return (inserts, removes, len(self.hunks))

    def stats_str(self):

        """Return a string of patch statistics"""

        return "%i inserts, %i removes in %i hunks" % \

            self.stats_values()

    def pos_in_mod(self, position):

        newpos = position

        for hunk in self.hunks:

            shift = hunk.shift_to_mod(position)

            if shift is None:

                return None

            newpos += shift

        return newpos

    def iter_inserted(self):

        """Iteraties through inserted lines

        :return: Pair of line number, line

        :rtype: iterator of (int, InsertLine)

        """

        for hunk in self.hunks:

            pos = hunk.mod_pos - 1;

            for line in hunk.lines:

                if isinstance(line, InsertLine):

                    yield (pos, line)

                    pos += 1

                if isinstance(line, ContextLine):

                    pos += 1

def parse_patch(iter_lines, allow_dirty=False):

    '''

    :arg iter_lines: iterable of lines to parse

    :kwarg allow_dirty: If True, allow the patch to have trailing junk.

        Default False

    '''

    iter_lines = iter_lines_handle_nl(iter_lines)

    try:

        (orig_name, mod_name) = get_patch_names(iter_lines)

    except BinaryFiles, e:

        return BinaryPatch(e.orig_name, e.mod_name)

    else:

        patch = Patch(orig_name, mod_name)

        for hunk in iter_hunks(iter_lines, allow_dirty):

            patch.hunks.append(hunk)

        return patch

def iter_file_patch(iter_lines, allow_dirty=False):

    '''

    :arg iter_lines: iterable of lines to parse for patches

    :kwarg allow_dirty: If True, allow comments and other non-patch text

        before the first patch.  Note that the algorithm here can only find

        such text before any patches have been found.  Comments after the

        first patch are stripped away in iter_hunks() if it is also passed

        allow_dirty=True.  Default False.

    '''

    ### FIXME: Docstring is not quite true.  We allow certain comments no

    # matter what, If they startwith '===', '***', or '#' Someone should

    # reexamine this logic and decide if we should include those in

    # allow_dirty or restrict those to only being before the patch is found

    # (as allow_dirty does).

    regex = re.compile(binary_files_re)

    saved_lines = []

    orig_range = 0

    beginning = True

    for line in iter_lines:

        if line.startswith('=== ') or line.startswith('*** '):

            continue

        if line.startswith('#'):

            continue

        elif orig_range > 0:

            if line.startswith('-') or line.startswith(' '):

                orig_range -= 1

        elif line.startswith('--- ') or regex.match(line):

            if allow_dirty and beginning:

                # Patches can have "junk" at the beginning

                # Stripping junk from the end of patches is handled when we

                # parse the patch

                beginning = False

            elif len(saved_lines) > 0:

                yield saved_lines

            saved_lines = []

        elif line.startswith('@@'):

            hunk = hunk_from_header(line)

            orig_range = hunk.orig_range

        saved_lines.append(line)

    if len(saved_lines) > 0:

        yield saved_lines

def iter_lines_handle_nl(iter_lines):

    """

    Iterates through lines, ensuring that lines that originally had no

    terminating \n are produced without one.  This transformation may be

    applied at any point up until hunk line parsing, and is safe to apply

    repeatedly.

    """

    last_line = None

    for line in iter_lines:

        if line == NO_NL:

            if not last_line.endswith('\n'):

                raise AssertionError()

            last_line = last_line[:-1]

            line = None

        if last_line is not None:

            yield last_line

        last_line = line

    if last_line is not None:

        yield last_line

def parse_patches(iter_lines, allow_dirty=False):

    '''

    :arg iter_lines: iterable of lines to parse for patches

    :kwarg allow_dirty: If True, allow text that's not part of the patch at

        selected places.  This includes comments before and after a patch

        for instance.  Default False.

    '''

    return [parse_patch(f.__iter__(), allow_dirty) for f in

                        iter_file_patch(iter_lines, allow_dirty)]

def difference_index(atext, btext):

    """Find the indext of the first character that differs between two texts

    :param atext: The first text

    :type atext: str

    :param btext: The second text

    :type str: str

    :return: The index, or None if there are no differences within the range

    :rtype: int or NoneType

    """

    length = len(atext)

    if len(btext) < length:

        length = len(btext)

    for i in range(length):

        if atext[i] != btext[i]:

            return i;

    return None

def iter_patched(orig_lines, patch_lines):

    """Iterate through a series of lines with a patch applied.

    This handles a single file, and does exact, not fuzzy patching.

    """

    patch_lines = iter_lines_handle_nl(iter(patch_lines))

    get_patch_names(patch_lines)

    return iter_patched_from_hunks(orig_lines, iter_hunks(patch_lines))

def iter_patched_from_hunks(orig_lines, hunks):

    """Iterate through a series of lines with a patch applied.

    This handles a single file, and does exact, not fuzzy patching.

    :param orig_lines: The unpatched lines.

    :param hunks: An iterable of Hunk instances.

    """

    seen_patch = []

    line_no = 1

    if orig_lines is not None:

        orig_lines = iter(orig_lines)

    for hunk in hunks:

        while line_no < hunk.orig_pos:

            orig_line = orig_lines.next()

            yield orig_line

            line_no += 1

        for hunk_line in hunk.lines:

            seen_patch.append(str(hunk_line))

            if isinstance(hunk_line, InsertLine):

                yield hunk_line.contents

            elif isinstance(hunk_line, (ContextLine, RemoveLine)):

                orig_line = orig_lines.next()

                if orig_line != hunk_line.contents:

                    raise PatchConflict(line_no, orig_line, "".join(seen_patch))

                if isinstance(hunk_line, ContextLine):

                    yield orig_line

                else:

                    if not isinstance(hunk_line, RemoveLine):

                        raise AssertionError(hunk_line)

                line_no += 1

    if orig_lines is not None:

        for line in orig_lines:

            yield line