changelog: optionally store added and removed files in changeset extras
As mentioned in an earlier patch, copies._chain() is used a lot in the
changeset-centric version of pathcopies(). It is expensive because it
needs to look at the manifest in order to filter out copies whose
target file has since been removed. I want to store the sets of added
and removed files in the changeset in order to speed that up. This
patch does the writing part of that. It could easily be a separate
config, but it's currently tied to experimental.copies.write-to since
that's the only real use case (it will also make the {file_*} template
keywords faster, but I doubt that anyone cares enough about those to
write extra metadata for them).
The new information is stored in the changeset extras. Since they're
always subsets of the changeset's "files" list, they're stored as
indexes into that list. I've stored the indexes as stringified ints
separated by NUL bytes. The size of 00changelog.d for the hg repo
increased in size by 0.28% percent (compared to the size with only
copy information in the changesets, which in turn is 0.17% larger than
without copy information). We could store only the delta between the
indexes and we could store them in binary, but the chosen format is
more readable.
We could also have implemented this as a cache outside the
changelog. One advantage of doing it that way is that we would get the
speedups from the {file_*} template keywords also on old
repos. Another advantage is that it we can rewrite the cache if we
find a bug in how we calculate the set of files. A disadvantage is
that it would be more complex. Another is that it would surely use
more space. We already write the copy information to the changeset
extras, so it seems like a small step to also write these file sets.
Differential Revision: https://phab.mercurial-scm.org/D6416
# changelog.py - changelog class for mercurial
#
# 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
from .i18n import _
from .node import (
bin,
hex,
nullid,
)
from .thirdparty import (
attr,
)
from . import (
encoding,
error,
pycompat,
revlog,
util,
)
from .utils import (
dateutil,
stringutil,
)
_defaultextra = {'branch': 'default'}
def _string_escape(text):
"""
>>> from .pycompat import bytechr as chr
>>> d = {b'nl': chr(10), b'bs': chr(92), b'cr': chr(13), b'nul': chr(0)}
>>> s = b"ab%(nl)scd%(bs)s%(bs)sn%(nul)s12ab%(cr)scd%(bs)s%(nl)s" % d
>>> s
'ab\\ncd\\\\\\\\n\\x0012ab\\rcd\\\\\\n'
>>> res = _string_escape(s)
>>> s == _string_unescape(res)
True
"""
# subset of the string_escape codec
text = text.replace('\\', '\\\\').replace('\n', '\\n').replace('\r', '\\r')
return text.replace('\0', '\\0')
def _string_unescape(text):
if '\\0' in text:
# fix up \0 without getting into trouble with \\0
text = text.replace('\\\\', '\\\\\n')
text = text.replace('\\0', '\0')
text = text.replace('\n', '')
return stringutil.unescapestr(text)
def decodeextra(text):
"""
>>> from .pycompat import bytechr as chr
>>> sorted(decodeextra(encodeextra({b'foo': b'bar', b'baz': chr(0) + b'2'})
... ).items())
[('baz', '\\x002'), ('branch', 'default'), ('foo', 'bar')]
>>> sorted(decodeextra(encodeextra({b'foo': b'bar',
... b'baz': chr(92) + chr(0) + b'2'})
... ).items())
[('baz', '\\\\\\x002'), ('branch', 'default'), ('foo', 'bar')]
"""
extra = _defaultextra.copy()
for l in text.split('\0'):
if l:
k, v = _string_unescape(l).split(':', 1)
extra[k] = v
return extra
def encodeextra(d):
# keys must be sorted to produce a deterministic changelog entry
items = [
_string_escape('%s:%s' % (k, pycompat.bytestr(d[k])))
for k in sorted(d)
]
return "\0".join(items)
def encodecopies(copies):
items = [
'%s\0%s' % (k, copies[k])
for k in sorted(copies)
]
return "\n".join(items)
def decodecopies(data):
try:
copies = {}
for l in data.split('\n'):
k, v = l.split('\0')
copies[k] = v
return copies
except ValueError:
# Perhaps someone had chosen the same key name (e.g. "p1copies") and
# used different syntax for the value.
return None
def encodefileindices(files, subset):
subset = set(subset)
indices = []
for i, f in enumerate(files):
if f in subset:
indices.append('%d' % i)
return '\0'.join(indices)
def stripdesc(desc):
"""strip trailing whitespace and leading and trailing empty lines"""
return '\n'.join([l.rstrip() for l in desc.splitlines()]).strip('\n')
class appender(object):
'''the changelog index must be updated last on disk, so we use this class
to delay writes to it'''
def __init__(self, vfs, name, mode, buf):
self.data = buf
fp = vfs(name, mode)
self.fp = fp
self.offset = fp.tell()
self.size = vfs.fstat(fp).st_size
self._end = self.size
def end(self):
return self._end
def tell(self):
return self.offset
def flush(self):
pass
@property
def closed(self):
return self.fp.closed
def close(self):
self.fp.close()
def seek(self, offset, whence=0):
'''virtual file offset spans real file and data'''
if whence == 0:
self.offset = offset
elif whence == 1:
self.offset += offset
elif whence == 2:
self.offset = self.end() + offset
if self.offset < self.size:
self.fp.seek(self.offset)
def read(self, count=-1):
'''only trick here is reads that span real file and data'''
ret = ""
if self.offset < self.size:
s = self.fp.read(count)
ret = s
self.offset += len(s)
if count > 0:
count -= len(s)
if count != 0:
doff = self.offset - self.size
self.data.insert(0, "".join(self.data))
del self.data[1:]
s = self.data[0][doff:doff + count]
self.offset += len(s)
ret += s
return ret
def write(self, s):
self.data.append(bytes(s))
self.offset += len(s)
self._end += len(s)
def __enter__(self):
self.fp.__enter__()
return self
def __exit__(self, *args):
return self.fp.__exit__(*args)
def _divertopener(opener, target):
"""build an opener that writes in 'target.a' instead of 'target'"""
def _divert(name, mode='r', checkambig=False):
if name != target:
return opener(name, mode)
return opener(name + ".a", mode)
return _divert
def _delayopener(opener, target, buf):
"""build an opener that stores chunks in 'buf' instead of 'target'"""
def _delay(name, mode='r', checkambig=False):
if name != target:
return opener(name, mode)
return appender(opener, name, mode, buf)
return _delay
@attr.s
class _changelogrevision(object):
# Extensions might modify _defaultextra, so let the constructor below pass
# it in
extra = attr.ib()
manifest = attr.ib(default=nullid)
user = attr.ib(default='')
date = attr.ib(default=(0, 0))
files = attr.ib(default=attr.Factory(list))
p1copies = attr.ib(default=None)
p2copies = attr.ib(default=None)
description = attr.ib(default='')
class changelogrevision(object):
"""Holds results of a parsed changelog revision.
Changelog revisions consist of multiple pieces of data, including
the manifest node, user, and date. This object exposes a view into
the parsed object.
"""
__slots__ = (
r'_offsets',
r'_text',
)
def __new__(cls, text):
if not text:
return _changelogrevision(extra=_defaultextra)
self = super(changelogrevision, cls).__new__(cls)
