xref: /titanic_41/usr/src/lib/pyzfs/common/util.py (revision 5203bc321053fb87d7073c7640548fab73634793)
1#! /usr/bin/python2.4
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 2010 Sun Microsystems, Inc.  All rights reserved.
23# Use is subject to license terms.
24#
25
26"""This module provides utility functions for ZFS.
27zfs.util.dev -- a file object of /dev/zfs """
28
29import gettext
30import errno
31import os
32import solaris.misc
33# Note: this module (zfs.util) should not import zfs.ioctl, because that
34# would introduce a circular dependency
35
36errno.ECANCELED = 47
37errno.ENOTSUP = 48
38
39dev = open("/dev/zfs", "w")
40
41try:
42	_ = gettext.translation("SUNW_OST_OSLIB", "/usr/lib/locale",
43	    fallback=True).gettext
44except:
45	_ = solaris.misc.gettext
46
47def default_repr(self):
48	"""A simple __repr__ function."""
49	if self.__slots__:
50		str = "<" + self.__class__.__name__
51		for v in self.__slots__:
52			str += " %s: %r" % (v, getattr(self, v))
53		return str + ">"
54	else:
55		return "<%s %s>" % \
56		    (self.__class__.__name__, repr(self.__dict__))
57
58class ZFSError(StandardError):
59	"""This exception class represents a potentially user-visible
60	ZFS error.  If uncaught, it will be printed and the process will
61	exit with exit code 1.
62
63	errno -- the error number (eg, from ioctl(2))."""
64
65	__slots__ = "why", "task", "errno"
66	__repr__ = default_repr
67
68	def __init__(self, eno, task=None, why=None):
69		"""Create a ZFS exception.
70		eno -- the error number (errno)
71		task -- a string describing the task that failed
72		why -- a string describing why it failed (defaults to
73		    strerror(eno))"""
74
75		self.errno = eno
76		self.task = task
77		self.why = why
78
79	def __str__(self):
80		s = ""
81		if self.task:
82			s += self.task + ": "
83		if self.why:
84			s += self.why
85		else:
86			s += self.strerror
87		return s
88
89	__strs = {
90		errno.EPERM: _("permission denied"),
91		errno.ECANCELED:
92		    _("delegated administration is disabled on pool"),
93		errno.EINTR: _("signal received"),
94		errno.EIO: _("I/O error"),
95		errno.ENOENT: _("dataset does not exist"),
96		errno.ENOSPC: _("out of space"),
97		errno.EEXIST: _("dataset already exists"),
98		errno.EBUSY: _("dataset is busy"),
99		errno.EROFS:
100		    _("snapshot permissions cannot be modified"),
101		errno.ENAMETOOLONG: _("dataset name is too long"),
102		errno.ENOTSUP: _("unsupported version"),
103		errno.EAGAIN: _("pool I/O is currently suspended"),
104	}
105
106	__strs[errno.EACCES] = __strs[errno.EPERM]
107	__strs[errno.ENXIO] = __strs[errno.EIO]
108	__strs[errno.ENODEV] = __strs[errno.EIO]
109	__strs[errno.EDQUOT] = __strs[errno.ENOSPC]
110
111	@property
112	def strerror(self):
113		return ZFSError.__strs.get(self.errno, os.strerror(self.errno))
114
115def nicenum(num):
116	"""Return a nice string (eg "1.23M") for this integer."""
117	index = 0;
118	n = num;
119
120	while n >= 1024:
121		n /= 1024
122		index += 1
123
124	u = " KMGTPE"[index]
125	if index == 0:
126		return "%u" % n;
127	elif n >= 100 or num & ((1024*index)-1) == 0:
128		# it's an exact multiple of its index, or it wouldn't
129		# fit as floating point, so print as an integer
130		return "%u%c" % (n, u)
131	else:
132		# due to rounding, it's tricky to tell what precision to
133		# use; try each precision and see which one fits
134		for i in (2, 1, 0):
135			s = "%.*f%c" % (i, float(num) / (1<<(10*index)), u)
136			if len(s) <= 5:
137				return s
138
139def append_with_opt(option, opt, value, parser):
140	"""A function for OptionParser which appends a tuple (opt, value)."""
141	getattr(parser.values, option.dest).append((opt, value))
142
143