tags: make argument 'tagtype' optional in '_updatetags'
This is the next step from the previous changesets, we are now ready to use this
function in a simpler way.
# tags.py - read tag info from local repository
#
# Copyright 2009 Matt Mackall <mpm@selenic.com>
# Copyright 2009 Greg Ward <greg@gerg.ca>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
# Currently this module only deals with reading and caching tags.
# Eventually, it could take care of updating (adding/removing/moving)
# tags too.
from __future__ import absolute_import
import errno
from .node import (
bin,
hex,
nullid,
short,
)
from .i18n import _
from . import (
encoding,
error,
match as matchmod,
scmutil,
util,
)
# Tags computation can be expensive and caches exist to make it fast in
# the common case.
#
# The "hgtagsfnodes1" cache file caches the .hgtags filenode values for
# each revision in the repository. The file is effectively an array of
# fixed length records. Read the docs for "hgtagsfnodescache" for technical
# details.
#
# The .hgtags filenode cache grows in proportion to the length of the
# changelog. The file is truncated when the # changelog is stripped.
#
# The purpose of the filenode cache is to avoid the most expensive part
# of finding global tags, which is looking up the .hgtags filenode in the
# manifest for each head. This can take dozens or over 100ms for
# repositories with very large manifests. Multiplied by dozens or even
# hundreds of heads and there is a significant performance concern.
#
# There also exist a separate cache file for each repository filter.
# These "tags-*" files store information about the history of tags.
#
# The tags cache files consists of a cache validation line followed by
# a history of tags.
#
# The cache validation line has the format:
#
# <tiprev> <tipnode> [<filteredhash>]
#
# <tiprev> is an integer revision and <tipnode> is a 40 character hex
# node for that changeset. These redundantly identify the repository
# tip from the time the cache was written. In addition, <filteredhash>,
# if present, is a 40 character hex hash of the contents of the filtered
# revisions for this filter. If the set of filtered revs changes, the
# hash will change and invalidate the cache.
#
# The history part of the tags cache consists of lines of the form:
#
# <node> <tag>
#
# (This format is identical to that of .hgtags files.)
#
# <tag> is the tag name and <node> is the 40 character hex changeset
# the tag is associated with.
#
# Tags are written sorted by tag name.
#
# Tags associated with multiple changesets have an entry for each changeset.
# The most recent changeset (in terms of revlog ordering for the head
# setting it) for each tag is last.
def findglobaltags(ui, repo):
'''Find global tags in a repo: return (alltags, tagtypes)
"alltags" maps tag name to (node, hist) 2-tuples.
"tagtypes" maps tag name to tag type. Global tags always have the
"global" tag type.
The tags cache is read and updated as a side-effect of calling.
'''
alltags = {}
tagtypes = {}
(heads, tagfnode, valid, cachetags, shouldwrite) = _readtagcache(ui, repo)
if cachetags is not None:
assert not shouldwrite
# XXX is this really 100% correct? are there oddball special
# cases where a global tag should outrank a local tag but won't,
# because cachetags does not contain rank info?
_updatetags(cachetags, alltags, 'global', tagtypes)
return alltags, tagtypes
seen = set() # set of fnode
fctx = None
for head in reversed(heads): # oldest to newest
assert head in repo.changelog.nodemap, \
"tag cache returned bogus head %s" % short(head)
fnode = tagfnode.get(head)
if fnode and fnode not in seen:
seen.add(fnode)
if not fctx:
fctx = repo.filectx('.hgtags', fileid=fnode)
else:
fctx = fctx.filectx(fnode)
filetags = _readtags(ui, repo, fctx.data().splitlines(), fctx)
_updatetags(filetags, alltags, 'global', tagtypes)
# and update the cache (if necessary)
if shouldwrite:
_writetagcache(ui, repo, valid, alltags)
return alltags, tagtypes
def readlocaltags(ui, repo, alltags, tagtypes):
'''Read local tags in repo. Update alltags and tagtypes.'''
try:
data = repo.vfs.read("localtags")
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
return
# localtags is in the local encoding; re-encode to UTF-8 on
# input for consistency with the rest of this module.
filetags = _readtags(
ui, repo, data.splitlines(), "localtags",
recode=encoding.fromlocal)
# remove tags pointing to invalid nodes
cl = repo.changelog
for t in filetags.keys():
try:
cl.rev(filetags[t][0])
except (LookupError, ValueError):
del filetags[t]
_updatetags(filetags, alltags, 'local', tagtypes)
def _readtaghist(ui, repo, lines, fn, recode=None, calcnodelines=False):
'''Read tag definitions from a file (or any source of lines).