# We could return here and implement the following as an __init__.
# But doing it here is equivalent and saves an extra function call.
# format used:
# nodeid\n : manifest node in ascii
# user\n : user, no \n or \r allowed
# time tz extra\n : date (time is int or float, timezone is int)
# : extra is metadata, encoded and separated by '\0'
# : older versions ignore it
# files\n\n : files modified by the cset, no \n or \r allowed
# (.*) : comment (free text, ideally utf-8)
#
# changelog v0 doesn't use extra
nl1 = text.index('\n')
nl2 = text.index('\n', nl1 + 1)
nl3 = text.index('\n', nl2 + 1)
# The list of files may be empty. Which means nl3 is the first of the
# double newline that precedes the description.
if text[nl3 + 1:nl3 + 2] == '\n':
doublenl = nl3
else:
doublenl = text.index('\n\n', nl3 + 1)
self._offsets = (nl1, nl2, nl3, doublenl)
self._text = text
return self
@property
def manifest(self):
return bin(self._text[0:self._offsets[0]])
@property
def user(self):
off = self._offsets
return encoding.tolocal(self._text[off[0] + 1:off[1]])
@property
def _rawdate(self):
off = self._offsets
dateextra = self._text[off[1] + 1:off[2]]
return dateextra.split(' ', 2)[0:2]
@property
def _rawextra(self):
off = self._offsets
dateextra = self._text[off[1] + 1:off[2]]
fields = dateextra.split(' ', 2)
if len(fields) != 3:
return None
return fields[2]
@property
def date(self):
raw = self._rawdate
time = float(raw[0])
# Various tools did silly things with the timezone.
try:
timezone = int(raw[1])
except ValueError:
timezone = 0
return time, timezone
@property
def extra(self):
raw = self._rawextra
if raw is None:
return _defaultextra
return decodeextra(raw)
@property
def files(self):
off = self._offsets
if off[2] == off[3]:
return []
return self._text[off[2] + 1:off[3]].split('\n')
@property
def p1copies(self):
rawcopies = self.extra.get('p1copies')
return rawcopies and decodecopies(rawcopies)
@property
def p2copies(self):
rawcopies = self.extra.get('p2copies')
return rawcopies and decodecopies(rawcopies)
@property
def description(self):
return encoding.tolocal(self._text[self._offsets[3] + 2:])
class changelog(revlog.revlog):
def __init__(self, opener, trypending=False):
"""Load a changelog revlog using an opener.
If ``trypending`` is true, we attempt to load the index from a
``00changelog.i.a`` file instead of the default ``00changelog.i``.
The ``00changelog.i.a`` file contains index (and possibly inline
revision) data for a transaction that hasn't been finalized yet.
It exists in a separate file to facilitate readers (such as
hooks processes) accessing data before a transaction is finalized.
"""
if trypending and opener.exists('00changelog.i.a'):
indexfile = '00changelog.i.a'
else:
indexfile = '00changelog.i'
datafile = '00changelog.d'
revlog.revlog.__init__(self, opener, indexfile, datafile=datafile,
checkambig=True, mmaplargeindex=True)
if self._initempty and (self.version & 0xFFFF == revlog.REVLOGV1):
# changelogs don't benefit from generaldelta.
self.version &= ~revlog.FLAG_GENERALDELTA
self._generaldelta = False
# Delta chains for changelogs tend to be very small because entries
# tend to be small and don't delta well with each. So disable delta
# chains.
self._storedeltachains = False
self._realopener = opener
self._delayed = False
self._delaybuf = None
self._divert = False
self.filteredrevs = frozenset()
def tiprev(self):
for i in pycompat.xrange(len(self) -1, -2, -1):
if i not in self.filteredrevs:
return i
def tip(self):
"""filtered version of revlog.tip"""
return self.node(self.tiprev())
def __contains__(self, rev):
"""filtered version of revlog.__contains__"""
return (0 <= rev < len(self)
and rev not in self.filteredrevs)
def __iter__(self):
"""filtered version of revlog.__iter__"""
if len(self.filteredrevs) == 0:
return revlog.revlog.__iter__(self)
def filterediter():
for i in pycompat.xrange(len(self)):
if i not in self.filteredrevs:
yield i
return filterediter()
def revs(self, start=0, stop=None):
"""filtered version of revlog.revs"""
for i in super(changelog, self).revs(start, stop):
if i not in self.filteredrevs:
yield i
def reachableroots(self, minroot, heads, roots, includepath=False):
return self.index.reachableroots2(minroot, heads, roots, includepath)
def _checknofilteredinrevs(self, revs):
"""raise the appropriate error if 'revs' contains a filtered revision
This returns a version of 'revs' to be used thereafter by the caller.
