# util.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
"""
Module for general utility functions
"""
import re
from collections import deque as Deque
from git.actor import Actor
def get_object_type_by_name(object_type_name):
"""
Returns
type suitable to handle the given object type name.
Use the type to create new instances.
``object_type_name``
Member of TYPES
Raises
ValueError: In case object_type_name is unknown
"""
if object_type_name == "commit":
import commit
return commit.Commit
elif object_type_name == "tag":
import tag
return tag.TagObject
elif object_type_name == "blob":
import blob
return blob.Blob
elif object_type_name == "tree":
import tree
return tree.Tree
else:
raise ValueError("Cannot handle unknown object type: %s" % object_type_name)
# precompiled regex
_re_actor_epoch = re.compile(r'^.+? (.*) (\d+) ([+-]\d+).*$')
def parse_actor_and_date(line):
"""
Parse out the actor (author or committer) info from a line like::
author Tom Preston-Werner 1191999972 -0700
Returns
[Actor, int_seconds_since_epoch, int_timezone_offset]
"""
m = _re_actor_epoch.search(line)
actor, epoch, offset = m.groups()
return (Actor._from_string(actor), int(epoch), -int(float(offset)/100*3600))
class ProcessStreamAdapter(object):
"""
Class wireing all calls to the contained Process instance.
Use this type to hide the underlying process to provide access only to a specified
stream. The process is usually wrapped into an AutoInterrupt class to kill
it if the instance goes out of scope.
"""
__slots__ = ("_proc", "_stream")
def __init__(self, process, stream_name):
self._proc = process
self._stream = getattr(process, stream_name)
def __getattr__(self, attr):
return getattr(self._stream, attr)
class Traversable(object):
"""Simple interface to perforam depth-first or breadth-first traversals
into one direction.
Subclasses only need to implement one function.
Instances of the Subclass must be hashable"""
__slots__ = tuple()
@classmethod
def _get_intermediate_items(cls, item):
"""
Returns:
List of items connected to the given item.
Must be implemented in subclass
"""
raise NotImplementedError("To be implemented in subclass")
def traverse( self, predicate = lambda i,d: True,
prune = lambda i,d: False, depth = -1, branch_first=True,
visit_once = True, ignore_self=1, as_edge = False ):
"""
``Returns``
iterator yieling of items found when traversing self
``predicate``
f(i,d) returns False if item i at depth d should not be included in the result
``prune``
f(i,d) return True if the search should stop at item i at depth d.
Item i will not be returned.
``depth``
define at which level the iteration should not go deeper
if -1, there is no limit
if 0, you would effectively only get self, the root of the iteration
i.e. if 1, you would only get the first level of predessessors/successors
``branch_first``
if True, items will be returned branch first, otherwise depth first
``visit_once``
if True, items will only be returned once, although they might be encountered
several times. Loops are prevented that way.
``ignore_self``
if True, self will be ignored and automatically pruned from
the result. Otherwise it will be the first item to be returned.
If as_edge is True, the source of the first edge is None
``as_edge``
if True, return a pair of items, first being the source, second the
destinatination, i.e. tuple(src, dest) with the edge spanning from
source to destination"""
visited = set()
stack = Deque()
stack.append( ( 0 ,self, None ) ) # self is always depth level 0
def addToStack( stack, item, branch_first, depth ):
lst = self._get_intermediate_items( item )
if not lst:
return
if branch_first:
stack.extendleft( ( depth , i, item ) for i in lst )
else:
reviter = ( ( depth , lst[i], item ) for i in range( len( lst )-1,-1,-1) )
stack.extend( reviter )
# END addToStack local method
while stack:
d, item, src = stack.pop() # depth of item, item, item_source
if visit_once and item in visited:
continue
if visit_once:
visited.add(item)
rval = ( as_edge and (src, item) ) or item
if prune( rval, d ):
continue
skipStartItem = ignore_self and ( item == self )
if not skipStartItem and predicate( rval, d ):
yield rval
# only continue to next level if this is appropriate !
nd = d + 1
if depth > -1 and nd > depth:
continue
addToStack( stack, item, branch_first, nd )
# END for each item on work stack