Mercurial > hg-stable
view mercurial/hgweb/server.py @ 30451:41a8106789ca
util: implement zstd compression engine
Now that zstd is vendored and being built (in some configurations), we
can implement a compression engine for zstd!
The zstd engine is a little different from existing engines. Because
it may not always be present, we have to defer load the module in case
importing it fails. We facilitate this via a cached property that holds
a reference to the module or None. The "available" method is
implemented to reflect reality.
The zstd engine declares its ability to handle bundles using the
"zstd" human name and the "ZS" internal name. The latter was chosen
because internal names are 2 characters (by only convention I think)
and "ZS" seems reasonable.
The engine, like others, supports specifying the compression level.
However, there are no consumers of this API that yet pass in that
argument. I have plans to change that, so stay tuned.
Since all we need to do to support bundle generation with a new
compression engine is implement and register the compression engine,
bundle generation with zstd "just works!" Tests demonstrating this
have been added.
How does performance of zstd for bundle generation compare? On the
mozilla-unified repo, `hg bundle --all -t <engine>-v2` yields the
following on my i7-6700K on Linux:
engine CPU time bundle size vs orig size throughput
none 97.0s 4,054,405,584 100.0% 41.8 MB/s
bzip2 (l=9) 393.6s 975,343,098 24.0% 10.3 MB/s
gzip (l=6) 184.0s 1,140,533,074 28.1% 22.0 MB/s
zstd (l=1) 108.2s 1,119,434,718 27.6% 37.5 MB/s
zstd (l=2) 111.3s 1,078,328,002 26.6% 36.4 MB/s
zstd (l=3) 113.7s 1,011,823,727 25.0% 35.7 MB/s
zstd (l=4) 116.0s 1,008,965,888 24.9% 35.0 MB/s
zstd (l=5) 121.0s 977,203,148 24.1% 33.5 MB/s
zstd (l=6) 131.7s 927,360,198 22.9% 30.8 MB/s
zstd (l=7) 139.0s 912,808,505 22.5% 29.2 MB/s
zstd (l=12) 198.1s 854,527,714 21.1% 20.5 MB/s
zstd (l=18) 681.6s 789,750,690 19.5% 5.9 MB/s
On compression, zstd for bundle generation delivers:
* better compression than gzip with significantly less CPU utilization
* better than bzip2 compression ratios while still being significantly
faster than gzip
* ability to aggressively tune compression level to achieve
significantly smaller bundles
That last point is important. With clone bundles, a server can
pre-generate a bundle file, upload it to a static file server, and
redirect clients to transparently download it during clone. The server
could choose to produce a zstd bundle with the highest compression
settings possible. This would take a very long time - a magnitude
longer than a typical zstd bundle generation - but the result would
be hundreds of megabytes smaller! For the clone volume we do at
Mozilla, this could translate to petabytes of bandwidth savings
per year and faster clones (due to smaller transfer size).
I don't have detailed numbers to report on decompression. However,
zstd decompression is fast: >1 GB/s output throughput on this machine,
even through the Python bindings. And it can do that regardless of the
compression level of the input. By the time you have enough data to
worry about overhead of decompression, you have plenty of other things
to worry about performance wise.
