Mercurial > hg
view mercurial/httpconnection.py @ 31765:264baeef3588
show: new extension for displaying various repository data
Currently, Mercurial has a number of commands to show information. And,
there are features coming down the pipe that will introduce more
commands for showing information.
Currently, when introducing a new class of data or a view that we
wish to expose to the user, the strategy is to introduce a new command
or overload an existing command, sometimes both. For example, there is
a desire to formalize the wip/smartlog/underway/mine functionality that
many have devised. There is also a desire to introduce a "topics"
concept. Others would like views of "the current stack." In the
current model, we'd need a new command for wip/smartlog/etc (that
behaves a lot like a pre-defined alias of `hg log`). For topics,
we'd likely overload `hg topic[s]` to both display and manipulate
topics.
Adding new commands for every pre-defined query doesn't scale well
and pollutes `hg help`. Overloading commands to perform read-only and
write operations is arguably an UX anti-pattern: while having all
functionality for a given concept in one command is nice, having a
single command doing multiple discrete operations is not. Furthermore,
a user may be surprised that a command they thought was read-only
actually changes something.
We discussed this at the Mercurial 4.0 Sprint in Paris and decided that
having a single command where we could hang pre-defined views of
various data would be a good idea. Having such a command would:
* Help prevent an explosion of new query-related commands
* Create a clear separation between read and write operations
(mitigates footguns)
* Avoids overloading the meaning of commands that manipulate data
(bookmark, tag, branch, etc) (while we can't take away the
existing behavior for BC reasons, we now won't introduce this
behavior on new commands)
* Allows users to discover informational views more easily by
aggregating them in a single location
* Lowers the barrier to creating the new views (since the barrier
to creating a top-level command is relatively high)
So, this commit introduces the `hg show` command via the "show"
extension. This command accepts a positional argument of the
"view" to show. New views can be registered with a decorator. To
prove it works, we implement the "bookmarks" view, which shows a
table of bookmarks and their associated nodes.
We introduce a new style to hold everything used by `hg show`.
For our initial bookmarks view, the output varies from `hg bookmarks`:
* Padding is performed in the template itself as opposed to Python
* Revision integers are not shown
* shortest() is used to display a 5 character node by default (as
opposed to static 12 characters)
I chose to implement the "bookmarks" view first because it is simple
and shouldn't invite too much bikeshedding that detracts from the
evaluation of `hg show` itself. But there is an important point
to consider: we now have 2 ways to show a list of bookmarks. I'm not
a fan of introducing multiple ways to do very similar things. So it
might be worth discussing how we wish to tackle this issue for
bookmarks, tags, branches, MQ series, etc.
I also made the choice of explicitly declaring the default show
template not part of the standard BC guarantees. History has shown
that we make mistakes and poor choices with output formatting but
can't fix these mistakes later because random tools are parsing
output and we don't want to break these tools. Optimizing for human
consumption is one of my goals for `hg show`. So, by not covering
the formatting as part of BC, the barrier to future change is much
lower and humans benefit.
There are some improvements that can be made to formatting. For
example, we don't yet use label() in the templates. We obviously
want this for color. But I'm not sure if we should reuse the existing
log.* labels or invent new ones. I figure we can punt that to a
follow-up.
At the aforementioned Sprint, we discussed and discarded various
alternatives to `hg show`.
We considered making `hg log <view>` perform this behavior. The main
reason we can't do this is because a positional argument to `hg log`
can be a file path and if there is a conflict between a path name and
a view name, behavior is ambiguous. We could have introduced
`hg log --view` or similar, but we felt that required too much typing
(we don't want to require a command flag to show a view) and wasn't
very discoverable. Furthermore, `hg log` is optimized for showing
changelog data and there are things that `hg display` could display
that aren't changelog centric.
There were concerns about using "show" as the command name.
Some users already have a "show" alias that is similar to `hg export`.
There were also concerns that Git users adapted to `git show` would
be confused by `hg show`'s different behavior. The main difference
here is `git show` prints an `hg export` like view of the current
commit by default and `hg show` requires an argument. `git show`
can also display any Git object. `git show` does not support
displaying more complex views: just single objects. If we
implemented `hg show <hash>` or `hg show <identifier>`, `hg show`
would be a superset of `git show`. Although, I'm hesitant to do that
at this time because I view `hg show` as a higher-level querying
command and there are namespace collisions between valid identifiers
and registered views.
There is also a prefix collision with `hg showconfig`, which is an
alias of `hg config`.
