view contrib/hgclient.py @ 27917:97e0dc6d248c stable

repoview: fix corrupted hiddencache crash Mercurial (issue5042)

Before this patch if the hiddencache existed but was empty, it would crash
mercurial. This patch adds exception handling when reading the hiddencache to
avoid the issue.
When encountering a corrupted cache file we print a devel warning. There would
be no point in issuing a normal warning as the user wouldn't be able to do
anything about the situation.

The warning looks like:

devel-warn: corrupted hidden cache, removing it at: /path/to/repoview.py

# A minimal client for Mercurial's command server

import os, sys, signal, struct, socket, subprocess, time, cStringIO

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()