# base.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

from git.util import LazyMixin, join_path_native, stream_copy, bin_to_hex

import gitdb.typ as dbtyp

import os.path as osp

from .util import get_object_type_by_name

_assertion_msg_format = "Created object %r whose python type %r disagrees with the acutal git object type %r"

__all__ = ("Object", "IndexObject")

class Object(LazyMixin):

"""Implements an Object which may be Blobs, Trees, Commits and Tags"""

NULL_HEX_SHA = '0' * 40

NULL_BIN_SHA = b'\0' * 20

TYPES = (dbtyp.str_blob_type, dbtyp.str_tree_type, dbtyp.str_commit_type, dbtyp.str_tag_type)

__slots__ = ("repo", "binsha", "size")

type = None # to be set by subclass

def __init__(self, repo, binsha):

"""Initialize an object by identifying it by its binary sha.

All keyword arguments will be set on demand if None.

:param repo: repository this object is located in

:param binsha: 20 byte SHA1"""

super(Object, self).__init__()

self.repo = repo

self.binsha = binsha

assert len(binsha) == 20, "Require 20 byte binary sha, got %r, len = %i" % (binsha, len(binsha))

@classmethod

def new(cls, repo, id): # @ReservedAssignment

"""

:return: New Object instance of a type appropriate to the object type behind

id. The id of the newly created object will be a binsha even though

the input id may have been a Reference or Rev-Spec

:param id: reference, rev-spec, or hexsha

:note: This cannot be a __new__ method as it would always call __init__

with the input id which is not necessarily a binsha."""

return repo.rev_parse(str(id))

@classmethod

def new_from_sha(cls, repo, sha1):

"""

:return: new object instance of a type appropriate to represent the given

binary sha1

:param sha1: 20 byte binary sha1"""

if sha1 == cls.NULL_BIN_SHA:

# the NULL binsha is always the root commit

return get_object_type_by_name(b'commit')(repo, sha1)

# END handle special case

oinfo = repo.odb.info(sha1)

inst = get_object_type_by_name(oinfo.type)(repo, oinfo.binsha)

inst.size = oinfo.size

return inst

def _set_cache_(self, attr):

"""Retrieve object information"""

if attr == "size":

oinfo = self.repo.odb.info(self.binsha)

self.size = oinfo.size

# assert oinfo.type == self.type, _assertion_msg_format % (self.binsha, oinfo.type, self.type)

else:

super(Object, self)._set_cache_(attr)

def __eq__(self, other):

""":return: True if the objects have the same SHA1"""

if not hasattr(other, 'binsha'):

return False

return self.binsha == other.binsha

def __ne__(self, other):

""":return: True if the objects do not have the same SHA1 """

if not hasattr(other, 'binsha'):

return True

return self.binsha != other.binsha

def __hash__(self):

""":return: Hash of our id allowing objects to be used in dicts and sets"""

return hash(self.binsha)

def __str__(self):

""":return: string of our SHA1 as understood by all git commands"""

return self.hexsha

def __repr__(self):

""":return: string with pythonic representation of our object"""

return '<git.%s "%s">' % (self.__class__.__name__, self.hexsha)

@property

def hexsha(self):

""":return: 40 byte hex version of our 20 byte binary sha"""

# b2a_hex produces bytes

return bin_to_hex(self.binsha).decode('ascii')

@property

def data_stream(self):

""" :return: File Object compatible stream to the uncompressed raw data of the object

:note: returned streams must be read in order"""

return self.repo.odb.stream(self.binsha)

def stream_data(self, ostream):

"""Writes our data directly to the given output stream

:param ostream: File object compatible stream object.

:return: self"""

istream = self.repo.odb.stream(self.binsha)

stream_copy(istream, ostream)

return self

class IndexObject(Object):

"""Base for all objects that can be part of the index file , namely Tree, Blob and

SubModule objects"""

__slots__ = ("path", "mode")

# for compatibility with iterable lists

_id_attribute_ = 'path'

def __init__(self, repo, binsha, mode=None, path=None):

"""Initialize a newly instanced IndexObject

:param repo: is the Repo we are located in

:param binsha: 20 byte sha1

:param mode:

is the stat compatible file mode as int, use the stat module

to evaluate the information

:param path:

is the path to the file in the file system, relative to the git repository root, i.e.

file.ext or folder/other.ext

:note:

Path may not be set of the index object has been created directly as it cannot

be retrieved without knowing the parent tree."""

super(IndexObject, self).__init__(repo, binsha)

if mode is not None:

self.mode = mode

if path is not None:

self.path = path

def __hash__(self):

"""

:return:

Hash of our path as index items are uniquely identifiable by path, not

by their data !"""

return hash(self.path)

def _set_cache_(self, attr):

if attr in IndexObject.__slots__:

# they cannot be retrieved lateron ( not without searching for them )

raise AttributeError(

"Attribute '%s' unset: path and mode attributes must have been set during %s object creation"

% (attr, type(self).__name__))

else:

super(IndexObject, self)._set_cache_(attr)

# END handle slot attribute

@property

def name(self):

""":return: Name portion of the path, effectively being the basename"""

return osp.basename(self.path)

@property

def abspath(self):

"""

:return:

Absolute path to this index object in the file system ( as opposed to the

.path field which is a path relative to the git repository ).

The returned path will be native to the system and contains '\' on windows. """

return join_path_native(self.repo.working_tree_dir, self.path)