This function returns two sortdicts with similar information:
- the first dict, bintaghist, contains the tag information as expected by
the _readtags function, i.e. a mapping from tag name to (node, hist):
- node is the node id from the last line read for that name,
- hist is the list of node ids previously associated with it (in file
order). All node ids are binary, not hex.
- the second dict, hextaglines, is a mapping from tag name to a list of
[hexnode, line number] pairs, ordered from the oldest to the newest node.
When calcnodelines is False the hextaglines dict is not calculated (an
empty dict is returned). This is done to improve this function's
performance in cases where the line numbers are not needed.
'''
bintaghist = util.sortdict()
hextaglines = util.sortdict()
count = 0
def dbg(msg):
ui.debug("%s, line %s: %s\n" % (fn, count, msg))
for nline, line in enumerate(lines):
count += 1
if not line:
continue
try:
(nodehex, name) = line.split(" ", 1)
except ValueError:
dbg("cannot parse entry")
continue
name = name.strip()
if recode:
name = recode(name)
try:
nodebin = bin(nodehex)
except TypeError:
dbg("node '%s' is not well formed" % nodehex)
continue
# update filetags
if calcnodelines:
# map tag name to a list of line numbers
if name not in hextaglines:
hextaglines[name] = []
hextaglines[name].append([nodehex, nline])
continue
# map tag name to (node, hist)
if name not in bintaghist:
bintaghist[name] = []
bintaghist[name].append(nodebin)
return bintaghist, hextaglines
def _readtags(ui, repo, lines, fn, recode=None, calcnodelines=False):
'''Read tag definitions from a file (or any source of lines).
Returns a mapping from tag name to (node, hist).
"node" is the node id from the last line read for that name. "hist"
is the list of node ids previously associated with it (in file order).
All node ids are binary, not hex.
'''
filetags, nodelines = _readtaghist(ui, repo, lines, fn, recode=recode,
calcnodelines=calcnodelines)
# util.sortdict().__setitem__ is much slower at replacing then inserting
# new entries. The difference can matter if there are thousands of tags.
# Create a new sortdict to avoid the performance penalty.
newtags = util.sortdict()
for tag, taghist in filetags.items():
newtags[tag] = (taghist[-1], taghist[:-1])
return newtags
def _updatetags(filetags, alltags, tagtype=None, tagtypes=None):
"""Incorporate the tag info read from one file into dictionnaries
The first one, 'alltags', is a "tagmaps" (see 'findglobaltags' for details).
The second one, 'tagtypes', is optional and will be updated to track the
"tagtype" of entries in the tagmaps. When set, the 'tagtype' argument also
needs to be set."""
if tagtype is None:
assert tagtypes is None
for name, nodehist in filetags.iteritems():
if name not in alltags:
alltags[name] = nodehist
if tagtype is not None:
tagtypes[name] = tagtype
continue
# we prefer alltags[name] if:
# it supersedes us OR
# mutual supersedes and it has a higher rank
# otherwise we win because we're tip-most
anode, ahist = nodehist
bnode, bhist = alltags[name]
if (bnode != anode and anode in bhist and
(bnode not in ahist or len(bhist) > len(ahist))):
anode = bnode
elif tagtype is not None:
tagtypes[name] = tagtype
ahist.extend([n for n in bhist if n not in ahist])
alltags[name] = anode, ahist
def _filename(repo):
"""name of a tagcache file for a given repo or repoview"""
filename = 'cache/tags2'
if repo.filtername:
filename = '%s-%s' % (filename, repo.filtername)
return filename
def _readtagcache(ui, repo):
'''Read the tag cache.
