text: import unittest
  from test import support
  import binascii
  import pickle
  import random
  import sys
  from test.support import bigmemtest, _1G, _4G
  
  zlib = support.import_module('zlib')
  
  requires_Compress_copy = unittest.skipUnless(
          hasattr(zlib.compressobj(), "copy"),
          'requires Compress.copy()')
  requires_Decompress_copy = unittest.skipUnless(
          hasattr(zlib.decompressobj(), "copy"),
          'requires Decompress.copy()')
  
  
  class VersionTestCase(unittest.TestCase):
  
      def test_library_version(self):
          # Test that the major version of the actual library in use matches the
          # major version that we were compiled against. We can't guarantee that
          # the minor versions will match (even on the machine on which the module
          # was compiled), and the API is stable between minor versions, so
          # testing only the major versions avoids spurious failures.
          self.assertEqual(zlib.ZLIB_RUNTIME_VERSION[0], zlib.ZLIB_VERSION[0])
  
  
  class ChecksumTestCase(unittest.TestCase):
      # checksum test cases
      def test_crc32start(self):
          self.assertEqual(zlib.crc32(b""), zlib.crc32(b"", 0))
          self.assertTrue(zlib.crc32(b"abc", 0xffffffff))
  
      def test_crc32empty(self):
          self.assertEqual(zlib.crc32(b"", 0), 0)
          self.assertEqual(zlib.crc32(b"", 1), 1)
          self.assertEqual(zlib.crc32(b"", 432), 432)
  
      def test_adler32start(self):
          self.assertEqual(zlib.adler32(b""), zlib.adler32(b"", 1))
          self.assertTrue(zlib.adler32(b"abc", 0xffffffff))
  
      def test_adler32empty(self):
          self.assertEqual(zlib.adler32(b"", 0), 0)
          self.assertEqual(zlib.adler32(b"", 1), 1)
          self.assertEqual(zlib.adler32(b"", 432), 432)
  
      def test_penguins(self):
          self.assertEqual(zlib.crc32(b"penguin", 0), 0x0e5c1a120)
          self.assertEqual(zlib.crc32(b"penguin", 1), 0x43b6aa94)
          self.assertEqual(zlib.adler32(b"penguin", 0), 0x0bcf02f6)
          self.assertEqual(zlib.adler32(b"penguin", 1), 0x0bd602f7)
  
          self.assertEqual(zlib.crc32(b"penguin"), zlib.crc32(b"penguin", 0))
          self.assertEqual(zlib.adler32(b"penguin"),zlib.adler32(b"penguin",1))
  
      def test_crc32_adler32_unsigned(self):
          foo = b'abcdefghijklmnop'
          # explicitly test signed behavior
          self.assertEqual(zlib.crc32(foo), 2486878355)
          self.assertEqual(zlib.crc32(b'spam'), 1138425661)
          self.assertEqual(zlib.adler32(foo+foo), 3573550353)
          self.assertEqual(zlib.adler32(b'spam'), 72286642)
  
      def test_same_as_binascii_crc32(self):
          foo = b'abcdefghijklmnop'
          crc = 2486878355
          self.assertEqual(binascii.crc32(foo), crc)
          self.assertEqual(zlib.crc32(foo), crc)
          self.assertEqual(binascii.crc32(b'spam'), zlib.crc32(b'spam'))
  
  
  # Issue #10276 - check that inputs >=4 GiB are handled correctly.
  class ChecksumBigBufferTestCase(unittest.TestCase):
  
      @bigmemtest(size=_4G + 4, memuse=1, dry_run=False)
      def test_big_buffer(self, size):
          data = b"nyan" * (_1G + 1)
          self.assertEqual(zlib.crc32(data), 1044521549)
          self.assertEqual(zlib.adler32(data), 2256789997)
  
  
  class ExceptionTestCase(unittest.TestCase):
      # make sure we generate some expected errors
      def test_badlevel(self):
          # specifying compression level out of range causes an error
          # (but -1 is Z_DEFAULT_COMPRESSION and apparently the zlib
          # accepts 0 too)
          self.assertRaises(zlib.error, zlib.compress, b'ERROR', 10)
  
      def test_badargs(self):
          self.assertRaises(TypeError, zlib.adler32)
          self.assertRaises(TypeError, zlib.crc32)
          self.assertRaises(TypeError, zlib.compress)
          self.assertRaises(TypeError, zlib.decompress)
          for arg in (42, None, '', 'abc', (), []):
              self.assertRaises(TypeError, zlib.adler32, arg)
              self.assertRaises(TypeError, zlib.crc32, arg)
              self.assertRaises(TypeError, zlib.compress, arg)
              self.assertRaises(TypeError, zlib.decompress, arg)
  
