# diff.py

# Copyright (C) 2008, 2009 Michael Trier (mtrier@gmail.com) and contributors

#

# This module is part of GitPython and is released under

# the BSD License: http://www.opensource.org/licenses/bsd-license.php

import re

from git.cmd import handle_process_output

from git.compat import (

defenc,

PY3

)

from git.util import finalize_process, hex_to_bin

from .compat import binary_type

from .objects.blob import Blob

from .objects.util import mode_str_to_int

__all__ = ('Diffable', 'DiffIndex', 'Diff', 'NULL_TREE')

# Special object to compare against the empty tree in diffs

NULL_TREE = object()

_octal_byte_re = re.compile(b'\\\\([0-9]{3})')

def _octal_repl(matchobj):

value = matchobj.group(1)

value = int(value, 8)

if PY3:

value = bytes(bytearray((value,)))

else:

value = chr(value)

return value

def decode_path(path, has_ab_prefix=True):

if path == b'/dev/null':

return None

if path.startswith(b'"') and path.endswith(b'"'):

path = (path[1:-1].replace(b'\\n', b'\n')

.replace(b'\\t', b'\t')

.replace(b'\\"', b'"')

.replace(b'\\\\', b'\\'))

path = _octal_byte_re.sub(_octal_repl, path)

if has_ab_prefix:

assert path.startswith(b'a/') or path.startswith(b'b/')

path = path[2:]

return path

class Diffable(object):

"""Common interface for all object that can be diffed against another object of compatible type.

:note:

Subclasses require a repo member as it is the case for Object instances, for practical

reasons we do not derive from Object."""

__slots__ = ()

# standin indicating you want to diff against the index

class Index(object):

pass

def _process_diff_args(self, args):

"""

:return:

possibly altered version of the given args list.

Method is called right before git command execution.

Subclasses can use it to alter the behaviour of the superclass"""

return args

def diff(self, other=Index, paths=None, create_patch=False, **kwargs):

"""Creates diffs between two items being trees, trees and index or an

index and the working tree. It will detect renames automatically.

:param other:

Is the item to compare us with.

If None, we will be compared to the working tree.

If Treeish, it will be compared against the respective tree

If Index ( type ), it will be compared against the index.

If git.NULL_TREE, it will compare against the empty tree.

It defaults to Index to assure the method will not by-default fail

on bare repositories.

:param paths:

is a list of paths or a single path to limit the diff to.

It will only include at least one of the given path or paths.

:param create_patch:

If True, the returned Diff contains a detailed patch that if applied

makes the self to other. Patches are somewhat costly as blobs have to be read

and diffed.

:param kwargs:

Additional arguments passed to git-diff, such as

R=True to swap both sides of the diff.

:return: git.DiffIndex

:note:

On a bare repository, 'other' needs to be provided as Index or as

as Tree/Commit, or a git command error will occur"""

args = []

args.append("--abbrev=40") # we need full shas

args.append("--full-index") # get full index paths, not only filenames

args.append("-M") # check for renames, in both formats

if create_patch:

args.append("-p")

else:

args.append("--raw")

# in any way, assure we don't see colored output,

# fixes https://github.com/gitpython-developers/GitPython/issues/172

args.append('--no-color')

if paths is not None and not isinstance(paths, (tuple, list)):

paths = [paths]

diff_cmd = self.repo.git.diff

if other is self.Index:

args.insert(0, '--cached')

elif other is NULL_TREE:

args.insert(0, '-r') # recursive diff-tree

args.insert(0, '--root')

diff_cmd = self.repo.git.diff_tree

elif other is not None:

args.insert(0, '-r') # recursive diff-tree

args.insert(0, other)

diff_cmd = self.repo.git.diff_tree

args.insert(0, self)

# paths is list here or None

if paths:

args.append("--")

args.extend(paths)

# END paths handling

kwargs['as_process'] = True

proc = diff_cmd(*self._process_diff_args(args), **kwargs)

diff_method = (Diff._index_from_patch_format

if create_patch

else Diff._index_from_raw_format)

index = diff_method(self.repo, proc)

proc.wait()

return index

class DiffIndex(list):

"""Implements an Index for diffs, allowing a list of Diffs to be queried by

the diff properties.

