Mercurial > hg
view mercurial/dirstatemap.py @ 50757:19108906abaf stable
extensions: imp module is removed in Python 3.12 - use importlib to load files
imp has been deprecated for a long time, and has finally been removed in Python
3.12 .
imp was only used for loading extensions that has been specified with direct
.py path or path to a package directory. The same use cases can be achieved
quite simple with importlib, , possiby with small changes in corner cases with
undefined behaviour, such as extensions without .py source.
There might also be corner cases and undefined behaviour around use of
sys.modules and reloading.
author | Mads Kiilerich <mads@kiilerich.com> |
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date | Wed, 28 Jun 2023 14:23:13 +0200 |
parents | bfbd84c57bda |
children | d718eddf01d9 |
line wrap: on
line source
# dirstatemap.py # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from .i18n import _ from . import ( error, pathutil, policy, testing, txnutil, util, ) from .dirstateutils import ( docket as docketmod, v2, ) parsers = policy.importmod('parsers') rustmod = policy.importrust('dirstate') propertycache = util.propertycache if rustmod is None: DirstateItem = parsers.DirstateItem else: DirstateItem = rustmod.DirstateItem rangemask = 0x7FFFFFFF WRITE_MODE_AUTO = 0 WRITE_MODE_FORCE_NEW = 1 WRITE_MODE_FORCE_APPEND = 2 V2_MAX_READ_ATTEMPTS = 5 class _dirstatemapcommon: """ Methods that are identical for both implementations of the dirstatemap class, with and without Rust extensions enabled. """ # please pytype _map = None copymap = None def __init__(self, ui, opener, root, nodeconstants, use_dirstate_v2): self._use_dirstate_v2 = use_dirstate_v2 self._nodeconstants = nodeconstants self._ui = ui self._opener = opener self._root = root self._filename = b'dirstate' self._nodelen = 20 # Also update Rust code when changing this! self._parents = None self._dirtyparents = False self._docket = None write_mode = ui.config(b"devel", b"dirstate.v2.data_update_mode") if write_mode == b"auto": self._write_mode = WRITE_MODE_AUTO elif write_mode == b"force-append": self._write_mode = WRITE_MODE_FORCE_APPEND elif write_mode == b"force-new": self._write_mode = WRITE_MODE_FORCE_NEW else: # unknown value, fallback to default self._write_mode = WRITE_MODE_AUTO # for consistent view between _pl() and _read() invocations self._pendingmode = None def _set_identity(self): self.identity = self._get_current_identity() def _get_current_identity(self): try: return util.cachestat(self._opener.join(self._filename)) except FileNotFoundError: return None def may_need_refresh(self): if 'identity' not in vars(self): # no existing identity, we need a refresh return True if self.identity is None: return True if not self.identity.cacheable(): # We cannot trust the entry # XXX this is a problem on windows, NFS, or other inode less system return True current_identity = self._get_current_identity() if current_identity is None: return True if not current_identity.cacheable(): # We cannot trust the entry # XXX this is a problem on windows, NFS, or other inode less system return True return current_identity != self.identity def preload(self): """Loads the underlying data, if it's not already loaded""" self._map def get(self, key, default=None): return self._map.get(key, default) def __len__(self): return len(self._map) def __iter__(self): return iter(self._map) def __contains__(self, key): return key in self._map def __getitem__(self, item): return self._map[item] ### disk interaction def _opendirstatefile(self): fp, mode = txnutil.trypending(self._root, self._opener, self._filename) if self._pendingmode is not None and self._pendingmode != mode: fp.close() raise error.Abort( _(b'working directory state may be changed parallelly') ) self._pendingmode = mode return fp def _readdirstatefile(self, size=-1): try: with self._opendirstatefile() as fp: return fp.read(size) except FileNotFoundError: # File doesn't exist, so the current state is empty return b'' @property def docket(self): if not self._docket: if not self._use_dirstate_v2: raise error.ProgrammingError( b'dirstate only has a docket in v2 format' ) self._set_identity() data = self._readdirstatefile() if data == b'' or data.startswith(docketmod.V2_FORMAT_MARKER): self._docket = docketmod.DirstateDocket.parse( data, self._nodeconstants ) else: raise error.CorruptedDirstate(b"dirstate is not in v2 format") return self._docket