      def test_badcompressobj(self):
          # verify failure on building compress object with bad params
          self.assertRaises(ValueError, zlib.compressobj, 1, zlib.DEFLATED, 0)
          # specifying total bits too large causes an error
          self.assertRaises(ValueError,
                  zlib.compressobj, 1, zlib.DEFLATED, zlib.MAX_WBITS + 1)
  
      def test_baddecompressobj(self):
          # verify failure on building decompress object with bad params
          self.assertRaises(ValueError, zlib.decompressobj, -1)
  
      def test_decompressobj_badflush(self):
          # verify failure on calling decompressobj.flush with bad params
          self.assertRaises(ValueError, zlib.decompressobj().flush, 0)
          self.assertRaises(ValueError, zlib.decompressobj().flush, -1)
  
      @support.cpython_only
      def test_overflow(self):
          with self.assertRaisesRegex(OverflowError, 'int too large'):
              zlib.decompress(b'', 15, sys.maxsize + 1)
          with self.assertRaisesRegex(OverflowError, 'int too large'):
              zlib.decompressobj().decompress(b'', sys.maxsize + 1)
          with self.assertRaisesRegex(OverflowError, 'int too large'):
              zlib.decompressobj().flush(sys.maxsize + 1)
  
  
  class BaseCompressTestCase(object):
      def check_big_compress_buffer(self, size, compress_func):
          _1M = 1024 * 1024
          # Generate 10 MiB worth of random, and expand it by repeating it.
          # The assumption is that zlib's memory is not big enough to exploit
          # such spread out redundancy.
          data = b''.join([random.getrandbits(8 * _1M).to_bytes(_1M, 'little')
                          for i in range(10)])
          data = data * (size // len(data) + 1)
          try:
              compress_func(data)
          finally:
              # Release memory
              data = None
  
      def check_big_decompress_buffer(self, size, decompress_func):
          data = b'x' * size
          try:
              compressed = zlib.compress(data, 1)
          finally:
              # Release memory
              data = None
          data = decompress_func(compressed)
          # Sanity check
          try:
              self.assertEqual(len(data), size)
              self.assertEqual(len(data.strip(b'x')), 0)
          finally:
              data = None
  
  
  class CompressTestCase(BaseCompressTestCase, unittest.TestCase):
      # Test compression in one go (whole message compression)
      def test_speech(self):
          x = zlib.compress(HAMLET_SCENE)
          self.assertEqual(zlib.decompress(x), HAMLET_SCENE)
  
      def test_keywords(self):
          x = zlib.compress(HAMLET_SCENE, level=3)
          self.assertEqual(zlib.decompress(x), HAMLET_SCENE)
          with self.assertRaises(TypeError):
              zlib.compress(data=HAMLET_SCENE, level=3)
          self.assertEqual(zlib.decompress(x,
                                           wbits=zlib.MAX_WBITS,
                                           bufsize=zlib.DEF_BUF_SIZE),
                           HAMLET_SCENE)
  
      def test_speech128(self):
          # compress more data
          data = HAMLET_SCENE * 128
          x = zlib.compress(data)
          self.assertEqual(zlib.compress(bytearray(data)), x)
          for ob in x, bytearray(x):
              self.assertEqual(zlib.decompress(ob), data)
  
      def test_incomplete_stream(self):
          # A useful error message is given
          x = zlib.compress(HAMLET_SCENE)
          self.assertRaisesRegex(zlib.error,
              "Error -5 while decompressing data: incomplete or truncated stream",
              zlib.decompress, x[:-1])
  
      # Memory use of the following functions takes into account overallocation
  
      @bigmemtest(size=_1G + 1024 * 1024, memuse=3)
      def test_big_compress_buffer(self, size):
          compress = lambda s: zlib.compress(s, 1)
          self.check_big_compress_buffer(size, compress)
  
      @bigmemtest(size=_1G + 1024 * 1024, memuse=2)
      def test_big_decompress_buffer(self, size):
          self.check_big_decompress_buffer(size, zlib.decompress)
  
      @bigmemtest(size=_4G, memuse=1)
      def test_large_bufsize(self, size):
          # Test decompress(bufsize) parameter greater than the internal limit
          data = HAMLET_SCENE * 10
          compressed = zlib.compress(data, 1)
          self.assertEqual(zlib.decompress(compressed, 15, size), data)
  
      def test_custom_bufsize(self):
          data = HAMLET_SCENE * 10
          compressed = zlib.compress(data, 1)
          self.assertEqual(zlib.decompress(compressed, 15, CustomInt()), data)
  
