manifest: break mancache into two caches
The old manifest cache cached both the inmemory representation and the raw text.
As part of the manifest refactor we want to separate the storage format from the
in memory representation, so let's split this cache into two caches.
This will let other manifest implementations participate in the in memory cache,
while allowing the revlog based implementations to still depend on the full text
caching where necessary.
# 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
import collections
from .i18n import _
from .node import (
bin,
hex,
nullid,
)
from . import (
encoding,
error,
revlog,
util,
)
_defaultextra = {'branch': 'default'}
def _string_escape(text):
"""
>>> d = {'nl': chr(10), 'bs': chr(92), 'cr': chr(13), 'nul': chr(0)}
>>> s = "ab%(nl)scd%(bs)s%(bs)sn%(nul)sab%(cr)scd%(bs)s%(nl)s" % d
>>> s
'ab\\ncd\\\\\\\\n\\x00ab\\rcd\\\\\\n'
>>> res = _string_escape(s)
>>> s == res.decode('string_escape')
True
"""
# subset of the string_escape codec
text = text.replace('\\', '\\\\').replace('\n', '\\n').replace('\r', '\\r')
return text.replace('\0', '\\0')
def decodeextra(text):
"""
>>> sorted(decodeextra(encodeextra({'foo': 'bar', 'baz': chr(0) + '2'})
... ).iteritems())
[('baz', '\\x002'), ('branch', 'default'), ('foo', 'bar')]
>>> sorted(decodeextra(encodeextra({'foo': 'bar',
... 'baz': chr(92) + chr(0) + '2'})
... ).iteritems())
[('baz', '\\\\\\x002'), ('branch', 'default'), ('foo', 'bar')]
"""
extra = _defaultextra.copy()
for l in text.split('\0'):
if l:
if '\\0' in l:
# fix up \0 without getting into trouble with \\0
l = l.replace('\\\\', '\\\\\n')
l = l.replace('\\0', '\0')
l = l.replace('\n', '')
k, v = l.decode('string_escape').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, d[k])) for k in sorted(d)]
return "\0".join(items)
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
def end(self):
return self.size + len("".join(self.data))
def tell(self):
return self.offset
def flush(self):
pass
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(str(s))
self.offset += len(s)
def _divertopener(opener, target):
"""build an opener that writes in 'target.a' instead of 'target'"""
def _divert(name, mode='r'):
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'):
if name != target:
return opener(name, mode)
return appender(opener, name, mode, buf)
return _delay
_changelogrevision = collections.namedtuple(u'changelogrevision',
(u'manifest', u'user', u'date',
u'files', u'description',
u'extra'))
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__ = (
u'_offsets',
u'_text',
)
def __new__(cls, text):
if not text:
return _changelogrevision(
manifest=nullid,
user='',
date=(0, 0),
files=[],
description='',
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] == '\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 description(self):
return encoding.tolocal(self._text[self._offsets[3] + 2:])
class changelog(revlog.revlog):
def __init__(self, opener):
revlog.revlog.__init__(self, opener, "00changelog.i")
if self._initempty:
# changelogs don't benefit from generaldelta
self.version &= ~revlog.REVLOGGENERALDELTA
self._generaldelta = False
self._realopener = opener
self._delayed = False
self._delaybuf = None
self._divert = False
self.filteredrevs = frozenset()
def tip(self):
"""filtered version of revlog.tip"""
for i in xrange(len(self) -1, -2, -1):
if i not in self.filteredrevs:
return self.node(i)
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 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
@util.propertycache
def nodemap(self):
# XXX need filtering too
self.rev(self.node(0))
return self._nodecache
def reachableroots(self, minroot, heads, roots, includepath=False):
return self.index.reachableroots2(minroot, heads, roots, includepath)
def headrevs(self):
if 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()
return super(changelog, self).headrevs()
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)
elif self._delaybuf:
fp = self.opener(self.indexfile, 'a')
fp.write("".join(self._delaybuf))
fp.close()
self._delaybuf = None
self._divert = False
# split when we're done
self.checkinlinesize(tr)
def readpending(self, file):
"""read index data from a "pending" file
During a transaction, the actual changeset data is already stored in the
main file, but not yet finalized in the on-disk index. Instead, a
"pending" index is written by the transaction logic. If this function
is running, we are likely in a subprocess invoked in a hook. The
subprocess is informed that it is within a transaction and needs to
access its content.
This function will read all the index data out of the pending file and
overwrite the main index."""
if not self.opener.exists(file):
return # no pending data for changelog
r = revlog.revlog(self.opener, file)
self.index = r.index
self.nodemap = r.nodemap
self._nodecache = r._nodecache
self._chunkcache = r._chunkcache
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 checkinlinesize(self, tr, fp=None):
if not self._delayed:
revlog.revlog.checkinlinesize(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):
# 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.RevlogError(_("empty username"))
if "\n" in user:
raise error.RevlogError(_("username %s contains a newline")
% repr(user))
desc = stripdesc(desc)
if date:
parseddate = "%d %d" % util.parsedate(date)
else:
parseddate = "%d %d" % util.makedate()
if extra:
branch = extra.get("branch")
if branch in ("default", ""):
del extra["branch"]
elif branch in (".", "null", "tip"):
raise error.RevlogError(_('the name \'%s\' is reserved')
% branch)
if extra:
extra = encodeextra(extra)
parseddate = "%s %s" % (parseddate, extra)
l = [hex(manifest), user, parseddate] + sorted(files) + ["", 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