The class improves the diff handling convenience"""

# change type invariant identifying possible ways a blob can have changed

# A = Added

# D = Deleted

# R = Renamed

# M = Modified

# T = Changed in the type

change_type = ("A", "D", "R", "M", "T")

def iter_change_type(self, change_type):

"""

:return:

iterator yielding Diff instances that match the given change_type

:param change_type:

Member of DiffIndex.change_type, namely:

* 'A' for added paths

* 'D' for deleted paths

* 'R' for renamed paths

* 'M' for paths with modified data

* 'T' for changed in the type paths

"""

if change_type not in self.change_type:

raise ValueError("Invalid change type: %s" % change_type)

for diff in self:

if diff.change_type == change_type:

yield diff

elif change_type == "A" and diff.new_file:

yield diff

elif change_type == "D" and diff.deleted_file:

yield diff

elif change_type == "R" and diff.renamed:

yield diff

elif change_type == "M" and diff.a_blob and diff.b_blob and diff.a_blob != diff.b_blob:

yield diff

# END for each diff

class Diff(object):

"""A Diff contains diff information between two Trees.

It contains two sides a and b of the diff, members are prefixed with

"a" and "b" respectively to inidcate that.

Diffs keep information about the changed blob objects, the file mode, renames,

deletions and new files.

There are a few cases where None has to be expected as member variable value:

``New File``::

a_mode is None

a_blob is None

a_path is None

``Deleted File``::

b_mode is None

b_blob is None

b_path is None

``Working Tree Blobs``

When comparing to working trees, the working tree blob will have a null hexsha

as a corresponding object does not yet exist. The mode will be null as well.

But the path will be available though.

If it is listed in a diff the working tree version of the file must

be different to the version in the index or tree, and hence has been modified."""

# precompiled regex

re_header = re.compile(br"""

^diff[ ]--git

[ ](?P<a_path_fallback>"?a/.+?"?)[ ](?P<b_path_fallback>"?b/.+?"?)\n

(?:^old[ ]mode[ ](?P<old_mode>\d+)\n

^new[ ]mode[ ](?P<new_mode>\d+)(?:\n|$))?

(?:^similarity[ ]index[ ]\d+%\n

^rename[ ]from[ ](?P<rename_from>.*)\n

^rename[ ]to[ ](?P<rename_to>.*)(?:\n|$))?

(?:^new[ ]file[ ]mode[ ](?P<new_file_mode>.+)(?:\n|$))?

(?:^deleted[ ]file[ ]mode[ ](?P<deleted_file_mode>.+)(?:\n|$))?

(?:^index[ ](?P<a_blob_id>[0-9A-Fa-f]+)

\.\.(?P<b_blob_id>[0-9A-Fa-f]+)[ ]?(?P<b_mode>.+)?(?:\n|$))?

(?:^---[ ](?P<a_path>[^\t\n\r\f\v]*)[\t\r\f\v]*(?:\n|$))?

(?:^\+\+\+[ ](?P<b_path>[^\t\n\r\f\v]*)[\t\r\f\v]*(?:\n|$))?

