# obsolete.py - obsolete markers handling # # Copyright 2012 Pierre-Yves David # Logilab SA # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """Obsolete marker handling An obsolete marker maps an old changeset to a list of new changesets. If the list of new changesets is empty, the old changeset is said to be "killed". Otherwise, the old changeset is being "replaced" by the new changesets. Obsolete markers can be used to record and distribute changeset graph transformations performed by history rewrite operations, and help building new tools to reconcile conflicting rewrite actions. To facilitate conflict resolution, markers include various annotations besides old and news changeset identifiers, such as creation date or author name. The old obsoleted changeset is called a "precursor" and possible replacements are called "successors". Markers that used changeset X as a precursor are called "successor markers of X" because they hold information about the successors of X. Markers that use changeset Y as a successors are call "precursor markers of Y" because they hold information about the precursors of Y. Examples: - When changeset A is replaced by changeset A', one marker is stored: (A, (A',)) - When changesets A and B are folded into a new changeset C, two markers are stored: (A, (C,)) and (B, (C,)) - When changeset A is simply "pruned" from the graph, a marker is created: (A, ()) - When changeset A is split into B and C, a single marker are used: (A, (C, C)) We use a single marker to distinguish the "split" case from the "divergence" case. If two independent operations rewrite the same changeset A in to A' and A'', we have an error case: divergent rewriting. We can detect it because two markers will be created independently: (A, (B,)) and (A, (C,)) Format ------ Markers are stored in an append-only file stored in '.hg/store/obsstore'. The file starts with a version header: - 1 unsigned byte: version number, starting at zero. The header is followed by the markers. Marker format depend of the version. See comment associated with each format for details. """ import struct import util, base85, node, parsers import phases from i18n import _ _pack = struct.pack _unpack = struct.unpack _calcsize = struct.calcsize propertycache = util.propertycache # the obsolete feature is not mature enough to be enabled by default. # you have to rely on third party extension extension to enable this. _enabled = False # Options for obsolescence createmarkersopt = 'createmarkers' allowunstableopt = 'allowunstable' exchangeopt = 'exchange' ### obsolescence marker flag ## bumpedfix flag # # When a changeset A' succeed to a changeset A which became public, we call A' # "bumped" because it's a successors of a public changesets # # o A' (bumped) # |`: # | o A # |/ # o Z # # The way to solve this situation is to create a new changeset Ad as children # of A. This changeset have the same content than A'. So the diff from A to A' # is the same than the diff from A to Ad. Ad is marked as a successors of A' # # o Ad # |`: # | x A' # |'| # o | A # |/ # o Z # # But by transitivity Ad is also a successors of A. To avoid having Ad marked # as bumped too, we add the `bumpedfix` flag to the marker. . # This flag mean that the successors express the changes between the public and # bumped version and fix the situation, breaking the transitivity of # "bumped" here. bumpedfix = 1 usingsha256 = 2 ## Parsing and writing of version "0" # # The header is followed by the markers. Each marker is made of: # # - 1 uint8 : number of new changesets "N", can be zero. # # - 1 uint32: metadata size "M" in bytes. # # - 1 byte: a bit field. It is reserved for flags used in common # obsolete marker operations, to avoid repeated decoding of metadata # entries. # # - 20 bytes: obsoleted changeset identifier. # # - N*20 bytes: new changesets identifiers. # # - M bytes: metadata as a sequence of nul-terminated strings. Each # string contains a key and a value, separated by a colon ':', without # additional encoding. Keys cannot contain '\0' or ':' and values # cannot contain '\0'. _fm0version = 0 _fm0fixed = '>BIB20s' _fm0node = '20s' _fm0fsize = _calcsize(_fm0fixed) _fm0fnodesize = _calcsize(_fm0node) def _fm0readmarkers(data, off): # Loop on markers l = len(data) while off + _fm0fsize <= l: # read fixed part cur = data[off:off + _fm0fsize] off += _fm0fsize numsuc, mdsize, flags, pre = _unpack(_fm0fixed, cur) # read replacement sucs = () if numsuc: s = (_fm0fnodesize * numsuc) cur = data[off:off + s] sucs = _unpack(_fm0node * numsuc, cur) off += s # read metadata # (metadata will be decoded on demand) metadata = data[off:off + mdsize] if len(metadata) != mdsize: raise util.Abort(_('parsing obsolete marker: metadata is too ' 'short, %d bytes expected, got %d') % (mdsize, len(metadata))) off += mdsize metadata = _fm0decodemeta(metadata) try: when, offset = metadata.pop('date', '0 0').split(' ') date = float(when), int(offset) except ValueError: date = (0., 0) parents = None if 'p2' in metadata: parents = (metadata.pop('p1', None), metadata.pop('p2', None)) elif 'p1' in metadata: parents = (metadata.pop('p1', None),) elif 'p0' in metadata: parents = () if parents is not None: try: parents = tuple(node.bin(p) for p in parents) # if parent content is not a nodeid, drop the data for p in parents: if len(p) != 20: parents = None break except TypeError: # if content cannot be translated to nodeid drop the data. parents = None metadata = tuple(sorted(metadata.iteritems())) yield (pre, sucs, flags, metadata, date, parents) def _fm0encodeonemarker(marker): pre, sucs, flags, metadata, date, parents = marker if flags & usingsha256: raise util.Abort(_('cannot handle sha256 with old obsstore format')) metadata = dict(metadata) time, tz = date metadata['date'] = '%r %i' % (time, tz) if parents is not None: if not parents: # mark that we explicitly recorded no parents metadata['p0'] = '' for i, p in enumerate(parents): metadata['p%i' % (i + 1)] = node.hex(p) metadata = _fm0encodemeta(metadata) numsuc = len(sucs) format = _fm0fixed + (_fm0node * numsuc) data = [numsuc, len(metadata), flags, pre] data.extend(sucs) return _pack(format, *data) + metadata def _fm0encodemeta(meta): """Return encoded metadata string to string mapping. Assume no ':' in key and no '\0' in both key and value.""" for key, value in meta.iteritems(): if ':' in key or '\0' in key: raise ValueError("':' and '\0' are forbidden in metadata key'") if '\0' in value: raise ValueError("':' is forbidden in metadata value'") return '\0'.join(['%s:%s' % (k, meta[k]) for k in sorted(meta)]) def _fm0decodemeta(data): """Return string to string dictionary from encoded version.""" d = {} for l in data.split('\0'): if l: key, value = l.split(':') d[key] = value return d ## Parsing and writing of version "1" # # The header is followed by the markers. Each marker is made of: # # - uint32: total size of the marker (including this field) # # - float64: date in seconds since epoch # # - int16: timezone offset in minutes # # - uint16: a bit field. It is reserved for flags used in common # obsolete marker operations, to avoid repeated decoding of metadata # entries. # # - uint8: number of successors "N", can be zero. # # - uint8: number of parents "P", can be zero. # # 0: parents data stored but no parent, # 1: one parent stored, # 2: two parents stored, # 3: no parent data stored # # - uint8: number of metadata entries M # # - 20 or 32 bytes: precursor changeset identifier. # # - N*(20 or 32) bytes: successors changesets identifiers. # # - P*(20 or 32) bytes: parents of the precursors changesets. # # - M*(uint8, uint8): size of all metadata entries (key and value) # # - remaining bytes: the metadata, each (key, value) pair after the other. _fm1version = 1 _fm1fixed = '>IdhHBBB20s' _fm1nodesha1 = '20s' _fm1nodesha256 = '32s' _fm1nodesha1size = _calcsize(_fm1nodesha1) _fm1nodesha256size = _calcsize(_fm1nodesha256) _fm1fsize = _calcsize(_fm1fixed) _fm1parentnone = 3 _fm1parentshift = 14 _fm1parentmask = (_fm1parentnone << _fm1parentshift) _fm1metapair = 'BB' _fm1metapairsize = _calcsize('BB') def _fm1purereadmarkers(data, off): # make some global constants local for performance noneflag = _fm1parentnone sha2flag = usingsha256 sha1size = _fm1nodesha1size sha2size = _fm1nodesha256size sha1fmt = _fm1nodesha1 sha2fmt = _fm1nodesha256 metasize = _fm1metapairsize metafmt = _fm1metapair fsize = _fm1fsize unpack = _unpack # Loop on markers stop = len(data) - _fm1fsize ufixed = struct.Struct(_fm1fixed).unpack while off <= stop: # read fixed part o1 = off + fsize t, secs, tz, flags, numsuc, numpar, nummeta, prec = ufixed(data[off:o1]) if flags & sha2flag: # FIXME: prec was read as a SHA1, needs to be amended # read 0 or more successors if numsuc == 1: o2 = o1 + sha2size sucs = (data[o1:o2],) else: o2 = o1 + sha2size * numsuc sucs = unpack(sha2fmt * numsuc, data[o1:o2]) # read parents if numpar == noneflag: o3 = o2 parents = None elif