def _read_v2_data(self): data = None attempts = 0 while attempts < V2_MAX_READ_ATTEMPTS: attempts += 1 try: # TODO: use mmap when possible data = self._opener.read(self.docket.data_filename()) except FileNotFoundError: # read race detected between docket and data file # reload the docket and retry self._docket = None if data is None: assert attempts >= V2_MAX_READ_ATTEMPTS msg = b"dirstate read race happened %d times in a row" msg %= attempts raise error.Abort(msg) return self._opener.read(self.docket.data_filename()) def write_v2_no_append(self, tr, st, meta, packed): try: old_docket = self.docket except error.CorruptedDirstate: # This means we've identified a dirstate-v1 file on-disk when we # were expecting a dirstate-v2 docket. We've managed to recover # from that unexpected situation, and now we want to write back a # dirstate-v2 file to make the on-disk situation right again. # # This shouldn't be triggered since `self.docket` is cached and # we would have called parents() or read() first, but it's here # just in case. old_docket = None new_docket = docketmod.DirstateDocket.with_new_uuid( self.parents(), len(packed), meta ) if old_docket is not None and old_docket.uuid == new_docket.uuid: raise error.ProgrammingError(b'dirstate docket name collision') data_filename = new_docket.data_filename() self._opener.write(data_filename, packed) # tell the transaction that we are adding a new file if tr is not None: tr.addbackup(data_filename, location=b'plain') # Write the new docket after the new data file has been # written. Because `st` was opened with `atomictemp=True`, # the actual `.hg/dirstate` file is only affected on close. st.write(new_docket.serialize()) st.close() # Remove the old data file after the new docket pointing to # the new data file was written. if old_docket is not None and old_docket.uuid: data_filename = old_docket.data_filename() if tr is not None: tr.addbackup(data_filename, location=b'plain') unlink = lambda _tr=None: self._opener.unlink(data_filename) if tr: category = b"dirstate-v2-clean-" + old_docket.uuid tr.addpostclose(category, unlink) else: unlink() self._docket = new_docket ### reading/setting parents def parents(self): if not self._parents: if self._use_dirstate_v2: try: self.docket except error.CorruptedDirstate as e: # fall back to dirstate-v1 if we fail to read v2 self._v1_parents(e) else: self._parents = self.docket.parents else: self._v1_parents() return self._parents def _v1_parents(self, from_v2_exception=None): read_len = self._nodelen * 2 st = self._readdirstatefile(read_len) l = len(st) if l == read_len: self._parents = ( st[: self._nodelen], st[self._nodelen : 2 * self._nodelen], ) elif l == 0: self._parents = ( self._nodeconstants.nullid, self._nodeconstants.nullid, ) else: hint = None if from_v2_exception is not None: hint = _(b"falling back to dirstate-v1 from v2 also failed") raise error.Abort( _(b'working directory state appears damaged!'), hint ) class dirstatemap(_dirstatemapcommon): """Map encapsulating the dirstate's contents. The dirstate contains the following state: - `identity` is the identity of the dirstate file, which can be used to detect when changes have occurred to the dirstate file. - `parents` is a pair containing the parents of the working copy. The parents are updated by calling `setparents`. - the state map maps filenames to tuples of (state, mode, size, mtime), where state is a single character representing 'normal', 'added', 'removed', or 'merged'. It is read by treating the dirstate as a dict. File state is updated by calling various methods (see each documentation for details): - `reset_state`, - `set_tracked` - `set_untracked` - `set_clean` - `set_possibly_dirty` - `copymap` maps destination filenames to their source filename. The dirstate also provides the following views onto the state: - `filefoldmap` is a dict mapping normalized filenames to the denormalized form that they appear as in the dirstate. - `dirfoldmap` is a dict mapping normalized directory names to the denormalized form that they appear as in the dirstate. """ ### Core data storage and access @propertycache def _map(self): self._map = {} self.read() return self._map @propertycache def copymap(self): self.copymap = {} self._map return self.copymap def clear(self): self._map.clear() self.copymap.clear() self.setparents(self._nodeconstants.nullid, self._nodeconstants.nullid) util.clearcachedproperty(self, b"_dirs") util.clearcachedproperty(self, b"_alldirs") util.clearcachedproperty(self, b"filefoldmap") util.clearcachedproperty(self, b"dirfoldmap") def