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_read_universal_newlines(self): 57 # Issue #5148: Reading breaks when mode contains 'U'. 58 self.test_write() 59 with gzip.GzipFile(self.filename, 'rU') as f: 60 d = f.read() 61 self.assertEqual(d, data1*50) 62 63 def test_io_on_closed_object(self): 64 # Test that I/O operations on closed GzipFile objects raise a 65 # ValueError, just like the corresponding functions on file objects. 66 67 # Write to a file, open it for reading, then close it. 68 self.test_write() 69 f = gzip.GzipFile(self.filename, 'r') 70 f.close() 71 with self.assertRaises(ValueError): 72 f.read(1) 73 with self.assertRaises(ValueError): 74 f.seek(0) 75 with self.assertRaises(ValueError): 76 f.tell() 77 # Open the file for writing, then close it. 78 f = gzip.GzipFile(self.filename, 'w') 79 f.close() 80 with self.assertRaises(ValueError): 81 f.write('') 82 with self.assertRaises(ValueError): 83 f.flush() 84 85 def test_append(self): 86 self.test_write() 87 # Append to the previous file 88 with gzip.GzipFile(self.filename, 'ab') as f: 89 f.write(data2 * 15) 90 91 with gzip.GzipFile(self.filename, 'rb') as f: 92 d = f.read() 93 self.assertEqual(d, (data1*50) + (data2*15)) 94 95 def test_many_append(self): 96 # Bug #1074261 was triggered when reading a file that contained 97 # many, many members. Create such a file and verify that reading it 98 # works. 99 with gzip.open(self.filename, 'wb', 9) as f: 100 f.write('a') 101 for i in range(0, 200): 102 with gzip.open(self.filename, "ab", 9) as f: # append 103 f.write('a') 104 105 # Try reading the file 106 with gzip.open(self.filename, "rb") as zgfile: 107 contents = "" 108 while 1: 109 ztxt = zgfile.read(8192) 110 contents += ztxt 111 if not ztxt: break 112 self.assertEqual(contents, 'a'*201) 113 114 def test_buffered_reader(self): 115 # Issue #7471: a GzipFile can be wrapped in a BufferedReader for 116 # performance. 117 self.test_write() 118 119 with gzip.GzipFile(self.filename, 'rb') as f: 120 with io.BufferedReader(f) as r: 121 lines = [line for line in r] 122 123 self.assertEqual(lines, 50 * data1.splitlines(True)) 124 125 def test_readline(self): 126 self.test_write() 127 # Try .readline() with varying line lengths 128 129 with gzip.GzipFile(self.filename, 'rb') as f: 130 line_length = 0 131 while 1: 132 L = f.readline(line_length) 133 if not L and line_length != 0: break 134 self.assertTrue(len(L) <= line_length) 135 line_length = (line_length + 1) % 50 136 137 def test_readlines(self): 138 self.test_write() 139 # Try .readlines() 140 141 with gzip.GzipFile(self.filename, 'rb') as f: 142 L = f.readlines() 143 144 with gzip.GzipFile(self.filename, 'rb') as f: 145 while 1: 146 L = f.readlines(150) 147 if L == []: break 148 149 def test_seek_read(self): 150 self.test_write() 151 # Try seek, read test 152 153 with gzip.GzipFile(self.filename) as f: 154 while 1: 155 oldpos = f.tell() 156 line1 = f.readline() 157 if not line1: break 158 newpos = f.tell() 159 f.seek(oldpos) # negative seek 160 if len(line1)>10: 161 amount = 10 162 else: 163 amount = len(line1) 164 line2 = f.read(amount) 165 self.assertEqual(line1[:amount], line2) 166 f.seek(newpos) # positive seek 167 168 def test_seek_whence(self): 169 self.test_write() 170 # Try seek(whence=1), read test 171 172 with gzip.GzipFile(self.filename) as f: 173 f.read(10) 174 f.seek(10, whence=1) 175 y = f.read(10) 176 self.assertEqual(y, data1[20:30]) 177 178 def test_seek_write(self): 179 # Try seek, write test 180 with gzip.GzipFile(self.filename, 'w') as f: 181 for pos in range(0, 256, 16): 182 f.seek(pos) 183 f.write('GZ\n') 184 185 def test_mode(self): 186 self.test_write() 187 with gzip.GzipFile(self.filename, 'r') as f: 188 self.assertEqual(f.myfileobj.mode, 'rb') 189 190 def test_1647484(self): 191 for mode in ('wb', 'rb'): 192 with gzip.GzipFile(self.filename, mode) as f: 193 self.assertTrue(hasattr(f, "name")) 194 self.assertEqual(f.name, self.filename) 195 196 def test_mtime(self): 197 mtime = 123456789 198 with gzip.GzipFile(self.filename, 'w', mtime = mtime) as fWrite: 199 fWrite.write(data1) 200 with gzip.GzipFile(self.filename) as fRead: 201 dataRead = fRead.read() 202 self.assertEqual(dataRead, data1) 203 self.assertTrue(hasattr(fRead, 'mtime')) 204 self.assertEqual(fRead.mtime, mtime) 205 206 def test_metadata(self): 207 mtime = 123456789 208 209 with gzip.GzipFile(self.filename, 'w', mtime = mtime) as fWrite: 210 fWrite.write(data1) 211 212 with open(self.filename, 'rb') as fRead: 213 # see RFC 1952: http://www.faqs.org/rfcs/rfc1952.html 214 215 idBytes = fRead.read(2) 216 self.assertEqual(idBytes, '\x1f\x8b') # gzip ID 217 218 cmByte = fRead.read(1) 219 self.assertEqual(cmByte, '\x08') # deflate 220 221 flagsByte = fRead.read(1) 222 self.assertEqual(flagsByte, '\x08') # only the FNAME flag is set 223 224 mtimeBytes = fRead.read(4) 225 self.assertEqual(mtimeBytes, struct.pack('<i', mtime)) # little-endian 226 227 xflByte = fRead.read(1) 228 self.assertEqual(xflByte, '\x02') # maximum compression 229 230 osByte = fRead.read(1) 231 self.assertEqual(osByte, '\xff') # OS "unknown" (OS-independent) 232 233 # Since the FNAME flag is set, the zero-terminated filename follows. 234 # RFC 1952 specifies that this is the name of the input file, if any. 235 # However, the gzip module defaults to storing the name of the output 236 # file in this field. 237 expected = self.filename.encode('Latin-1') + '\x00' 238 nameBytes = fRead.read(len(expected)) 239 self.assertEqual(nameBytes, expected) 240 241 # Since no other flags were set, the header ends here. 242 # Rather than process the compressed data, let's seek to the trailer. 243 fRead.seek(os.stat(self.filename).st_size - 8) 244 245 crc32Bytes = fRead.read(4) # CRC32 of uncompressed data [data1] 246 self.assertEqual(crc32Bytes, '\xaf\xd7d\x83') 247 248 isizeBytes = fRead.read(4) 249 self.assertEqual(isizeBytes, struct.pack('<i', len(data1))) 250 251 def test_with_open(self): 252 # GzipFile supports the context management protocol 253 with gzip.GzipFile(self.filename, "wb") as f: 254 f.write(b"xxx") 255 f = gzip.GzipFile(self.filename, "rb") 256 f.close() 257 try: 258 with f: 259 pass 260 except ValueError: 261 pass 262 else: 263 self.fail("__enter__ on a closed file didn't raise an exception") 264 try: 265 with gzip.GzipFile(self.filename, "wb") as f: 266 1 // 0 267 except ZeroDivisionError: 268 pass 269 else: 270 self.fail("1 // 0 didn't raise an exception") 271 272 def test_zero_padded_file(self): 273 with gzip.GzipFile(self.filename, "wb") as f: 274 f.write(data1 * 50) 275 276 # Pad the file with zeroes 277 with open(self.filename, "ab") as f: 278 f.write("\x00" * 50) 279 280 with gzip.GzipFile(self.filename, "rb") as f: 281 d = f.read() 282 self.assertEqual(d, data1 * 50, "Incorrect data in file") 283 284 def test_fileobj_from_fdopen(self): 285 # Issue #13781: Creating a GzipFile using a fileobj from os.fdopen() 286 # should not embed the fake filename "<fdopen>" in the output file. 287 fd = os.open(self.filename, os.O_WRONLY | os.O_CREAT) 288 with os.fdopen(fd, "wb") as f: 289 with gzip.GzipFile(fileobj=f, mode="w") as g: 290 self.assertEqual(g.name, "") 291 292 def test_read_with_extra(self): 293 # Gzip data with an extra field 294 gzdata = (b'\x1f\x8b\x08\x04\xb2\x17cQ\x02\xff' 295 b'\x05\x00Extra' 296 b'\x0bI-.\x01\x002\xd1Mx\x04\x00\x00\x00') 297 with gzip.GzipFile(fileobj=io.BytesIO(gzdata)) as f: 298 self.assertEqual(f.read(), b'Test') 299 300 def test_main(verbose=None): 301 test_support.run_unittest(TestGzip) 302 303 if __name__ == "__main__": 304 test_main(verbose=True) 305