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# Copyright (C) 2006, 2009, 2010, 2011 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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"""Tests for tuned_gzip."""
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# do not use bzrlib test cases here - this should be suitable for sending
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from cStringIO import StringIO
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class FakeDecompress(object):
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"""A fake decompressor for testing GzipFile."""
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def decompress(self, buf):
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"""Return an empty string as though we are at eof."""
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# note that the zlib module *overwrites* unused data
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# on writes after EOF.
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self.unused_data = buf
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class TestFakeDecompress(tests.TestCase):
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"""We use a fake decompressor to test GzipFile.
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This class tests the behaviours we want from it.
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def test_decompress(self):
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# decompressing returns no data.
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decompress = FakeDecompress()
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self.assertEqual('', decompress.decompress('0'))
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def test_unused_data(self):
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# after decompressing, we have 1 unused byte.
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# this is normally set by decompressors when they
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# detect the end of a compressed stream.
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decompress = FakeDecompress()
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decompress.decompress('0')
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self.assertEqual('0', decompress.unused_data)
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# decompressing again (when the short read is read)
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# will give us the latest input in the unused_data
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# this is arguably a bug in zlib but ...
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decompress.decompress('1234567')
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self.assertEqual('1234567', decompress.unused_data)
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class TestGzip(tests.TestCase):
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def test__read_short_remainder(self):
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# a _read call at the end of a compressed hunk should
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# read more bytes if there is less than 8 bytes (the
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# gzip trailer) unread.
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stream = StringIO('\0\0\0\0\0\0\0\0')
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myfile = self.applyDeprecated(
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symbol_versioning.deprecated_in((2, 3, 0)),
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tuned_gzip.GzipFile, fileobj=stream)
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# disable the _new_member check, we are microtesting.
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myfile._new_member = False
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myfile.crc = zlib.crc32('')
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myfile.decompress = FakeDecompress()
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# all the data should have been read now
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self.assertEqual('', stream.read())
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# and it should be new member time in the stream.
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self.failUnless(myfile._new_member)
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def test_negative_crc(self):
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"""Content with a negative crc should not break when written"""
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gfile = self.applyDeprecated(
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symbol_versioning.deprecated_in((2, 3, 0)),
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tuned_gzip.GzipFile, mode="w", fileobj=sio)
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self.assertEqual(gfile.crc & 0xFFFFFFFFL, 0xFF000000L)
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self.assertEqual(sio.getvalue()[-8:-4], "\x00\x00\x00\xFF")
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class TestToGzip(tests.TestCase):
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def assertToGzip(self, chunks):
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bytes = ''.join(chunks)
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gzfromchunks = tuned_gzip.chunks_to_gzip(chunks)
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gzfrombytes = tuned_gzip.bytes_to_gzip(bytes)
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self.assertEqual(gzfrombytes, gzfromchunks)
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decoded = self.applyDeprecated(
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symbol_versioning.deprecated_in((2, 3, 0)),
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tuned_gzip.GzipFile, fileobj=StringIO(gzfromchunks)).read()
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self.assertEqual(bytes, decoded)
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def test_single_chunk(self):
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self.assertToGzip(['a modest chunk\nwith some various\nbits\n'])
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def test_simple_text(self):
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self.assertToGzip(['some\n', 'strings\n', 'to\n', 'process\n'])
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def test_large_chunks(self):
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self.assertToGzip(['a large string\n'*1024])
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self.assertToGzip(['a large string\n']*1024)
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def test_enormous_chunks(self):
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self.assertToGzip(['a large string\n'*1024*256])
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self.assertToGzip(['a large string\n']*1024*256)