Returns a tuple (heads, fnodes, validinfo, cachetags, shouldwrite).
If the cache is completely up-to-date, "cachetags" is a dict of the
form returned by _readtags() and "heads", "fnodes", and "validinfo" are
None and "shouldwrite" is False.
If the cache is not up to date, "cachetags" is None. "heads" is a list
of all heads currently in the repository, ordered from tip to oldest.
"validinfo" is a tuple describing cache validation info. This is used
when writing the tags cache. "fnodes" is a mapping from head to .hgtags
filenode. "shouldwrite" is True.
If the cache is not up to date, the caller is responsible for reading tag
info from each returned head. (See findglobaltags().)
'''
try:
cachefile = repo.vfs(_filename(repo), 'r')
# force reading the file for static-http
cachelines = iter(cachefile)
except IOError:
cachefile = None
cacherev = None
cachenode = None
cachehash = None
if cachefile:
try:
validline = next(cachelines)
validline = validline.split()
cacherev = int(validline[0])
cachenode = bin(validline[1])
if len(validline) > 2:
cachehash = bin(validline[2])
except Exception:
# corruption of the cache, just recompute it.
pass
tipnode = repo.changelog.tip()
tiprev = len(repo.changelog) - 1
# Case 1 (common): tip is the same, so nothing has changed.
# (Unchanged tip trivially means no changesets have been added.
# But, thanks to localrepository.destroyed(), it also means none
# have been destroyed by strip or rollback.)
if (cacherev == tiprev
and cachenode == tipnode
and cachehash == scmutil.filteredhash(repo, tiprev)):
tags = _readtags(ui, repo, cachelines, cachefile.name)
cachefile.close()
return (None, None, None, tags, False)
if cachefile:
cachefile.close() # ignore rest of file
valid = (tiprev, tipnode, scmutil.filteredhash(repo, tiprev))
repoheads = repo.heads()
# Case 2 (uncommon): empty repo; get out quickly and don't bother
# writing an empty cache.
if repoheads == [nullid]:
return ([], {}, valid, {}, False)
# Case 3 (uncommon): cache file missing or empty.
# Case 4 (uncommon): tip rev decreased. This should only happen
# when we're called from localrepository.destroyed(). Refresh the
# cache so future invocations will not see disappeared heads in the
# cache.
# Case 5 (common): tip has changed, so we've added/replaced heads.
# As it happens, the code to handle cases 3, 4, 5 is the same.
# N.B. in case 4 (nodes destroyed), "new head" really means "newly
# exposed".
if not len(repo.file('.hgtags')):
# No tags have ever been committed, so we can avoid a
# potentially expensive search.
return ([], {}, valid, None, True)
# Now we have to lookup the .hgtags filenode for every new head.
# This is the most expensive part of finding tags, so performance
# depends primarily on the size of newheads. Worst case: no cache
# file, so newheads == repoheads.
cachefnode = _getfnodes(ui, repo, repoheads)
# Caller has to iterate over all heads, but can use the filenodes in
# cachefnode to get to each .hgtags revision quickly.
return (repoheads, cachefnode, valid, None, True)
def _getfnodes(ui, repo, nodes):
"""return .hgtags fnodes for a list of changeset nodes
Return value is a {node: fnode} mapping. There will be no entry for nodes
without a '.hgtags' file.
"""
starttime = util.timer()
fnodescache = hgtagsfnodescache(repo.unfiltered())
cachefnode = {}
for head in reversed(nodes):
fnode = fnodescache.getfnode(head)
if fnode != nullid:
cachefnode[head] = fnode
fnodescache.write()
duration = util.timer() - starttime
ui.log('tagscache',
'%d/%d cache hits/lookups in %0.4f '
'seconds\n',
fnodescache.hitcount, fnodescache.lookupcount, duration)
return cachefnode
def _writetagcache(ui, repo, valid, cachetags):
filename = _filename(repo)
try:
cachefile = repo.vfs(filename, 'w', atomictemp=True)
except (OSError, IOError):
return
ui.log('tagscache', 'writing .hg/%s with %d tags\n',
filename, len(cachetags))
if valid[2]:
cachefile.write('%d %s %s\n' % (valid[0], hex(valid[1]), hex(valid[2])))
else:
cachefile.write('%d %s\n' % (valid[0], hex(valid[1])))