zstd is wins all around. I can't wait to implement support for it
on the wire protocol and in revlogs.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 11 Nov 2016 01:10:07 -0800 |
parents | dd3dd80fca10 |
children | d524c88511a7 |
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# hgweb/server.py - The standalone hg web server. # # Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net> # 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 errno import os import socket import sys import traceback from ..i18n import _ from .. import ( error, util, ) httpservermod = util.httpserver socketserver = util.socketserver urlerr = util.urlerr urlreq = util.urlreq from . import ( common, ) def _splitURI(uri): """Return path and query that has been split from uri Just like CGI environment, the path is unquoted, the query is not. """ if '?' in uri: path, query = uri.split('?', 1) else: path, query = uri, '' return urlreq.unquote(path), query class _error_logger(object): def __init__(self, handler): self.handler = handler def flush(self): pass def write(self, str): self.writelines(str.split('\n')) def writelines(self, seq): for msg in seq: self.handler.log_error("HG error: %s", msg) class _httprequesthandler(httpservermod.basehttprequesthandler): url_scheme = 'http' @staticmethod def preparehttpserver(httpserver, ui): """Prepare .socket of new HTTPServer instance""" pass def __init__(self, *args, **kargs): self.protocol_version = 'HTTP/1.1' httpservermod.basehttprequesthandler.__init__(self, *args, **kargs) def _log_any(self, fp, format, *args): fp.write("%s - - [%s] %s\n" % (self.client_address[0], self.log_date_time_string(), format % args)) fp.flush() def log_error(self, format, *args): self._log_any(self.server.errorlog, format, *args) def log_message(self, format, *args): self._log_any(self.server.accesslog, format, *args) def log_request(self, code='-', size='-'): xheaders = [] if util.safehasattr(self, 'headers'): xheaders = [h for h in self.headers.items() if h[0].startswith('x-')] self.log_message('"%s" %s %s%s', self.requestline, str(code), str(size), ''.join([' %s:%s' % h for h in sorted(xheaders)])) def do_write(self): try: self.do_hgweb() except socket.error as inst: if inst[0] != errno.EPIPE: raise def do_POST(self): try: self.do_write() except Exception: self._start_response("500 Internal Server Error", []) self._write("Internal Server Error") self._done() tb = "".join(traceback.format_exception(*sys.exc_info())) self.log_error("Exception happened during processing " "request '%s':\n%s", self.path, tb) def do_GET(self): self.do_POST() def do_hgweb(self): path, query = _splitURI(self.path) env = {} env['GATEWAY_INTERFACE'] = 'CGI/1.1' env['REQUEST_METHOD'] = self.command env['SERVER_NAME'] = self.server.server_name env['SERVER_PORT'] = str(self.server.server_port) env['REQUEST_URI'] = self.path env['SCRIPT_NAME'] = self.server.prefix env['PATH_INFO'] = path[len(self.server.prefix):] env['REMOTE_HOST'] = self.client_address[0] env['REMOTE_ADDR'] = self.client_address[0] if query: env['QUERY_STRING'] = query if self.headers.typeheader is None: env['CONTENT_TYPE'] = self.headers.type else: env['CONTENT_TYPE'] = self.headers.typeheader length = self.headers.getheader('content-length') if length: env['CONTENT_LENGTH'] = length for header in [h for h in self.headers.keys() if h not in ('content-type', 'content-length')]: hkey = 'HTTP_' + header.replace('-', '_').upper() hval = self.headers.getheader(header) hval = hval.replace('\n', '').strip() if hval: env[hkey] = hval env['SERVER_PROTOCOL'] = self.request_version env['wsgi.version'] = (1, 0) env['wsgi.url_scheme'] = self.url_scheme if env.get('HTTP_EXPECT', '').lower() == '100-continue': self.rfile = common.continuereader(self.rfile, self.wfile.write) env['wsgi.input'] = self.rfile env['wsgi.errors'] = _error_logger(self) env['wsgi.multithread'] = isinstance(self.server, socketserver.ThreadingMixIn) env['wsgi.multiprocess'] = isinstance(self.server, socketserver.ForkingMixIn) env['wsgi.run_once'] = 0 self.saved_status = None self.saved_headers = [] self.sent_headers = False self.length = None self._chunked = None for chunk in self.server.application(env, self._start_response): self._write(chunk) if not self.sent_headers: self.send_headers() self._done() def send_headers(self): if not self.saved_status: raise AssertionError("Sending headers before " "start_response() called") saved_status = self.saved_status.split(None, 1) saved_status[0] = int(saved_status[0]) self.send_response(*saved_status) self.length = None self._chunked = False for h in self.saved_headers: self.send_header(*h) if h[0].lower() == 'content-length': self.length = int(h[1]) if (self.length is None and saved_status[0] != common.HTTP_NOT_MODIFIED): self._chunked = (not self.close_connection and self.request_version == "HTTP/1.1") if self._chunked: self.send_header('Transfer-Encoding', 'chunked') else: self.send_header('Connection', 'close') self.end_headers() self.sent_headers = True def _start_response(self, http_status, headers, exc_info=None): code, msg = http_status.split(None, 1) code = int(code) self.saved_status = http_status bad_headers = ('connection', 'transfer-encoding') self.saved_headers = [h for h in headers if h[0].lower() not in bad_headers] return self._write def _write(self, data): if not self.saved_status: raise AssertionError("data written before start_response() called") elif not self.sent_headers: self.send_headers() if self.length is not None: if len(data) > self.length: raise AssertionError("Content-length header sent, but more " "bytes than specified are being written.") self.length = self.length - len(data) elif self._chunked and data: data = '%x\r\n%s\r\n' % (len(data), data) self.wfile.write(data) self.wfile.flush() def _done(self): if self._chunked: self.wfile.write('0\r\n\r\n') self.wfile.flush() class _httprequesthandlerssl(_httprequesthandler): """HTTPS handler based on Python's ssl module""" url_scheme = 'https' @staticmethod def preparehttpserver(httpserver, ui): try: from .. import sslutil sslutil.modernssl except ImportError: raise error.Abort(_("SSL support is unavailable")) certfile = ui.config('web', 'certificate') # These config options are currently only meant for testing. Use # at your own risk. cafile = ui.config('devel', 'servercafile') reqcert = ui.configbool('devel', 'serverrequirecert') httpserver.socket = sslutil.wrapserversocket(httpserver.socket, ui, certfile=certfile, cafile=cafile, requireclientcert=reqcert) def setup(self): self.connection = self.request self.rfile = socket._fileobject(self.request, "rb", self.rbufsize) self.wfile = socket._fileobject(self.request, "wb", self.wbufsize) try: import threading threading.activeCount() # silence pyflakes and bypass demandimport _mixin = socketserver.ThreadingMixIn except ImportError: if util.safehasattr(os, "fork"): _mixin = socketserver.ForkingMixIn else: class _mixin(object): pass def openlog(opt, default): if opt and opt != '-': return open(opt, 'a') return default class MercurialHTTPServer(_mixin, httpservermod.httpserver, object): # SO_REUSEADDR has broken semantics on windows if os.name == 'nt': allow_reuse_address = 0 def __init__(self, ui, app, addr, handler, **kwargs): httpservermod.httpserver.__init__(self, addr, handler, **kwargs) self.daemon_threads = True self.application = app handler.preparehttpserver(self, ui) prefix = ui.config('web', 'prefix', '') if prefix: prefix = '/' + prefix.strip('/') self.prefix = prefix alog = openlog(ui.config('web', 'accesslog', '-'), ui.fout) elog = openlog(ui.config('web', 'errorlog', '-'), ui.ferr) self.accesslog = alog self.errorlog = elog self.addr, self.port = self.socket.getsockname()[0:2] self.fqaddr = socket.getfqdn(addr[0]) class IPv6HTTPServer(MercurialHTTPServer): address_family = getattr(socket, 'AF_INET6', None) def __init__(self, *args, **kwargs): if self.address_family is None: raise error.RepoError(_('IPv6 is not available on this system')) super(IPv6HTTPServer, self).__init__(*args, **kwargs) def create_server(ui, app): if ui.config('web', 'certificate'): handler = _httprequesthandlerssl else: handler = _httprequesthandler if ui.configbool('web', 'ipv6'): cls = IPv6HTTPServer else: cls = MercurialHTTPServer # ugly hack due to python issue5853 (for threaded use) try: import mimetypes mimetypes.init() except UnicodeDecodeError: # Python 2.x's mimetypes module attempts to decode strings # from Windows' ANSI APIs as ascii (fail), then re-encode them # as ascii (clown fail), because the default Python Unicode # codec is hardcoded as ascii. sys.argv # unwrap demand-loader so that reload() works reload(sys) # resurrect sys.setdefaultencoding() oldenc = sys.getdefaultencoding() sys.setdefaultencoding("latin1") # or any full 8-bit encoding mimetypes.init() sys.setdefaultencoding(oldenc) address = ui.config('web', 'address', '') port = util.getport(ui.config('web', 'port', 8000)) try: return cls(ui, app, (address, port), handler) except socket.error as inst: raise error.Abort(_("cannot start server at '%s:%d': %s") % (address, port, inst.args[1]))