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Diffstat (limited to 'gitdb/ref/symbolic.py')
| -rw-r--r-- | gitdb/ref/symbolic.py | 652 |
1 files changed, 0 insertions, 652 deletions
diff --git a/gitdb/ref/symbolic.py b/gitdb/ref/symbolic.py index 70cfc7d..8b13789 100644 --- a/gitdb/ref/symbolic.py +++ b/gitdb/ref/symbolic.py @@ -1,653 +1 @@ -import os -import re -from gitdb.object import ( - Object, - Commit - ) -from gitdb.util import ( - join_path, - join_path_native, - to_native_path_linux, - assure_directory_exists, - join, - dirname, - isdir, - exists, - isfile, - rename, - hex_to_bin, - LockedFD - ) - -from gitdb.exc import BadObject -from log import RefLog - -__all__ = ["SymbolicReference"] - -class SymbolicReference(object): - """Represents a special case of a reference such that this reference is symbolic. - It does not point to a specific commit, but to another Head, which itself - specifies a commit. - - A typical example for a symbolic reference is HEAD.""" - __slots__ = ("repo", "path") - - _resolve_ref_on_create = False - _points_to_commits_only = True - _common_path_default = "" - _id_attribute_ = "name" - - re_hexsha_only = re.compile('^[0-9A-Fa-f]{40}$') - - #{ Configuration - # Object class to be used when instantiating objects - ObjectCls = Object - CommitCls = Commit - - # all of the following are set by the package initializer - HEADCls = None - HeadCls = None - RemoteReferenceCls = None - TagReferenceCls = None - ReferenceCls = None - #}END configuration - - def __init__(self, repo, path): - self.repo = repo - self.path = path - - def __str__(self): - return self.path - - def __repr__(self): - return '<git.%s "%s">' % (self.__class__.__name__, self.path) - - def __eq__(self, other): - return self.path == other.path - - def __ne__(self, other): - return not ( self == other ) - - def __hash__(self): - return hash(self.path) - - @property - def name(self): - """ - :return: - In case of symbolic references, the shortest assumable name - is the path itself.""" - return self.path - - @property - def abspath(self): - return join_path_native(self.repo.git_path(), self.path) - - @classmethod - def _get_packed_refs_path(cls, repo): - return join(repo.git_path(), 'packed-refs') - - @classmethod - def _iter_packed_refs(cls, repo): - """Returns an iterator yielding pairs of sha1/path pairs for the corresponding refs. - :note: The packed refs file will be kept open as long as we iterate""" - try: - fp = open(cls._get_packed_refs_path(repo), 'r') - for line in fp: - line = line.strip() - if not line: - continue - if line.startswith('#'): - if line.startswith('# pack-refs with:') and not line.endswith('peeled'): - raise TypeError("PackingType of packed-Refs not understood: %r" % line) - # END abort if we do not understand the packing scheme - continue - # END parse comment - - # skip dereferenced tag object entries - previous line was actual - # tag reference for it - if line[0] == '^': - continue - - yield tuple(line.split(' ', 1)) - # END for each line - except (OSError,IOError): - raise StopIteration - # END no packed-refs file handling - # NOTE: Had try-finally block around here to close the fp, - # but some python version woudn't allow yields within that. - # I believe files are closing themselves on destruction, so it is - # alright. - - @classmethod - def dereference_recursive(cls, repo, ref_path): - """ - :return: hexsha stored in the reference at the given ref_path, recursively dereferencing all - intermediate references as required - :param repo: the repository containing the reference at ref_path""" - while True: - hexsha, ref_path = cls._get_ref_info(repo, ref_path) - if hexsha is not None: - return hexsha - # END recursive dereferencing - - @classmethod - def _get_ref_info(cls, repo, ref_path): - """Return: (sha, target_ref_path) if available, the sha the file at - rela_path points to, or None. target_ref_path is the reference we - point to, or None""" - tokens = None - try: - fp = open(join(repo.git_path(), ref_path), 'r') - value = fp.read().rstrip() - fp.close() - tokens = value.split(" ") - except (OSError,IOError): - # Probably we are just packed, find our entry in the packed refs file - # NOTE: We are not a