Mercurial > hg
view mercurial/commandserver.py @ 20801:9c5183cb9bca
bundle2: very first version of a bundle2 bundler
This changeset is the very first of a long series. It create a new bundle2
module and add a simple class that generate and empty bundle2 container.
The module is documented with the current state of the implementation. For
information about the final goal you may want to consult the mercurial wiki
page:
http://mercurial.selenic.com/wiki/BundleFormat2
The documentation of the module will be updated with later patches adding more and
more feature to the format.
This patches also introduce a test case. This test case build and use its own
small extension that use the new bundle2 module. Since the new format is unable
to do anything right now, we could not use real mercurial code to test it.
Moreover, some advanced feature of the bundle2 spec will not be used by core
mercurial at all. So we need to have them tested.
author | Pierre-Yves David <pierre-yves.david@fb.com> |
---|---|
date | Tue, 18 Mar 2014 14:00:50 -0700 |
parents | e811b93f2cb1 |
children | 9336bc7dca8e |
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# commandserver.py - communicate with Mercurial's API over a pipe # # Copyright 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 i18n import _ import struct import sys, os import dispatch, encoding, util logfile = None def log(*args): if not logfile: return for a in args: logfile.write(str(a)) logfile.flush() class channeledoutput(object): """ Write data from in_ to out in the following format: data length (unsigned int), data """ def __init__(self, in_, out, channel): self.in_ = in_ self.out = out self.channel = channel def write(self, data): if not data: return self.out.write(struct.pack('>cI', self.channel, len(data))) self.out.write(data) self.out.flush() def __getattr__(self, attr): if attr in ('isatty', 'fileno'): raise AttributeError(attr) return getattr(self.in_, attr) class channeledinput(object): """ Read data from in_. Requests for input are written to out in the following format: channel identifier - 'I' for plain input, 'L' line based (1 byte) how many bytes to send at most (unsigned int), The client replies with: data length (unsigned int), 0 meaning EOF data """ maxchunksize = 4 * 1024 def __init__(self, in_, out, channel): self.in_ = in_ self.out = out self.channel = channel def read(self, size=-1): if size < 0: # if we need to consume all the clients input, ask for 4k chunks # so the pipe doesn't fill up risking a deadlock size = self.maxchunksize s = self._read(size, self.channel) buf = s while s: s = self._read(size, self.channel) buf += s return buf else: return self._read(size, self.channel) def _read(self, size, channel): if not size: return '' assert size > 0 # tell the client we need at most size bytes self.out.write(struct.pack('>cI', channel, size)) self.out.flush() length = self.in_.read(4) length = struct.unpack('>I', length)[0] if not length: return '' else: return self.in_.read(length) def readline(self, size=-1): if size < 0: size = self.maxchunksize s = self._read(size, 'L') buf = s # keep asking for more until there's either no more or # we got a full line while s and s[-1] != '\n': s = self._read(size, 'L') buf += s return buf else: return self._read(size, 'L') def __iter__(self): return self def next(self): l = self.readline() if not l: raise StopIteration return l def __getattr__(self, attr): if attr in ('isatty', 'fileno'): raise AttributeError(attr) return getattr(self.in_, attr) class server(object): """ Listens for commands on stdin, runs them and writes the output on a channel based stream to stdout. """ def __init__(self, ui, repo, mode): self.cwd = os.getcwd() logpath = ui.config("cmdserver", "log", None) if logpath: global logfile if logpath == '-': # write log on a special 'd' (debug) channel logfile = channeledoutput(sys.stdout, sys.stdout, 'd') else: logfile = open(logpath, 'a') if repo: # the ui here is really the repo ui so take its baseui so we don't # end up with its local configuration self.ui = repo.baseui self.repo = repo self.repoui = repo.ui else: self.ui = ui self.repo = self.repoui = None if mode == 'pipe': self.cerr = channeledoutput(sys.stderr, sys.stdout, 'e') self.cout = channeledoutput(sys.stdout, sys.stdout, 'o') self.cin = channeledinput(sys.stdin, sys.stdout, 'I') self.cresult = channeledoutput(sys.stdout, sys.stdout, 'r') self.client = sys.stdin else: raise util.Abort(_('unknown mode %s') % mode) def _read(self, size): if not size: return '' data = self.client.read(size) # is the other end closed? if not data: raise EOFError return data def runcommand(self): """ reads a list of \0 terminated arguments, executes and writes the return code to the result channel """ length = struct.unpack('>I', self._read(4))[0] if not length: args = [] else: args = self._read(length).split('\0') # copy the uis so changes (e.g. --config or --verbose) don't # persist between requests copiedui = self.ui.copy() if self.repo: self.repo.baseui = copiedui # clone ui without using ui.copy because this is protected repoui = self.repoui.__class__(self.repoui) repoui.copy = copiedui.copy # redo copy protection self.repo.ui = self.repo.dirstate._ui = repoui self.repo.invalidateall() req = dispatch.request(args[:], copiedui, self.repo, self.cin, self.cout, self.cerr) ret = (dispatch.dispatch(req) or 0) & 255 # might return None # restore old cwd if '--cwd' in args: os.chdir(self.cwd) self.cresult.write(struct.pack('>i', int(ret))) def getencoding(self): """ writes the current encoding to the result channel """ self.cresult.write(encoding.encoding) def serveone(self): cmd = self.client.readline()[:-1] if cmd: handler = self.capabilities.get(cmd) if handler: handler(self) else: # clients are expected to check what commands are supported by # looking at the servers capabilities raise util.Abort(_('unknown command %s') % cmd) return cmd != '' capabilities = {'runcommand' : runcommand, 'getencoding' : getencoding} def serve(self): hellomsg = 'capabilities: ' + ' '.join(sorted(self.capabilities)) hellomsg += '\n' hellomsg += 'encoding: ' + encoding.encoding # write the hello msg in -one- chunk self.cout.write(hellomsg) try: while self.serveone(): pass except EOFError: # we'll get here if the client disconnected while we were reading # its request return 1 return 0