Mercurial > hg
view contrib/hgclient.py @ 29859:a1092e2d70a3
help: internals topic for wire protocol
The Mercurial wire protocol is under-documented. This includes a lack
of source docstrings and comments as well as pages on the official
wiki.
This patch adds the beginnings of "internals" documentation on the
wire protocol.
The documentation should have nearly complete coverage on the
lower-level parts of the protocol, such as the different transport
mechanims, how commands and arguments are sent, capabilities, and,
of course, the commands themselves.
As part of writing this documentation, I discovered a number of
deficiencies in the protocol and bugs in the implementation. I've
started sending patches for some of the issues. I hope to send a lot
more.
This patch starts with the scaffolding for a new internals page.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Mon, 22 Aug 2016 19:46:39 -0700 |
parents | 3f45488d70df |
children | 73c2b9c9cd3c |
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# A minimal client for Mercurial's command server from __future__ import absolute_import, print_function import os import signal import socket import struct import subprocess import sys import time try: import cStringIO as io stringio = io.StringIO except ImportError: import io stringio = io.StringIO def connectpipe(path=None): cmdline = ['hg', 'serve', '--cmdserver', 'pipe'] if path: cmdline += ['-R', path] server = subprocess.Popen(cmdline, stdin=subprocess.PIPE, stdout=subprocess.PIPE) return server class unixconnection(object): def __init__(self, sockpath): self.sock = sock = socket.socket(socket.AF_UNIX) sock.connect(sockpath) self.stdin = sock.makefile('wb') self.stdout = sock.makefile('rb') def wait(self): self.stdin.close() self.stdout.close() self.sock.close() class unixserver(object): def __init__(self, sockpath, logpath=None, repopath=None): self.sockpath = sockpath cmdline = ['hg', 'serve', '--cmdserver', 'unix', '-a', sockpath] if repopath: cmdline += ['-R', repopath] if logpath: stdout = open(logpath, 'a') stderr = subprocess.STDOUT else: stdout = stderr = None self.server = subprocess.Popen(cmdline, stdout=stdout, stderr=stderr) # wait for listen() while self.server.poll() is None: if os.path.exists(sockpath): break time.sleep(0.1) def connect(self): return unixconnection(self.sockpath) def shutdown(self): os.kill(self.server.pid, signal.SIGTERM) self.server.wait() def writeblock(server, data): server.stdin.write(struct.pack('>I', len(data))) server.stdin.write(data) server.stdin.flush() def readchannel(server): data = server.stdout.read(5) if not data: raise EOFError channel, length = struct.unpack('>cI', data) if channel in 'IL': return channel, length else: return channel, server.stdout.read(length) def sep(text): return text.replace('\\', '/') def runcommand(server, args, output=sys.stdout, error=sys.stderr, input=None, outfilter=lambda x: x): print('*** runcommand', ' '.join(args)) sys.stdout.flush() server.stdin.write('runcommand\n') writeblock(server, '\0'.join(args)) if not input: input = stringio() while True: ch, data = readchannel(server) if ch == 'o': output.write(outfilter(data)) output.flush() elif ch == 'e': error.write(data) error.flush() elif ch == 'I': writeblock(server, input.read(data)) elif ch == 'L': writeblock(server, input.readline(data)) elif ch == 'r': ret, = struct.unpack('>i', data) if ret != 0: print(' [%d]' % ret) return ret else: print("unexpected channel %c: %r" % (ch, data)) if ch.isupper(): return def check(func, connect=connectpipe): sys.stdout.flush() server = connect() try: return func(server) finally: server.stdin.close() server.wait()