config: read configs from directories in lexicographical order
Mercurial currently reads the .rc files specified in HGRCPATH (and the
system-default paths) in directory order, which is unspecified. My
team at work maintains a set of .rc files. So far there has been no
overlap between them, so we had not noticed this behavior. However, we
would now like to release some common .rc files and then have another
one per plaform with platform-specific overrides. It would be nice if
we can determine the load order by choosing names carefully. This
patch enables that by loading the .rc files in lexicographical order.
Before this patch, the added test case would consistently say "30" on
my file system (whatever I have -- some Linux FS).
Differential Revision: https://phab.mercurial-scm.org/D6193
# branchmap.py - logic to computes, maintain and stores branchmap for local repo
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import struct
from .node import (
bin,
hex,
nullid,
nullrev,
)
from . import (
encoding,
error,
pycompat,
scmutil,
util,
)
from .utils import (
stringutil,
)
calcsize = struct.calcsize
pack_into = struct.pack_into
unpack_from = struct.unpack_from
### Nearest subset relation
# Nearest subset of filter X is a filter Y so that:
# * Y is included in X,
# * X - Y is as small as possible.
# This create and ordering used for branchmap purpose.
# the ordering may be partial
subsettable = {None: 'visible',
'visible-hidden': 'visible',
'visible': 'served',
'served': 'immutable',
'immutable': 'base'}
class BranchMapCache(object):
"""mapping of filtered views of repo with their branchcache"""
def __init__(self):
self._per_filter = {}
def __getitem__(self, repo):
self.updatecache(repo)
return self._per_filter[repo.filtername]
def updatecache(self, repo):
"""Update the cache for the given filtered view on a repository"""
# This can trigger updates for the caches for subsets of the filtered
# view, e.g. when there is no cache for this filtered view or the cache
# is stale.
cl = repo.changelog
filtername = repo.filtername
bcache = self._per_filter.get(filtername)
if bcache is None or not bcache.validfor(repo):
# cache object missing or cache object stale? Read from disk
bcache = branchcache.fromfile(repo)
revs = []
if bcache is None:
# no (fresh) cache available anymore, perhaps we can re-use
# the cache for a subset, then extend that to add info on missing
# revisions.
subsetname = subsettable.get(filtername)
if subsetname is not None:
subset = repo.filtered(subsetname)
bcache = self[subset].copy()
extrarevs = subset.changelog.filteredrevs - cl.filteredrevs
revs.extend(r for r in extrarevs if r <= bcache.tiprev)
else:
# nothing to fall back on, start empty.
bcache = branchcache()
revs.extend(cl.revs(start=bcache.tiprev + 1))
if revs:
bcache.update(repo, revs)
assert bcache.validfor(repo), filtername
self._per_filter[repo.filtername] = bcache
def replace(self, repo, remotebranchmap):
"""Replace the branchmap cache for a repo with a branch mapping.
This is likely only called during clone with a branch map from a
remote.
"""
cl = repo.changelog
clrev = cl.rev
clbranchinfo = cl.branchinfo
rbheads = []
closed = []
for bheads in remotebranchmap.itervalues():
rbheads += bheads
for h in bheads:
r = clrev(h)
b, c = clbranchinfo(r)
if c:
closed.append(h)
if rbheads:
rtiprev = max((int(clrev(node)) for node in rbheads))
cache = branchcache(
remotebranchmap, repo[rtiprev].node(), rtiprev,
closednodes=closed)
# Try to stick it as low as possible
# filter above served are unlikely to be fetch from a clone
for candidate in ('base', 'immutable', 'served'):
rview = repo.filtered(candidate)
if cache.validfor(rview):
self._per_filter[candidate] = cache
cache.write(rview)
return
def clear(self):
self._per_filter.clear()
class branchcache(object):
"""A dict like object that hold branches heads cache.
This cache is used to avoid costly computations to determine all the
branch heads of a repo.
The cache is serialized on disk in the following format:
<tip hex node> <tip rev number> [optional filtered repo hex hash]
<branch head hex node> <open/closed state> <branch name>
<branch head hex node> <open/closed state> <branch name>
...