We also considered `hg view`, but that is already used by the "hgk"
extension.
`hg display` was also proposed at one point. It has a prefix collision
with `hg diff`. General consensus was "show" or "view" are the best
verbs. And since "view" was taken, "show" was chosen.
There are a number of inline TODOs in this patch. Some of these
represent decisions yet to be made. Others represent features
requiring non-trivial complexity. Rather than bloat the patch or
invite additional bikeshedding, I figured I'd document future
enhancements via TODO so we can get a minimal implmentation landed.
Something is better than nothing.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 24 Mar 2017 19:19:00 -0700 |
parents | 766364caae14 |
children | 566cb89050b7 |
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# httpconnection.py - urllib2 handler for new http support # # Copyright 2005, 2006, 2007, 2008 Matt Mackall <mpm@selenic.com> # Copyright 2006, 2007 Alexis S. L. Carvalho <alexis@cecm.usp.br> # Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com> # Copyright 2011 Google, 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 logging import os import socket from .i18n import _ from . import ( httpclient, sslutil, util, ) urlerr = util.urlerr urlreq = util.urlreq # moved here from url.py to avoid a cycle class httpsendfile(object): """This is a wrapper around the objects returned by python's "open". Its purpose is to send file-like objects via HTTP. It do however not define a __len__ attribute because the length might be more than Py_ssize_t can handle. """ def __init__(self, ui, *args, **kwargs): self.ui = ui self._data = open(*args, **kwargs) self.seek = self._data.seek self.close = self._data.close self.write = self._data.write self.length = os.fstat(self._data.fileno()).st_size self._pos = 0 self._total = self.length // 1024 * 2 def read(self, *args, **kwargs): ret = self._data.read(*args, **kwargs) if not ret: self.ui.progress(_('sending'), None) return ret self._pos += len(ret) # We pass double the max for total because we currently have # to send the bundle twice in the case of a server that # requires authentication. Since we can't know until we try # once whether authentication will be required, just lie to # the user and maybe the push succeeds suddenly at 50%. self.ui.progress(_('sending'), self._pos // 1024, unit=_('kb'), total=self._total) return ret def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): self.close() # moved here from url.py to avoid a cycle def readauthforuri(ui, uri, user): # Read configuration groups = {} for key, val in ui.configitems('auth'): if '.' not in key: ui.warn(_("ignoring invalid [auth] key '%s'\n") % key) continue group, setting = key.rsplit('.', 1) gdict = groups.setdefault(group, {}) if setting in ('username', 'cert', 'key'): val = util.expandpath(val) gdict[setting] = val # Find the best match scheme, hostpath = uri.split('://', 1) bestuser = None bestlen = 0 bestauth = None for group, auth in groups.iteritems(): if user and user != auth.get('username', user): # If a username was set in the URI, the entry username # must either match it or be unset continue prefix = auth.get('prefix') if not prefix: continue p = prefix.split('://', 1) if len(p) > 1: schemes, prefix = [p[0]], p[1] else: schemes = (auth.get('schemes') or 'https').split() if (prefix == '*' or hostpath.startswith(prefix)) and \ (len(prefix) > bestlen or (len(prefix) == bestlen and \ not bestuser and 'username' in auth)) \ and scheme in schemes: bestlen = len(prefix) bestauth = group, auth bestuser = auth.get('username') if user and not bestuser: auth['username'] = user return bestauth # Mercurial (at least until we can remove the old codepath) requires # that the http response object be sufficiently file-like, so we # provide a close() method here. class HTTPResponse(httpclient.HTTPResponse): def close(self): pass class HTTPConnection(httpclient.HTTPConnection): response_class = HTTPResponse def request(self, method, uri, body=None, headers=None): if headers is None: headers = {} if isinstance(body, httpsendfile): body.seek(0) httpclient.HTTPConnection.request(self, method, uri, body=body, headers=headers) _configuredlogging = False LOGFMT = '%(levelname)s:%(name)s:%(lineno)d:%(message)s' # Subclass BOTH of these because otherwise urllib2 "helpfully" # reinserts them since it notices we don't include any subclasses of # them. class http2handler(urlreq.httphandler, urlreq.httpshandler): def __init__(self, ui, pwmgr): global _configuredlogging urlreq.abstracthttphandler.