# 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 objects.blob import Blob

from objects.util import mode_str_to_int

from exc import GitCommandError

from git.util import hex_to_bin

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

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__ = tuple()

# 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.

: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.

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 givne 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 somwhat 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:

Rename detection will only work if create_patch is True.

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

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

args = list()

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

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

if create_patch:

args.append("-p")

args.append("-M") # check for renames

else:

args.append("--raw")

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

paths = [paths]

if other is not None and other is not self.Index:

args.insert(0, other)

if other is self.Index:

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

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 = self.repo.git.diff(*self._process_diff_args(args), **kwargs)

diff_method = Diff._index_from_raw_format

if create_patch:

diff_method = Diff._index_from_patch_format

index = diff_method(self.repo, proc.stdout)

status = 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

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

def iter_change_type(self, change_type):

"""

:return:

iterator yieling 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"""

if change_type not in self.change_type:

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

for diff in self:

if 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

``Deleted File``::

b_mode is None

b_blob 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(r"""

#^diff[ ]--git

[ ]a/(?P<a_path>.+?)[ ]b/(?P<b_path>.+?)\n

(?:^similarity[ ]index[ ](?P<similarity_index>\d+)%\n

^rename[ ]from[ ](?P<rename_from>\S+)\n

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

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

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

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

# can be used for comparisons

NULL_HEX_SHA = "0" * 40

NULL_BIN_SHA = "\0" * 20

__slots__ = ("a_blob", "b_blob", "a_mode", "b_mode", "new_file", "deleted_file",

"rename_from", "rename_to", "diff")

def __init__(self, repo, a_path, b_path, a_blob_id, b_blob_id, a_mode,

b_mode, new_file, deleted_file, rename_from,

rename_to, diff):

self.a_mode = a_mode

self.b_mode = b_mode

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:

self.a_blob = None

else:

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

if b_blob_id is None:

self.b_blob = None

else:

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

self.new_file = new_file

self.deleted_file = deleted_file

# be clear and use None instead of empty strings

self.rename_from = rename_from or None

self.rename_to = rename_to or None

self.diff = diff

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 = ''

l = None # temp line

ll = 0 # line length

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

if b:

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

else:

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

# END if blob is not None

ll = max(len(l), ll)

msg += l

# END for each blob

# add headline

h += '\n' + '=' * ll

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---'

msg += self.diff

msg += '\n---'

# END diff info

return h + msg

@property

def renamed(self):

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

return self.rename_from != self.rename_to

@classmethod

def _index_from_patch_format(cls, repo, stream):

"""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 """

# for now, we have to bake the stream

text = stream.read()

index = DiffIndex()

diff_header = cls.re_header.match

for diff in ('\n' + text).split('\ndiff --git')[1:]:

header = diff_header(diff)

a_path, b_path, similarity_index, rename_from, rename_to, \

old_mode, new_mode, new_file_mode, deleted_file_mode, \

a_blob_id, b_blob_id, b_mode = header.groups()

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

index.append(Diff(repo, a_path, b_path, a_blob_id, b_blob_id,

old_mode or deleted_file_mode, new_mode or new_file_mode or b_mode,

new_file, deleted_file, rename_from, rename_to, diff[header.end():]))

return index

@classmethod

def _index_from_raw_format(cls, repo, stream):

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

:return: git.DiffIndex"""

# handles

# :100644 100644 6870991011cc8d9853a7a8a6f02061512c6a8190 37c5e30c879213e9ae83b21e9d11e55fc20c54b7 M .gitignore

# or

# :100644 100644 4aab7ea753e2867dd464f2a50dd266d426ddc8c8 4aab7ea753e2867dd464f2a50dd266d426ddc8c8 R100 src/bootstrap/package.json package.json

index = DiffIndex()

for line in stream:

if not line.startswith(":"):

continue

# END its not a valid diff line

old_mode, new_mode, a_blob_id, b_blob_id, change_type, path = line[1:].split(None, 5)

path = path.strip()

if change_type[0] != 'R':

a_path = b_path = path

rename_from = rename_to = None

else:

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

rename_from, rename_to = a_path, b_path

deleted_file = False

new_file = False

# NOTE: We cannot conclude from the existance 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

# 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, '')

index.append(diff)

# END for each line

return index