items(self): return self._map.items() # forward for python2,3 compat iteritems = items def debug_iter(self, all): """ Return an iterator of (filename, state, mode, size, mtime) tuples `all` is unused when Rust is not enabled """ for (filename, item) in self.items(): yield (filename, item.state, item.mode, item.size, item.mtime) def keys(self): return self._map.keys() ### reading/setting parents def setparents(self, p1, p2, fold_p2=False): self._parents = (p1, p2) self._dirtyparents = True copies = {} if fold_p2: for f, s in self._map.items(): # Discard "merged" markers when moving away from a merge state if s.p2_info: source = self.copymap.pop(f, None) if source: copies[f] = source s.drop_merge_data() return copies ### disk interaction def read(self): testing.wait_on_cfg(self._ui, b'dirstate.pre-read-file') if self._use_dirstate_v2: try: self.docket except error.CorruptedDirstate: # fall back to dirstate-v1 if we fail to read v2 self._set_identity() st = self._readdirstatefile() else: if not self.docket.uuid: return testing.wait_on_cfg(self._ui, b'dirstate.post-docket-read-file') st = self._read_v2_data() else: self._set_identity() st = self._readdirstatefile() if not st: return # TODO: adjust this estimate for dirstate-v2 if util.safehasattr(parsers, 'dict_new_presized'): # Make an estimate of the number of files in the dirstate based on # its size. This trades wasting some memory for avoiding costly # resizes. Each entry have a prefix of 17 bytes followed by one or # two path names. Studies on various large-scale real-world repositories # found 54 bytes a reasonable upper limit for the average path names. # Copy entries are ignored for the sake of this estimate. self._map = parsers.dict_new_presized(len(st) // 71) # Python's garbage collector triggers a GC each time a certain number # of container objects (the number being defined by # gc.get_threshold()) are allocated. parse_dirstate creates a tuple # for each file in the dirstate. The C version then immediately marks # them as not to be tracked by the collector. However, this has no # effect on when GCs are triggered, only on what objects the GC looks # into. This means that O(number of files) GCs are unavoidable. # Depending on when in the process's lifetime the dirstate is parsed, # this can get very expensive. As a workaround, disable GC while # parsing the dirstate. # # (we cannot decorate the function directly since it is in a C module) if self._use_dirstate_v2: try: self.docket except error.CorruptedDirstate: # fall back to dirstate-v1 if we fail to parse v2 parse_dirstate = util.nogc(parsers.parse_dirstate) p = parse_dirstate(self._map, self.copymap, st) else: p = self.docket.parents meta = self.docket.tree_metadata parse_dirstate = util.nogc(v2.parse_dirstate) parse_dirstate(self._map, self.copymap, st, meta) else: parse_dirstate = util.nogc(parsers.parse_dirstate) p = parse_dirstate(self._map, self.copymap, st) if not self._dirtyparents: self.setparents(*p) # Avoid excess attribute lookups by fast pathing certain checks self.__contains__ = self._map.__contains__ self.__getitem__ = self._map.__getitem__ self.get = self._map.get def write(self, tr, st): if self._use_dirstate_v2: packed, meta = v2.pack_dirstate(self._map, self.copymap) self.write_v2_no_append(tr, st, meta, packed) else: packed = parsers.pack_dirstate( self._map, self.copymap, self.parents() ) st.write(packed) st.close() self._dirtyparents = False @propertycache def identity(self): self._map return self.identity ### code related to maintaining and accessing "extra" property # (e.g. "has_dir") def _dirs_incr(self, filename, old_entry=None): """increment the dirstate counter if applicable""" if ( old_entry is None or old_entry.removed ) and "_dirs" in self.__dict__: self._dirs.addpath(filename) if old_entry is None and "_alldirs" in self.__dict__: self._alldirs.addpath(filename) def _dirs_decr(self, filename, old_entry=None, remove_variant=False): """decrement the dirstate counter if applicable""" if old_entry is not None: if "_dirs" in self.__dict__ and not old_entry.removed: self._dirs.delpath(filename) if "_alldirs" in self.__dict__ and not remove_variant: self._alldirs.delpath(filename) elif remove_variant and "_alldirs" in self.__dict__: self._alldirs.addpath(filename) if "filefoldmap" in self.