numpar == 1: o3 = o2 + sha2size parents = (data[o2:o3],) else: o3 = o2 + sha2size * numpar parents = unpack(sha2fmt * numpar, data[o2:o3]) else: # read 0 or more successors if numsuc == 1: o2 = o1 + sha1size sucs = (data[o1:o2],) else: o2 = o1 + sha1size * numsuc sucs = unpack(sha1fmt * numsuc, data[o1:o2]) # read parents if numpar == noneflag: o3 = o2 parents = None elif numpar == 1: o3 = o2 + sha1size parents = (data[o2:o3],) else: o3 = o2 + sha1size * numpar parents = unpack(sha1fmt * numpar, data[o2:o3]) # read metadata off = o3 + metasize * nummeta metapairsize = unpack('>' + (metafmt * nummeta), data[o3:off]) metadata = [] for idx in xrange(0, len(metapairsize), 2): o1 = off + metapairsize[idx] o2 = o1 + metapairsize[idx + 1] metadata.append((data[off:o1], data[o1:o2])) off = o2 yield (prec, sucs, flags, tuple(metadata), (secs, tz * 60), parents) def _fm1encodeonemarker(marker): pre, sucs, flags, metadata, date, parents = marker # determine node size _fm1node = _fm1nodesha1 if flags & usingsha256: _fm1node = _fm1nodesha256 numsuc = len(sucs) numextranodes = numsuc if parents is None: numpar = _fm1parentnone else: numpar = len(parents) numextranodes += numpar formatnodes = _fm1node * numextranodes formatmeta = _fm1metapair * len(metadata) format = _fm1fixed + formatnodes + formatmeta # tz is stored in minutes so we divide by 60 tz = date[1]//60 data = [None, date[0], tz, flags, numsuc, numpar, len(metadata), pre] data.extend(sucs) if parents is not None: data.extend(parents) totalsize = _calcsize(format) for key, value in metadata: lk = len(key) lv = len(value) data.append(lk) data.append(lv) totalsize += lk + lv data[0] = totalsize data = [_pack(format, *data)] for key, value in metadata: data.append(key) data.append(value) return ''.join(data) def _fm1readmarkers(data, off): native = getattr(parsers, 'fm1readmarkers', None) if not native: return _fm1purereadmarkers(data, off) stop = len(data) - _fm1fsize return native(data, off, stop) # mapping to read/write various marker formats # -> (decoder, encoder) formats = {_fm0version: (_fm0readmarkers, _fm0encodeonemarker), _fm1version: (_fm1readmarkers, _fm1encodeonemarker)} @util.nogc def _readmarkers(data): """Read and enumerate markers from raw data""" off = 0 diskversion = _unpack('>B', data[off:off + 1])[0] off += 1 if diskversion not in formats: raise util.Abort(_('parsing obsolete marker: unknown version %r') % diskversion) return diskversion, formats[diskversion][0](data, off) def encodemarkers(markers, addheader=False, version=_fm0version): # Kept separate from flushmarkers(), it will be reused for # markers exchange. encodeone = formats[version][1] if addheader: yield _pack('>B', version) for marker in markers: yield encodeone(marker) class marker(object): """Wrap obsolete marker raw data""" def __init__(self, repo, data): # the repo argument will be used to create changectx in later version self._repo = repo self._data = data self._decodedmeta = None def __hash__(self): return hash(self._data) def __eq__(self, other): if type(other) != type(self): return False return self._data == other._data def precnode(self): """Precursor changeset node identifier""" return self._data[0] def succnodes(self): """List of successor changesets node identifiers""" return self._data[1] def parentnodes(self): """Parents of the precursors (None if not recorded)""" return self._data[5] def metadata(self): """Decoded metadata dictionary""" return dict(self._data[3]) def date(self): """Creation date as (unixtime, offset)""" return self._data[4] def flags(self): """The flags field of the marker""" return self._data[2] @util.nogc def _addsuccessors(successors, markers): for mark in markers: successors.setdefault(mark[0], set()).add(mark) @util.nogc def _addprecursors(precursors, markers): for mark in markers: for suc in mark[1]: precursors.setdefault(suc, set()).add(mark) @util.nogc def _addchildren(children, markers): for mark in markers: parents = mark[5] if parents is not None: for p in parents: children.setdefault(p, set()).add(mark) def _checkinvalidmarkers(markers): """search for marker with invalid data and raise error if needed Exist as a separated function to allow the evolve extension for a more subtle handling. """ for mark in markers: if node.nullid in mark[1]: raise util.Abort(_('bad obsolescence marker detected: ' 'invalid successors nullid')) class obsstore(object): """Store obsolete markers Markers can be accessed with two mappings: - precursors[x] -> set(markers