#! /usr/bin/env python
"""Test script for the gzip module.
"""
import unittest
from test import test_support
import os
import io
import struct
gzip = test_support.import_module('gzip')
data1 = """ int length=DEFAULTALLOC, err = Z_OK;
PyObject *RetVal;
int flushmode = Z_FINISH;
unsigned long start_total_out;
"""
data2 = """/* zlibmodule.c -- gzip-compatible data compression */
/* See http://www.gzip.org/zlib/
/* See http://www.winimage.com/zLibDll for Windows */
"""
class TestGzip(unittest.TestCase):
filename = test_support.TESTFN
def setUp(self):
test_support.unlink(self.filename)
def tearDown(self):
test_support.unlink(self.filename)
def test_write(self):
with gzip.GzipFile(self.filename, 'wb') as f:
f.write(data1 * 50)
# Try flush and fileno.
f.flush()
f.fileno()
if hasattr(os, 'fsync'):
os.fsync(f.fileno())
f.close()
# Test multiple close() calls.
f.close()
def test_read(self):
self.test_write()
# Try reading.
with gzip.GzipFile(self.filename, 'r') as f:
d = f.read()
self.assertEqual(d, data1*50)
def test_read_universal_newlines(self):
# Issue #5148: Reading breaks when mode contains 'U'.
self.test_write()
with gzip.GzipFile(self.filename, 'rU') as f:
d = f.read()
self.assertEqual(d, data1*50)
def test_io_on_closed_object(self):
# Test that I/O operations on closed GzipFile objects raise a
# ValueError, just like the corresponding functions on file objects.
# Write to a file, open it for reading, then close it.
self.test_write()
f = gzip.GzipFile(self.filename, 'r')
f.close()
with self.assertRaises(ValueError):
f.read(1)
with self.assertRaises(ValueError):
f.seek(0)
with self.assertRaises(ValueError):
f.tell()
# Open the file for writing, then close it.
f = gzip.GzipFile(self.filename, 'w')
f.close()
with self.assertRaises(ValueError):
f.write('')
with self.assertRaises(ValueError):
f.flush()
def test_append(self):
self.test_write()
# Append to the previous file
with gzip.GzipFile(self.filename, 'ab') as f:
f.write(data2 * 15)
with gzip.GzipFile(self.filename, 'rb') as f:
d = f.read()
self.assertEqual(d, (data1*50) + (data2*15))
def test_many_append(self):
# Bug #1074261 was triggered when reading a file that contained
# many, many members. Create such a file and verify that reading it
# works.
with gzip.open(self.filename, 'wb', 9) as f:
f.write('a')
for i in range(0, 200):
with gzip.open(self.filename, "ab", 9) as f: # append
f.write('a')
# Try reading the file
with gzip.open(self.filename, "rb") as zgfile:
contents = ""
while 1:
ztxt = zgfile.read(8192)
contents += ztxt
if not ztxt: break
self.assertEqual(contents, 'a'*201)
def test_buffered_reader(self):
# Issue #7471: a GzipFile can be wrapped in a BufferedReader for
# performance.
self.test_write()
with gzip.GzipFile(self.filename, 'rb') as f:
with io.BufferedReader(f) as r:
lines = [line for line in r]
self.assertEqual(lines, 50 * data1.splitlines(True))
def test_readline(self):
self.test_write()
# Try .readline() with varying line lengths
with gzip.GzipFile(self.filename, 'rb') as f:
line_length = 0
while 1:
L = f.readline(line_length)
if not L and line_length != 0: break
self.assertTrue(len(L) <= line_length)
line_length = (line_length + 1) % 50
def test_readlines(self):
self.test_write()
# Try .readlines()
with gzip.GzipFile(self.filename, 'rb') as f:
L = f.readlines()
with gzip.GzipFile(self.filename, 'rb') as f:
while 1:
L = f.readlines(150)
if L == []: break
def test_seek_read(self):
self.test_write()
# Try seek, read test
with gzip.GzipFile(self.filename) as f:
while 1:
oldpos = f.tell()
line1 = f.readline()
if not line1: break
newpos = f.tell()
f.seek(oldpos) # negative seek
if len(line1)>10:
amount = 10
else:
amount = len(line1)
line2 = f.read(amount)
self.assertEqual(line1[:amount], line2)
f.seek(newpos) # positive seek
def test_seek_whence(self):
self.test_write()