In particular, if revs is an iterator, it is converted into a set.
"""
safehasattr = util.safehasattr
if safehasattr(revs, '__next__'):
# Note that inspect.isgenerator() is not true for iterators,
revs = set(revs)
filteredrevs = self.filteredrevs
if safehasattr(revs, 'first'): # smartset
offenders = revs & filteredrevs
else:
offenders = filteredrevs.intersection(revs)
for rev in offenders:
raise error.FilteredIndexError(rev)
return revs
def headrevs(self, revs=None):
if revs is None and self.filteredrevs:
try:
return self.index.headrevsfiltered(self.filteredrevs)
# AttributeError covers non-c-extension environments and
# old c extensions without filter handling.
except AttributeError:
return self._headrevs()
if self.filteredrevs:
revs = self._checknofilteredinrevs(revs)
return super(changelog, self).headrevs(revs)
def strip(self, *args, **kwargs):
# XXX make something better than assert
# We can't expect proper strip behavior if we are filtered.
assert not self.filteredrevs
super(changelog, self).strip(*args, **kwargs)
def rev(self, node):
"""filtered version of revlog.rev"""
r = super(changelog, self).rev(node)
if r in self.filteredrevs:
raise error.FilteredLookupError(hex(node), self.indexfile,
_('filtered node'))
return r
def node(self, rev):
"""filtered version of revlog.node"""
if rev in self.filteredrevs:
raise error.FilteredIndexError(rev)
return super(changelog, self).node(rev)
def linkrev(self, rev):
"""filtered version of revlog.linkrev"""
if rev in self.filteredrevs:
raise error.FilteredIndexError(rev)
return super(changelog, self).linkrev(rev)
def parentrevs(self, rev):
"""filtered version of revlog.parentrevs"""
if rev in self.filteredrevs:
raise error.FilteredIndexError(rev)
return super(changelog, self).parentrevs(rev)
def flags(self, rev):
"""filtered version of revlog.flags"""
if rev in self.filteredrevs:
raise error.FilteredIndexError(rev)
return super(changelog, self).flags(rev)
def delayupdate(self, tr):
"delay visibility of index updates to other readers"
if not self._delayed:
if len(self) == 0:
self._divert = True
if self._realopener.exists(self.indexfile + '.a'):
self._realopener.unlink(self.indexfile + '.a')
self.opener = _divertopener(self._realopener, self.indexfile)
else:
self._delaybuf = []
self.opener = _delayopener(self._realopener, self.indexfile,
self._delaybuf)
self._delayed = True
tr.addpending('cl-%i' % id(self), self._writepending)
tr.addfinalize('cl-%i' % id(self), self._finalize)
def _finalize(self, tr):
"finalize index updates"
self._delayed = False
self.opener = self._realopener
# move redirected index data back into place
if self._divert:
assert not self._delaybuf
tmpname = self.indexfile + ".a"
nfile = self.opener.open(tmpname)
nfile.close()
self.opener.rename(tmpname, self.indexfile, checkambig=True)
elif self._delaybuf:
fp = self.opener(self.indexfile, 'a', checkambig=True)
fp.write("".join(self._delaybuf))
fp.close()
self._delaybuf = None
self._divert = False
# split when we're done
self._enforceinlinesize(tr)
def _writepending(self, tr):
"create a file containing the unfinalized state for pretxnchangegroup"
if self._delaybuf:
# make a temporary copy of the index
fp1 = self._realopener(self.indexfile)
pendingfilename = self.indexfile + ".a"
# register as a temp file to ensure cleanup on failure
tr.registertmp(pendingfilename)
# write existing data
fp2 = self._realopener(pendingfilename, "w")
fp2.write(fp1.read())
# add pending data
fp2.write("".join(self._delaybuf))
fp2.close()
# switch modes so finalize can simply rename
self._delaybuf = None
self._divert = True
self.opener = _divertopener(self._realopener, self.indexfile)
if self._divert:
return True
return False
def _enforceinlinesize(self, tr, fp=None):
if not self._delayed:
revlog.revlog._enforceinlinesize(self, tr, fp)
def read(self, node):
"""Obtain data from a parsed changelog revision.
