contrib/hgclient.py

graphmod: allow edges to end early

Rather than draw an edge all the way to the bottom of the graph, make it
possible to end an edge to parents that are not part of the graph early on.
This results in a far cleaner graph.

Any edge type can be set to end early; set the ui.graphstyle.<edgetype>
parameter to the empty string to enable this.

For example, setting the following configuration:

    [ui]
    graphstyle.grandparent = :
    graphstyle.missing =

would result in a graph like this:

  o    changeset:   32:d06dffa21a31
  |\   parent:      27:886ed638191b
  | :  parent:      31:621d83e11f67
  | :
  o :  changeset:   31:621d83e11f67
  |\:  parent:      21:d42a756af44d
  | :  parent:      30:6e11cd4b648f
  | :
  o :    changeset:   30:6e11cd4b648f
  |\ \   parent:      28:44ecd0b9ae99
  | ~ :  parent:      29:cd9bb2be7593
  |  /
  o :    changeset:   28:44ecd0b9ae99
  |\ \   parent:      1:6db2ef61d156
  | ~ :  parent:      26:7f25b6c2f0b9
  |  /
  o :    changeset:   26:7f25b6c2f0b9
  |\ \   parent:      18:1aa84d96232a
  | | :  parent:      25:91da8ed57247
  | | :
  | o :  changeset:   25:91da8ed57247
  | |\:  parent:      21:d42a756af44d
  | | :  parent:      24:a9c19a3d96b7
  | | :
  | o :    changeset:   24:a9c19a3d96b7
  | |\ \   parent:      0:e6eb3150255d
  | | ~ :  parent:      23:a01cddf0766d
  | |  /
  | o :    changeset:   23:a01cddf0766d
  | |\ \   parent:      1:6db2ef61d156
  | | ~ :  parent:      22:e0d9cccacb5d
  | |  /
  | o :  changeset:   22:e0d9cccacb5d
  |/:/   parent:      18:1aa84d96232a
  | :    parent:      21:d42a756af44d
  | :
  | o    changeset:   21:d42a756af44d
  | |\   parent:      19:31ddc2c1573b
  | | |  parent:      20:d30ed6450e32
  | | |
  +---o  changeset:   20:d30ed6450e32
  | | |  parent:      0:e6eb3150255d
  | | ~  parent:      18:1aa84d96232a
  | |
  | o    changeset:   19:31ddc2c1573b
  | |\   parent:      15:1dda3f72782d
  | ~ ~  parent:      17:44765d7c06e0
  |
  o  changeset:   18:1aa84d96232a
     parent:      1:6db2ef61d156
     parent:      15:1dda3f72782d

The default configuration leaves all 3 types set to |.

This is part of the work towards moving smartlog upstream; currently smartlog
injects extra nodes into the graph to indicate grandparent relationships (nodes
elided).

# A minimal client for Mercurial's command server

from __future__ import absolute_import, print_function
import cStringIO
import os
import signal
import socket
import struct
import subprocess
import sys
import time

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 = cStringIO.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()