##// END OF EJS Templates
git: skeleton of a new extension to _directly_ operate on git repos...
git: skeleton of a new extension to _directly_ operate on git repos This is based in part of work I did years ago in hgit, but it's mostly new code since I'm using pygit2 instead of dulwich and the hg storage interfaces have improved. Some cleanup of old hgit code by Pulkit, which I greatly appreciate. test-git-interop.t does not cover a whole lot of cases, but it passes. It includes status, diff, making a new commit, and `hg annotate` working on the git repository. This is _not_ (yet) production quality code: this is an experiment. Known technical debt lurking in this implementation: * Writing bookmarks just totally ignores transactions. * The way progress is threaded down into the gitstore is awful. * Ideally we'd find a way to incrementally reindex DAGs. I'm not sure how to do that efficiently, so we might need a "known only fast-forwards" mode on the DAG indexer for use on `hg commit` and friends. * We don't even _try_ to do anything reasonable for `hg pull` or `hg push`. * Mercurial need an interface for the changelog type. Tests currently require git 2.24 as far as I'm aware: `git status` has some changed output that I didn't try and handle in a compatible way. This patch has produced some interesting cleanups, most recently on the manifest type. I expect continuing down this road will produce other meritorious cleanups throughout our code. Differential Revision: https://phab.mercurial-scm.org/D6734

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fileserverclient.py
669 lines | 22.3 KiB | text/x-python | PythonLexer
# fileserverclient.py - client for communicating with the cache process
#
# Copyright 2013 Facebook, Inc.
#
# 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 io
import os
import threading
import time
import zlib
from mercurial.i18n import _
from mercurial.node import bin, hex, nullid
from mercurial import (
error,
node,
pycompat,
revlog,
sshpeer,
util,
wireprotov1peer,
)
from mercurial.utils import (
hashutil,
procutil,
)
from . import (
constants,
contentstore,
metadatastore,
)
_sshv1peer = sshpeer.sshv1peer
# Statistics for debugging
fetchcost = 0
fetches = 0
fetched = 0
fetchmisses = 0
_lfsmod = None
def getcachekey(reponame, file, id):
pathhash = node.hex(hashutil.sha1(file).digest())
return os.path.join(reponame, pathhash[:2], pathhash[2:], id)
def getlocalkey(file, id):
pathhash = node.hex(hashutil.sha1(file).digest())
return os.path.join(pathhash, id)
def peersetup(ui, peer):
class remotefilepeer(peer.__class__):
@wireprotov1peer.batchable
def x_rfl_getfile(self, file, node):
if not self.capable(b'x_rfl_getfile'):
raise error.Abort(
b'configured remotefile server does not support getfile'
)
f = wireprotov1peer.future()
yield {b'file': file, b'node': node}, f
code, data = f.value.split(b'\0', 1)
if int(code):
raise error.LookupError(file, node, data)
yield data
@wireprotov1peer.batchable
def x_rfl_getflogheads(self, path):
if not self.capable(b'x_rfl_getflogheads'):
raise error.Abort(
b'configured remotefile server does not '
b'support getflogheads'
)
f = wireprotov1peer.future()
yield {b'path': path}, f
heads = f.value.split(b'\n') if f.value else []
yield heads
def _updatecallstreamopts(self, command, opts):
if command != b'getbundle':
return
if (
constants.NETWORK_CAP_LEGACY_SSH_GETFILES
not in self.capabilities()
):
return
if not util.safehasattr(self, '_localrepo'):
return
if (
constants.SHALLOWREPO_REQUIREMENT
not in self._localrepo.requirements
):
return
bundlecaps = opts.get(b'bundlecaps')
if bundlecaps:
bundlecaps = [bundlecaps]
else:
bundlecaps = []
# shallow, includepattern, and excludepattern are a hacky way of
# carrying over data from the local repo to this getbundle
# command. We need to do it this way because bundle1 getbundle
# doesn't provide any other place we can hook in to manipulate
# getbundle args before it goes across the wire. Once we get rid
# of bundle1, we can use bundle2's _pullbundle2extraprepare to
# do this more cleanly.
bundlecaps.append(constants.BUNDLE2_CAPABLITY)
if self._localrepo.includepattern:
patterns = b'\0'.join(self._localrepo.includepattern)
includecap = b"includepattern=" + patterns
bundlecaps.append(includecap)
if self._localrepo.excludepattern:
patterns = b'\0'.join(self._localrepo.excludepattern)
excludecap = b"excludepattern=" + patterns
bundlecaps.append(excludecap)
opts[b'bundlecaps'] = b','.join(bundlecaps)
def _sendrequest(self, command, args, **opts):
self._updatecallstreamopts(command, args)
return super(remotefilepeer, self)._sendrequest(
command, args, **opts
)
def _callstream(self, command, **opts):
supertype = super(remotefilepeer, self)
if not util.safehasattr(supertype, '_sendrequest'):
self._updatecallstreamopts(command, pycompat.byteskwargs(opts))
return super(remotefilepeer, self)._callstream(command, **opts)
peer.__class__ = remotefilepeer
class cacheconnection(object):
"""The connection for communicating with the remote cache. Performs
gets and sets by communicating with an external process that has the
cache-specific implementation.