symbolic ref if we are in a packed file, as these - # are excluded explictly - for sha, path in cls._iter_packed_refs(repo): - if path != ref_path: continue - tokens = (sha, path) - break - # END for each packed ref - # END handle packed refs - if tokens is None: - raise ValueError("Reference at %r does not exist" % ref_path) - - # is it a reference ? - if tokens[0] == 'ref:': - return (None, tokens[1]) - - # its a commit - if cls.re_hexsha_only.match(tokens[0]): - return (tokens[0], None) - - raise ValueError("Failed to parse reference information from %r" % ref_path) - - def _get_object_sha(self): - """ - :return: - The binary sha to the object our ref currently refers to. Refs can be cached, they will - always point to the actual object as it gets re-created on each query""" - return hex_to_bin(self.dereference_recursive(self.repo, self.path)) - - def _get_object(self): - """ - :return: - The object our ref currently refers to.""" - # have to be dynamic here as we may be a tag which can point to anything - # Our path will be resolved to the hexsha which will be used accordingly - return self.ObjectCls.new_from_sha(self.repo, self._get_object_sha()) - - def set_object(self, object_id, logmsg = None): - """Set the object we point to, possibly dereference our symbolic reference first. - If the reference does not exist, it will be created - - :param object: a reference specifier string, a SymbolicReference or an object hex sha. - SymbolicReferences will be dereferenced beforehand to obtain the object they point to - :param logmsg: If not None, the message will be used in the reflog entry to be - written. Otherwise the reflog is not altered - :note: plain SymbolicReferences may not actually point to objects by convention - :return: self""" - if isinstance(object_id, SymbolicReference): - object = object.object - #END resolve references - - is_detached = True - try: - is_detached = self.is_detached - except ValueError: - pass - # END handle non-existing ones - - if is_detached: - return self.set_reference(object_id, logmsg) - - # set the commit on our reference - return self._get_reference().set_object(object_id, logmsg) - - def _get_commit(self): - """ - :return: - Commit object we point to, works for detached and non-detached - SymbolicReferences. The symbolic reference will be dereferenced recursively.""" - obj = self._get_object() - if obj.type == 'tag': - obj = obj.object - #END dereference tag - - if obj.type != self.CommitCls.type: - raise TypeError("Symbolic Reference pointed to object %r, commit was required" % obj) - #END handle type - return obj - - def set_commit(self, commit, logmsg = None): - """As set_object, but restricts the type of object to be a Commit - - :raise ValueError: If commit is not a Commit object or doesn't point to - a commit - :return: self""" - # check the type - assume the best if it is a base-string - is_invalid_type = False - if isinstance(commit, self.ObjectCls): - is_invalid_type = commit.type != self.CommitCls.type - elif isinstance(commit, SymbolicReference): - is_invalid_type = commit.object.type != self.CommitCls.type - else: - try: - is_invalid_type = self.repo.resolve(commit).type != self.CommitCls.type - except BadObject: - raise ValueError("Invalid object: %s" % commit) - #END handle exception - # END verify type - - if is_invalid_type: - raise ValueError("Need commit, got %r" % commit) - #END handle raise - - # we leave strings to the rev-parse method below - self.set_object(commit, logmsg) - - return self - - - commit = property(_get_commit, set_commit, doc="Query or set commits directly") - object = property(_get_object, set_object, doc="Return the object our ref currently refers to") - object_binsha = property(_get_object_sha, set_object, doc="Return the object our ref currently refers to") - - def _get_reference(self): - """:return: Reference Object we point to - :raise TypeError: If this symbolic reference is detached, hence it doesn't point - to a reference, but to a commit""" - sha, target_ref_path = self._get_ref_info(self.repo, self.path) - if target_ref_path is None: - raise TypeError("%s is a detached symbolic reference as it points to %r" % (self, sha)) - return self.from_path(self.repo, target_ref_path) - - def