      @unittest.skipUnless(sys.maxsize > 2**32, 'requires 64bit platform')
      @bigmemtest(size=_4G + 100, memuse=4)
      def test_64bit_compress(self, size):
          data = b'x' * size
          try:
              comp = zlib.compress(data, 0)
              self.assertEqual(zlib.decompress(comp), data)
          finally:
              comp = data = None
  
  
  class CompressObjectTestCase(BaseCompressTestCase, unittest.TestCase):
      # Test compression object
      def test_pair(self):
          # straightforward compress/decompress objects
          datasrc = HAMLET_SCENE * 128
          datazip = zlib.compress(datasrc)
          # should compress both bytes and bytearray data
          for data in (datasrc, bytearray(datasrc)):
              co = zlib.compressobj()
              x1 = co.compress(data)
              x2 = co.flush()
              self.assertRaises(zlib.error, co.flush) # second flush should not work
              self.assertEqual(x1 + x2, datazip)
          for v1, v2 in ((x1, x2), (bytearray(x1), bytearray(x2))):
              dco = zlib.decompressobj()
              y1 = dco.decompress(v1 + v2)
              y2 = dco.flush()
              self.assertEqual(data, y1 + y2)
              self.assertIsInstance(dco.unconsumed_tail, bytes)
              self.assertIsInstance(dco.unused_data, bytes)
  
      def test_keywords(self):
          level = 2
          method = zlib.DEFLATED
          wbits = -12
          memLevel = 9
          strategy = zlib.Z_FILTERED
          co = zlib.compressobj(level=level,
                                method=method,
                                wbits=wbits,
                                memLevel=memLevel,
                                strategy=strategy,
                                zdict=b"")
          do = zlib.decompressobj(wbits=wbits, zdict=b"")
          with self.assertRaises(TypeError):
              co.compress(data=HAMLET_SCENE)
          with self.assertRaises(TypeError):
              do.decompress(data=zlib.compress(HAMLET_SCENE))
          x = co.compress(HAMLET_SCENE) + co.flush()
          y = do.decompress(x, max_length=len(HAMLET_SCENE)) + do.flush()
          self.assertEqual(HAMLET_SCENE, y)
  
      def test_compressoptions(self):
          # specify lots of options to compressobj()
          level = 2
          method = zlib.DEFLATED
          wbits = -12
          memLevel = 9
          strategy = zlib.Z_FILTERED
          co = zlib.compressobj(level, method, wbits, memLevel, strategy)
          x1 = co.compress(HAMLET_SCENE)
          x2 = co.flush()
          dco = zlib.decompressobj(wbits)
          y1 = dco.decompress(x1 + x2)
          y2 = dco.flush()
          self.assertEqual(HAMLET_SCENE, y1 + y2)
  
      def test_compressincremental(self):
          # compress object in steps, decompress object as one-shot
          data = HAMLET_SCENE * 128
          co = zlib.compressobj()
          bufs = []
          for i in range(0, len(data), 256):
              bufs.append(co.compress(data[i:i+256]))
          bufs.append(co.flush())
          combuf = b''.join(bufs)
  
          dco = zlib.decompressobj()
          y1 = dco.decompress(b''.join(bufs))
          y2 = dco.flush()
          self.assertEqual(data, y1 + y2)
  
      def test_decompinc(self, flush=False, source=None, cx=256, dcx=64):
          # compress object in steps, decompress object in steps
          source = source or HAMLET_SCENE
          data = source * 128
          co = zlib.compressobj()
          bufs = []
          for i in range(0, len(data), cx):
              bufs.append(co.compress(data[i:i+cx]))
          bufs.append(co.flush())
          combuf = b''.join(bufs)
  
          decombuf = zlib.decompress(combuf)
          # Test type of return value
          self.assertIsInstance(decombuf, bytes)
  
          self.assertEqual(data, decombuf)
  
          dco = zlib.decompressobj()
          bufs = []
          for i in range(0, len(combuf), dcx):
              bufs.append(dco.decompress(combuf[i:i+dcx]))
              self.assertEqual(b'', dco.unconsumed_tail, ########
                               "(A) uct should be b'': not %d long" %
                                         len(dco.unconsumed_tail))
              self.assertEqual(b'', dco.unused_data)
          if flush:
              bufs.append(dco.flush())
          else:
              while True:
                  chunk = dco.decompress(b'')
                  if chunk:
                      bufs.append(chunk)
                  else:
                      break
          self.assertEqual(b'', dco.unconsumed_tail, ########
                           "(B) uct should be b'': not %d long" %
                                         len(dco.unconsumed_tail))
          self.assertEqual(b'', dco.unused_data)
          self.assertEqual(data, b''.join(bufs))
          # Failure means: "decompressobj with init options failed"
  