"""
def __init__(self):
self.pipeo = self.pipei = self.pipee = None
self.subprocess = None
self.connected = False
def connect(self, cachecommand):
if self.pipeo:
raise error.Abort(_(b"cache connection already open"))
self.pipei, self.pipeo, self.pipee, self.subprocess = procutil.popen4(
cachecommand
)
self.connected = True
def close(self):
def tryclose(pipe):
try:
pipe.close()
except Exception:
pass
if self.connected:
try:
self.pipei.write(b"exit\n")
except Exception:
pass
tryclose(self.pipei)
self.pipei = None
tryclose(self.pipeo)
self.pipeo = None
tryclose(self.pipee)
self.pipee = None
try:
# Wait for process to terminate, making sure to avoid deadlock.
# See https://docs.python.org/2/library/subprocess.html for
# warnings about wait() and deadlocking.
self.subprocess.communicate()
except Exception:
pass
self.subprocess = None
self.connected = False
def request(self, request, flush=True):
if self.connected:
try:
self.pipei.write(request)
if flush:
self.pipei.flush()
except IOError:
self.close()
def receiveline(self):
if not self.connected:
return None
try:
result = self.pipeo.readline()[:-1]
if not result:
self.close()
except IOError:
self.close()
return result
def _getfilesbatch(
remote, receivemissing, progresstick, missed, idmap, batchsize
):
# Over http(s), iterbatch is a streamy method and we can start
# looking at results early. This means we send one (potentially
# large) request, but then we show nice progress as we process
# file results, rather than showing chunks of $batchsize in
# progress.
#
# Over ssh, iterbatch isn't streamy because batch() wasn't
# explicitly designed as a streaming method. In the future we
# should probably introduce a streambatch() method upstream and
# use that for this.
with remote.commandexecutor() as e:
futures = []
for m in missed:
futures.append(
e.callcommand(
b'x_rfl_getfile', {b'file': idmap[m], b'node': m[-40:]}
)
)
for i, m in enumerate(missed):
r = futures[i].result()
futures[i] = None # release memory
file_ = idmap[m]
node = m[-40:]
receivemissing(io.BytesIO(b'%d\n%s' % (len(r), r)), file_, node)
progresstick()
def _getfiles_optimistic(
remote, receivemissing, progresstick, missed, idmap, step
):
remote._callstream(b"x_rfl_getfiles")
i = 0
pipeo = remote._pipeo
pipei = remote._pipei
while i < len(missed):
# issue a batch of requests
start = i
end = min(len(missed), start + step)
i = end
for missingid in missed[start:end]:
# issue new request
versionid = missingid[-40:]
file = idmap[missingid]
sshrequest = b"%s%s\n" % (versionid, file)
pipeo.write(sshrequest)
pipeo.flush()
# receive batch results
for missingid in missed[start:end]:
versionid = missingid[-40:]
file = idmap[missingid]
receivemissing(pipei, file, versionid)
progresstick()
# End the command
pipeo.write(b'\n')
pipeo.flush()
def _getfiles_threaded(
remote, receivemissing, progresstick, missed, idmap, step
):
remote._callstream(b"getfiles")
pipeo = remote._pipeo
pipei = remote._pipei
def writer():
for missingid in missed:
versionid = missingid[-40:]
file = idmap[missingid]
sshrequest = b"%s%s\n" % (versionid, file)
pipeo.write(sshrequest)
pipeo.flush()
writerthread = threading.Thread(target=writer)
writerthread.daemon = True
writerthread.start()
for missingid in missed:
versionid = missingid[-40:]
file = idmap[missingid]
receivemissing(pipei, file, versionid)
progresstick()
writerthread.join()
# End the command
pipeo.write(b'\n')
pipeo.flush()
class fileserverclient(object):
"""A client for requesting files from the remote file server.
