class DeflaterDest(Dest):
'''
Dest-like class, reading from a file-like object initially, but
switching to a Deflater object if written to.
dest = DeflaterDest(original_file)
dest.read() # Reads original_file
dest.write(data) # Creates a Deflater and write data there
dest.read() # Re-opens the Deflater and reads from it
'''
def __init__(self, orig=None, compress=True):
self.mode = None
self.deflater = orig
self.compress = compress
def read(self, length=-1):
if self.mode != 'r':
assert self.mode is None
self.mode = 'r'
return self.deflater.read(length)
def write(self, data):
if self.mode != 'w':
from mozpack.mozjar import Deflater
self.deflater = Deflater(self.compress)
self.mode = 'w'
self.deflater.write(data)
def exists(self):
return self.deflater is not None
def write(self, data):
if self.mode != "w":
from mozpack.mozjar import Deflater
self.deflater = Deflater(self.compress)
self.mode = "w"
self.deflater.write(data)
class DeflaterDest(Dest):
'''
Dest-like class, reading from a file-like object initially, but
switching to a Deflater object if written to.
dest = DeflaterDest(original_file)
dest.read() # Reads original_file
dest.write(data) # Creates a Deflater and write data there
dest.read() # Re-opens the Deflater and reads from it
'''
def __init__(self, orig=None, compress=True):
self.mode = None
self.deflater = orig
self.compress = compress
def read(self, length=-1):
if self.mode != 'r':
assert self.mode is None
self.mode = 'r'
return self.deflater.read(length)
def write(self, data):
if self.mode != 'w':
from mozpack.mozjar import Deflater
self.deflater = Deflater(self.compress)
self.mode = 'w'
self.deflater.write(data)
def exists(self):
return self.deflater is not None
def test_deflater_no_compress(self):
deflater = Deflater(False)
deflater.write(self.wrap(b"abc"))
self.assertFalse(deflater.compressed)
self.assertEqual(deflater.uncompressed_size, 3)
self.assertEqual(deflater.compressed_size, deflater.uncompressed_size)
self.assertEqual(deflater.compressed_data, b"abc")
self.assertEqual(deflater.crc32, 0x352441C2)
def test_deflater_compress_no_gain(self):
deflater = Deflater(True)
deflater.write(self.wrap('abc'))
self.assertFalse(deflater.compressed)
self.assertEqual(deflater.uncompressed_size, 3)
self.assertEqual(deflater.compressed_size, deflater.uncompressed_size)
self.assertEqual(deflater.compressed_data, 'abc')
self.assertEqual(deflater.crc32, 0x352441c2)
def test_deflater_compress_no_gain(self):
deflater = Deflater(True)
deflater.write(self.wrap('abc'))
self.assertFalse(deflater.compressed)
self.assertEqual(deflater.uncompressed_size, 3)
self.assertEqual(deflater.compressed_size, deflater.uncompressed_size)
self.assertEqual(deflater.compressed_data, 'abc')
self.assertEqual(deflater.crc32, 0x352441c2)
def test_deflater_empty(self):
deflater = Deflater(False)
self.assertFalse(deflater.compressed)
self.assertEqual(deflater.uncompressed_size, 0)
self.assertEqual(deflater.compressed_size, deflater.uncompressed_size)
self.assertEqual(deflater.compressed_data, b"")
self.assertEqual(deflater.crc32, 0)
def write(self, data):
if self.mode != "w":
from mozpack.mozjar import Deflater
self.deflater = Deflater(self.compress)
self.mode = "w"
self.deflater.write(data)
def test_deflater_compress(self):
deflater = Deflater(True)
deflater.write(self.wrap(b"aaaaaaaaaaaaanopqrstuvwxyz"))
self.assertTrue(deflater.compressed)
self.assertEqual(deflater.uncompressed_size, 26)
self.assertNotEqual(deflater.compressed_size,
deflater.uncompressed_size)
self.assertEqual(deflater.crc32, 0xD46B97ED)
# The CRC is the same as when not compressed
deflater = Deflater(False)
self.assertFalse(deflater.compressed)
deflater.write(self.wrap(b"aaaaaaaaaaaaanopqrstuvwxyz"))
self.assertEqual(deflater.crc32, 0xD46B97ED)
def test_deflater_compress(self):
deflater = Deflater(True)
deflater.write(self.wrap('aaaaaaaaaaaaanopqrstuvwxyz'))
self.assertTrue(deflater.compressed)
self.assertEqual(deflater.uncompressed_size, 26)
self.assertNotEqual(deflater.compressed_size,
deflater.uncompressed_size)
self.assertEqual(deflater.crc32, 0xd46b97ed)
# The CRC is the same as when not compressed
deflater = Deflater(False)
self.assertFalse(deflater.compressed)
deflater.write(self.wrap('aaaaaaaaaaaaanopqrstuvwxyz'))
self.assertEqual(deflater.crc32, 0xd46b97ed)