      def test_decompincflush(self):
          self.test_decompinc(flush=True)
  
      def test_decompimax(self, source=None, cx=256, dcx=64):
          # compress in steps, decompress in length-restricted steps
          source = source or HAMLET_SCENE
          # Check a decompression object with max_length specified
          data = source * 128
          co = zlib.compressobj()
          bufs = []
          for i in range(0, len(data), cx):
              bufs.append(co.compress(data[i:i+cx]))
          bufs.append(co.flush())
          combuf = b''.join(bufs)
          self.assertEqual(data, zlib.decompress(combuf),
                           'compressed data failure')
  
          dco = zlib.decompressobj()
          bufs = []
          cb = combuf
          while cb:
              #max_length = 1 + len(cb)//10
              chunk = dco.decompress(cb, dcx)
              self.assertFalse(len(chunk) > dcx,
                      'chunk too big (%d>%d)' % (len(chunk), dcx))
              bufs.append(chunk)
              cb = dco.unconsumed_tail
          bufs.append(dco.flush())
          self.assertEqual(data, b''.join(bufs), 'Wrong data retrieved')
  
      def test_decompressmaxlen(self, flush=False):
          # Check a decompression object with max_length specified
          data = HAMLET_SCENE * 128
          co = zlib.compressobj()
          bufs = []
          for i in range(0, len(data), 256):
              bufs.append(co.compress(data[i:i+256]))
          bufs.append(co.flush())
          combuf = b''.join(bufs)
          self.assertEqual(data, zlib.decompress(combuf),
                           'compressed data failure')
  
          dco = zlib.decompressobj()
          bufs = []
          cb = combuf
          while cb:
              max_length = 1 + len(cb)//10
              chunk = dco.decompress(cb, max_length)
              self.assertFalse(len(chunk) > max_length,
                          'chunk too big (%d>%d)' % (len(chunk),max_length))
              bufs.append(chunk)
              cb = dco.unconsumed_tail
          if flush:
              bufs.append(dco.flush())
          else:
              while chunk:
                  chunk = dco.decompress(b'', max_length)
                  self.assertFalse(len(chunk) > max_length,
                              'chunk too big (%d>%d)' % (len(chunk),max_length))
                  bufs.append(chunk)
          self.assertEqual(data, b''.join(bufs), 'Wrong data retrieved')
  
      def test_decompressmaxlenflush(self):
          self.test_decompressmaxlen(flush=True)
  
      def test_maxlenmisc(self):
          # Misc tests of max_length
          dco = zlib.decompressobj()
          self.assertRaises(ValueError, dco.decompress, b"", -1)
          self.assertEqual(b'', dco.unconsumed_tail)
  
      def test_maxlen_large(self):
          # Sizes up to sys.maxsize should be accepted, although zlib is
          # internally limited to expressing sizes with unsigned int
          data = HAMLET_SCENE * 10
          self.assertGreater(len(data), zlib.DEF_BUF_SIZE)
          compressed = zlib.compress(data, 1)
          dco = zlib.decompressobj()
          self.assertEqual(dco.decompress(compressed, sys.maxsize), data)
  
      def test_maxlen_custom(self):
          data = HAMLET_SCENE * 10
          compressed = zlib.compress(data, 1)
          dco = zlib.decompressobj()
          self.assertEqual(dco.decompress(compressed, CustomInt()), data[:100])
  
      def test_clear_unconsumed_tail(self):
          # Issue #12050: calling decompress() without providing max_length
          # should clear the unconsumed_tail attribute.
          cdata = b"x\x9cKLJ\x06\x00\x02M\x01"    # "abc"
          dco = zlib.decompressobj()
          ddata = dco.decompress(cdata, 1)
          ddata += dco.decompress(dco.unconsumed_tail)
          self.assertEqual(dco.unconsumed_tail, b"")
  
      def test_flushes(self):
          # Test flush() with the various options, using all the
          # different levels in order to provide more variations.
          sync_opt = ['Z_NO_FLUSH', 'Z_SYNC_FLUSH', 'Z_FULL_FLUSH',
                      'Z_PARTIAL_FLUSH', 'Z_BLOCK']
          sync_opt = [getattr(zlib, opt) for opt in sync_opt
                      if hasattr(zlib, opt)]
          data = HAMLET_SCENE * 8
  
          for sync in sync_opt:
              for level in range(10):
                  obj = zlib.compressobj( level )
                  a = obj.compress( data[:3000] )
                  b = obj.flush( sync )
                  c = obj.compress( data[3000:] )
                  d = obj.flush()
                  self.assertEqual(zlib.decompress(b''.join([a,b,c,d])),
                                   data, ("Decompress failed: flush "
                                          "mode=%i, level=%i") % (sync, level))
                  del obj
  