The first line is used to check if the cache is still valid. If the
branch cache is for a filtered repo view, an optional third hash is
included that hashes the hashes of all filtered revisions.
The open/closed state is represented by a single letter 'o' or 'c'.
This field can be used to avoid changelog reads when determining if a
branch head closes a branch or not.
"""
def __init__(self, entries=(), tipnode=nullid, tiprev=nullrev,
filteredhash=None, closednodes=None, hasnode=None):
""" hasnode is a function which can be used to verify whether changelog
has a given node or not. If it's not provided, we assume that every node
we have exists in changelog """
self.tipnode = tipnode
self.tiprev = tiprev
self.filteredhash = filteredhash
# closednodes is a set of nodes that close their branch. If the branch
# cache has been updated, it may contain nodes that are no longer
# heads.
if closednodes is None:
self._closednodes = set()
else:
self._closednodes = closednodes
self._entries = dict(entries)
# whether closed nodes are verified or not
self._closedverified = False
# branches for which nodes are verified
self._verifiedbranches = set()
self._hasnode = hasnode
if self._hasnode is None:
self._hasnode = lambda x: True
def __iter__(self):
return iter(self._entries)
def __setitem__(self, key, value):
self._entries[key] = value
def __getitem__(self, key):
return self._entries[key]
def iteritems(self):
return self._entries.iteritems()
def hasbranch(self, label):
""" checks whether a branch of this name exists or not """
return label in self._entries
@classmethod
def fromfile(cls, repo):
f = None
try:
f = repo.cachevfs(cls._filename(repo))
lineiter = iter(f)
cachekey = next(lineiter).rstrip('\n').split(" ", 2)
last, lrev = cachekey[:2]
last, lrev = bin(last), int(lrev)
filteredhash = None
hasnode = repo.changelog.hasnode
if len(cachekey) > 2:
filteredhash = bin(cachekey[2])
bcache = cls(tipnode=last, tiprev=lrev, filteredhash=filteredhash,
hasnode=hasnode)
if not bcache.validfor(repo):
# invalidate the cache
raise ValueError(r'tip differs')
bcache.load(repo, lineiter)
except (IOError, OSError):
return None
except Exception as inst:
if repo.ui.debugflag:
msg = 'invalid branchheads cache'
if repo.filtername is not None:
msg += ' (%s)' % repo.filtername
msg += ': %s\n'
repo.ui.debug(msg % pycompat.bytestr(inst))
bcache = None
finally:
if f:
f.close()
return bcache
def load(self, repo, lineiter):
""" fully loads the branchcache by reading from the file using the line
iterator passed"""
cl = repo.changelog
for line in lineiter:
line = line.rstrip('\n')
if not line:
continue
node, state, label = line.split(" ", 2)
if state not in 'oc':
raise ValueError(r'invalid branch state')
label = encoding.tolocal(label.strip())
node = bin(node)
if not cl.hasnode(node):
raise ValueError(
r'node %s does not exist' % pycompat.sysstr(hex(node)))
self._entries.setdefault(label, []).append(node)
self._verifiedbranches.add(label)
if state == 'c':
self._closednodes.add(node)
self._closedverified = True
@staticmethod
def _filename(repo):
"""name of a branchcache file for a given repo or repoview"""
filename = "branch2"
if repo.filtername:
filename = '%s-%s' % (filename, repo.filtername)
return filename
def validfor(self, repo):
"""Is the cache content valid regarding a repo
- False when cached tipnode is unknown or if we detect a strip.
- True when cache is up to date or a subset of current repo."""
try:
return ((self.tipnode == repo.changelog.node(self.tiprev))
and (self.filteredhash ==
scmutil.filteredhash(repo, self.tiprev)))
except IndexError:
return False
def _branchtip(self, heads):
'''Return tuple with last open head in heads and false,
otherwise return last closed head and true.'''
tip = heads[-1]
closed = True
for h in reversed(heads):
if h not in self._closednodes:
tip = h
closed = False
break
return tip, closed
def branchtip(self, branch):
'''Return the tipmost open head on branch head, otherwise return the
tipmost closed head on branch.
