dirstate: check dirstate race condition around commit
Once in a while, rhg is the only one to behave right here.
# 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
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 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._docket = docketmod.DirstateDocket.parse(
self._readdirstatefile(), self._nodeconstants
)
return self._docket
def write_v2_no_append(self, tr, st, meta, packed):
old_docket = self.docket
new_docket = docketmod.DirstateDocket.with_new_uuid(
self.parents(), len(packed), meta
)
if 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)
# 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.uuid:
data_filename = old_docket.data_filename()
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:
self._parents = self.docket.parents
else:
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:
raise error.Abort(
_(b'working directory state appears damaged!')
)
return self._parents
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):
# ignore HG_PENDING because identity is used only for writing
self.identity = util.filestat.frompath(
self._opener.join(self._filename)
)
testing.wait_on_cfg(self._ui, b'dirstate.pre-read-file')
if self._use_dirstate_v2:
if not self.docket.uuid:
return
st = self._opener.read(self.docket.data_filename())
else:
st = self._readdirstatefile()
if not st:
return
# TODO: adjust this estimate for dirstate-v2
if util.safehasattr(parsers, b'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:
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.identity = util.filestat.frompath(
self._opener.join(self._filename)
)
testing.wait_on_cfg(self._ui, b'dirstate.pre-read-file')
if self._use_dirstate_v2:
if self.docket.uuid:
# TODO: use mmap when possible
data = self._opener.read(self.docket.data_filename())
else:
data = b''
self._map = rustmod.DirstateMap.new_v2(
data, self.docket.data_size, self.docket.tree_metadata
)
parents = self.docket.parents
else:
self._map, parents = rustmod.DirstateMap.new_v1(
self._readdirstatefile()
)
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
@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
# We can only append to an existing data file if there is one
write_mode = self._write_mode
if self.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()
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,
)