      @unittest.skipUnless(hasattr(zlib, 'Z_SYNC_FLUSH'),
                           'requires zlib.Z_SYNC_FLUSH')
      def test_odd_flush(self):
          # Test for odd flushing bugs noted in 2.0, and hopefully fixed in 2.1
          import random
          # Testing on 17K of "random" data
  
          # Create compressor and decompressor objects
          co = zlib.compressobj(zlib.Z_BEST_COMPRESSION)
          dco = zlib.decompressobj()
  
          # Try 17K of data
          # generate random data stream
          try:
              # In 2.3 and later, WichmannHill is the RNG of the bug report
              gen = random.WichmannHill()
          except AttributeError:
              try:
                  # 2.2 called it Random
                  gen = random.Random()
              except AttributeError:
                  # others might simply have a single RNG
                  gen = random
          gen.seed(1)
          data = genblock(1, 17 * 1024, generator=gen)
  
          # compress, sync-flush, and decompress
          first = co.compress(data)
          second = co.flush(zlib.Z_SYNC_FLUSH)
          expanded = dco.decompress(first + second)
  
          # if decompressed data is different from the input data, choke.
          self.assertEqual(expanded, data, "17K random source doesn't match")
  
      def test_empty_flush(self):
          # Test that calling .flush() on unused objects works.
          # (Bug #1083110 -- calling .flush() on decompress objects
          # caused a core dump.)
  
          co = zlib.compressobj(zlib.Z_BEST_COMPRESSION)
          self.assertTrue(co.flush())  # Returns a zlib header
          dco = zlib.decompressobj()
          self.assertEqual(dco.flush(), b"") # Returns nothing
  
      def test_dictionary(self):
          h = HAMLET_SCENE
          # Build a simulated dictionary out of the words in HAMLET.
          words = h.split()
          random.shuffle(words)
          zdict = b''.join(words)
          # Use it to compress HAMLET.
          co = zlib.compressobj(zdict=zdict)
          cd = co.compress(h) + co.flush()
          # Verify that it will decompress with the dictionary.
          dco = zlib.decompressobj(zdict=zdict)
          self.assertEqual(dco.decompress(cd) + dco.flush(), h)
          # Verify that it fails when not given the dictionary.
          dco = zlib.decompressobj()
          self.assertRaises(zlib.error, dco.decompress, cd)
  
      def test_dictionary_streaming(self):
          # This simulates the reuse of a compressor object for compressing
          # several separate data streams.
          co = zlib.compressobj(zdict=HAMLET_SCENE)
          do = zlib.decompressobj(zdict=HAMLET_SCENE)
          piece = HAMLET_SCENE[1000:1500]
          d0 = co.compress(piece) + co.flush(zlib.Z_SYNC_FLUSH)
          d1 = co.compress(piece[100:]) + co.flush(zlib.Z_SYNC_FLUSH)
          d2 = co.compress(piece[:-100]) + co.flush(zlib.Z_SYNC_FLUSH)
          self.assertEqual(do.decompress(d0), piece)
          self.assertEqual(do.decompress(d1), piece[100:])
          self.assertEqual(do.decompress(d2), piece[:-100])
  
      def test_decompress_incomplete_stream(self):
          # This is 'foo', deflated
          x = b'x\x9cK\xcb\xcf\x07\x00\x02\x82\x01E'
          # For the record
          self.assertEqual(zlib.decompress(x), b'foo')
          self.assertRaises(zlib.error, zlib.decompress, x[:-5])
          # Omitting the stream end works with decompressor objects
          # (see issue #8672).
          dco = zlib.decompressobj()
          y = dco.decompress(x[:-5])
          y += dco.flush()
          self.assertEqual(y, b'foo')
  
      def test_decompress_eof(self):
          x = b'x\x9cK\xcb\xcf\x07\x00\x02\x82\x01E'  # 'foo'
          dco = zlib.decompressobj()
          self.assertFalse(dco.eof)
          dco.decompress(x[:-5])
          self.assertFalse(dco.eof)
          dco.decompress(x[-5:])
          self.assertTrue(dco.eof)
          dco.flush()
          self.assertTrue(dco.eof)
  
      def test_decompress_eof_incomplete_stream(self):
          x = b'x\x9cK\xcb\xcf\x07\x00\x02\x82\x01E'  # 'foo'
          dco = zlib.decompressobj()
          self.assertFalse(dco.eof)
          dco.decompress(x[:-5])
          self.assertFalse(dco.eof)
          dco.flush()
          self.assertFalse(dco.eof)
  