Raise KeyError for unknown branch.'''
return self._branchtip(self[branch])[0]
def iteropen(self, nodes):
return (n for n in nodes if n not in self._closednodes)
def branchheads(self, branch, closed=False):
heads = self[branch]
if not closed:
heads = list(self.iteropen(heads))
return heads
def iterbranches(self):
for bn, heads in self.iteritems():
yield (bn, heads) + self._branchtip(heads)
def iterheads(self):
""" returns all the heads """
return self._entries.itervalues()
def copy(self):
"""return an deep copy of the branchcache object"""
return branchcache(
self._entries, self.tipnode, self.tiprev, self.filteredhash,
self._closednodes)
def write(self, repo):
try:
f = repo.cachevfs(self._filename(repo), "w", atomictemp=True)
cachekey = [hex(self.tipnode), '%d' % self.tiprev]
if self.filteredhash is not None:
cachekey.append(hex(self.filteredhash))
f.write(" ".join(cachekey) + '\n')
nodecount = 0
for label, nodes in sorted(self.iteritems()):
label = encoding.fromlocal(label)
for node in nodes:
nodecount += 1
if node in self._closednodes:
state = 'c'
else:
state = 'o'
f.write("%s %s %s\n" % (hex(node), state, label))
f.close()
repo.ui.log('branchcache',
'wrote %s branch cache with %d labels and %d nodes\n',
repo.filtername, len(self._entries), nodecount)
except (IOError, OSError, error.Abort) as inst:
# Abort may be raised by read only opener, so log and continue
repo.ui.debug("couldn't write branch cache: %s\n" %
stringutil.forcebytestr(inst))
def update(self, repo, revgen):
"""Given a branchhead cache, self, that may have extra nodes or be
missing heads, and a generator of nodes that are strictly a superset of
heads missing, this function updates self to be correct.
"""
starttime = util.timer()
cl = repo.changelog
# collect new branch entries
newbranches = {}
getbranchinfo = repo.revbranchcache().branchinfo
for r in revgen:
branch, closesbranch = getbranchinfo(r)
newbranches.setdefault(branch, []).append(r)
if closesbranch:
self._closednodes.add(cl.node(r))
# fetch current topological heads to speed up filtering
topoheads = set(cl.headrevs())
# if older branchheads are reachable from new ones, they aren't
# really branchheads. Note checking parents is insufficient:
# 1 (branch a) -> 2 (branch b) -> 3 (branch a)
for branch, newheadrevs in newbranches.iteritems():
bheads = self._entries.setdefault(branch, [])
bheadset = set(cl.rev(node) for node in bheads)
# This have been tested True on all internal usage of this function.
# run it again in case of doubt
# assert not (set(bheadrevs) & set(newheadrevs))
bheadset.update(newheadrevs)
# This prunes out two kinds of heads - heads that are superseded by
# a head in newheadrevs, and newheadrevs that are not heads because
# an existing head is their descendant.
uncertain = bheadset - topoheads
if uncertain:
floorrev = min(uncertain)
ancestors = set(cl.ancestors(newheadrevs, floorrev))
bheadset -= ancestors
bheadrevs = sorted(bheadset)
self[branch] = [cl.node(rev) for rev in bheadrevs]
tiprev = bheadrevs[-1]
if tiprev > self.tiprev:
self.tipnode = cl.node(tiprev)
self.tiprev = tiprev
if not self.validfor(repo):
# cache key are not valid anymore
self.tipnode = nullid
self.tiprev = nullrev
for heads in self.iterheads():
tiprev = max(cl.rev(node) for node in heads)
if tiprev > self.tiprev:
self.tipnode = cl.node(tiprev)
self.tiprev = tiprev
self.filteredhash = scmutil.filteredhash(repo, self.tiprev)
duration = util.timer() - starttime
repo.ui.log('branchcache', 'updated %s branch cache in %.4f seconds\n',
repo.filtername or b'None', duration)
self.write(repo)
class remotebranchcache(branchcache):
"""Branchmap info for a remote connection, should not write locally"""
def write(self, repo):
pass
# Revision branch info cache
_rbcversion = '-v1'
_rbcnames = 'rbc-names' + _rbcversion
_rbcrevs = 'rbc-revs' + _rbcversion
# [4 byte hash prefix][4 byte branch name number with sign bit indicating open]
_rbcrecfmt = '>4sI'
_rbcrecsize = calcsize(_rbcrecfmt)
_rbcnodelen = 4
_rbcbranchidxmask = 0x7fffffff
_rbccloseflag = 0x80000000
class revbranchcache(object):
"""Persistent cache, mapping from revision number to branch name and close.
