Mercurial > hg
view mercurial/httppeer.py @ 36367:043e77f3be09
sshpeer: return framed file object when needed
Currently, wireproto.wirepeer has a default implementation of
_submitbatch() and sshv1peer has a very similar implementation.
The main difference is that sshv1peer is aware of the total amount
of bytes it can read whereas the default implementation reads the
stream until no more data is returned. The default implementation
works for HTTP, since there is a known end to HTTP responses (either
Content-Length or 0 sized chunk).
This commit teaches sshv1peer to use our just-introduced "cappedreader"
class for wrapping a file object to limit the number of bytes that
can be read. We do this by introducing an argument to specify whether
the response is framed. If set, we returned a cappedreader instance
instead of the raw pipe.
_call() always has framed responses. So we set this argument
unconditionally and then .read() the entirety of the result.
Strictly speaking, we don't need to use cappedreader in this case
and can inline frame decoding/read logic. But I like when things
are consistent. The overhead should be negligible.
_callstream() and _callcompressable() are special: whether framing
is used depends on the specific command. So, we define a set
of commands that have framed response. It currently only
contains "batch."
As a result of this change, the one-off implementation of
_submitbatch() in sshv1peer can be removed since it is now
safe to .read() the response's file object until end of stream.
cappedreader takes care of not overrunning the frame.
Differential Revision: https://phab.mercurial-scm.org/D2380
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 21 Feb 2018 08:35:48 -0800 |
parents | a59ff82154b8 |
children | 23d12524a202 |
line wrap: on
line source
# httppeer.py - HTTP repository proxy classes for mercurial # # Copyright 2005, 2006 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 errno import io import os import socket import struct import tempfile from .i18n import _ from . import ( bundle2, error, httpconnection, pycompat, statichttprepo, url, util, wireproto, ) httplib = util.httplib urlerr = util.urlerr urlreq = util.urlreq def encodevalueinheaders(value, header, limit): """Encode a string value into multiple HTTP headers. ``value`` will be encoded into 1 or more HTTP headers with the names ``header-<N>`` where ``<N>`` is an integer starting at 1. Each header name + value will be at most ``limit`` bytes long. Returns an iterable of 2-tuples consisting of header names and values as native strings. """ # HTTP Headers are ASCII. Python 3 requires them to be unicodes, # not bytes. This function always takes bytes in as arguments. fmt = pycompat.strurl(header) + r'-%s' # Note: it is *NOT* a bug that the last bit here is a bytestring # and not a unicode: we're just getting the encoded length anyway, # and using an r-string to make it portable between Python 2 and 3 # doesn't work because then the \r is a literal backslash-r # instead of a carriage return. valuelen = limit - len(fmt % r'000') - len(': \r\n') result = [] n = 0 for i in xrange(0, len(value), valuelen): n += 1 result.append((fmt % str(n), pycompat.strurl(value[i:i + valuelen]))) return result def _wraphttpresponse(resp): """Wrap an HTTPResponse with common error handlers. This ensures that any I/O from any consumer raises the appropriate error and messaging. """ origread = resp.read class readerproxy(resp.__class__): def read(self, size=None): try: return origread(size) except httplib.IncompleteRead as e: # e.expected is an integer if length known or None otherwise. if e.expected: msg = _('HTTP request error (incomplete response; ' 'expected %d bytes got %d)') % (e.expected, len(e.partial)) else: msg = _('HTTP request error (incomplete response)') raise error.PeerTransportError( msg, hint=_('this may be an intermittent network failure; ' 'if the error persists, consider contacting the ' 'network or server operator')) except httplib.HTTPException as e: raise error.PeerTransportError( _('HTTP request error (%s)') % e, hint=_('this may be an intermittent network failure; ' 'if the error persists, consider contacting the ' 'network or server operator')) resp.__class__ = readerproxy class _multifile(object): def __init__(self, *fileobjs): for f in fileobjs: if not util.safehasattr(f, 'length'): raise ValueError( '_multifile only supports file objects that ' 'have a length but this one does not:', type(f), f) self._fileobjs = fileobjs self._index = 0 @property def length(self): return sum(f.length for f in self._fileobjs) def read(self, amt=None): if amt <= 0: return ''.join(f.read() for f in self._fileobjs) parts = [] while amt and self._index < len(self._fileobjs): parts.append(self._fileobjs[self._index].read(amt)) got = len(parts[-1]) if got < amt: self._index += 1 amt -= got return ''.join(parts) def seek(self, offset, whence=os.SEEK_SET): if whence != os.SEEK_SET: raise NotImplementedError( '_multifile does not support anything other' ' than os.SEEK_SET for whence on seek()') if offset != 0: raise NotImplementedError( '_multifile only supports seeking to start, but that ' 'could be fixed if you need it') for f in self._fileobjs: f.seek(0) self._index = 0 class httppeer(wireproto.wirepeer): def __init__(self, ui, path): self._path = path self._caps = None self._urlopener = None self._requestbuilder = None u = util.url(path) if u.query or u.fragment: raise error.Abort(_('unsupported URL component: "%s"') % (u.query or u.fragment)) # urllib cannot handle URLs with embedded user or passwd self._url, authinfo = u.authinfo() self._ui = ui ui.debug('using %s\n' % self._url) self._urlopener = url.opener(ui, authinfo) self._requestbuilder = urlreq.request def __del__(self): urlopener = getattr(self, '_urlopener', None) if urlopener: for h in urlopener.handlers: h.close() getattr(h, "close_all", lambda: None)() def _openurl(self, req): if (self._ui.debugflag and self._ui.configbool('devel', 'debug.peer-request')): dbg = self._ui.debug line = 'devel-peer-request: %s\n' dbg(line % '%s %s' % (req.get_method(), req.get_full_url())) hgargssize = None for header, value in sorted(req.header_items()): if header.startswith('X-hgarg-'): if hgargssize is None: hgargssize = 0 hgargssize += len(value) else: dbg(line % ' %s %s' % (header, value)) if hgargssize is not None: dbg(line % ' %d bytes of commands arguments in headers' % hgargssize) if req.has_data(): data = req.get_data() length = getattr(data, 'length', None) if length is None: length = len(data) dbg(line % ' %d bytes of data' % length) start = util.timer() ret = self._urlopener.open(req) if self._ui.configbool('devel', 'debug.peer-request'): dbg(line % ' finished in %.4f seconds (%s)' % (util.timer() - start, ret.code)) return ret # Begin of _basepeer interface. @util.propertycache def ui(self): return self._ui def url(self): return self._path def local(self): return None def peer(self): return self def canpush(self): return True def close(self): pass # End of _basepeer interface. # Begin of _basewirepeer interface. def capabilities(self): # self._fetchcaps() should have been called as part of peer # handshake. So self._caps should always be set. assert self._caps is not None return self._caps # End of _basewirepeer interface. # look up capabilities only when needed def _fetchcaps(self): self._caps = set(self._call('capabilities').split()) def _callstream(self, cmd, _compressible=False, **args): args = pycompat.byteskwargs(args) if cmd == 'pushkey': args['data'] = '' data = args.pop('data', None) headers = args.pop('headers', {}) self.ui.debug("sending %s command\n" % cmd) q = [('cmd', cmd)] headersize = 0 varyheaders = [] # Important: don't use self.capable() here or else you end up # with infinite recursion when trying to look up capabilities # for the first time. postargsok = self._caps is not None and 'httppostargs' in self._caps # Send arguments via POST. if postargsok and args: strargs = urlreq.urlencode(sorted(args.items())) if not data: data = strargs else: if isinstance(data, bytes): i = io.BytesIO(data) i.length = len(data) data = i argsio = io.BytesIO(strargs) argsio.length = len(strargs) data = _multifile(argsio, data) headers[r'X-HgArgs-Post'] = len(strargs) elif args: # Calling self.capable() can infinite loop if we are calling # "capabilities". But that command should never accept wire # protocol arguments. So this should never happen. assert cmd != 'capabilities' httpheader = self.capable('httpheader') if httpheader: headersize = int(httpheader.split(',', 1)[0]) # Send arguments via HTTP headers. if headersize > 0: # The headers can typically carry more data than the URL. encargs = urlreq.urlencode(sorted(args.items())) for header, value in encodevalueinheaders(encargs, 'X-HgArg', headersize): headers[header] = value varyheaders.append(header) # Send arguments via query string (Mercurial <1.9). else: q += sorted(args.items()) qs = '?%s' % urlreq.urlencode(q) cu = "%s%s" % (self._url, qs) size = 0 if util.safehasattr(data, 'length'): size = data.length elif data is not None: size = len(data) if size and self.ui.configbool('ui', 'usehttp2'): headers[r'Expect'] = r'100-Continue' headers[r'X-HgHttp2'] = r'1' if data is not None and r'Content-Type' not in headers: headers[r'Content-Type'] = r'application/mercurial-0.1' # Tell the server we accept application/mercurial-0.2 and multiple # compression formats if the server is capable of emitting those # payloads. protoparams = [] mediatypes = set() if self._caps is not None: mt = self.capable('httpmediatype') if mt: protoparams.append('0.1') mediatypes = set(mt.split(',')) if '0.2tx' in mediatypes: protoparams.append('0.2') if '0.2tx' in mediatypes and self.capable('compression'): # We /could/ compare supported compression formats and prune # non-mutually supported or error if nothing is mutually supported. # For now, send the full list to the server and have it error. comps = [e.wireprotosupport().name for e in util.compengines.supportedwireengines(util.CLIENTROLE)] protoparams.append('comp=%s' % ','.join(comps)) if protoparams: protoheaders = encodevalueinheaders(' '.join(protoparams), 'X-HgProto', headersize or 1024) for header, value in protoheaders: headers[header] = value varyheaders.append(header) if varyheaders: headers[r'Vary'] = r','.join(varyheaders) req = self._requestbuilder(pycompat.strurl(cu), data, headers) if data is not None: self.ui.debug("sending %d bytes\n" % size) req.add_unredirected_header(r'Content-Length', r'%d' % size) try: resp = self._openurl(req) except urlerr.httperror as inst: if inst.code == 401: raise error.Abort(_('authorization failed')) raise except httplib.HTTPException as inst: self.ui.debug('http error while sending %s command\n' % cmd) self.ui.traceback() raise IOError(None, inst) # Insert error handlers for common I/O failures. _wraphttpresponse(resp) # record the url we got redirected to resp_url = pycompat.bytesurl(resp.geturl()) if resp_url.endswith(qs): resp_url = resp_url[:-len(qs)] if self._url.rstrip('/') != resp_url.rstrip('/'): if not self.ui.quiet: self.ui.warn(_('real URL is %s\n') % resp_url) self._url = resp_url try: proto = pycompat.bytesurl(resp.getheader(r'content-type', r'')) except AttributeError: proto = pycompat.bytesurl(resp.headers.get(r'content-type', r'')) safeurl = util.hidepassword(self._url) if proto.startswith('application/hg-error'): raise error.OutOfBandError(resp.read()) # accept old "text/plain" and "application/hg-changegroup" for now if not (proto.startswith('application/mercurial-') or (proto.startswith('text/plain') and not resp.headers.get('content-length')) or proto.startswith('application/hg-changegroup')): self.ui.debug("requested URL: '%s'\n" % util.hidepassword(cu)) raise error.RepoError( _("'%s' does not appear to be an hg repository:\n" "---%%<--- (%s)\n%s\n---%%<---\n") % (safeurl, proto or 'no content-type', resp.read(1024))) if proto.startswith('application/mercurial-'): try: version = proto.split('-', 1)[1] version_info = tuple([int(n) for n in version.split('.')]) except ValueError: raise error.RepoError(_("'%s' sent a broken Content-Type " "header (%s)") % (safeurl, proto)) # TODO consider switching to a decompression reader that uses # generators. if version_info == (0, 1): if _compressible: return util.compengines['zlib'].decompressorreader(resp) return resp elif version_info == (0, 2): # application/mercurial-0.2 always identifies the compression # engine in the payload header. elen = struct.unpack('B', resp.read(1))[0] ename = resp.read(elen) engine = util.compengines.forwiretype(ename) return engine.decompressorreader(resp) else: raise error.RepoError(_("'%s' uses newer protocol %s") % (safeurl, version)) if _compressible: return util.compengines['zlib'].decompressorreader(resp) return resp def _call(self, cmd, **args): fp = self._callstream(cmd, **args) try: return fp.read() finally: # if using keepalive, allow connection to be reused fp.close() def _callpush(self, cmd, cg, **args): # have to stream bundle to a temp file because we do not have # http 1.1 chunked transfer. types = self.capable('unbundle') try: types = types.split(',') except AttributeError: # servers older than d1b16a746db6 will send 'unbundle' as a # boolean capability. They only support headerless/uncompressed # bundles. types = [""] for x in types: if x in bundle2.bundletypes: type = x break tempname = bundle2.writebundle(self.ui, cg, None, type) fp = httpconnection.httpsendfile(self.ui, tempname, "rb") headers = {r'Content-Type': r'application/mercurial-0.1'} try: r = self._call(cmd, data=fp, headers=headers, **args) vals = r.split('\n', 1) if len(vals) < 2: raise error.ResponseError(_("unexpected response:"), r) return vals except socket.error as err: if err.args[0] in (errno.ECONNRESET, errno.EPIPE): raise error.Abort(_('push failed: %s') % err.args[1]) raise error.Abort(err.args[1]) finally: fp.close() os.unlink(tempname) def _calltwowaystream(self, cmd, fp, **args): fh = None fp_ = None filename = None try: # dump bundle to disk fd, filename = tempfile.mkstemp(prefix="hg-bundle-", suffix=".hg") fh = os.fdopen(fd, pycompat.sysstr("wb")) d = fp.read(4096) while d: fh.write(d) d = fp.read(4096) fh.close() # start http push fp_ = httpconnection.httpsendfile(self.ui, filename, "rb") headers = {r'Content-Type': r'application/mercurial-0.1'} return self._callstream(cmd, data=fp_, headers=headers, **args) finally: if fp_ is not None: fp_.close() if fh is not None: fh.close() os.unlink(filename) def _callcompressable(self, cmd, **args): return self._callstream(cmd, _compressible=True, **args) def _abort(self, exception): raise exception def instance(ui, path, create): if create: raise error.Abort(_('cannot create new http repository')) try: if path.startswith('https:') and not url.has_https: raise error.Abort(_('Python support for SSL and HTTPS ' 'is not installed')) inst = httppeer(ui, path) inst._fetchcaps() return inst except error.RepoError as httpexception: try: r = statichttprepo.instance(ui, "static-" + path, create) ui.note(_('(falling back to static-http)\n')) return r except error.RepoError: raise httpexception # use the original http RepoError instead