      def test_decompress_unused_data(self):
          # Repeated calls to decompress() after EOF should accumulate data in
          # dco.unused_data, instead of just storing the arg to the last call.
          source = b'abcdefghijklmnopqrstuvwxyz'
          remainder = b'0123456789'
          y = zlib.compress(source)
          x = y + remainder
          for maxlen in 0, 1000:
              for step in 1, 2, len(y), len(x):
                  dco = zlib.decompressobj()
                  data = b''
                  for i in range(0, len(x), step):
                      if i < len(y):
                          self.assertEqual(dco.unused_data, b'')
                      if maxlen == 0:
                          data += dco.decompress(x[i : i + step])
                          self.assertEqual(dco.unconsumed_tail, b'')
                      else:
                          data += dco.decompress(
                                  dco.unconsumed_tail + x[i : i + step], maxlen)
                  data += dco.flush()
                  self.assertTrue(dco.eof)
                  self.assertEqual(data, source)
                  self.assertEqual(dco.unconsumed_tail, b'')
                  self.assertEqual(dco.unused_data, remainder)
  
      # issue27164
      def test_decompress_raw_with_dictionary(self):
          zdict = b'abcdefghijklmnopqrstuvwxyz'
          co = zlib.compressobj(wbits=-zlib.MAX_WBITS, zdict=zdict)
          comp = co.compress(zdict) + co.flush()
          dco = zlib.decompressobj(wbits=-zlib.MAX_WBITS, zdict=zdict)
          uncomp = dco.decompress(comp) + dco.flush()
          self.assertEqual(zdict, uncomp)
  
      def test_flush_with_freed_input(self):
          # Issue #16411: decompressor accesses input to last decompress() call
          # in flush(), even if this object has been freed in the meanwhile.
          input1 = b'abcdefghijklmnopqrstuvwxyz'
          input2 = b'QWERTYUIOPASDFGHJKLZXCVBNM'
          data = zlib.compress(input1)
          dco = zlib.decompressobj()
          dco.decompress(data, 1)
          del data
          data = zlib.compress(input2)
          self.assertEqual(dco.flush(), input1[1:])
  
      @bigmemtest(size=_4G, memuse=1)
      def test_flush_large_length(self, size):
          # Test flush(length) parameter greater than internal limit UINT_MAX
          input = HAMLET_SCENE * 10
          data = zlib.compress(input, 1)
          dco = zlib.decompressobj()
          dco.decompress(data, 1)
          self.assertEqual(dco.flush(size), input[1:])
  
      def test_flush_custom_length(self):
          input = HAMLET_SCENE * 10
          data = zlib.compress(input, 1)
          dco = zlib.decompressobj()
          dco.decompress(data, 1)
          self.assertEqual(dco.flush(CustomInt()), input[1:])
  
      @requires_Compress_copy
      def test_compresscopy(self):
          # Test copying a compression object
          data0 = HAMLET_SCENE
          data1 = bytes(str(HAMLET_SCENE, "ascii").swapcase(), "ascii")
          c0 = zlib.compressobj(zlib.Z_BEST_COMPRESSION)
          bufs0 = []
          bufs0.append(c0.compress(data0))
  
          c1 = c0.copy()
          bufs1 = bufs0[:]
  
          bufs0.append(c0.compress(data0))
          bufs0.append(c0.flush())
          s0 = b''.join(bufs0)
  
          bufs1.append(c1.compress(data1))
          bufs1.append(c1.flush())
          s1 = b''.join(bufs1)
  
          self.assertEqual(zlib.decompress(s0),data0+data0)
          self.assertEqual(zlib.decompress(s1),data0+data1)
  
      @requires_Compress_copy
      def test_badcompresscopy(self):
          # Test copying a compression object in an inconsistent state
          c = zlib.compressobj()
          c.compress(HAMLET_SCENE)
          c.flush()
          self.assertRaises(ValueError, c.copy)
  
      @requires_Decompress_copy
      def test_decompresscopy(self):
          # Test copying a decompression object
          data = HAMLET_SCENE
          comp = zlib.compress(data)
          # Test type of return value
          self.assertIsInstance(comp, bytes)
  
          d0 = zlib.decompressobj()
          bufs0 = []
          bufs0.append(d0.decompress(comp[:32]))
  
          d1 = d0.copy()
          bufs1 = bufs0[:]
  
          bufs0.append(d0.decompress(comp[32:]))
          s0 = b''.join(bufs0)
  
          bufs1.append(d1.decompress(comp[32:]))
          s1 = b''.join(bufs1)
  
          self.assertEqual(s0,s1)
          self.assertEqual(s0,data)
  