This is a low level cache, independent of filtering.
Branch names are stored in rbc-names in internal encoding separated by 0.
rbc-names is append-only, and each branch name is only stored once and will
thus have a unique index.
The branch info for each revision is stored in rbc-revs as constant size
records. The whole file is read into memory, but it is only 'parsed' on
demand. The file is usually append-only but will be truncated if repo
modification is detected.
The record for each revision contains the first 4 bytes of the
corresponding node hash, and the record is only used if it still matches.
Even a completely trashed rbc-revs fill thus still give the right result
while converging towards full recovery ... assuming no incorrectly matching
node hashes.
The record also contains 4 bytes where 31 bits contains the index of the
branch and the last bit indicate that it is a branch close commit.
The usage pattern for rbc-revs is thus somewhat similar to 00changelog.i
and will grow with it but be 1/8th of its size.
"""
def __init__(self, repo, readonly=True):
assert repo.filtername is None
self._repo = repo
self._names = [] # branch names in local encoding with static index
self._rbcrevs = bytearray()
self._rbcsnameslen = 0 # length of names read at _rbcsnameslen
try:
bndata = repo.cachevfs.read(_rbcnames)
self._rbcsnameslen = len(bndata) # for verification before writing
if bndata:
self._names = [encoding.tolocal(bn)
for bn in bndata.split('\0')]
except (IOError, OSError):
if readonly:
# don't try to use cache - fall back to the slow path
self.branchinfo = self._branchinfo
if self._names:
try:
data = repo.cachevfs.read(_rbcrevs)
self._rbcrevs[:] = data
except (IOError, OSError) as inst:
repo.ui.debug("couldn't read revision branch cache: %s\n" %
stringutil.forcebytestr(inst))
# remember number of good records on disk
self._rbcrevslen = min(len(self._rbcrevs) // _rbcrecsize,
len(repo.changelog))
if self._rbcrevslen == 0:
self._names = []
self._rbcnamescount = len(self._names) # number of names read at
# _rbcsnameslen
def _clear(self):
self._rbcsnameslen = 0
del self._names[:]
self._rbcnamescount = 0
self._rbcrevslen = len(self._repo.changelog)
self._rbcrevs = bytearray(self._rbcrevslen * _rbcrecsize)
util.clearcachedproperty(self, '_namesreverse')
@util.propertycache
def _namesreverse(self):
return dict((b, r) for r, b in enumerate(self._names))
def branchinfo(self, rev):
"""Return branch name and close flag for rev, using and updating
persistent cache."""