__dict__: normed = util.normcase(filename) self.filefoldmap.pop(normed, None) @propertycache def filefoldmap(self): """Returns a dictionary mapping normalized case paths to their non-normalized versions. """ try: makefilefoldmap = parsers.make_file_foldmap except AttributeError: pass else: return makefilefoldmap( self._map, util.normcasespec, util.normcasefallback ) f = {} normcase = util.normcase for name, s in self._map.items(): if not s.removed: f[normcase(name)] = name f[b'.'] = b'.' # prevents useless util.fspath() invocation return f @propertycache def dirfoldmap(self): f = {} normcase = util.normcase for name in self._dirs: f[normcase(name)] = name return f def hastrackeddir(self, d): """ Returns True if the dirstate contains a tracked (not removed) file in this directory. """ return d in self._dirs def hasdir(self, d): """ Returns True if the dirstate contains a file (tracked or removed) in this directory. """ return d in self._alldirs @propertycache def _dirs(self): return pathutil.dirs(self._map, only_tracked=True) @propertycache def _alldirs(self): return pathutil.dirs(self._map) ### code related to manipulation of entries and copy-sources def reset_state( self, filename, wc_tracked=False, p1_tracked=False, p2_info=False, has_meaningful_mtime=True, parentfiledata=None, ): """Set a entry to a given state, diregarding all previous state This is to be used by the part of the dirstate API dedicated to adjusting the dirstate after a update/merge. note: calling this might result to no entry existing at all if the dirstate map does not see any point at having one for this file anymore. """ # copy information are now outdated # (maybe new information should be in directly passed to this function) self.copymap.pop(filename, None) if not (p1_tracked or p2_info or wc_tracked): old_entry = self._map.get(filename) self._drop_entry(filename) self._dirs_decr(filename, old_entry=old_entry) return old_entry = self._map.get(filename) self._dirs_incr(filename, old_entry) entry = DirstateItem( wc_tracked=wc_tracked, p1_tracked=p1_tracked, p2_info=p2_info, has_meaningful_mtime=has_meaningful_mtime, parentfiledata=parentfiledata, ) self._map[filename] = entry def set_tracked(self, filename): new = False entry = self.get(filename) if entry is None: self._dirs_incr(filename) entry = DirstateItem( wc_tracked=True, ) self._map[filename] = entry new = True elif not entry.tracked: self._dirs_incr(filename, entry) entry.set_tracked() self._refresh_entry(filename, entry) new = True else: # XXX This is probably overkill for more case, but we need this to # fully replace the `normallookup` call with `set_tracked` one. # Consider smoothing this in the future. entry.set_possibly_dirty() self._refresh_entry(filename, entry) return new def set_untracked(self, f): """Mark a file as no longer tracked in the dirstate map""" entry = self.get(f) if entry is None: return False else: self._dirs_decr(f, old_entry=entry, remove_variant=not entry.added) if not entry.p2_info: self.copymap.pop(f, None) entry.set_untracked() self._refresh_entry(f, entry) return True def set_clean(self, filename, mode, size, mtime): """mark a file as back to a clean state""" entry = self[filename] size = size & rangemask entry.set_clean(mode, size, mtime) self._refresh_entry(filename, entry) self.copymap.pop(filename, None) def set_possibly_dirty(self, filename): """record that the current state of the file on disk is unknown""" entry = self[filename] entry.set_possibly_dirty() self._refresh_entry(filename, entry) def _refresh_entry(self, f, entry): """record updated state of an entry""" if not entry.any_tracked: self._map.pop(f, None) def _drop_entry(self, f): """remove any entry for file f This should also drop associated copy information The fact we actually need to drop it is the responsability of the caller""" self._map.pop(f, None) self.copymap.pop(f, None) if rustmod is not None: class dirstatemap(_dirstatemapcommon): ### Core data storage and access @propertycache def _map(self): """ Fills the Dirstatemap when called. """ # ignore HG_PENDING because identity is used only for writing self._set_identity() testing.wait_on_cfg(self._ui, b'dirstate.pre-read-file') if self._use_dirstate_v2: try: self.docket except error.CorruptedDirstate as e: # fall back to dirstate-v1 if we fail to read v2 parents = self._v1_map(e) else: parents = self.docket.parents inode = ( self.identity.stat.st_ino if self.identity is not None and self.identity.stat is not None else None ) testing.wait_on_cfg( self._ui, b'dirstate.post-docket-read-file' ) if not self.docket.uuid: data = b'' self._map = rustmod.DirstateMap.new_empty() else: data = self._read_v2_data() self._map = rustmod.DirstateMap.new_v2( data, self.docket.data_size, self.docket.tree_metadata, self.docket.uuid, inode, ) parents = self.docket.parents else: parents = self._v1_map() if parents and not self._dirtyparents: self.setparents(*parents) self.