__init__(self) self.ui = ui self.pwmgr = pwmgr self._connections = {} # developer config: ui.http2debuglevel loglevel = ui.config('ui', 'http2debuglevel', default=None) if loglevel and not _configuredlogging: _configuredlogging = True logger = logging.getLogger('mercurial.httpclient') logger.setLevel(getattr(logging, loglevel.upper())) handler = logging.StreamHandler() handler.setFormatter(logging.Formatter(LOGFMT)) logger.addHandler(handler) def close_all(self): """Close and remove all connection objects being kept for reuse.""" for openconns in self._connections.values(): for conn in openconns: conn.close() self._connections = {} # shamelessly borrowed from urllib2.AbstractHTTPHandler def do_open(self, http_class, req, use_ssl): """Return an addinfourl object for the request, using http_class. http_class must implement the HTTPConnection API from httplib. The addinfourl return value is a file-like object. It also has methods and attributes including: - info(): return a mimetools.Message object for the headers - geturl(): return the original request URL - code: HTTP status code """ # If using a proxy, the host returned by get_host() is # actually the proxy. On Python 2.6.1, the real destination # hostname is encoded in the URI in the urllib2 request # object. On Python 2.6.5, it's stored in the _tunnel_host # attribute which has no accessor. tunhost = getattr(req, '_tunnel_host', None) host = req.get_host() if tunhost: proxyhost = host host = tunhost elif req.has_proxy(): proxyhost = req.get_host() host = req.get_selector().split('://', 1)[1].split('/', 1)[0] else: proxyhost = None if proxyhost: if ':' in proxyhost: # Note: this means we'll explode if we try and use an # IPv6 http proxy. This isn't a regression, so we # won't worry about it for now. proxyhost, proxyport = proxyhost.rsplit(':', 1) else: proxyport = 3128 # squid default proxy = (proxyhost, proxyport) else: proxy = None if not host: raise urlerr.urlerror('no host given') connkey = use_ssl, host, proxy allconns = self._connections.get(connkey, []) conns = [c for c in allconns if not c.busy()] if conns: h = conns[0] else: if allconns: self.ui.debug('all connections for %s busy, making a new ' 'one\n' % host) timeout = None if req.timeout is not socket._GLOBAL_DEFAULT_TIMEOUT: timeout = req.timeout h = http_class(host, timeout=timeout, proxy_hostport=proxy) self._connections.setdefault(connkey, []).append(h) headers = dict(req.headers) headers.update(req.unredirected_hdrs) headers = dict( (name.title(), val) for name, val in headers.items()) try: path = req.get_selector() if '://' in path: path = path.split('://', 1)[1].split('/', 1)[1] if path[0] != '/': path = '/' + path h.request(req.get_method(), path, req.data, headers) r = h.getresponse() except socket.error as err: # XXX what error? raise urlerr.urlerror(err) # Pick apart the HTTPResponse object to get the addinfourl # object initialized properly. r.recv = r.read resp = urlreq.addinfourl(r, r.headers, req.get_full_url()) resp.code = r.status resp.msg = r.reason return resp # httplib always uses the given host/port as the socket connect # target, and then allows full URIs in the request path, which it # then observes and treats as a signal to do proxying instead. def http_open(self, req): if req.get_full_url().startswith('https'): return self.https_open(req) def makehttpcon(*args, **kwargs): k2 = dict(kwargs) k2['use_ssl'] = False return HTTPConnection(*args, **k2) return self.do_open(makehttpcon, req, False) def https_open(self, req): # req.get_full_url() does not contain credentials and we may # need them to match the certificates. url = req.get_full_url() user, password = self.pwmgr.find_stored_password(url) res = readauthforuri(self.ui, url, user) if res: group, auth = res self.auth = auth self.ui.debug("using auth.%s.* for authentication\n" % group) else: self.auth = None return self.do_open(self._makesslconnection, req, True) def _makesslconnection(self, host, port=443, *args, **kwargs): keyfile = None certfile = None if args: # key_file keyfile = args.pop(0) if args: # cert_file certfile = args.pop(0) # if the user has specified different key/cert files in # hgrc, we prefer these if self.auth and 'key' in self.auth and 'cert' in self.auth: keyfile = self.auth['key'] certfile = self.auth['cert'] # let host port take precedence if ':' in host and '[' not in host or ']:' in host: host, port = host.rsplit(':', 1) port = int(port) if '[' in host: host = host[1:-1] kwargs['keyfile'] = keyfile kwargs['certfile'] = certfile con = HTTPConnection(host, port, use_ssl=True, ssl_wrap_socket=sslutil.wrapsocket, ssl_validator=sslutil.validatesocket, ui=self.ui, **kwargs) return con