xref: /illumos-gate/usr/src/lib/pyzfs/common/util.py (revision f3041bfa)
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.
26zfs.util.dev -- a file object of /dev/zfs """
27
28import gettext
29import errno
30import os
31import solaris.misc
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
40try:
41	_ = gettext.translation("SUNW_OST_OSLIB", "/usr/lib/locale",
42	    fallback=True).gettext
43except:
44	_ = solaris.misc.gettext
45
46def 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
57class 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
114def 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
138def 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
142