~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2004 - 2006 Aaron Bentley

# <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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

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()

        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):

    if not line.startswith("@@") or not line.endswith("@@\n") \

        or not len(line) > 4:

        raise MalformedHunkHeader("Does not start and end with @@.", line)

    try:

        (orig, mod) = line[3:-4].split(" ")

    except Exception, 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 Exception, e:

        raise MalformedHunkHeader(str(e), line)

    if mod_range < 0 or orig_range < 0:

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

    return Hunk(orig_pos, orig_range, mod_pos, mod_range)

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:])

    elif line == NO_NL:

        return NO_NL

    else:

        raise MalformedLine("Unknown line type", line)

__pychecker__=""

class Hunk:

    def __init__(self, orig_pos, orig_range, mod_pos, mod_range):

        self.orig_pos = orig_pos

        self.orig_range = orig_range

        self.mod_pos = mod_pos

        self.mod_range = mod_range

        self.lines = []

    def get_header(self):

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

                                                   self.orig_range),

                                    self.range_str(self.mod_pos, 

                                                   self.mod_range))

    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):

        assert (pos >= self.orig_pos-1 and pos <= self.orig_pos+self.orig_range)

        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):

    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

        hunk = hunk_from_header(line)

        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 Patch:

    def __init__(self, oldname, newname):

        self.oldname = oldname

        self.newname = 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_str(self):

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

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

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

    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):

    (orig_name, mod_name) = get_patch_names(iter_lines)

    patch = Patch(orig_name, mod_name)

    for hunk in iter_hunks(iter_lines):

        patch.hunks.append(hunk)

    return patch

def iter_file_patch(iter_lines):

    saved_lines = []

    for line in iter_lines:

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

            continue

        elif line.startswith('--- '):

            if len(saved_lines) > 0:

                yield saved_lines

            saved_lines = []

        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:

            assert last_line.endswith('\n')

            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):

    iter_lines = iter_lines_handle_nl(iter_lines)

    return [parse_patch(f.__iter__()) for f in iter_file_patch(iter_lines)]

def difference_index(atext, btext):

    """Find the indext of the first character that differs betweeen 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.

    """

    if orig_lines is not None:

        orig_lines = orig_lines.__iter__()

    seen_patch = []

    patch_lines = iter_lines_handle_nl(patch_lines.__iter__())

    get_patch_names(patch_lines)

    line_no = 1

    for hunk in iter_hunks(patch_lines):

        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:

                    assert isinstance(hunk_line, RemoveLine)

                line_no += 1

    if orig_lines is not None:

        for line in orig_lines:

            yield line