# tree.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 join_path

import git.diff as diff

from git.util import to_bin_sha

from . import util

from .base import IndexObject

from .blob import Blob

from .submodule.base import Submodule

from .fun import (

tree_entries_from_data,

tree_to_stream

)

cmp = lambda a, b: (a > b) - (a < b)

__all__ = ("TreeModifier", "Tree")

def git_cmp(t1, t2):

a, b = t1[2], t2[2]

len_a, len_b = len(a), len(b)

min_len = min(len_a, len_b)

min_cmp = cmp(a[:min_len], b[:min_len])

if min_cmp:

return min_cmp

return len_a - len_b

def merge_sort(a, cmp):

if len(a) < 2:

return

mid = len(a) // 2

lefthalf = a[:mid]

righthalf = a[mid:]

merge_sort(lefthalf, cmp)

merge_sort(righthalf, cmp)

i = 0

j = 0

k = 0

while i < len(lefthalf) and j < len(righthalf):

if cmp(lefthalf[i], righthalf[j]) <= 0:

a[k] = lefthalf[i]

i = i + 1

else:

a[k] = righthalf[j]

j = j + 1

k = k + 1

while i < len(lefthalf):

a[k] = lefthalf[i]

i = i + 1

k = k + 1

while j < len(righthalf):

a[k] = righthalf[j]

j = j + 1

k = k + 1

class TreeModifier(object):

"""A utility class providing methods to alter the underlying cache in a list-like fashion.

Once all adjustments are complete, the _cache, which really is a reference to

the cache of a tree, will be sorted. Assuring it will be in a serializable state"""

__slots__ = '_cache'

def __init__(self, cache):

self._cache = cache

def _index_by_name(self, name):

""":return: index of an item with name, or -1 if not found"""

for i, t in enumerate(self._cache):

if t[2] == name:

return i

# END found item

# END for each item in cache

return -1

#{ Interface

def set_done(self):

"""Call this method once you are done modifying the tree information.

It may be called several times, but be aware that each call will cause

a sort operation

:return self:"""

merge_sort(self._cache, git_cmp)

return self

#} END interface

#{ Mutators

def add(self, sha, mode, name, force=False):

"""Add the given item to the tree. If an item with the given name already

exists, nothing will be done, but a ValueError will be raised if the

sha and mode of the existing item do not match the one you add, unless

force is True

:param sha: The 20 or 40 byte sha of the item to add

:param mode: int representing the stat compatible mode of the item

:param force: If True, an item with your name and information will overwrite

any existing item with the same name, no matter which information it has

:return: self"""

if '/' in name:

raise ValueError("Name must not contain '/' characters")

if (mode >> 12) not in Tree._map_id_to_type:

raise ValueError("Invalid object type according to mode %o" % mode)

sha = to_bin_sha(sha)

index = self._index_by_name(name)

item = (sha, mode, name)

if index == -1:

self._cache.append(item)

else:

if force:

self._cache[index] = item

else:

ex_item = self._cache[index]

if ex_item[0] != sha or ex_item[1] != mode:

raise ValueError("Item %r existed with different properties" % name)

# END handle mismatch

# END handle force

# END handle name exists

return self

def add_unchecked(self, binsha, mode, name):

"""Add the given item to the tree, its correctness is assumed, which

puts the caller into responsibility to assure the input is correct.

For more information on the parameters, see ``add``

:param binsha: 20 byte binary sha"""

self._cache.append((binsha, mode, name))

def __delitem__(self, name):

"""Deletes an item with the given name if it exists"""

index = self._index_by_name(name)

if index > -1:

del(self._cache[index])

#} END mutators

class Tree(IndexObject, diff.Diffable, util.Traversable, util.Serializable):

"""Tree objects represent an ordered list of Blobs and other Trees.

``Tree as a list``::

Access a specific blob using the

tree['filename'] notation.