on precursors edges of x) - successors[x] -> set(markers on successors edges of x) - children[x] -> set(markers on precursors edges of children(x) """ fields = ('prec', 'succs', 'flag', 'meta', 'date', 'parents') # prec: nodeid, precursor changesets # succs: tuple of nodeid, successor changesets (0-N length) # flag: integer, flag field carrying modifier for the markers (see doc) # meta: binary blob, encoded metadata dictionary # date: (float, int) tuple, date of marker creation # parents: (tuple of nodeid) or None, parents of precursors # None is used when no data has been recorded def __init__(self, svfs, defaultformat=_fm1version, readonly=False): # caches for various obsolescence related cache self.caches = {} self._all = [] self.svfs = svfs data = svfs.tryread('obsstore') self._version = defaultformat self._readonly = readonly if data: self._version, markers = _readmarkers(data) self._addmarkers(markers) def __iter__(self): return iter(self._all) def __len__(self): return len(self._all) def __nonzero__(self): return bool(self._all) def create(self, transaction, prec, succs=(), flag=0, parents=None, date=None, metadata=None): """obsolete: add a new obsolete marker * ensuring it is hashable * check mandatory metadata * encode metadata If you are a human writing code creating marker you want to use the `createmarkers` function in this module instead. return True if a new marker have been added, False if the markers already existed (no op). """ if metadata is None: metadata = {} if date is None: if 'date' in metadata: # as a courtesy for out-of-tree extensions date = util.parsedate(metadata.pop('date')) else: date = util.makedate() if len(prec) != 20: raise ValueError(prec) for succ in succs: if len(succ) != 20: raise ValueError(succ) if prec in succs: raise ValueError(_('in-marker cycle with %s') % node.hex(prec)) metadata = tuple(sorted(metadata.iteritems())) marker = (str(prec), tuple(succs), int(flag), metadata, date, parents) return bool(self.add(transaction, [marker])) def add(self, transaction, markers): """Add new markers to the store Take care of filtering duplicate. Return the number of new marker.""" if self._readonly: raise util.Abort('creating obsolete markers is not enabled on this ' 'repo') known = set(self._all) new = [] for m in markers: if m not in known: known.add(m) new.append(m) if new: f = self.svfs('obsstore', 'ab') try: offset = f.tell() transaction.add('obsstore', offset) # offset == 0: new file - add the version header for bytes in encodemarkers(new, offset == 0, self._version): f.write(bytes) finally: # XXX: f.close() == filecache invalidation == obsstore rebuilt. # call 'filecacheentry.refresh()' here f.close() self._addmarkers(new) # new marker *may* have changed several set. invalidate the cache. self.caches.clear() # records the number of new markers for the transaction hooks previous = int(transaction.hookargs.get('new_obsmarkers', '0')) transaction.hookargs['new_obsmarkers'] = str(previous + len(new)) return len(new) def mergemarkers(self, transaction, data): """merge a binary stream of markers inside the obsstore Returns the number of new markers added.""" version, markers = _readmarkers(data) return self.add(transaction, markers) @propertycache def successors(self): successors = {} _addsuccessors(successors, self._all) return successors @propertycache def precursors(self): precursors = {} _addprecursors(precursors, self._all) return precursors @propertycache def children(self): children = {} _addchildren(children, self._all) return children def _cached(self, attr): return attr in self.__dict__ def _addmarkers(self, markers): markers = list(markers) # to allow repeated iteration self._all.extend(markers) if self._cached('successors'): _addsuccessors(self.successors, markers) if self._cached('precursors'): _addprecursors(self.precursors, markers) if self._cached('children'): _addchildren(self.children, markers) _checkinvalidmarkers(markers) def relevantmarkers(self, nodes): """return a set of all obsolescence markers relevant to a set of nodes. "relevant" to a set of nodes mean: - marker that use this changeset as successor - prune marker of direct children on this changeset - recursive application of the two rules on precursors of these markers It is a set so you cannot rely on order.""" pendingnodes = set(nodes) seenmarkers = set() seennodes = set(pendingnodes) precursorsmarkers = self.precursors children = self.children while pendingnodes: direct = set() for