Mercurial > hg
view mercurial/sshserver.py @ 27895:2d6a89e79b48
scmutil: support background file closing
Closing files that have been appended to is relatively slow on
Windows/NTFS. This makes several Mercurial operations slower on
Windows.
The workaround to this issue is conceptually simple: use multiple
threads for I/O. Unfortunately, Python doesn't scale well to multiple
threads because of the GIL. And, refactoring our code to use threads
everywhere would be a huge undertaking. So, we decide to tackle this
problem by starting small: establishing a thread pool for closing
files.
This patch establishes a mechanism for closing file handles on separate
threads. The coordinator object is basically a queue of file handles to
operate on and a thread pool consuming from the queue.
When files are opened through the VFS layer, the caller can specify
that delay closing is allowed.
A proxy class for file handles has been added. We must use a proxy
because it isn't possible to modify __class__ on built-in types. This
adds some overhead. But as future patches will show, this overhead
is cancelled out by the benefit of closing file handles on background
threads.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 14 Jan 2016 13:34:59 -0800 |
parents | 56b2bcea2529 |
children | 98e8313dcd9e |
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# sshserver.py - ssh protocol server support for mercurial # # Copyright 2005-2007 Matt Mackall <mpm@selenic.com> # Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.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 os import sys from . import ( error, hook, util, wireproto, ) class sshserver(wireproto.abstractserverproto): def __init__(self, ui, repo): self.ui = ui self.repo = repo self.lock = None self.fin = ui.fin self.fout = ui.fout hook.redirect(True) ui.fout = repo.ui.fout = ui.ferr # Prevent insertion/deletion of CRs util.setbinary(self.fin) util.setbinary(self.fout) def getargs(self, args): data = {} keys = args.split() for n in xrange(len(keys)): argline = self.fin.readline()[:-1] arg, l = argline.split() if arg not in keys: raise error.Abort("unexpected parameter %r" % arg) if arg == '*': star = {} for k in xrange(int(l)): argline = self.fin.readline()[:-1] arg, l = argline.split() val = self.fin.read(int(l)) star[arg] = val data['*'] = star else: val = self.fin.read(int(l)) data[arg] = val return [data[k] for k in keys] def getarg(self, name): return self.getargs(name)[0] def getfile(self, fpout): self.sendresponse('') count = int(self.fin.readline()) while count: fpout.write(self.fin.read(count)) count = int(self.fin.readline()) def redirect(self): pass def groupchunks(self, changegroup): while True: d = changegroup.read(4096) if not d: break yield d def sendresponse(self, v): self.fout.write("%d\n" % len(v)) self.fout.write(v) self.fout.flush() def sendstream(self, source): write = self.fout.write for chunk in source.gen: write(chunk) self.fout.flush() def sendpushresponse(self, rsp): self.sendresponse('') self.sendresponse(str(rsp.res)) def sendpusherror(self, rsp): self.sendresponse(rsp.res) def sendooberror(self, rsp): self.ui.ferr.write('%s\n-\n' % rsp.message) self.ui.ferr.flush() self.fout.write('\n') self.fout.flush() def serve_forever(self): try: while self.serve_one(): pass finally: if self.lock is not None: self.lock.release() sys.exit(0) handlers = { str: sendresponse, wireproto.streamres: sendstream, wireproto.pushres: sendpushresponse, wireproto.pusherr: sendpusherror, wireproto.ooberror: sendooberror, } def serve_one(self): cmd = self.fin.readline()[:-1] if cmd and cmd in wireproto.commands: rsp = wireproto.dispatch(self.repo, self, cmd) self.handlers[rsp.__class__](self, rsp) elif cmd: impl = getattr(self, 'do_' + cmd, None) if impl: r = impl() if r is not None: self.sendresponse(r) else: self.sendresponse("") return cmd != '' def _client(self): client = os.environ.get('SSH_CLIENT', '').split(' ', 1)[0] return 'remote:ssh:' + client