Mercurial > hg
view mercurial/httppeer.py @ 31626:0febf8e4e2ce
repair: use context manager for lock management
If repo.lock() raised inside of the try block, 'tr' would have been None in the
finally block where it tries to release(). Modernize the syntax instead of just
winching the lock out of the try block.
I found several other instances of acquiring the lock inside of the 'try', but
those finally blocks handle None references. I also started switching some
trivial try/finally blocks to context managers, but didn't get them all because
indenting over 3x for lock, wlock and transaction would have spilled over 80
characters. That got me wondering if there should be a repo.rwlock(), to handle
locking and unlocking in the proper order.
It also looks like py27 supports supports multiple context managers for a single
'with' statement. Should I hold off on the rest until py26 is dropped?
author | Matt Harbison <matt_harbison@yahoo.com> |
---|---|
date | Thu, 23 Mar 2017 23:47:23 -0400 |
parents | 48dea083f66d |
children | bf855efe5664 |
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# 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 os import socket import struct import tempfile from .i18n import _ from .node import nullid from . import ( bundle2, error, httpconnection, pycompat, statichttprepo, url, util, wireproto, ) httplib = util.httplib urlerr = util.urlerr urlreq = util.urlreq # FUTURE: consider refactoring this API to use generators. This will # require a compression engine API to emit generators. def decompressresponse(response, engine): try: reader = engine.decompressorreader(response) except httplib.HTTPException: raise IOError(None, _('connection ended unexpectedly')) # We need to wrap reader.read() so HTTPException on subsequent # reads is also converted. # Ideally we'd use super() here. However, if ``reader`` isn't a new-style # class, this can raise: # TypeError: super() argument 1 must be type, not classobj origread = reader.read class readerproxy(reader.__class__): def read(self, *args, **kwargs): try: return origread(*args, **kwargs) except httplib.HTTPException: raise IOError(None, _('connection ended unexpectedly')) reader.__class__ = readerproxy return reader 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. """ fmt = header + '-%s' valuelen = limit - len(fmt % '000') - len(': \r\n') result = [] n = 0 for i in xrange(0, len(value), valuelen): n += 1 result.append((fmt % str(n), value[i:i + valuelen])) return result class httppeer(wireproto.wirepeer): def __init__(self, ui, path): self.path = path self.caps = None self.handler = 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 self.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 url(self): return self.path # look up capabilities only when needed def _fetchcaps(self): self.caps = set(self._call('capabilities').split()) def _capabilities(self): if self.caps is None: try: self._fetchcaps() except error.RepoError: self.caps = set() self.ui.debug('capabilities: %s\n' % (' '.join(self.caps or ['none']))) return self.caps def lock(self): raise error.Abort(_('operation not supported over http')) def _callstream(self, cmd, _compressible=False, **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 # TODO: support for httppostargs when data is a file-like # object rather than a basestring canmungedata = not data or isinstance(data, basestring) if postargsok and canmungedata: strargs = urlreq.urlencode(sorted(args.items())) if strargs: if not data: data = strargs elif isinstance(data, basestring): data = strargs + data headers['X-HgArgs-Post'] = len(strargs) else: if len(args) > 0: httpheader = self.capable('httpheader') if httpheader: headersize = int(httpheader.split(',', 1)[0]) 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) 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', False): headers['Expect'] = '100-Continue' headers['X-HgHttp2'] = '1' if data is not None and 'Content-Type' not in headers: headers['Content-Type'] = '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) headers['Vary'] = ','.join(varyheaders) req = self.requestbuilder(cu, data, headers) if data is not None: self.ui.debug("sending %s bytes\n" % size) req.add_unredirected_header('Content-Length', '%d' % size) try: resp = self.urlopener.open(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) # record the url we got redirected to resp_url = 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 = resp.getheader('content-type') except AttributeError: proto = resp.headers.get('content-type', '') 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)) if version_info == (0, 1): if _compressible: return decompressresponse(resp, util.compengines['zlib']) 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 decompressresponse(resp, engine) else: raise error.RepoError(_("'%s' uses newer protocol %s") % (safeurl, version)) if _compressible: return decompressresponse(resp, util.compengines['zlib']) 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 = {'Content-Type': '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 = {'Content-Type': '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 class httpspeer(httppeer): def __init__(self, ui, path): if not url.has_https: raise error.Abort(_('Python support for SSL and HTTPS ' 'is not installed')) httppeer.__init__(self, ui, path) def instance(ui, path, create): if create: raise error.Abort(_('cannot create new http repository')) try: if path.startswith('https:'): inst = httpspeer(ui, path) else: inst = httppeer(ui, path) try: # Try to do useful work when checking compatibility. # Usually saves a roundtrip since we want the caps anyway. inst._fetchcaps() except error.RepoError: # No luck, try older compatibility check. inst.between([(nullid, nullid)]) 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