"""
def __init__(self, repo):
ui = repo.ui
self.repo = repo
self.ui = ui
self.cacheprocess = ui.config(b"remotefilelog", b"cacheprocess")
if self.cacheprocess:
self.cacheprocess = util.expandpath(self.cacheprocess)
# This option causes remotefilelog to pass the full file path to the
# cacheprocess instead of a hashed key.
self.cacheprocesspasspath = ui.configbool(
b"remotefilelog", b"cacheprocess.includepath"
)
self.debugoutput = ui.configbool(b"remotefilelog", b"debug")
self.remotecache = cacheconnection()
def setstore(self, datastore, historystore, writedata, writehistory):
self.datastore = datastore
self.historystore = historystore
self.writedata = writedata
self.writehistory = writehistory
def _connect(self):
return self.repo.connectionpool.get(self.repo.fallbackpath)
def request(self, fileids):
"""Takes a list of filename/node pairs and fetches them from the
server. Files are stored in the local cache.
A list of nodes that the server couldn't find is returned.
If the connection fails, an exception is raised.
"""
if not self.remotecache.connected:
self.connect()
cache = self.remotecache
writedata = self.writedata
repo = self.repo
total = len(fileids)
request = b"get\n%d\n" % total
idmap = {}
reponame = repo.name
for file, id in fileids:
fullid = getcachekey(reponame, file, id)
if self.cacheprocesspasspath:
request += file + b'\0'
request += fullid + b"\n"
idmap[fullid] = file
cache.request(request)
progress = self.ui.makeprogress(_(b'downloading'), total=total)
progress.update(0)
missed = []
while True:
missingid = cache.receiveline()
if not missingid:
missedset = set(missed)
for missingid in idmap:
if not missingid in missedset:
missed.append(missingid)
self.ui.warn(
_(
b"warning: cache connection closed early - "
+ b"falling back to server\n"
)
)
break
if missingid == b"0":
break
if missingid.startswith(b"_hits_"):
# receive progress reports
parts = missingid.split(b"_")
progress.increment(int(parts[2]))
continue
missed.append(missingid)
global fetchmisses
fetchmisses += len(missed)
fromcache = total - len(missed)
progress.update(fromcache, total=total)
self.ui.log(
b"remotefilelog",
b"remote cache hit rate is %r of %r\n",
fromcache,
total,
hit=fromcache,
total=total,
)
oldumask = os.umask(0o002)
try:
# receive cache misses from master
if missed:
# When verbose is true, sshpeer prints 'running ssh...'
# to stdout, which can interfere with some command
# outputs
verbose = self.ui.verbose
self.ui.verbose = False
try:
with self._connect() as conn:
remote = conn.peer
if remote.capable(
constants.NETWORK_CAP_LEGACY_SSH_GETFILES
):
if not isinstance(remote, _sshv1peer):
raise error.Abort(
b'remotefilelog requires ssh servers'
)
step = self.ui.configint(
b'remotefilelog', b'getfilesstep'
)
getfilestype = self.ui.config(
b'remotefilelog', b'getfilestype'
)
if getfilestype == b'threaded':
_getfiles = _getfiles_threaded
else:
_getfiles = _getfiles_optimistic
_getfiles(
remote,
self.receivemissing,
progress.increment,
missed,
idmap,
step,
)
elif remote.capable(b"x_rfl_getfile"):
if remote.capable(b'batch'):
batchdefault = 100
else:
batchdefault = 10
batchsize = self.ui.configint(
b'remotefilelog', b'batchsize', batchdefault
)
self.ui.debug(
b'requesting %d files from '
b'remotefilelog server...\n' % len(missed)
)
_getfilesbatch(
remote,
self.receivemissing,
progress.increment,
missed,
idmap,
batchsize,
)
else:
raise error.Abort(
b"configured remotefilelog server"
b" does not support remotefilelog"
)
self.ui.log(
b"remotefilefetchlog",
b"Success\n",
fetched_files=progress.pos - fromcache,
total_to_fetch=total - fromcache,
)
except Exception:
self.ui.log(
b"remotefilefetchlog",
b"Fail\n",
fetched_files=progress.pos - fromcache,
total_to_fetch=total - fromcache,
)
raise
finally:
self.ui.verbose = verbose
# send to memcache
request = b"set\n%d\n%s\n" % (len(missed), b"\n".join(missed))
cache.request(request)
progress.complete()
# mark ourselves as a user of this cache
writedata.markrepo(self.repo.path)
finally:
os.umask(oldumask)
def receivemissing(self, pipe, filename, node):
line = pipe.readline()[:-1]
if not line:
raise error.ResponseError(
_(b"error downloading file contents:"),
_(b"connection closed early"),
)
size = int(line)
data = pipe.read(size)
if len(data) != size:
raise error.ResponseError(
_(b"error downloading file contents:"),
_(b"only received %s of %s bytes") % (len(data), size),
)
self.writedata.addremotefilelognode(
filename, bin(node), zlib.decompress(data)
)
def connect(self):
if self.cacheprocess:
cmd = b"%s %s" % (self.cacheprocess, self.writedata._path)
self.remotecache.connect(cmd)
else:
# If no cache process is specified, we fake one that always
# returns cache misses. This enables tests to run easily
# and may eventually allow us to be a drop in replacement
# for the largefiles extension.
class simplecache(object):
def __init__(self):
self.missingids = []
self.connected = True
def close(self):
pass
def request(self, value, flush=True):
lines = value.split(b"\n")
if lines[0] != b"get":
return
self.missingids = lines[2:-1]
self.missingids.append(b'0')
def receiveline(self):
if len(self.missingids) > 0:
return self.missingids.pop(0)
return None
self.remotecache = simplecache()
def close(self):
if fetches:
msg = (
b"%d files fetched over %d fetches - "
+ b"(%d misses, %0.2f%% hit ratio) over %0.2fs\n"
) % (
fetched,
fetches,
fetchmisses,
float(fetched - fetchmisses) / float(fetched) * 100.0,
fetchcost,
)
if self.debugoutput:
self.ui.warn(msg)
self.ui.log(
b"remotefilelog.prefetch",
msg.replace(b"%", b"%%"),
remotefilelogfetched=fetched,
remotefilelogfetches=fetches,
remotefilelogfetchmisses=fetchmisses,
remotefilelogfetchtime=fetchcost * 1000,
)
if self.remotecache.connected:
self.remotecache.close()
def prefetch(
self, fileids, force=False, fetchdata=True, fetchhistory=False
):
"""downloads the given file versions to the cache
"""
repo = self.repo
idstocheck = []
for file, id in fileids:
# hack
# - we don't use .hgtags
# - workingctx produces ids with length 42,
# which we skip since they aren't in any cache
if (
file == b'.hgtags'
or len(id) == 42
or not repo.shallowmatch(file)
):
continue
idstocheck.append((file, bin(id)))
datastore = self.datastore
historystore = self.historystore
if force:
datastore = contentstore.unioncontentstore(*repo.shareddatastores)
historystore = metadatastore.unionmetadatastore(
*repo.sharedhistorystores
)
missingids = set()
if fetchdata:
missingids.update(datastore.getmissing(idstocheck))
if fetchhistory:
missingids.update(historystore.getmissing(idstocheck))
# partition missing nodes into nullid and not-nullid so we can
# warn about this filtering potentially shadowing bugs.
nullids = len([None for unused, id in missingids if id == nullid])
if nullids:
missingids = [(f, id) for f, id in missingids if id != nullid]
repo.ui.develwarn(
(
b'remotefilelog not fetching %d null revs'
b' - this is likely hiding bugs' % nullids
),
config=b'remotefilelog-ext',
)
if missingids:
global fetches, fetched, fetchcost
fetches += 1
# We want to be able to detect excess individual file downloads, so
# let's log that information for debugging.
if fetches >= 15 and fetches < 18:
if fetches == 15:
fetchwarning = self.ui.config(
b'remotefilelog', b'fetchwarning'
)
if fetchwarning:
self.ui.warn(fetchwarning + b'\n')
self.logstacktrace()
missingids = [(file, hex(id)) for file, id in sorted(missingids)]
fetched += len(missingids)
start = time.time()
missingids = self.request(missingids)
if missingids:
raise error.Abort(
_(b"unable to download %d files") % len(missingids)
)
fetchcost += time.time() - start
self._lfsprefetch(fileids)
def _lfsprefetch(self, fileids):
if not _lfsmod or not util.safehasattr(
self.repo.svfs, b'lfslocalblobstore'
):
return
if not _lfsmod.wrapper.candownload(self.repo):
return
pointers = []
store = self.repo.svfs.lfslocalblobstore
for file, id in fileids:
node = bin(id)
rlog = self.repo.file(file)
if rlog.flags(node) & revlog.REVIDX_EXTSTORED:
text = rlog.rawdata(node)
p = _lfsmod.pointer.deserialize(text)
oid = p.oid()
if not store.has(oid):
pointers.append(p)
if len(pointers) > 0:
self.repo.svfs.lfsremoteblobstore.readbatch(pointers, store)
assert all(store.has(p.oid()) for p in pointers)
def logstacktrace(self):
import traceback
self.ui.log(
b'remotefilelog',
b'excess remotefilelog fetching:\n%s\n',
b''.join(pycompat.sysbytes(s) for s in traceback.format_stack()),
)