""", re.VERBOSE | re.MULTILINE)

# can be used for comparisons

NULL_HEX_SHA = "0" * 40

NULL_BIN_SHA = b"\0" * 20

__slots__ = ("a_blob", "b_blob", "a_mode", "b_mode", "a_rawpath", "b_rawpath",

"new_file", "deleted_file", "raw_rename_from", "raw_rename_to",

"diff", "change_type", "score")

def __init__(self, repo, a_rawpath, b_rawpath, a_blob_id, b_blob_id, a_mode,

b_mode, new_file, deleted_file, raw_rename_from,

raw_rename_to, diff, change_type, score):

self.a_mode = a_mode

self.b_mode = b_mode

assert a_rawpath is None or isinstance(a_rawpath, binary_type)

assert b_rawpath is None or isinstance(b_rawpath, binary_type)

self.a_rawpath = a_rawpath

self.b_rawpath = b_rawpath

if self.a_mode:

self.a_mode = mode_str_to_int(self.a_mode)

if self.b_mode:

self.b_mode = mode_str_to_int(self.b_mode)

if a_blob_id is None or a_blob_id == self.NULL_HEX_SHA:

self.a_blob = None

else:

self.a_blob = Blob(repo, hex_to_bin(a_blob_id), mode=self.a_mode, path=self.a_path)

if b_blob_id is None or b_blob_id == self.NULL_HEX_SHA:

self.b_blob = None

else:

self.b_blob = Blob(repo, hex_to_bin(b_blob_id), mode=self.b_mode, path=self.b_path)

self.new_file = new_file

self.deleted_file = deleted_file

# be clear and use None instead of empty strings

assert raw_rename_from is None or isinstance(raw_rename_from, binary_type)

assert raw_rename_to is None or isinstance(raw_rename_to, binary_type)

self.raw_rename_from = raw_rename_from or None

self.raw_rename_to = raw_rename_to or None

self.diff = diff

self.change_type = change_type

self.score = score

def __eq__(self, other):

for name in self.__slots__:

if getattr(self, name) != getattr(other, name):

return False

# END for each name

return True

def __ne__(self, other):

return not (self == other)

def __hash__(self):

return hash(tuple(getattr(self, n) for n in self.__slots__))

def __str__(self):

h = "%s"

if self.a_blob:

h %= self.a_blob.path

elif self.b_blob:

h %= self.b_blob.path

msg = ''

line = None # temp line

line_length = 0 # line length

for b, n in zip((self.a_blob, self.b_blob), ('lhs', 'rhs')):

if b:

line = "\n%s: %o | %s" % (n, b.mode, b.hexsha)

else:

line = "\n%s: None" % n

# END if blob is not None

line_length = max(len(line), line_length)

msg += line

# END for each blob

# add headline

h += '\n' + '=' * line_length

if self.deleted_file:

msg += '\nfile deleted in rhs'

if self.new_file:

msg += '\nfile added in rhs'

if self.rename_from:

msg += '\nfile renamed from %r' % self.rename_from

if self.rename_to:

msg += '\nfile renamed to %r' % self.rename_to

if self.diff:

msg += '\n---'

try:

msg += self.diff.decode(defenc)

except UnicodeDecodeError:

msg += 'OMITTED BINARY DATA'

# end handle encoding

msg += '\n---'

# END diff info

# Python2 silliness: have to assure we convert our likely to be unicode object to a string with the

# right encoding. Otherwise it tries to convert it using ascii, which may fail ungracefully

res = h + msg

if not PY3:

res = res.encode(defenc)

# end

return res

@property

def a_path(self):

return self.a_rawpath.decode(defenc, 'replace') if self.a_rawpath else None

@property

def b_path(self):

return self.b_rawpath.decode(defenc, 'replace') if self.b_rawpath else None

@property

def rename_from(self):

return self.raw_rename_from.decode(defenc, 'replace') if self.raw_rename_from else None

@property

def rename_to(self):

return self.raw_rename_to.decode(defenc, 'replace') if self.raw_rename_to else None

@property

def renamed(self):

""":returns: True if the blob of our diff has been renamed

:note: This property is deprecated, please use ``renamed_file`` instead.

