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Diffstat (limited to 'lib/git/objects/util.py')
| -rw-r--r-- | lib/git/objects/util.py | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/lib/git/objects/util.py b/lib/git/objects/util.py new file mode 100644 index 00000000..fd648f09 --- /dev/null +++ b/lib/git/objects/util.py @@ -0,0 +1,365 @@ +# 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 +import platform + +from string import digits +import time +import os + +__all__ = ('get_object_type_by_name', 'get_user_id', 'parse_date', 'parse_actor_and_date', + 'ProcessStreamAdapter', 'Traversable', 'altz_to_utctz_str', 'utctz_to_altz', + 'verify_utctz') + +#{ Functions + +def mode_str_to_int(modestr): + """ + :param modestr: string like 755 or 644 or 100644 - only the last 6 chars will be used + :return: + String identifying a mode compatible to the mode methods ids of the + stat module regarding the rwx permissions for user, group and other, + special flags and file system flags, i.e. whether it is a symlink + for example.""" + mode = 0 + for iteration, char in enumerate(reversed(modestr[-6:])): + mode += int(char) << iteration*3 + # END for each char + return mode + +def get_object_type_by_name(object_type_name): + """ + :return: type suitable to handle the given object type name. + Use the type to create new instances. + + :param object_type_name: Member of TYPES + + :raise 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) + + +def get_user_id(): + """:return: string identifying the currently active system user as name@node + :note: user can be set with the 'USER' environment variable, usually set on windows""" + ukn = 'UNKNOWN' + username = os.environ.get('USER', ukn) + if username == ukn and hasattr(os, 'getlogin'): + username = os.getlogin() + # END get username from login + return "%s@%s" % (username, platform.node()) + + +def utctz_to_altz(utctz): + """we convert utctz to the timezone in seconds, it is the format time.altzone + returns. Git stores it as UTC timezon which has the opposite sign as well, + which explains the -1 * ( that was made explicit here ) + :param utctz: git utc timezone string, i.e. +0200""" + return -1 * int(float(utctz)/100*3600) + +def altz_to_utctz_str(altz): + """As above, but inverses the operation, returning a string that can be used + in commit objects""" + utci = -1 * int((altz / 3600)*100) + utcs = str(abs(utci)) + utcs = "0"*(4-len(utcs)) + utcs + prefix = (utci < 0 and '-') or '+' + return prefix + utcs + + +def verify_utctz(offset): + """:raise ValueError: if offset is incorrect + :return: offset""" + fmt_exc = ValueError("Invalid timezone offset format: %s" % offset) + if len(offset) != 5: + raise fmt_exc + if offset[0] not in "+-": + raise fmt_exc + if offset[1] not in digits or \ + offset[2] not in digits or \ + offset[3] not in digits or \ + offset[4] not in digits: + raise fmt_exc + # END for each char + return offset + +def parse_date(string_date): + """ + Parse the given date as one of the following + + * Git internal format: timestamp offset + * RFC 2822: Thu, 07 Apr 2005 22:13:13 +0200. + * ISO 8601 2005-04-07T22:13:13 + The T can be a space as well + + :return: Tuple(int(timestamp), int(offset)), both in seconds since epoch + :raise ValueError: If the format could not be understood + :note: Date can also be YYYY.MM.DD, MM/DD/YYYY and DD.MM.YYYY""" + # git time + try: + if string_date.count(' ') == 1 and string_date.rfind(':') == -1: + timestamp, offset = string_date.split() + timestamp = int(timestamp) + return timestamp, utctz_to_altz(verify_utctz(offset)) + else: + offset = "+0000" # local time by default + if string_date[-5] in '-+': + offset = verify_utctz(string_date[-5:]) + string_date = string_date[:-6] # skip space as well + # END split timezone info + + # now figure out the date and time portion - split time + date_formats = list() + splitter = -1 + if ',' in string_date: + date_formats.append("%a, %d %b %Y") + splitter = string_date.rfind(' ') + else: + # iso plus additional + date_formats.append("%Y-%m-%d") + date_formats.append("%Y.%m.%d") + date_formats.append("%m/%d/%Y") + date_formats.append("%d.%m.%Y") + + splitter = string_date.rfind('T') + if splitter == -1: + splitter = string_date.rfind(' ') + # END handle 'T' and ' ' + # END handle rfc or iso + + assert splitter > -1 + + # split date and time + time_part = string_date[splitter+1:] # skip space + date_part = string_date[:splitter] + + # parse time + tstruct = time.strptime(time_part, "%H:%M:%S") + + for fmt in date_formats: + try: + dtstruct = time.strptime(date_part, fmt) + fstruct = time.struct_time((dtstruct.tm_year, dtstruct.tm_mon, dtstruct.tm_mday, + tstruct.tm_hour, tstruct.tm_min, tstruct.tm_sec, + dtstruct.tm_wday, dtstruct.tm_yday, tstruct.tm_isdst)) + return int(time.mktime(fstruct)), utctz_to_altz(offset) + except ValueError: + continue + # END exception handling + # END for each fmt + + # still here ? fail + raise ValueError("no format matched") + # END handle format + except Exception: + raise ValueError("Unsupported date format: %s" % string_date) + # END handle exceptions + + +# 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 <tom@mojombo.com> 1191999972 -0700 + + :return: [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), utctz_to_altz(offset)) + + +#} END functions + + +#{ Classes + +class Actor(object): + """Actors hold information about a person acting on the repository. They + can be committers and authors or anything with a name and an email as + mentioned in the git log entries.""" + # precompiled regex + name_only_regex = re.compile( r'<(.+)>' ) + name_email_regex = re.compile( r'(.*) <(.+?)>' ) + + def __init__(self, name, email): + self.name = name + self.email = email + + def __eq__(self, other): + return self.name == other.name and self.email == other.email + + def __ne__(self, other): + return not (self == other) + + def __hash__(self): + return hash((self.name, self.email)) + + def __str__(self): + return self.name + + def __repr__(self): + return '<git.Actor "%s <%s>">' % (self.name, self.email) + + @classmethod + def _from_string(cls, string): + """Create an Actor from a string. + :param string: is the string, which is expected to be in regular git format + + John Doe <jdoe@example.com> + + :return: Actor """ + m = cls.name_email_regex.search(string) + if m: + name, email = m.groups() + return Actor(name, email) + else: + m = cls.name_only_regex.search(string) + if m: + return Actor(m.group(1), None) + else: + # assume best and use the whole string as name + return Actor(string, None) + # END special case name + # END handle name/email matching + + +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 ): + """:return: iterator yieling of items found when traversing self + + :param predicate: f(i,d) returns False if item i at depth d should not be included in the result + + :param prune: + f(i,d) return True if the search should stop at item i at depth d. + Item i will not be returned. + + :param 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 + + :param branch_first: + if True, items will be returned branch first, otherwise depth first + + :param visit_once: + if True, items will only be returned once, although they might be encountered + several times. Loops are prevented that way. + + :param 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 + + :param 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 + + +class Serializable(object): + """Defines methods to serialize and deserialize objects from and into a data stream""" + + def _serialize(self, stream): + """Serialize the data of this object into the given data stream + :note: a serialized object would ``_deserialize`` into the same objet + :param stream: a file-like object + :return: self""" + raise NotImplementedError("To be implemented in subclass") + + def _deserialize(self, stream): + """Deserialize all information regarding this object from the stream + :param stream: a file-like object + :return: self""" + raise NotImplementedError("To be implemented in subclass") |