set_reference(self, ref, logmsg = None): - """Set ourselves to the given ref. It will stay a symbol if the ref is a Reference. - Otherwise an Object, given as Object instance or refspec, is assumed and if valid, - will be set which effectively detaches the refererence if it was a purely - symbolic one. - - :param ref: SymbolicReference instance, hexadecimal sha string or refspec string - Only if the ref is a SymbolicRef instance, we will point to it. Everthiny - else is dereferenced to obtain the actual object. - :param logmsg: If set to a string, the message will be used in the reflog. - Otherwise, a reflog entry is not written for the changed reference. - The previous commit of the entry will be the commit we point to now. - - See also: log_append() - - :return: self - :note: This symbolic reference will not be dereferenced. For that, see - ``set_object(...)``""" - write_value = None - obj = None - if isinstance(ref, SymbolicReference): - write_value = "ref: %s" % ref.path - elif isinstance(ref, self.ObjectCls): - obj = ref - write_value = ref.hexsha - elif isinstance(ref, basestring): - try: - obj = self.repo.resolve(ref+"^{}") # optionally deref tags - write_value = obj.hexsha - except BadObject: - raise ValueError("Could not extract object from %s" % ref) - # END end try string - else: - raise ValueError("Unrecognized Value: %r" % ref) - # END try commit attribute - - # typecheck - if obj is not None and self._points_to_commits_only and obj.type != Commit.type: - raise TypeError("Require commit, got %r" % obj) - #END verify type - - oldbinsha = None - if logmsg is not None: - try: - oldbinsha = self.commit.binsha - except ValueError: - oldbinsha = Commit.NULL_BIN_SHA - #END handle non-existing - #END retrieve old hexsha - - fpath = self.abspath - assure_directory_exists(fpath, is_file=True) - - lfd = LockedFD(fpath) - fd = lfd.open(write=True, stream=True) - fd.write(write_value) - lfd.commit() - - # Adjust the reflog - if logmsg is not None: - self.log_append(oldbinsha, logmsg) - #END handle reflog - - return self - - - # aliased reference - reference = property(_get_reference, set_reference, doc="Returns the Reference we point to") - ref = reference - - def is_valid(self): - """ - :return: - True if the reference is valid, hence it can be read and points to - a valid object or reference.""" - try: - self.object - except (OSError, ValueError, BadObject): - return False - else: - return True - - @property - def is_detached(self): - """ - :return: - True if we are a detached reference, hence we point to a specific commit - instead to another reference""" - try: - self.ref - return False - except TypeError: - return True - - def log(self): - """ - :return: RefLog for this reference. Its last entry reflects the latest change - applied to this reference - - .. note:: As the log is parsed every time, its recommended to cache it for use - instead of calling this method repeatedly. It should be considered read-only.""" - return RefLog.from_file(RefLog.path(self)) - - def log_append(self, oldbinsha, message, newbinsha=None): - """Append a logentry to the logfile of this ref - - :param oldbinsha: binary sha this ref used to point to - :param message: A message describing the change - :param newbinsha: The sha the ref points to now. If None, our current commit sha - will be used - :return: added RefLogEntry instance""" - return RefLog.append_entry(self.repo.config_reader(), RefLog.path(self), oldbinsha, - (newbinsha is None and self.commit.binsha) or newbinsha, - message) - - def log_entry(self, index): - """:return: RefLogEntry at the given index - :param index: python list compatible positive or negative index - - .. note:: This method must read part of the reflog during execution, hence - it should be used sparringly, or only if you need just one index. - In that case, it will be faster than the ``log()`` method""" - return RefLog.entry_at(RefLog.path(self), index) - - @classmethod - def to_full_path(cls, path): - """ - :return: string with a full repository-relative path which can be used to initialize - a Reference instance, for instance by using ``Reference.from_path``""" - if isinstance(path, SymbolicReference): - path = path.path - full_ref_path = path - if not cls._common_path_default: - return full_ref_path - if not path.startswith(cls._common_path_default+"/"): - full_ref_path = '%s/%s' % (cls._common_path_default, path) - return full_ref_path - - @classmethod - def delete(cls, repo, path): - """Delete the reference at the given path - - :param repo: - Repository to delete the reference from - - :param path: - Short or full path pointing to the reference, i.e. refs/myreference - or just "myreference", hence 'refs/' is implied. - Alternatively the symbolic reference to be deleted""" - full_ref_path = cls.to_full_path(path) - abs_path = join(repo.git_path(), full_ref_path) - if exists(abs_path): - os.remove(abs_path) - else: - # check packed refs - pack_file_path = cls._get_packed_refs_path(repo) - try: - reader = open(pack_file_path) - except (OSError,IOError): - pass # it didnt exist at all - else: - new_lines = list() - made_change = False - dropped_last_line = False - for line in reader: - # keep line if it is a comment or if the ref to delete is not - # in the line - # If we deleted the last line and this one is a tag-reference object, - # we drop it as well - if ( line.startswith('#') or full_ref_path not in line ) and \ - ( not dropped_last_line or dropped_last_line and not line.startswith('^') ): - new_lines.append(line) - dropped_last_line = False - continue - # END skip comments and lines without our path - - # drop this line - made_change = True - dropped_last_line = True - # END for each line in packed refs - reader.close() - - # write the new lines - if made_change: - open(pack_file_path, 'w').writelines(new_lines) - # END open exception handling - # END handle deletion - - # delete the reflog - reflog_path = RefLog.path(cls(repo, full_ref_path)) - if os.path.isfile(reflog_path): - os.remove(reflog_path) - #END remove reflog - - - @classmethod - def _create(cls, repo, path, resolve, reference, force, logmsg=None): - """internal method used to create a new symbolic reference. - If resolve is False, the reference will be taken as is, creating - a proper symbolic reference. Otherwise it will be resolved to the - corresponding object and a detached symbolic reference will be created - instead""" - full_ref_path = cls.to_full_path(path) - abs_ref_path = join(repo.git_path(), full_ref_path) - - # figure out target data - target = reference - if resolve: - # could just use the resolve method, but it could be expensive - # so we handle most common cases ourselves - if isinstance(reference, cls.ObjectCls): - target = reference.hexsha - elif isinstance(reference, SymbolicReference): - target = reference.object.hexsha - else: - target = repo.resolve(str(reference)) - #END handle resoltion - #END need resolution - - if not force and isfile(abs_ref_path): - target_data = str(target) - if isinstance(target, SymbolicReference): - target_data = target.path - if not resolve: - target_data = "ref: " + target_data - existing_data = open(abs_ref_path, 'rb').read().strip() - if existing_data != target_data: - raise OSError("Reference at %r does already exist, pointing to %r, requested was %r" % (full_ref_path, existing_data, target_data)) - # END no force handling - - ref = cls(repo, full_ref_path) - ref.set_reference(target, logmsg) - return ref - - @classmethod - def create(cls, repo, path, reference='HEAD', force=False, logmsg=None): - """Create a new symbolic reference, hence a reference pointing to another reference. - - :param repo: - Repository to create the reference in - - :param path: - full path at which the new symbolic reference is supposed to be - created at, i.e. "NEW_HEAD" or "symrefs/my_new_symref" - - :param reference: - The reference to which the new symbolic reference should point to. - If it is a commit'ish, the symbolic ref will be detached. - - :param force: - if True, force creation even if a symbolic reference with that name already exists. - Raise OSError otherwise - - :param logmsg: - If not None, the message to append to the reflog. Otherwise no reflog - entry is written. - - :return: Newly created symbolic Reference - - :raise OSError: - If a (Symbolic)Reference with the same name but different contents - already exists. - - :note: This does not alter the current HEAD, index or Working Tree""" - return cls._create(repo, path, cls._resolve_ref_on_create, reference, force, logmsg) - - def rename(self, new_path, force=False): - """Rename self to a new path - - :param new_path: - Either a simple name or a full path, i.e. new_name or features/new_name. - The prefix refs/ is implied for references and will be set as needed. - In case this is a symbolic ref, there is no implied prefix - - :param force: - If True, the rename will succeed even if a head with the target name - already exists. It will be overwritten in that case - - :return: self - :raise OSError: In case a file at path but a different contents already exists """ - new_path = self.to_full_path(new_path) - if self.path == new_path: - return self - - new_abs_path = join(self.repo.git_path(), new_path) - cur_abs_path = join(self.repo.git_path(), self.path) - if isfile(new_abs_path): - if not force: - # if they point to the same file, its not an error - if open(new_abs_path,'rb').read().strip() != open(cur_abs_path,'rb').read().strip(): - raise OSError("File at path %r already exists" % new_abs_path) - # else: we could remove ourselves and use the otherone, but - # but clarity we just continue as usual - # END not force handling - os.remove(new_abs_path) - # END handle existing target file - - dname = dirname(new_abs_path) - if not isdir(dname): - os.makedirs(dname) - # END create directory - - rename(cur_abs_path, new_abs_path) - self.path = new_path - - return self - - @classmethod - def _iter_items(cls, repo, common_path = None): - if common_path is None: - common_path = cls._common_path_default - rela_paths = set() - - # walk loose refs - # Currently we do not follow links - for root, dirs, files in os.walk(join_path_native(repo.git_path(), common_path)): - if 'refs/' not in root: # skip non-refs subfolders - refs_id = [ i for i,d in enumerate(dirs) if d == 'refs' ] - if refs_id: - dirs[0:] = ['refs'] - # END prune non-refs folders - - for f in files: - abs_path = to_native_path_linux(join_path(root, f)) - rela_paths.add(abs_path.replace(to_native_path_linux(repo.git_path()) + '/', "")) - # END for each file in root directory - # END for each directory to walk - - # read packed refs - for sha, rela_path in cls._iter_packed_refs(repo): - if rela_path.startswith(common_path): - rela_paths.add(rela_path) - # END relative path matches common path - # END packed refs reading - - # return paths in sorted order - for path in sorted(rela_paths): - try: - yield cls.from_path(repo, path) - except ValueError: - continue - # END for each sorted relative refpath - - @classmethod - def iter_items(cls, repo, common_path = None): - """Find all refs in the repository - - :param repo: is the repo - - :param common_path: - Optional keyword argument to the path which is to be shared by all - returned Ref objects. - Defaults to class specific portion if None assuring that only - refs suitable for the actual class are returned. - - :return: - git.SymbolicReference[], each of them is guaranteed to be a *only* a symbolic - ref, or a derived class which is not detached - - List is lexigraphically sorted - The returned objects represent actual subclasses, such as Head or TagReference""" - return ( r for r in cls._iter_items(repo, common_path) if r.__class__ == cls or not r.is_detached ) - - @classmethod - def from_path(cls, repo, path): - """ - :param path: full .git-directory-relative path name to the Reference to instantiate - :note: use to_full_path() if you only have a partial path of a known Reference Type - :return: - Instance of type Reference, Head, or Tag - depending on the given path""" - if not path: - raise ValueError("Cannot create Reference from %r" % path) - - for ref_type in (cls.HEADCls, cls.HeadCls, cls.RemoteReferenceCls, cls.TagReferenceCls, cls.ReferenceCls, cls): - try: - instance = ref_type(repo, path) - if instance.__class__ == SymbolicReference and instance.is_detached: - raise ValueError("SymbolRef was detached, we drop it") - return instance - except ValueError: - pass - # END exception handling - # END for each type to try - raise ValueError("Could not find reference type suitable to handle path %r" % path) |