      @requires_Decompress_copy
      def test_baddecompresscopy(self):
          # Test copying a compression object in an inconsistent state
          data = zlib.compress(HAMLET_SCENE)
          d = zlib.decompressobj()
          d.decompress(data)
          d.flush()
          self.assertRaises(ValueError, d.copy)
  
      def test_compresspickle(self):
          for proto in range(pickle.HIGHEST_PROTOCOL + 1):
              with self.assertRaises((TypeError, pickle.PicklingError)):
                  pickle.dumps(zlib.compressobj(zlib.Z_BEST_COMPRESSION), proto)
  
      def test_decompresspickle(self):
          for proto in range(pickle.HIGHEST_PROTOCOL + 1):
              with self.assertRaises((TypeError, pickle.PicklingError)):
                  pickle.dumps(zlib.decompressobj(), proto)
  
      # Memory use of the following functions takes into account overallocation
  
      @bigmemtest(size=_1G + 1024 * 1024, memuse=3)
      def test_big_compress_buffer(self, size):
          c = zlib.compressobj(1)
          compress = lambda s: c.compress(s) + c.flush()
          self.check_big_compress_buffer(size, compress)
  
      @bigmemtest(size=_1G + 1024 * 1024, memuse=2)
      def test_big_decompress_buffer(self, size):
          d = zlib.decompressobj()
          decompress = lambda s: d.decompress(s) + d.flush()
          self.check_big_decompress_buffer(size, decompress)
  
      @unittest.skipUnless(sys.maxsize > 2**32, 'requires 64bit platform')
      @bigmemtest(size=_4G + 100, memuse=4)
      def test_64bit_compress(self, size):
          data = b'x' * size
          co = zlib.compressobj(0)
          do = zlib.decompressobj()
          try:
              comp = co.compress(data) + co.flush()
              uncomp = do.decompress(comp) + do.flush()
              self.assertEqual(uncomp, data)
          finally:
              comp = uncomp = data = None
  
      @unittest.skipUnless(sys.maxsize > 2**32, 'requires 64bit platform')
      @bigmemtest(size=_4G + 100, memuse=3)
      def test_large_unused_data(self, size):
          data = b'abcdefghijklmnop'
          unused = b'x' * size
          comp = zlib.compress(data) + unused
          do = zlib.decompressobj()
          try:
              uncomp = do.decompress(comp) + do.flush()
              self.assertEqual(unused, do.unused_data)
              self.assertEqual(uncomp, data)
          finally:
              unused = comp = do = None
  
      @unittest.skipUnless(sys.maxsize > 2**32, 'requires 64bit platform')
      @bigmemtest(size=_4G + 100, memuse=5)
      def test_large_unconsumed_tail(self, size):
          data = b'x' * size
          do = zlib.decompressobj()
          try:
              comp = zlib.compress(data, 0)
              uncomp = do.decompress(comp, 1) + do.flush()
              self.assertEqual(uncomp, data)
              self.assertEqual(do.unconsumed_tail, b'')
          finally:
              comp = uncomp = data = None
  
      def test_wbits(self):
          # wbits=0 only supported since zlib v1.2.3.5
          # Register "1.2.3" as "1.2.3.0"
          # or "1.2.0-linux","1.2.0.f","1.2.0.f-linux"
          v = zlib.ZLIB_RUNTIME_VERSION.split('-', 1)[0].split('.')
          if len(v) < 4:
              v.append('0')
          elif not v[-1].isnumeric():
              v[-1] = '0'
  
          v = tuple(map(int, v))
          supports_wbits_0 = v >= (1, 2, 3, 5)
  
          co = zlib.compressobj(level=1, wbits=15)
          zlib15 = co.compress(HAMLET_SCENE) + co.flush()
          self.assertEqual(zlib.decompress(zlib15, 15), HAMLET_SCENE)
          if supports_wbits_0:
              self.assertEqual(zlib.decompress(zlib15, 0), HAMLET_SCENE)
          self.assertEqual(zlib.decompress(zlib15, 32 + 15), HAMLET_SCENE)
          with self.assertRaisesRegex(zlib.error, 'invalid window size'):
              zlib.decompress(zlib15, 14)
          dco = zlib.decompressobj(wbits=32 + 15)
          self.assertEqual(dco.decompress(zlib15), HAMLET_SCENE)
          dco = zlib.decompressobj(wbits=14)
          with self.assertRaisesRegex(zlib.error, 'invalid window size'):
              dco.decompress(zlib15)
  