# Try seek(whence=1), read test
with gzip.GzipFile(self.filename) as f:
f.read(10)
f.seek(10, whence=1)
y = f.read(10)
self.assertEqual(y, data1[20:30])
def test_seek_write(self):
# Try seek, write test
with gzip.GzipFile(self.filename, 'w') as f:
for pos in range(0, 256, 16):
f.seek(pos)
f.write('GZ\n')
def test_mode(self):
self.test_write()
with gzip.GzipFile(self.filename, 'r') as f:
self.assertEqual(f.myfileobj.mode, 'rb')
def test_1647484(self):
for mode in ('wb', 'rb'):
with gzip.GzipFile(self.filename, mode) as f:
self.assertTrue(hasattr(f, "name"))
self.assertEqual(f.name, self.filename)
def test_mtime(self):
mtime = 123456789
with gzip.GzipFile(self.filename, 'w', mtime = mtime) as fWrite:
fWrite.write(data1)
with gzip.GzipFile(self.filename) as fRead:
dataRead = fRead.read()
self.assertEqual(dataRead, data1)
self.assertTrue(hasattr(fRead, 'mtime'))
self.assertEqual(fRead.mtime, mtime)
def test_metadata(self):
mtime = 123456789
with gzip.GzipFile(self.filename, 'w', mtime = mtime) as fWrite:
fWrite.write(data1)
with open(self.filename, 'rb') as fRead:
# see RFC 1952: http://www.faqs.org/rfcs/rfc1952.html
idBytes = fRead.read(2)
self.assertEqual(idBytes, '\x1f\x8b') # gzip ID
cmByte = fRead.read(1)
self.assertEqual(cmByte, '\x08') # deflate
flagsByte = fRead.read(1)
self.assertEqual(flagsByte, '\x08') # only the FNAME flag is set
mtimeBytes = fRead.read(4)
self.assertEqual(mtimeBytes, struct.pack('<i', mtime)) # little-endian
xflByte = fRead.read(1)
self.assertEqual(xflByte, '\x02') # maximum compression
osByte = fRead.read(1)
self.assertEqual(osByte, '\xff') # OS "unknown" (OS-independent)
# Since the FNAME flag is set, the zero-terminated filename follows.
# RFC 1952 specifies that this is the name of the input file, if any.
# However, the gzip module defaults to storing the name of the output
# file in this field.
expected = self.filename.encode('Latin-1') + '\x00'
nameBytes = fRead.read(len(expected))
self.assertEqual(nameBytes, expected)
# Since no other flags were set, the header ends here.
# Rather than process the compressed data, let's seek to the trailer.
fRead.seek(os.stat(self.filename).st_size - 8)
crc32Bytes = fRead.read(4) # CRC32 of uncompressed data [data1]
self.assertEqual(crc32Bytes, '\xaf\xd7d\x83')
isizeBytes = fRead.read(4)
self.assertEqual(isizeBytes, struct.pack('<i', len(data1)))
def test_with_open(self):
# GzipFile supports the context management protocol
with gzip.GzipFile(self.filename, "wb") as f:
f.write(b"xxx")
f = gzip.GzipFile(self.filename, "rb")
f.close()
try:
with f:
pass
except ValueError:
pass
else:
self.fail("__enter__ on a closed file didn't raise an exception")
try:
with gzip.GzipFile(self.filename, "wb") as f:
1 // 0
except ZeroDivisionError:
pass
else:
self.fail("1 // 0 didn't raise an exception")
def test_zero_padded_file(self):
with gzip.GzipFile(self.filename, "wb") as f:
f.write(data1 * 50)
# Pad the file with zeroes
with open(self.filename, "ab") as f:
f.write("\x00" * 50)
with gzip.GzipFile(self.filename, "rb") as f:
d = f.read()
self.assertEqual(d, data1 * 50, "Incorrect data in file")
def test_fileobj_from_fdopen(self):
# Issue #13781: Creating a GzipFile using a fileobj from os.fdopen()
# should not embed the fake filename "<fdopen>" in the output file.
fd = os.open(self.filename, os.O_WRONLY | os.O_CREAT)
with os.fdopen(fd, "wb") as f:
with gzip.GzipFile(fileobj=f, mode="w") as g:
self.assertEqual(g.name, "")
def test_read_with_extra(self):
# Gzip data with an extra field
gzdata = (b'\x1f\x8b\x08\x04\xb2\x17cQ\x02\xff'
b'\x05\x00Extra'
b'\x0bI-.\x01\x002\xd1Mx\x04\x00\x00\x00')
with gzip.GzipFile(fileobj=io.BytesIO(gzdata)) as f:
self.assertEqual(f.read(), b'Test')
def test_main(verbose=None):
test_support.run_unittest(TestGzip)
if __name__ == "__main__":
test_main(verbose=True)