1
# Copyright (C) 2006 Canonical Ltd
3
# This program is free software; you can redistribute it and/or modify
4
# it under the terms of the GNU General Public License as published by
5
# the Free Software Foundation; either version 2 of the License, or
6
# (at your option) any later version.
8
# This program is distributed in the hope that it will be useful,
9
# but WITHOUT ANY WARRANTY; without even the implied warranty of
10
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11
# GNU General Public License for more details.
13
# You should have received a copy of the GNU General Public License
14
# along with this program; if not, write to the Free Software
15
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18
"""Tests for tuned_gzip."""
21
# do not use bzrlib test cases here - this should be suitable for sending
23
from cStringIO import StringIO
24
from unittest import TestCase
28
from bzrlib import tuned_gzip
31
class FakeDecompress(object):
32
"""A fake decompressor for testing GzipFile."""
37
def decompress(self, buf):
38
"""Return an empty string as though we are at eof."""
39
# note that the zlib module *overwrites* unused data
40
# on writes after EOF.
41
self.unused_data = buf
45
class TestFakeDecompress(TestCase):
46
"""We use a fake decompressor to test GzipFile.
48
This class tests the behaviours we want from it.
51
def test_decompress(self):
52
# decompressing returns no data.
53
decompress = FakeDecompress()
54
self.assertEqual('', decompress.decompress('0'))
56
def test_unused_data(self):
57
# after decompressing, we have 1 unused byte.
58
# this is normally set by decompressors when they
59
# detect the end of a compressed stream.
60
decompress = FakeDecompress()
61
decompress.decompress('0')
62
self.assertEqual('0', decompress.unused_data)
63
# decompressing again (when the short read is read)
64
# will give us the latest input in the unused_data
65
# this is arguably a bug in zlib but ...
66
decompress.decompress('1234567')
67
self.assertEqual('1234567', decompress.unused_data)
70
class TestGzip(TestCase):
72
def test__read_short_remainder(self):
73
# a _read call at the end of a compressed hunk should
74
# read more bytes if there is less than 8 bytes (the
75
# gzip trailer) unread.
76
stream = StringIO('\0\0\0\0\0\0\0\0')
77
myfile = tuned_gzip.GzipFile(fileobj=stream)
78
# disable the _new_member check, we are microtesting.
79
myfile._new_member = False
80
myfile.crc = zlib.crc32('')
81
myfile.decompress = FakeDecompress()
84
# all the data should have been read now
85
self.assertEqual('', stream.read())
86
# and it should be new member time in the stream.
87
self.failUnless(myfile._new_member)
90
class TestToGzip(TestCase):
92
def assertToGzip(self, chunks):
93
bytes = ''.join(chunks)
94
gzfromchunks = tuned_gzip.chunks_to_gzip(chunks)
95
gzfrombytes = tuned_gzip.bytes_to_gzip(bytes)
96
self.assertEqual(gzfrombytes, gzfromchunks)
97
decoded = tuned_gzip.GzipFile(fileobj=StringIO(gzfromchunks)).read()
98
self.assertEqual(bytes, decoded)
100
def test_single_chunk(self):
101
self.assertToGzip(['a modest chunk\nwith some various\nbits\n'])
103
def test_simple_text(self):
104
self.assertToGzip(['some\n', 'strings\n', 'to\n', 'process\n'])
106
def test_large_chunks(self):
107
self.assertToGzip(['a large string\n'*1024])
108
self.assertToGzip(['a large string\n']*1024)
110
def test_enormous_chunks(self):
111
self.assertToGzip(['a large string\n'*1024*256])
112
self.assertToGzip(['a large string\n']*1024*256)