__contains__ = self._map.__contains__ self.__getitem__ = self._map.__getitem__ self.get = self._map.get return self._map def _v1_map(self, from_v2_exception=None): self._set_identity() inode = ( self.identity.stat.st_ino if self.identity is not None and self.identity.stat is not None else None ) try: self._map, parents = rustmod.DirstateMap.new_v1( self._readdirstatefile(), inode ) except OSError as e: if from_v2_exception is not None: raise e from from_v2_exception raise return parents @property def copymap(self): return self._map.copymap() def debug_iter(self, all): """ Return an iterator of (filename, state, mode, size, mtime) tuples `all`: also include with `state == b' '` dirstate tree nodes that don't have an associated `DirstateItem`. """ return self._map.debug_iter(all) def clear(self): self._map.clear() self.setparents( self._nodeconstants.nullid, self._nodeconstants.nullid ) util.clearcachedproperty(self, b"_dirs") util.clearcachedproperty(self, b"_alldirs") util.clearcachedproperty(self, b"dirfoldmap") def items(self): return self._map.items() # forward for python2,3 compat iteritems = items def keys(self): return iter(self._map) ### reading/setting parents def setparents(self, p1, p2, fold_p2=False): self._parents = (p1, p2) self._dirtyparents = True copies = {} if fold_p2: copies = self._map.setparents_fixup() return copies ### disk interaction @propertycache def identity(self): self._map return self.identity def write(self, tr, st): if not self._use_dirstate_v2: p1, p2 = self.parents() packed = self._map.write_v1(p1, p2) st.write(packed) st.close() self._dirtyparents = False return write_mode = self._write_mode try: docket = self.docket except error.CorruptedDirstate: # fall back to dirstate-v1 if we fail to parse v2 docket = None # We can only append to an existing data file if there is one if docket is None or docket.uuid is None: write_mode = WRITE_MODE_FORCE_NEW packed, meta, append = self._map.write_v2(write_mode) if append: docket = self.docket data_filename = docket.data_filename() # We mark it for backup to make sure a future `hg rollback` (or # `hg recover`?) call find the data it needs to restore a # working repository. # # The backup can use a hardlink because the format is resistant # to trailing "dead" data. if tr is not None: tr.addbackup(data_filename, location=b'plain') with self._opener(data_filename, b'r+b') as fp: fp.seek(docket.data_size) assert fp.tell() == docket.data_size written = fp.write(packed) if written is not None: # py2 may return None assert written == len(packed), (written, len(packed)) docket.data_size += len(packed) docket.parents = self.parents() docket.tree_metadata = meta st.write(docket.serialize()) st.close() else: self.write_v2_no_append(tr, st, meta, packed) # Reload from the newly-written file util.clearcachedproperty(self, b"_map") self._dirtyparents = False ### code related to maintaining and accessing "extra" property # (e.g. "has_dir") @propertycache def filefoldmap(self): """Returns a dictionary mapping normalized case paths to their non-normalized versions. """ return self._map.filefoldmapasdict() def hastrackeddir(self, d): return self._map.hastrackeddir(d) def hasdir(self, d): return self._map.hasdir(d) @propertycache def dirfoldmap(self): f = {} normcase = util.normcase for name in self._map.tracked_dirs(): f[normcase(name)] = name return f ### code related to manipulation of entries and copy-sources def set_tracked(self, f): return self._map.set_tracked(f) def set_untracked(self, f): return self._map.set_untracked(f) def set_clean(self, filename, mode, size, mtime): self._map.set_clean(filename, mode, size, mtime) def set_possibly_dirty(self, f): self._map.set_possibly_dirty(f) def reset_state( self, filename, wc_tracked=False, p1_tracked=False, p2_info=False, has_meaningful_mtime=True, parentfiledata=None, ): return self._map.reset_state( filename, wc_tracked, p1_tracked, p2_info, has_meaningful_mtime, parentfiledata, )