changelog = self._repo.changelog
rbcrevidx = rev * _rbcrecsize
# avoid negative index, changelog.read(nullrev) is fast without cache
if rev == nullrev:
return changelog.branchinfo(rev)
# if requested rev isn't allocated, grow and cache the rev info
if len(self._rbcrevs) < rbcrevidx + _rbcrecsize:
return self._branchinfo(rev)
# fast path: extract data from cache, use it if node is matching
reponode = changelog.node(rev)[:_rbcnodelen]
cachenode, branchidx = unpack_from(
_rbcrecfmt, util.buffer(self._rbcrevs), rbcrevidx)
close = bool(branchidx & _rbccloseflag)
if close:
branchidx &= _rbcbranchidxmask
if cachenode == '\0\0\0\0':
pass
elif cachenode == reponode:
try:
return self._names[branchidx], close
except IndexError:
# recover from invalid reference to unknown branch
self._repo.ui.debug("referenced branch names not found"
" - rebuilding revision branch cache from scratch\n")
self._clear()
else:
# rev/node map has changed, invalidate the cache from here up
self._repo.ui.debug("history modification detected - truncating "
"revision branch cache to revision %d\n" % rev)
truncate = rbcrevidx + _rbcrecsize
del self._rbcrevs[truncate:]
self._rbcrevslen = min(self._rbcrevslen, truncate)
# fall back to slow path and make sure it will be written to disk
return self._branchinfo(rev)
def _branchinfo(self, rev):
"""Retrieve branch info from changelog and update _rbcrevs"""
changelog = self._repo.changelog
b, close = changelog.branchinfo(rev)
if b in self._namesreverse:
branchidx = self._namesreverse[b]
else:
branchidx = len(self._names)
self._names.append(b)
self._namesreverse[b] = branchidx
reponode = changelog.node(rev)
if close:
branchidx |= _rbccloseflag
self._setcachedata(rev, reponode, branchidx)
return b, close
def setdata(self, branch, rev, node, close):
"""add new data information to the cache"""
if branch in self._namesreverse:
branchidx = self._namesreverse[branch]
else:
branchidx = len(self._names)
self._names.append(branch)
self._namesreverse[branch] = branchidx
if close:
branchidx |= _rbccloseflag
self._setcachedata(rev, node, branchidx)
# If no cache data were readable (non exists, bad permission, etc)
# the cache was bypassing itself by setting:
#
# self.branchinfo = self._branchinfo
#
# Since we now have data in the cache, we need to drop this bypassing.
if r'branchinfo' in vars(self):
del self.branchinfo
def _setcachedata(self, rev, node, branchidx):
"""Writes the node's branch data to the in-memory cache data."""
if rev == nullrev:
return
rbcrevidx = rev * _rbcrecsize
if len(self._rbcrevs) < rbcrevidx + _rbcrecsize:
self._rbcrevs.extend('\0' *
(len(self._repo.changelog) * _rbcrecsize -
len(self._rbcrevs)))
pack_into(_rbcrecfmt, self._rbcrevs, rbcrevidx, node, branchidx)
self._rbcrevslen = min(self._rbcrevslen, rev)
tr = self._repo.currenttransaction()
if tr:
tr.addfinalize('write-revbranchcache', self.write)
def write(self, tr=None):
"""Save branch cache if it is dirty."""
repo = self._repo
wlock = None
step = ''
try:
if self._rbcnamescount < len(self._names):
step = ' names'
wlock = repo.wlock(wait=False)
if self._rbcnamescount != 0:
f = repo.cachevfs.open(_rbcnames, 'ab')
if f.tell() == self._rbcsnameslen:
f.write('\0')
else:
f.close()
repo.ui.debug("%s changed - rewriting it\n" % _rbcnames)
self._rbcnamescount = 0
self._rbcrevslen = 0
if self._rbcnamescount == 0:
# before rewriting names, make sure references are removed
repo.cachevfs.unlinkpath(_rbcrevs, ignoremissing=True)
f = repo.cachevfs.open(_rbcnames, 'wb')
f.write('\0'.join(encoding.fromlocal(b)
for b in self._names[self._rbcnamescount:]))
self._rbcsnameslen = f.tell()
f.close()
self._rbcnamescount = len(self._names)
start = self._rbcrevslen * _rbcrecsize
if start != len(self._rbcrevs):
step = ''
if wlock is None:
wlock = repo.wlock(wait=False)
revs = min(len(repo.changelog),
len(self._rbcrevs) // _rbcrecsize)
f = repo.cachevfs.open(_rbcrevs, 'ab')
if f.tell() != start:
repo.ui.debug("truncating cache/%s to %d\n"
% (_rbcrevs, start))
f.seek(start)
if f.tell() != start:
start = 0
f.seek(start)
f.truncate()
end = revs * _rbcrecsize
f.write(self._rbcrevs[start:end])
f.close()
self._rbcrevslen = revs
except (IOError, OSError, error.Abort, error.LockError) as inst:
repo.ui.debug("couldn't write revision branch cache%s: %s\n"
% (step, stringutil.forcebytestr(inst)))
finally:
if wlock is not None:
wlock.release()