Returns a 6-tuple of:
- manifest node in binary
- author/user as a localstr
- date as a 2-tuple of (time, timezone)
- list of files
- commit message as a localstr
- dict of extra metadata
Unless you need to access all fields, consider calling
``changelogrevision`` instead, as it is faster for partial object
access.
"""
c = changelogrevision(self.revision(node))
return (
c.manifest,
c.user,
c.date,
c.files,
c.description,
c.extra
)
def changelogrevision(self, nodeorrev):
"""Obtain a ``changelogrevision`` for a node or revision."""
return changelogrevision(self.revision(nodeorrev))
def readfiles(self, node):
"""
short version of read that only returns the files modified by the cset
"""
text = self.revision(node)
if not text:
return []
last = text.index("\n\n")
l = text[:last].split('\n')
return l[3:]
def add(self, manifest, files, desc, transaction, p1, p2,
user, date=None, extra=None, p1copies=None, p2copies=None,
filesadded=None, filesremoved=None):
# Convert to UTF-8 encoded bytestrings as the very first
# thing: calling any method on a localstr object will turn it
# into a str object and the cached UTF-8 string is thus lost.
user, desc = encoding.fromlocal(user), encoding.fromlocal(desc)
user = user.strip()
# An empty username or a username with a "\n" will make the
# revision text contain two "\n\n" sequences -> corrupt
# repository since read cannot unpack the revision.
if not user:
raise error.StorageError(_("empty username"))
if "\n" in user:
raise error.StorageError(_("username %r contains a newline")
% pycompat.bytestr(user))
desc = stripdesc(desc)
if date:
parseddate = "%d %d" % dateutil.parsedate(date)
else:
parseddate = "%d %d" % dateutil.makedate()
if extra:
branch = extra.get("branch")
if branch in ("default", ""):
del extra["branch"]
elif branch in (".", "null", "tip"):
raise error.StorageError(_('the name \'%s\' is reserved')
% branch)
extrasentries = p1copies, p2copies, filesadded, filesremoved
if extra is None and any(x is not None for x in extrasentries):
extra = {}
if p1copies is not None:
extra['p1copies'] = encodecopies(p1copies)
if p2copies is not None:
extra['p2copies'] = encodecopies(p2copies)
sortedfiles = sorted(files)
if filesadded is not None:
extra['filesadded'] = encodefileindices(sortedfiles, filesadded)
if filesremoved is not None:
extra['filesremoved'] = encodefileindices(sortedfiles, filesremoved)
if extra:
extra = encodeextra(extra)
parseddate = "%s %s" % (parseddate, extra)
l = [hex(manifest), user, parseddate] + sortedfiles + ["", desc]
text = "\n".join(l)
return self.addrevision(text, transaction, len(self), p1, p2)
def branchinfo(self, rev):
"""return the branch name and open/close state of a revision
This function exists because creating a changectx object
just to access this is costly."""
extra = self.read(rev)[5]
return encoding.tolocal(extra.get("branch")), 'close' in extra
def _nodeduplicatecallback(self, transaction, node):
# keep track of revisions that got "re-added", eg: unbunde of know rev.
#
# We track them in a list to preserve their order from the source bundle
duplicates = transaction.changes.setdefault('revduplicates', [])
duplicates.append(self.rev(node))