usr/src/lib/pyzfs/common/util.py

   1 #!@PYTHON@
   2 #
   3 # CDDL HEADER START
   4 #
   5 # The contents of this file are subject to the terms of the
   6 # Common Development and Distribution License (the "License").
   7 # You may not use this file except in compliance with the License.
   8 #
   9 # You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10 # or http://www.opensolaris.org/os/licensing.
  11 # See the License for the specific language governing permissions
  12 # and limitations under the License.
  13 #
  14 # When distributing Covered Code, include this CDDL HEADER in each
  15 # file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16 # If applicable, add the following below this CDDL HEADER, with the
  17 # fields enclosed by brackets "[]" replaced with your own identifying
  18 # information: Portions Copyright [yyyy] [name of copyright owner]
  19 #
  20 # CDDL HEADER END
  21 #
  22 # Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  23 #
  24
  25 """This module provides utility functions for ZFS.
  26 zfs.util.dev -- a file object of /dev/zfs """
  27
  28 import gettext
  29 import errno
  30 import os
  31 import solaris.misc
  32 # Note: this module (zfs.util) should not import zfs.ioctl, because that
  33 # would introduce a circular dependency
  34
  35 errno.ECANCELED = 47
  36 errno.ENOTSUP = 48
  37
  38 dev = open("/dev/zfs", "w")
  39
  40 try:
  41         _ = gettext.translation("SUNW_OST_OSLIB", "/usr/lib/locale",
  42             fallback=True).gettext
  43 except:
  44         _ = solaris.misc.gettext
  45
  46 def default_repr(self):
  47         """A simple __repr__ function."""
  48         if self.__slots__:
  49                 str = "<" + self.__class__.__name__
  50                 for v in self.__slots__:
  51                         str += " %s: %r" % (v, getattr(self, v))
  52                 return str + ">"
  53         else:
  54                 return "<%s %s>" % \
  55                     (self.__class__.__name__, repr(self.__dict__))
  56
  57 class ZFSError(StandardError):
  58         """This exception class represents a potentially user-visible
  59         ZFS error.  If uncaught, it will be printed and the process will
  60         exit with exit code 1.
  61
  62         errno -- the error number (eg, from ioctl(2))."""
  63
  64         __slots__ = "why", "task", "errno"
  65         __repr__ = default_repr
  66
  67         def __init__(self, eno, task=None, why=None):
  68                 """Create a ZFS exception.
  69                 eno -- the error number (errno)
  70                 task -- a string describing the task that failed
  71                 why -- a string describing why it failed (defaults to
  72                     strerror(eno))"""
  73
  74                 self.errno = eno
  75                 self.task = task
  76                 self.why = why
  77
  78         def __str__(self):
  79                 s = ""
  80                 if self.task:
  81                         s += self.task + ": "
  82                 if self.why:
  83                         s += self.why
  84                 else:
  85                         s += self.strerror
  86                 return s
  87
  88         __strs = {
  89                 errno.EPERM: _("permission denied"),
  90                 errno.ECANCELED:
  91                     _("delegated administration is disabled on pool"),
  92                 errno.EINTR: _("signal received"),
  93                 errno.EIO: _("I/O error"),
  94                 errno.ENOENT: _("dataset does not exist"),
  95                 errno.ENOSPC: _("out of space"),
  96                 errno.EEXIST: _("dataset already exists"),
  97                 errno.EBUSY: _("dataset is busy"),
  98                 errno.EROFS:
  99                     _("snapshot permissions cannot be modified"),
 100                 errno.ENAMETOOLONG: _("dataset name is too long"),
 101                 errno.ENOTSUP: _("unsupported version"),
 102                 errno.EAGAIN: _("pool I/O is currently suspended"),
 103         }
 104
 105         __strs[errno.EACCES] = __strs[errno.EPERM]
 106         __strs[errno.ENXIO] = __strs[errno.EIO]
 107         __strs[errno.ENODEV] = __strs[errno.EIO]
 108         __strs[errno.EDQUOT] = __strs[errno.ENOSPC]
 109
 110         @property
 111         def strerror(self):
 112                 return ZFSError.__strs.get(self.errno, os.strerror(self.errno))
 113
 114 def nicenum(num):
 115         """Return a nice string (eg "1.23M") for this integer."""
 116         index = 0;
 117         n = num;
 118
 119         while n >= 1024:
 120                 n /= 1024
 121                 index += 1
 122
 123         u = " KMGTPE"[index]
 124         if index == 0:
 125                 return "%u" % n;
 126         elif n >= 100 or num & ((1024*index)-1) == 0:
 127                 # it's an exact multiple of its index, or it wouldn't
 128                 # fit as floating point, so print as an integer
 129                 return "%u%c" % (n, u)
 130         else:
 131                 # due to rounding, it's tricky to tell what precision to
 132                 # use; try each precision and see which one fits
 133                 for i in (2, 1, 0):
 134                         s = "%.*f%c" % (i, float(num) / (1<<(10*index)), u)
 135                         if len(s) <= 5:
 136                                 return s
 137
 138 def append_with_opt(option, opt, value, parser):
 139         """A function for OptionParser which appends a tuple (opt, value)."""
 140         getattr(parser.values, option.dest).append((opt, value))
 141