AppPkg/Applications/Python/Python-2.7.2/Lib/test/test_gzip.py

   1 #! /usr/bin/env python
   2 """Test script for the gzip module.
   3 """
   4
   5 import unittest
   6 from test import test_support
   7 import os
   8 import io
   9 import struct
  10 gzip = test_support.import_module('gzip')
  11
  12 data1 = """  int length=DEFAULTALLOC, err = Z_OK;
  13   PyObject *RetVal;
  14   int flushmode = Z_FINISH;
  15   unsigned long start_total_out;
  16
  17 """
  18
  19 data2 = """/* zlibmodule.c -- gzip-compatible data compression */
  20 /* See http://www.gzip.org/zlib/
  21 /* See http://www.winimage.com/zLibDll for Windows */
  22 """
  23
  24
  25 class TestGzip(unittest.TestCase):
  26     filename = test_support.TESTFN
  27
  28     def setUp(self):
  29         test_support.unlink(self.filename)
  30
  31     def tearDown(self):
  32         test_support.unlink(self.filename)
  33
  34
  35     def test_write(self):
  36         with gzip.GzipFile(self.filename, 'wb') as f:
  37             f.write(data1 * 50)
  38
  39             # Try flush and fileno.
  40             f.flush()
  41             f.fileno()
  42             if hasattr(os, 'fsync'):
  43                 os.fsync(f.fileno())
  44             f.close()
  45
  46         # Test multiple close() calls.
  47         f.close()
  48
  49     def test_read(self):
  50         self.test_write()
  51         # Try reading.
  52         with gzip.GzipFile(self.filename, 'r') as f:
  53             d = f.read()
  54         self.assertEqual(d, data1*50)
  55
  56     def test_io_on_closed_object(self):
  57         # Test that I/O operations on closed GzipFile objects raise a
  58         # ValueError, just like the corresponding functions on file objects.
  59
  60         # Write to a file, open it for reading, then close it.
  61         self.test_write()
  62         f = gzip.GzipFile(self.filename, 'r')
  63         f.close()
  64         with self.assertRaises(ValueError):
  65             f.read(1)
  66         with self.assertRaises(ValueError):
  67             f.seek(0)
  68         with self.assertRaises(ValueError):
  69             f.tell()
  70         # Open the file for writing, then close it.
  71         f = gzip.GzipFile(self.filename, 'w')
  72         f.close()
  73         with self.assertRaises(ValueError):
  74             f.write('')
  75         with self.assertRaises(ValueError):
  76             f.flush()
  77
  78     def test_append(self):
  79         self.test_write()
  80         # Append to the previous file
  81         with gzip.GzipFile(self.filename, 'ab') as f:
  82             f.write(data2 * 15)
  83
  84         with gzip.GzipFile(self.filename, 'rb') as f:
  85             d = f.read()
  86         self.assertEqual(d, (data1*50) + (data2*15))
  87
  88     def test_many_append(self):
  89         # Bug #1074261 was triggered when reading a file that contained
  90         # many, many members.  Create such a file and verify that reading it
  91         # works.
  92         with gzip.open(self.filename, 'wb', 9) as f:
  93             f.write('a')
  94         for i in range(0, 200):
  95             with gzip.open(self.filename, "ab", 9) as f: # append
  96                 f.write('a')
  97
  98         # Try reading the file
  99         with gzip.open(self.filename, "rb") as zgfile:
 100             contents = ""
 101             while 1:
 102                 ztxt = zgfile.read(8192)
 103                 contents += ztxt
 104                 if not ztxt: break
 105         self.assertEqual(contents, 'a'*201)
 106
 107     def test_buffered_reader(self):
 108         # Issue #7471: a GzipFile can be wrapped in a BufferedReader for
 109         # performance.
