xref: /titanic_41/usr/src/lib/pyzfs/common/util.py (revision d24234c24aeaca4ca56ee3ac2794507968f274c4)
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 2009 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
32# Note: this module (zfs.util) should not import zfs.ioctl, because that
33# would introduce a circular dependency
34
35errno.ECANCELED = 47
36errno.ENOTSUP = 48
37
38dev = open("/dev/zfs", "w")
39
40_ = gettext.translation("SUNW_OST_OSLIB", "/usr/lib/locale",
41    fallback=True).gettext
42
43def default_repr(self):
44	"""A simple __repr__ function."""
45	if self.__slots__:
46		str = "<" + self.__class__.__name__
47		for v in self.__slots__:
48			str += " %s: %r" % (v, getattr(self, v))
49		return str + ">"
50	else:
51		return "<%s %s>" % \
52		    (self.__class__.__name__, repr(self.__dict__))
53
54class ZFSError(StandardError):
55	"""This exception class represents a potentially user-visible
56	ZFS error.  If uncaught, it will be printed and the process will
57	exit with exit code 1.
58
59	errno -- the error number (eg, from ioctl(2))."""
60
61	__slots__ = "why", "task", "errno"
62	__repr__ = default_repr
63
64	def __init__(self, eno, task=None, why=None):
65		"""Create a ZFS exception.
66		eno -- the error number (errno)
67		task -- a string describing the task that failed
68		why -- a string describing why it failed (defaults to
69		    strerror(eno))"""
70
71		self.errno = eno
72		self.task = task
73		self.why = why
74
75	def __str__(self):
76		s = ""
77		if self.task:
78			s += self.task + ": "
79		if self.why:
80			s += self.why
81		else:
82			s += self.strerror
83		return s
84
85	__strs = {
86		errno.EPERM: _("permission denied"),
87		errno.ECANCELED:
88		    _("delegated administration is disabled on pool"),
89		errno.EINTR: _("signal received"),
90		errno.EIO: _("I/O error"),
91		errno.ENOENT: _("dataset does not exist"),
92		errno.ENOSPC: _("out of space"),
93		errno.EEXIST: _("dataset already exists"),
94		errno.EBUSY: _("dataset is busy"),
95		errno.EROFS:
96		    _("snapshot permissions cannot be modified"),
97		errno.ENAMETOOLONG: _("dataset name is too long"),
98		errno.ENOTSUP: _("unsupported version"),
99		errno.EAGAIN: _("pool I/O is currently suspended"),
100	}
101
102	__strs[errno.EACCES] = __strs[errno.EPERM]
103	__strs[errno.ENXIO] = __strs[errno.EIO]
104	__strs[errno.ENODEV] = __strs[errno.EIO]
105	__strs[errno.EDQUOT] = __strs[errno.ENOSPC]
106
107	@property
108	def strerror(self):
109		return ZFSError.__strs.get(self.errno, os.strerror(self.errno))
110
111def nicenum(num):
112	"""Return a nice string (eg "1.23M") for this integer."""
113	index = 0;
114	n = num;
115
116	while n >= 1024:
117		n /= 1024
118		index += 1
119
120	u = " KMGTPE"[index]
121	if index == 0:
122		return "%u" % n;
123	elif n >= 100 or num & ((1024*index)-1) == 0:
124		# it's an exact multiple of its index, or it wouldn't
125		# fit as floating point, so print as an integer
126		return "%u%c" % (n, u)
127	else:
128		# due to rounding, it's tricky to tell what precision to
129		# use; try each precision and see which one fits
130		for i in (2, 1, 0):
131			s = "%.*f%c" % (i, float(num) / (1<<(10*index)), u)
132			if len(s) <= 5:
133				return s
134
135def append_with_opt(option, opt, value, parser):
136	"""A function for OptionParser which appends a tuple (opt, value)."""
137	getattr(parser.values, option.dest).append((opt, value))
138
139