current in pendingnodes: direct.update(precursorsmarkers.get(current, ())) pruned = [m for m in children.get(current, ()) if not m[1]] direct.update(pruned) direct -= seenmarkers pendingnodes = set([m[0] for m in direct]) seenmarkers |= direct pendingnodes -= seennodes seennodes |= pendingnodes return seenmarkers def commonversion(versions): """Return the newest version listed in both versions and our local formats. Returns None if no common version exists. """ versions.sort(reverse=True) # search for highest version known on both side for v in versions: if v in formats: return v return None # arbitrary picked to fit into 8K limit from HTTP server # you have to take in account: # - the version header # - the base85 encoding _maxpayload = 5300 def _pushkeyescape(markers): """encode markers into a dict suitable for pushkey exchange - binary data is base85 encoded - split in chunks smaller than 5300 bytes""" keys = {} parts = [] currentlen = _maxpayload * 2 # ensure we create a new part for marker in markers: nextdata = _fm0encodeonemarker(marker) if (len(nextdata) + currentlen > _maxpayload): currentpart = [] currentlen = 0 parts.append(currentpart) currentpart.append(nextdata) currentlen += len(nextdata) for idx, part in enumerate(reversed(parts)): data = ''.join([_pack('>B', _fm0version)] + part) keys['dump%i' % idx] = base85.b85encode(data) return keys def listmarkers(repo): """List markers over pushkey""" if not repo.obsstore: return {} return _pushkeyescape(sorted(repo.obsstore)) def pushmarker(repo, key, old, new): """Push markers over pushkey""" if not key.startswith('dump'): repo.ui.warn(_('unknown key: %r') % key) return 0 if old: repo.ui.warn(_('unexpected old value for %r') % key) return 0 data = base85.b85decode(new) lock = repo.lock() try: tr = repo.transaction('pushkey: obsolete markers') try: repo.obsstore.mergemarkers(tr, data) tr.close() return 1 finally: tr.release() finally: lock.release() def getmarkers(repo, nodes=None): """returns markers known in a repository If is specified, only markers "relevant" to those nodes are are returned""" if nodes is None: rawmarkers = repo.obsstore else: rawmarkers = repo.obsstore.relevantmarkers(nodes) for markerdata in rawmarkers: yield marker(repo, markerdata) def relevantmarkers(repo, node): """all obsolete markers relevant to some revision""" for markerdata in repo.obsstore.relevantmarkers(node): yield marker(repo, markerdata) def precursormarkers(ctx): """obsolete marker marking this changeset as a successors""" for data in ctx.repo().obsstore.precursors.get(ctx.node(), ()): yield marker(ctx.repo(), data) def successormarkers(ctx): """obsolete marker making this changeset obsolete""" for data in ctx.repo().obsstore.successors.get(ctx.node(), ()): yield marker(ctx.repo(), data) def allsuccessors(obsstore, nodes, ignoreflags=0): """Yield node for every successor of . Some successors may be unknown locally. This is a linear yield unsuited to detecting split changesets. It includes initial nodes too.""" remaining = set(nodes) seen = set(remaining) while remaining: current = remaining.pop() yield current for mark in obsstore.successors.get(current, ()): # ignore marker flagged with specified flag if mark[2] & ignoreflags: continue for suc in mark[1]: if suc not in seen: seen.add(suc) remaining.add(suc) def allprecursors(obsstore, nodes, ignoreflags=0): """Yield node for every precursors of . Some precursors may be unknown locally. This is a linear yield unsuited to detecting folded changesets. It includes initial nodes too.""" remaining = set(nodes) seen = set(remaining) while remaining: current = remaining.pop() yield current for mark in obsstore.precursors.get(current, ()): # ignore marker flagged with specified flag if mark[2] & ignoreflags: continue suc = mark[0] if suc not in seen: seen.add(suc) remaining.add(suc) def foreground(repo, nodes): """return all nodes in the "foreground" of other node The foreground of a revision is anything reachable using parent -> children or precursor -> successor relation. It is very similar to "descendant" but augmented with obsolescence information. Beware that possible obsolescence cycle may result if complex situation. """ repo = repo.unfiltered() foreground = set(repo.set('%ln::', nodes)) if repo.obsstore: # We only need this complicated logic if there is obsolescence # XXX will probably deserve an optimised revset. nm = repo.changelog.nodemap plen = -1 # compute the whole set of successors or descendants