# Tag names in the cache are in UTF-8 -- which is the whole reason
# we keep them in UTF-8 throughout this module. If we converted
# them local encoding on input, we would lose info writing them to
# the cache.
for (name, (node, hist)) in sorted(cachetags.iteritems()):
for n in hist:
cachefile.write("%s %s\n" % (hex(n), name))
cachefile.write("%s %s\n" % (hex(node), name))
try:
cachefile.close()
except (OSError, IOError):
pass
def tag(repo, names, node, message, local, user, date, editor=False):
'''tag a revision with one or more symbolic names.
names is a list of strings or, when adding a single tag, names may be a
string.
if local is True, the tags are stored in a per-repository file.
otherwise, they are stored in the .hgtags file, and a new
changeset is committed with the change.
keyword arguments:
local: whether to store tags in non-version-controlled file
(default False)
message: commit message to use if committing
user: name of user to use if committing
date: date tuple to use if committing'''
if not local:
m = matchmod.exact(repo.root, '', ['.hgtags'])
if any(repo.status(match=m, unknown=True, ignored=True)):
raise error.Abort(_('working copy of .hgtags is changed'),
hint=_('please commit .hgtags manually'))
repo.tags() # instantiate the cache
_tag(repo.unfiltered(), names, node, message, local, user, date,
editor=editor)
def _tag(repo, names, node, message, local, user, date, extra=None,
editor=False):
if isinstance(names, str):
names = (names,)
branches = repo.branchmap()
for name in names:
repo.hook('pretag', throw=True, node=hex(node), tag=name,
local=local)
if name in branches:
repo.ui.warn(_("warning: tag %s conflicts with existing"
" branch name\n") % name)
def writetags(fp, names, munge, prevtags):
fp.seek(0, 2)
if prevtags and prevtags[-1] != '\n':
fp.write('\n')
for name in names:
if munge:
m = munge(name)
else:
m = name
if (repo._tagscache.tagtypes and
name in repo._tagscache.tagtypes):
old = repo.tags().get(name, nullid)
fp.write('%s %s\n' % (hex(old), m))
fp.write('%s %s\n' % (hex(node), m))
fp.close()
prevtags = ''
if local:
try:
fp = repo.vfs('localtags', 'r+')
except IOError:
fp = repo.vfs('localtags', 'a')
else:
prevtags = fp.read()
# local tags are stored in the current charset
writetags(fp, names, None, prevtags)
for name in names:
repo.hook('tag', node=hex(node), tag=name, local=local)
return
try:
fp = repo.wvfs('.hgtags', 'rb+')
except IOError as e:
if e.errno != errno.ENOENT:
raise
fp = repo.wvfs('.hgtags', 'ab')
else:
prevtags = fp.read()
# committed tags are stored in UTF-8
writetags(fp, names, encoding.fromlocal, prevtags)
fp.close()
repo.invalidatecaches()
if '.hgtags' not in repo.dirstate:
repo[None].add(['.hgtags'])
m = matchmod.exact(repo.root, '', ['.hgtags'])
tagnode = repo.commit(message, user, date, extra=extra, match=m,
editor=editor)
for name in names:
repo.hook('tag', node=hex(node), tag=name, local=local)
return tagnode
_fnodescachefile = 'cache/hgtagsfnodes1'
_fnodesrecsize = 4 + 20 # changeset fragment + filenode
_fnodesmissingrec = '\xff' * 24
class hgtagsfnodescache(object):
"""Persistent cache mapping revisions to .hgtags filenodes.
The cache is an array of records. Each item in the array corresponds to
a changelog revision. Values in the array contain the first 4 bytes of
the node hash and the 20 bytes .hgtags filenode for that revision.
The first 4 bytes are present as a form of verification. Repository
stripping and rewriting may change the node at a numeric revision in the
changelog. The changeset fragment serves as a verifier to detect
rewriting. This logic is shared with the rev branch cache (see
branchmap.py).
The instance holds in memory the full cache content but entries are
only parsed on read.