          co = zlib.compressobj(level=1, wbits=9)
          zlib9 = co.compress(HAMLET_SCENE) + co.flush()
          self.assertEqual(zlib.decompress(zlib9, 9), HAMLET_SCENE)
          self.assertEqual(zlib.decompress(zlib9, 15), HAMLET_SCENE)
          if supports_wbits_0:
              self.assertEqual(zlib.decompress(zlib9, 0), HAMLET_SCENE)
          self.assertEqual(zlib.decompress(zlib9, 32 + 9), HAMLET_SCENE)
          dco = zlib.decompressobj(wbits=32 + 9)
          self.assertEqual(dco.decompress(zlib9), HAMLET_SCENE)
  
          co = zlib.compressobj(level=1, wbits=-15)
          deflate15 = co.compress(HAMLET_SCENE) + co.flush()
          self.assertEqual(zlib.decompress(deflate15, -15), HAMLET_SCENE)
          dco = zlib.decompressobj(wbits=-15)
          self.assertEqual(dco.decompress(deflate15), HAMLET_SCENE)
  
          co = zlib.compressobj(level=1, wbits=-9)
          deflate9 = co.compress(HAMLET_SCENE) + co.flush()
          self.assertEqual(zlib.decompress(deflate9, -9), HAMLET_SCENE)
          self.assertEqual(zlib.decompress(deflate9, -15), HAMLET_SCENE)
          dco = zlib.decompressobj(wbits=-9)
          self.assertEqual(dco.decompress(deflate9), HAMLET_SCENE)
  
          co = zlib.compressobj(level=1, wbits=16 + 15)
          gzip = co.compress(HAMLET_SCENE) + co.flush()
          self.assertEqual(zlib.decompress(gzip, 16 + 15), HAMLET_SCENE)
          self.assertEqual(zlib.decompress(gzip, 32 + 15), HAMLET_SCENE)
          dco = zlib.decompressobj(32 + 15)
          self.assertEqual(dco.decompress(gzip), HAMLET_SCENE)
  
  
  def genblock(seed, length, step=1024, generator=random):
      """length-byte stream of random data from a seed (in step-byte blocks)."""
      if seed is not None:
          generator.seed(seed)
      randint = generator.randint
      if length < step or step < 2:
          step = length
      blocks = bytes()
      for i in range(0, length, step):
          blocks += bytes(randint(0, 255) for x in range(step))
      return blocks
  
  
  
  def choose_lines(source, number, seed=None, generator=random):
      """Return a list of number lines randomly chosen from the source"""
      if seed is not None:
          generator.seed(seed)
      sources = source.split('\n')
      return [generator.choice(sources) for n in range(number)]
  
  
  
  HAMLET_SCENE = b"""
  LAERTES
  
         O, fear me not.
         I stay too long: but here my father comes.
  
         Enter POLONIUS
  
         A double blessing is a double grace,
         Occasion smiles upon a second leave.
  
  LORD POLONIUS
  
         Yet here, Laertes! aboard, aboard, for shame!
         The wind sits in the shoulder of your sail,
         And you are stay'd for. There; my blessing with thee!
         And these few precepts in thy memory
         See thou character. Give thy thoughts no tongue,
         Nor any unproportioned thought his act.
         Be thou familiar, but by no means vulgar.
         Those friends thou hast, and their adoption tried,
         Grapple them to thy soul with hoops of steel;
         But do not dull thy palm with entertainment
         Of each new-hatch'd, unfledged comrade. Beware
         Of entrance to a quarrel, but being in,
         Bear't that the opposed may beware of thee.
         Give every man thy ear, but few thy voice;
         Take each man's censure, but reserve thy judgment.
         Costly thy habit as thy purse can buy,
         But not express'd in fancy; rich, not gaudy;
         For the apparel oft proclaims the man,
         And they in France of the best rank and station
         Are of a most select and generous chief in that.
         Neither a borrower nor a lender be;
         For loan oft loses both itself and friend,
         And borrowing dulls the edge of husbandry.
         This above all: to thine ownself be true,
         And it must follow, as the night the day,
         Thou canst not then be false to any man.
         Farewell: my blessing season this in thee!
  
  LAERTES
  
         Most humbly do I take my leave, my lord.
  
  LORD POLONIUS
  
         The time invites you; go; your servants tend.
  
  LAERTES
  
         Farewell, Ophelia; and remember well
         What I have said to you.
  
  OPHELIA
  
         'Tis in my memory lock'd,
         And you yourself shall keep the key of it.
  
  LAERTES
  
         Farewell.
  """
  
  
  class CustomInt:
      def __int__(self):
          return 100
  
  
  if __name__ == "__main__":
      unittest.main()
  