while len(foreground) != plen: plen = len(foreground) succs = set(c.node() for c in foreground) mutable = [c.node() for c in foreground if c.mutable()] succs.update(allsuccessors(repo.obsstore, mutable)) known = (n for n in succs if n in nm) foreground = set(repo.set('%ln::', known)) return set(c.node() for c in foreground) def successorssets(repo, initialnode, cache=None): """Return all set of successors of initial nodes The successors set of a changeset A are a group of revisions that succeed A. It succeeds A as a consistent whole, each revision being only a partial replacement. The successors set contains non-obsolete changesets only. This function returns the full list of successor sets which is why it returns a list of tuples and not just a single tuple. Each tuple is a valid successors set. Not that (A,) may be a valid successors set for changeset A (see below). In most cases, a changeset A will have a single element (e.g. the changeset A is replaced by A') in its successors set. Though, it is also common for a changeset A to have no elements in its successor set (e.g. the changeset has been pruned). Therefore, the returned list of successors sets will be [(A',)] or [], respectively. When a changeset A is split into A' and B', however, it will result in a successors set containing more than a single element, i.e. [(A',B')]. Divergent changesets will result in multiple successors sets, i.e. [(A',), (A'')]. If a changeset A is not obsolete, then it will conceptually have no successors set. To distinguish this from a pruned changeset, the successor set will only contain itself, i.e. [(A,)]. Finally, successors unknown locally are considered to be pruned (obsoleted without any successors). The optional `cache` parameter is a dictionary that may contain precomputed successors sets. It is meant to reuse the computation of a previous call to `successorssets` when multiple calls are made at the same time. The cache dictionary is updated in place. The caller is responsible for its live spawn. Code that makes multiple calls to `successorssets` *must* use this cache mechanism or suffer terrible performances. """ succmarkers = repo.obsstore.successors # Stack of nodes we search successors sets for toproceed = [initialnode] # set version of above list for fast loop detection # element added to "toproceed" must be added here stackedset = set(toproceed) if cache is None: cache = {} # This while loop is the flattened version of a recursive search for # successors sets # # def successorssets(x): # successors = directsuccessors(x) # ss = [[]] # for succ in directsuccessors(x): # # product as in itertools cartesian product # ss = product(ss, successorssets(succ)) # return ss # # But we can not use plain recursive calls here: # - that would blow the python call stack # - obsolescence markers may have cycles, we need to handle them. # # The `toproceed` list act as our call stack. Every node we search # successors set for are stacked there. # # The `stackedset` is set version of this stack used to check if a node is # already stacked. This check is used to detect cycles and prevent infinite # loop. # # successors set of all nodes are stored in the `cache` dictionary. # # After this while loop ends we use the cache to return the successors sets # for the node requested by the caller. while toproceed: # Every iteration tries to compute the successors sets of the topmost # node of the stack: CURRENT. # # There are four possible outcomes: # # 1) We already know the successors sets of CURRENT: # -> mission accomplished, pop it from the stack. # 2) Node is not obsolete: # -> the node is its own successors sets. Add it to the cache. # 3) We do not know successors set of direct successors of CURRENT: # -> We add those successors to the stack. # 4) We know successors sets of all direct successors of CURRENT: # -> We can compute CURRENT successors set and add it to the # cache. # current = toproceed[-1] if current in cache: # case (1): We already know the successors sets stackedset.remove(toproceed.pop()) elif current not in succmarkers: # case (2): The node is not obsolete. if current in repo: # We have a valid last successors. cache[current] = [(current,)] else: # Final obsolete version is unknown locally. # Do not count that as a valid successors cache[current] = [] else: # cases (3) and (4) # # We proceed in two phases. Phase 1 aims to distinguish case (3) # from case (4): # # For each direct successors of CURRENT, we