QMP/qom-fuse

#!/usr/bin/python
##
# QEMU Object Model test tools
#
# Copyright IBM, Corp. 2012
#
# Authors:
#  Anthony Liguori   <aliguori@us.ibm.com>
#
# This work is licensed under the terms of the GNU GPL, version 2 or later.  See
# the COPYING file in the top-level directory.
##

import fuse, stat
from fuse import Fuse
import os, posix
from errno import *
from qmp import QEMUMonitorProtocol

fuse.fuse_python_api = (0, 2)

class QOMFS(Fuse):
    def __init__(self, qmp, *args, **kwds):
        Fuse.__init__(self, *args, **kwds)
        self.qmp = qmp
        self.qmp.connect()
        self.ino_map = {}
        self.ino_count = 1

    def get_ino(self, path):
        if self.ino_map.has_key(path):
            return self.ino_map[path]
        self.ino_map[path] = self.ino_count
        self.ino_count += 1
        return self.ino_map[path]

    def is_object(self, path):
        try:
            items = self.qmp.command('qom-list', path=path)
            return True
        except:
            return False

    def is_property(self, path):
        try:
            path, prop = path.rsplit('/', 1)
            for item in self.qmp.command('qom-list', path=path):
                if item['name'] == prop:
                    return True
            return False
        except:
            return False

    def is_link(self, path):
        try:
            path, prop = path.rsplit('/', 1)
            for item in self.qmp.command('qom-list', path=path):
                if item['name'] == prop:
                    if item['type'].startswith('link<'):
                        return True
                    return False
            return False
        except:
            return False

    def read(self, path, length, offset):
        if not self.is_property(path):
            return -ENOENT

        path, prop = path.rsplit('/', 1)
        try:
            data = str(self.qmp.command('qom-get', path=path, property=prop))
            data += '\n' # make values shell friendly
        except:
            return -EPERM

        if offset > len(data):
            return ''

        return str(data[offset:][:length])

    def readlink(self, path):
        if not self.is_link(path):
            return False
        path, prop = path.rsplit('/', 1)
        prefix = '/'.join(['..'] * (len(path.split('/')) - 1))
        return prefix + str(self.qmp.command('qom-get', path=path,
                                             property=prop))

    def getattr(self, path):
        if self.is_link(path):
            value = posix.stat_result((0755 | stat.S_IFLNK,
                                       self.get_ino(path),
                                       0,
                                       2,
                                       1000,
                                       1000,
                                       4096,
                                       0,
                                       0,
                                       0))
        elif self.is_object(path):
            value = posix.stat_result((0755 | stat.S_IFDIR,
                                       self.get_ino(path),
                                       0,
                                       2,
                                       1000,
                                       1000,
                                       4096,
                                       0,
                                       0,
                                       0))
        elif self.is_property(path):
            value = posix.stat_result((0644 | stat.S_IFREG,
                                       self.get_ino(path),
                                       0,
                                       1,
                                       1000,
                                       1000,
                                       4096,
                                       0,
                                       0,
                                       0))
        else:
            value = -ENOENT
        return value

    def readdir(self, path, offset):
        yield fuse.Direntry('.')
        yield fuse.Direntry('..')
        for item in self.qmp.command('qom-list', path=path):
            yield fuse.Direntry(str(item['name']))

if __name__ == '__main__':
    import sys, os

    fs = QOMFS(QEMUMonitorProtocol(os.environ['QMP_SOCKET']))
    fs.main(sys.argv)