"""

return self.renamed_file

@property

def renamed_file(self):

""":returns: True if the blob of our diff has been renamed

"""

return self.rename_from != self.rename_to

@classmethod

def _pick_best_path(cls, path_match, rename_match, path_fallback_match):

if path_match:

return decode_path(path_match)

if rename_match:

return decode_path(rename_match, has_ab_prefix=False)

if path_fallback_match:

return decode_path(path_fallback_match)

return None

@classmethod

def _index_from_patch_format(cls, repo, proc):

"""Create a new DiffIndex from the given text which must be in patch format

:param repo: is the repository we are operating on - it is required

:param stream: result of 'git diff' as a stream (supporting file protocol)

:return: git.DiffIndex """

## FIXME: Here SLURPING raw, need to re-phrase header-regexes linewise.

text = []

handle_process_output(proc, text.append, None, finalize_process, decode_streams=False)

# for now, we have to bake the stream

text = b''.join(text)

index = DiffIndex()

previous_header = None

for header in cls.re_header.finditer(text):

a_path_fallback, b_path_fallback, \

old_mode, new_mode, \

rename_from, rename_to, \

new_file_mode, deleted_file_mode, \

a_blob_id, b_blob_id, b_mode, \

a_path, b_path = header.groups()

new_file, deleted_file = bool(new_file_mode), bool(deleted_file_mode)

a_path = cls._pick_best_path(a_path, rename_from, a_path_fallback)

b_path = cls._pick_best_path(b_path, rename_to, b_path_fallback)

# Our only means to find the actual text is to see what has not been matched by our regex,

# and then retro-actively assign it to our index

if previous_header is not None:

index[-1].diff = text[previous_header.end():header.start()]

# end assign actual diff

# Make sure the mode is set if the path is set. Otherwise the resulting blob is invalid

# We just use the one mode we should have parsed

a_mode = old_mode or deleted_file_mode or (a_path and (b_mode or new_mode or new_file_mode))

b_mode = b_mode or new_mode or new_file_mode or (b_path and a_mode)

index.append(Diff(repo,

a_path,

b_path,

a_blob_id and a_blob_id.decode(defenc),

b_blob_id and b_blob_id.decode(defenc),

a_mode and a_mode.decode(defenc),

b_mode and b_mode.decode(defenc),

new_file, deleted_file,

rename_from,

rename_to,

None, None, None))

previous_header = header

# end for each header we parse

if index:

index[-1].diff = text[header.end():]

# end assign last diff

return index

@classmethod

def _index_from_raw_format(cls, repo, proc):

"""Create a new DiffIndex from the given stream which must be in raw format.

:return: git.DiffIndex"""

# handles

# :100644 100644 687099101... 37c5e30c8... M .gitignore

index = DiffIndex()

def handle_diff_line(line):

line = line.decode(defenc)

if not line.startswith(":"):

return

meta, _, path = line[1:].partition('\t')

old_mode, new_mode, a_blob_id, b_blob_id, _change_type = meta.split(None, 4)

# Change type can be R100

# R: status letter

# 100: score (in case of copy and rename)

change_type = _change_type[0]

score_str = ''.join(_change_type[1:])

score = int(score_str) if score_str.isdigit() else None

path = path.strip()

a_path = path.encode(defenc)

b_path = path.encode(defenc)

deleted_file = False

new_file = False

rename_from = None

rename_to = None

# NOTE: We cannot conclude from the existence of a blob to change type

# as diffs with the working do not have blobs yet

if change_type == 'D':

b_blob_id = None

deleted_file = True

elif change_type == 'A':

a_blob_id = None

new_file = True

elif change_type == 'R':

a_path, b_path = path.split('\t', 1)

a_path = a_path.encode(defenc)

b_path = b_path.encode(defenc)

rename_from, rename_to = a_path, b_path

elif change_type == 'T':

# Nothing to do

pass

# END add/remove handling

diff = Diff(repo, a_path, b_path, a_blob_id, b_blob_id, old_mode, new_mode,

new_file, deleted_file, rename_from, rename_to, '',

change_type, score)

index.append(diff)

handle_process_output(proc, handle_diff_line, None, finalize_process, decode_streams=False)

return index