check whether its # successors sets are known. If they are not, we stack the # unknown node and proceed to the next iteration of the while # loop. (case 3) # # During this step, we may detect obsolescence cycles: a node # with unknown successors sets but already in the call stack. # In such a situation, we arbitrary set the successors sets of # the node to nothing (node pruned) to break the cycle. # # If no break was encountered we proceed to phase 2. # # Phase 2 computes successors sets of CURRENT (case 4); see details # in phase 2 itself. # # Note the two levels of iteration in each phase. # - The first one handles obsolescence markers using CURRENT as # precursor (successors markers of CURRENT). # # Having multiple entry here means divergence. # # - The second one handles successors defined in each marker. # # Having none means pruned node, multiple successors means split, # single successors are standard replacement. # for mark in sorted(succmarkers[current]): for suc in mark[1]: if suc not in cache: if suc in stackedset: # cycle breaking cache[suc] = [] else: # case (3) If we have not computed successors sets # of one of those successors we add it to the # `toproceed` stack and stop all work for this # iteration. toproceed.append(suc) stackedset.add(suc) break else: continue break else: # case (4): we know all successors sets of all direct # successors # # Successors set contributed by each marker depends on the # successors sets of all its "successors" node. # # Each different marker is a divergence in the obsolescence # history. It contributes successors sets distinct from other # markers. # # Within a marker, a successor may have divergent successors # sets. In such a case, the marker will contribute multiple # divergent successors sets. If multiple successors have # divergent successors sets, a Cartesian product is used. # # At the end we post-process successors sets to remove # duplicated entry and successors set that are strict subset of # another one. succssets = [] for mark in sorted(succmarkers[current]): # successors sets contributed by this marker markss = [[]] for suc in mark[1]: # cardinal product with previous successors productresult = [] for prefix in markss: for suffix in cache[suc]: newss = list(prefix) for part in suffix: # do not duplicated entry in successors set # first entry wins. if part not in newss: newss.append(part) productresult.append(newss) markss = productresult succssets.extend(markss) # remove duplicated and subset seen = [] final = [] candidate = sorted(((set(s), s) for s in succssets if s), key=lambda x: len(x[1]), reverse=True) for setversion, listversion in candidate: for seenset in seen: if setversion.issubset(seenset): break else: final.append(listversion) seen.append(setversion) final.reverse() # put small successors set first cache[current] = final return cache[initialnode] def _knownrevs(repo, nodes): """yield revision numbers of known nodes passed in parameters Unknown revisions are silently ignored.""" torev = repo.changelog.nodemap.get for n in nodes: rev = torev(n) if rev is not None: yield rev # mapping of 'set-name' -> cachefuncs = {} def cachefor(name): """Decorator to register a function as computing the cache for a set""" def decorator(func): assert name not in cachefuncs cachefuncs[name] = func return func return decorator def getrevs(repo, name): """Return the set of revision that belong to the set Such access may compute the set and cache it for future use""" repo = repo.unfiltered() if not repo.obsstore: return frozenset() if name not in repo.obsstore.caches: repo.obsstore.caches[name] = cachefuncs[name](repo) return repo.obsstore.caches[name] # To be simple we need to invalidate obsolescence cache when: # # - new changeset is added: # - public phase is changed # - obsolescence marker are added # - strip is used a repo def clearobscaches(repo): """Remove all obsolescence related cache from a repo This remove all cache in obsstore is the obsstore already exist on the repo. (We could be smarter here given the exact event that trigger the cache clearing)""" # only clear cache is there is obsstore data in this repo if 'obsstore' in repo._filecache: repo.obsstore.caches.clear() @cachefor('obsolete') def _computeobsoleteset(repo): """the set of obsolete revisions""" obs = set() getrev = repo.changelog.nodemap.get getphase = repo._phasecache.phase for n in repo.obsstore.successors: rev = getrev(n) if rev is not None and getphase(repo, rev): obs.add(rev) return