You may as well access by index

blob = tree[0]

"""

type = "tree"

__slots__ = "_cache"

# actual integer ids for comparison

commit_id = 0o16 # equals stat.S_IFDIR | stat.S_IFLNK - a directory link

blob_id = 0o10

symlink_id = 0o12

tree_id = 0o04

_map_id_to_type = {

commit_id: Submodule,

blob_id: Blob,

symlink_id: Blob

# tree id added once Tree is defined

}

def __init__(self, repo, binsha, mode=tree_id << 12, path=None):

super(Tree, self).__init__(repo, binsha, mode, path)

@classmethod

def _get_intermediate_items(cls, index_object):

if index_object.type == "tree":

return tuple(index_object._iter_convert_to_object(index_object._cache))

return ()

def _set_cache_(self, attr):

if attr == "_cache":

# Set the data when we need it

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

self._cache = tree_entries_from_data(ostream.read())

else:

super(Tree, self)._set_cache_(attr)

# END handle attribute

def _iter_convert_to_object(self, iterable):

"""Iterable yields tuples of (binsha, mode, name), which will be converted

to the respective object representation"""

for binsha, mode, name in iterable:

path = join_path(self.path, name)

try:

yield self._map_id_to_type[mode >> 12](self.repo, binsha, mode, path)

except KeyError as e:

raise TypeError("Unknown mode %o found in tree data for path '%s'" % (mode, path)) from e

# END for each item

def join(self, file):

"""Find the named object in this tree's contents

:return: ``git.Blob`` or ``git.Tree`` or ``git.Submodule``

:raise KeyError: if given file or tree does not exist in tree"""

msg = "Blob or Tree named %r not found"

if '/' in file:

tree = self

item = self

tokens = file.split('/')

for i, token in enumerate(tokens):

item = tree[token]

if item.type == 'tree':

tree = item

else:

# safety assertion - blobs are at the end of the path

if i != len(tokens) - 1:

raise KeyError(msg % file)

return item

# END handle item type

# END for each token of split path

if item == self:

raise KeyError(msg % file)

return item

else:

for info in self._cache:

if info[2] == file: # [2] == name

return self._map_id_to_type[info[1] >> 12](self.repo, info[0], info[1],

join_path(self.path, info[2]))

# END for each obj

raise KeyError(msg % file)

# END handle long paths

def __div__(self, file):

"""For PY2 only"""

return self.join(file)

def __truediv__(self, file):

"""For PY3 only"""

return self.join(file)

@property

def trees(self):

""":return: list(Tree, ...) list of trees directly below this tree"""

return [i for i in self if i.type == "tree"]

@property

def blobs(self):

""":return: list(Blob, ...) list of blobs directly below this tree"""

return [i for i in self if i.type == "blob"]

@property

def cache(self):

"""

:return: An object allowing to modify the internal cache. This can be used

to change the tree's contents. When done, make sure you call ``set_done``

on the tree modifier, or serialization behaviour will be incorrect.

See the ``TreeModifier`` for more information on how to alter the cache"""

return TreeModifier(self._cache)

def traverse(self, predicate=lambda i, d: True,

prune=lambda i, d: False, depth=-1, branch_first=True,

visit_once=False, ignore_self=1):

"""For documentation, see util.Traversable.traverse

Trees are set to visit_once = False to gain more performance in the traversal"""

return super(Tree, self).traverse(predicate, prune, depth, branch_first, visit_once, ignore_self)

# List protocol

def __getslice__(self, i, j):

return list(self._iter_convert_to_object(self._cache[i:j]))

def __iter__(self):

return self._iter_convert_to_object(self._cache)

def __len__(self):

return len(self._cache)

def __getitem__(self, item):

if isinstance(item, int):

info = self._cache[item]

return self._map_id_to_type[info[1] >> 12](self.repo, info[0], info[1], join_path(self.path, info[2]))

if isinstance(item, str):

# compatibility

return self.join(item)

# END index is basestring

raise TypeError("Invalid index type: %r" % item)

def __contains__(self, item):

if isinstance(item, IndexObject):

for info in self._cache:

if item.binsha == info[0]:

return True

# END compare sha

# END for each entry

# END handle item is index object

# compatibility

# treat item as repo-relative path

path = self.path

for info in self._cache:

if item == join_path(path, info[2]):

return True

# END for each item

return False

def __reversed__(self):

return reversed(self._iter_convert_to_object(self._cache))

def _serialize(self, stream):

"""Serialize this tree into the stream. Please note that we will assume

our tree data to be in a sorted state. If this is not the case, serialization

will not generate a correct tree representation as these are assumed to be sorted

by algorithms"""

tree_to_stream(self._cache, stream.write)

return self

def _deserialize(self, stream):

self._cache = tree_entries_from_data(stream.read())

return self

# END tree

# finalize map definition

Tree._map_id_to_type[Tree.tree_id] = Tree

#