Instances behave like lists. ``c[i]`` works where i is a rev or
changeset node. Missing indexes are populated automatically on access.
"""
def __init__(self, repo):
assert repo.filtername is None
self._repo = repo
# Only for reporting purposes.
self.lookupcount = 0
self.hitcount = 0
try:
data = repo.vfs.read(_fnodescachefile)
except (OSError, IOError):
data = ""
self._raw = bytearray(data)
# The end state of self._raw is an array that is of the exact length
# required to hold a record for every revision in the repository.
# We truncate or extend the array as necessary. self._dirtyoffset is
# defined to be the start offset at which we need to write the output
# file. This offset is also adjusted when new entries are calculated
# for array members.
cllen = len(repo.changelog)
wantedlen = cllen * _fnodesrecsize
rawlen = len(self._raw)
self._dirtyoffset = None
if rawlen < wantedlen:
self._dirtyoffset = rawlen
self._raw.extend('\xff' * (wantedlen - rawlen))
elif rawlen > wantedlen:
# There's no easy way to truncate array instances. This seems
# slightly less evil than copying a potentially large array slice.
for i in range(rawlen - wantedlen):
self._raw.pop()
self._dirtyoffset = len(self._raw)
def getfnode(self, node, computemissing=True):
"""Obtain the filenode of the .hgtags file at a specified revision.
If the value is in the cache, the entry will be validated and returned.
Otherwise, the filenode will be computed and returned unless
"computemissing" is False, in which case None will be returned without
any potentially expensive computation being performed.
If an .hgtags does not exist at the specified revision, nullid is
returned.
"""
ctx = self._repo[node]
rev = ctx.rev()
self.lookupcount += 1
offset = rev * _fnodesrecsize
record = '%s' % self._raw[offset:offset + _fnodesrecsize]
properprefix = node[0:4]
# Validate and return existing entry.
if record != _fnodesmissingrec:
fileprefix = record[0:4]
if fileprefix == properprefix:
self.hitcount += 1
return record[4:]
# Fall through.
# If we get here, the entry is either missing or invalid.
if not computemissing:
return None
# Populate missing entry.
try:
fnode = ctx.filenode('.hgtags')
except error.LookupError:
# No .hgtags file on this revision.
fnode = nullid
self._writeentry(offset, properprefix, fnode)
return fnode
def setfnode(self, node, fnode):
"""Set the .hgtags filenode for a given changeset."""
assert len(fnode) == 20
ctx = self._repo[node]
# Do a lookup first to avoid writing if nothing has changed.
if self.getfnode(ctx.node(), computemissing=False) == fnode:
return
self._writeentry(ctx.rev() * _fnodesrecsize, node[0:4], fnode)
def _writeentry(self, offset, prefix, fnode):
# Slices on array instances only accept other array.
entry = bytearray(prefix + fnode)
self._raw[offset:offset + _fnodesrecsize] = entry
# self._dirtyoffset could be None.
self._dirtyoffset = min(self._dirtyoffset, offset) or 0
def write(self):
"""Perform all necessary writes to cache file.
This may no-op if no writes are needed or if a write lock could
not be obtained.
"""
if self._dirtyoffset is None:
return
data = self._raw[self._dirtyoffset:]
if not data:
return
repo = self._repo
try:
lock = repo.wlock(wait=False)
except error.LockError:
repo.ui.log('tagscache',
'not writing .hg/%s because lock cannot be acquired\n' %
(_fnodescachefile))
return
try:
f = repo.vfs.open(_fnodescachefile, 'ab')
try:
# if the file has been truncated
actualoffset = f.tell()
if actualoffset < self._dirtyoffset:
self._dirtyoffset = actualoffset
data = self._raw[self._dirtyoffset:]
f.seek(self._dirtyoffset)
f.truncate()
repo.ui.log('tagscache',
'writing %d bytes to %s\n' % (
len(data), _fnodescachefile))
f.write(data)
self._dirtyoffset = None
finally:
f.close()
except (IOError, OSError) as inst:
repo.ui.log('tagscache',
"couldn't write %s: %s\n" % (
_fnodescachefile, inst))
finally:
lock.release()