obs @cachefor('unstable') def _computeunstableset(repo): """the set of non obsolete revisions with obsolete parents""" revs = [(ctx.rev(), ctx) for ctx in repo.set('(not public()) and (not obsolete())')] revs.sort(key=lambda x:x[0]) unstable = set() for rev, ctx in revs: # A rev is unstable if one of its parent is obsolete or unstable # this works since we traverse following growing rev order if any((x.obsolete() or (x.rev() in unstable)) for x in ctx.parents()): unstable.add(rev) return unstable @cachefor('suspended') def _computesuspendedset(repo): """the set of obsolete parents with non obsolete descendants""" suspended = repo.changelog.ancestors(getrevs(repo, 'unstable')) return set(r for r in getrevs(repo, 'obsolete') if r in suspended) @cachefor('extinct') def _computeextinctset(repo): """the set of obsolete parents without non obsolete descendants""" return getrevs(repo, 'obsolete') - getrevs(repo, 'suspended') @cachefor('bumped') def _computebumpedset(repo): """the set of revs trying to obsolete public revisions""" bumped = set() # util function (avoid attribute lookup in the loop) phase = repo._phasecache.phase # would be faster to grab the full list public = phases.public cl = repo.changelog torev = cl.nodemap.get for ctx in repo.set('(not public()) and (not obsolete())'): rev = ctx.rev() # We only evaluate mutable, non-obsolete revision node = ctx.node() # (future) A cache of precursors may worth if split is very common for pnode in allprecursors(repo.obsstore, [node], ignoreflags=bumpedfix): prev = torev(pnode) # unfiltered! but so is phasecache if (prev is not None) and (phase(repo, prev) <= public): # we have a public precursors bumped.add(rev) break # Next draft! return bumped @cachefor('divergent') def _computedivergentset(repo): """the set of rev that compete to be the final successors of some revision. """ divergent = set() obsstore = repo.obsstore newermap = {} for ctx in repo.set('(not public()) - obsolete()'): mark = obsstore.precursors.get(ctx.node(), ()) toprocess = set(mark) seen = set() while toprocess: prec = toprocess.pop()[0] if prec in seen: continue # emergency cycle hanging prevention seen.add(prec) if prec not in newermap: successorssets(repo, prec, newermap) newer = [n for n in newermap[prec] if n] if len(newer) > 1: divergent.add(ctx.rev()) break toprocess.update(obsstore.precursors.get(prec, ())) return divergent def createmarkers(repo, relations, flag=0, date=None, metadata=None): """Add obsolete markers between changesets in a repo must be an iterable of (, (, ...)[,{metadata}]) tuple. `old` and `news` are changectx. metadata is an optional dictionary containing metadata for this marker only. It is merged with the global metadata specified through the `metadata` argument of this function, Trying to obsolete a public changeset will raise an exception. Current user and date are used except if specified otherwise in the metadata attribute. This function operates within a transaction of its own, but does not take any lock on the repo. """ # prepare metadata if metadata is None: metadata = {} if 'user' not in metadata: metadata['user'] = repo.ui.username() tr = repo.transaction('add-obsolescence-marker') try: for rel in relations: prec = rel[0] sucs = rel[1] localmetadata = metadata.copy() if 2 < len(rel): localmetadata.update(rel[2]) if not prec.mutable(): raise util.Abort("cannot obsolete public changeset: %s" % prec, hint='see "hg help phases" for details') nprec = prec.node() nsucs = tuple(s.node() for s in sucs) npare = None if not nsucs: npare = tuple(p.node() for p in prec.parents()) if nprec in nsucs: raise util.Abort("changeset %s cannot obsolete itself" % prec) repo.obsstore.create(tr, nprec, nsucs, flag, parents=npare, date=date, metadata=localmetadata) repo.filteredrevcache.clear() tr.close() finally: tr.release() def isenabled(repo, option): """Returns True if the given repository has the given obsolete option enabled. """ result = set(repo.ui.configlist('experimental', 'evolution')) if 'all' in result: return True # For migration purposes, temporarily return true if the config hasn't been # set but _enabled is true. if len(result) == 0 and _enabled: return True # createmarkers must be enabled if other options are enabled if ((allowunstableopt in result or exchangeopt in result) and not createmarkersopt in result): raise util.Abort(_("'createmarkers' obsolete option must be enabled " "if other obsolete options are enabled")) return option in result