 110         self.test_write()
 111
 112         with gzip.GzipFile(self.filename, 'rb') as f:
 113             with io.BufferedReader(f) as r:
 114                 lines = [line for line in r]
 115
 116         self.assertEqual(lines, 50 * data1.splitlines(True))
 117
 118     def test_readline(self):
 119         self.test_write()
 120         # Try .readline() with varying line lengths
 121
 122         with gzip.GzipFile(self.filename, 'rb') as f:
 123             line_length = 0
 124             while 1:
 125                 L = f.readline(line_length)
 126                 if not L and line_length != 0: break
 127                 self.assertTrue(len(L) <= line_length)
 128                 line_length = (line_length + 1) % 50
 129
 130     def test_readlines(self):
 131         self.test_write()
 132         # Try .readlines()
 133
 134         with gzip.GzipFile(self.filename, 'rb') as f:
 135             L = f.readlines()
 136
 137         with gzip.GzipFile(self.filename, 'rb') as f:
 138             while 1:
 139                 L = f.readlines(150)
 140                 if L == []: break
 141
 142     def test_seek_read(self):
 143         self.test_write()
 144         # Try seek, read test
 145
 146         with gzip.GzipFile(self.filename) as f:
 147             while 1:
 148                 oldpos = f.tell()
 149                 line1 = f.readline()
 150                 if not line1: break
 151                 newpos = f.tell()
 152                 f.seek(oldpos)  # negative seek
 153                 if len(line1)>10:
 154                     amount = 10
 155                 else:
 156                     amount = len(line1)
 157                 line2 = f.read(amount)
 158                 self.assertEqual(line1[:amount], line2)
 159                 f.seek(newpos)  # positive seek
 160
 161     def test_seek_whence(self):
 162         self.test_write()
 163         # Try seek(whence=1), read test
 164
 165         with gzip.GzipFile(self.filename) as f:
 166             f.read(10)
 167             f.seek(10, whence=1)
 168             y = f.read(10)
 169         self.assertEqual(y, data1[20:30])
 170
 171     def test_seek_write(self):
 172         # Try seek, write test
 173         with gzip.GzipFile(self.filename, 'w') as f:
 174             for pos in range(0, 256, 16):
 175                 f.seek(pos)
 176                 f.write('GZ\n')
 177
 178     def test_mode(self):
 179         self.test_write()
 180         with gzip.GzipFile(self.filename, 'r') as f:
 181             self.assertEqual(f.myfileobj.mode, 'rb')
 182
 183     def test_1647484(self):
 184         for mode in ('wb', 'rb'):
 185             with gzip.GzipFile(self.filename, mode) as f:
 186                 self.assertTrue(hasattr(f, "name"))
 187                 self.assertEqual(f.name, self.filename)
 188
 189     def test_mtime(self):
 190         mtime = 123456789
 191         with gzip.GzipFile(self.filename, 'w', mtime = mtime) as fWrite:
 192             fWrite.write(data1)
 193         with gzip.GzipFile(self.filename) as fRead:
 194             dataRead = fRead.read()
 195             self.assertEqual(dataRead, data1)
 196             self.assertTrue(hasattr(fRead, 'mtime'))
 197             self.assertEqual(fRead.mtime, mtime)
 198
 199     def test_metadata(self):
 200         mtime = 123456789
 201
 202         with gzip.GzipFile(self.filename, 'w', mtime = mtime) as fWrite:
 203             fWrite.write(data1)
 204
 205         with open(self.filename, 'rb') as fRead:
 206             # see RFC 1952: http://www.faqs.org/rfcs/rfc1952.html
 207
 208             idBytes = fRead.read(2)
 209             self.assertEqual(idBytes, '\x1f\x8b') # gzip ID
 210
 211             cmByte = fRead.read(1)
 212             self.assertEqual(cmByte, '\x08') # deflate
 213
 214             flagsByte = fRead.read(1)
 215             self.assertEqual(flagsByte, '\x08') # only the FNAME flag is set
 216
 217             mtimeBytes = fRead.read(4)
 218             self.assertEqual(mtimeBytes, struct.pack('<i', mtime)) # little-endian
 219
 220             xflByte = fRead.read(1)
 221             self.assertEqual(xflByte, '\x02') # maximum compression
 222
 223             osByte = fRead.read(1)
 224             self.assertEqual(osByte, '\xff') # OS "unknown" (OS-independent)
 225
 226             # Since the FNAME flag is set, the zero-terminated filename follows.
 227             # RFC 1952 specifies that this is the name of the input file, if any.
 228             # However, the gzip module defaults to storing the name of the output
 229             # file in this field.
 230             expected = self.filename.encode('Latin-1') + '\x00'
 231             nameBytes = fRead.read(len(expected))
 232             self.assertEqual(nameBytes, expected)
 233
 234             # Since no other flags were set, the header ends here.
 235             # Rather than process the compressed data, let's seek to the trailer.
 236             fRead.seek(os.stat(self.filename).st_size - 8)
 237
 238             crc32Bytes = fRead.read(4) # CRC32 of uncompressed data [data1]
 239             self.assertEqual(crc32Bytes, '\xaf\xd7d\x83')
 240
 241             isizeBytes = fRead.read(4)
 242             self.assertEqual(isizeBytes, struct.pack('<i', len(data1)))
 243
 244     def test_with_open(self):
 245         # GzipFile supports the context management protocol
 246         with gzip.GzipFile(self.filename, "wb") as f:
 247             f.write(b"xxx")
 248         f = gzip.GzipFile(self.filename, "rb")
 249         f.close()
 250         try:
 251             with f:
 252                 pass
 253         except ValueError:
 254             pass
 255         else:
 256             self.fail("__enter__ on a closed file didn't raise an exception")
 257         try:
 258             with gzip.GzipFile(self.filename, "wb") as f:
 259                 1 // 0
 260         except ZeroDivisionError:
 261             pass
 262         else:
 263             self.fail("1 // 0 didn't raise an exception")
 264
 265     def test_zero_padded_file(self):
 266         with gzip.GzipFile(self.filename, "wb") as f:
 267             f.write(data1 * 50)
 268
 269         # Pad the file with zeroes
 270         with open(self.filename, "ab") as f:
 271             f.write("\x00" * 50)
 272
 273         with gzip.GzipFile(self.filename, "rb") as f:
 274             d = f.read()
 275             self.assertEqual(d, data1 * 50, "Incorrect data in file")
 276
 277 def test_main(verbose=None):
 278     test_support.run_unittest(TestGzip)
 279
 280 if __name__ == "__main__":
 281     test_main(verbose=True)