text: """Functions that read and write gzipped files.
  
  The user of the file doesn't have to worry about the compression,
  but random access is not allowed."""
  
  # based on Andrew Kuchling's minigzip.py distributed with the zlib module
  
  import struct, sys, time, os
  import zlib
  import builtins
  import io
  
  __all__ = ["GzipFile", "open", "compress", "decompress"]
  
  FTEXT, FHCRC, FEXTRA, FNAME, FCOMMENT = 1, 2, 4, 8, 16
  
  READ, WRITE = 1, 2
  
  def open(filename, mode="rb", compresslevel=9,
           encoding=None, errors=None, newline=None):
      """Open a gzip-compressed file in binary or text mode.
  
      The filename argument can be an actual filename (a str or bytes object), or
      an existing file object to read from or write to.
  
      The mode argument can be "r", "rb", "w", "wb", "x", "xb", "a" or "ab" for
      binary mode, or "rt", "wt", "xt" or "at" for text mode. The default mode is
      "rb", and the default compresslevel is 9.
  
      For binary mode, this function is equivalent to the GzipFile constructor:
      GzipFile(filename, mode, compresslevel). In this case, the encoding, errors
      and newline arguments must not be provided.
  
      For text mode, a GzipFile object is created, and wrapped in an
      io.TextIOWrapper instance with the specified encoding, error handling
      behavior, and line ending(s).
  
      """
      if "t" in mode:
          if "b" in mode:
              raise ValueError("Invalid mode: %r" % (mode,))
      else:
          if encoding is not None:
              raise ValueError("Argument 'encoding' not supported in binary mode")
          if errors is not None:
              raise ValueError("Argument 'errors' not supported in binary mode")
          if newline is not None:
              raise ValueError("Argument 'newline' not supported in binary mode")
  
      gz_mode = mode.replace("t", "")
      if isinstance(filename, (str, bytes)):
          binary_file = GzipFile(filename, gz_mode, compresslevel)
      elif hasattr(filename, "read") or hasattr(filename, "write"):
          binary_file = GzipFile(None, gz_mode, compresslevel, filename)
      else:
          raise TypeError("filename must be a str or bytes object, or a file")
  
      if "t" in mode:
          return io.TextIOWrapper(binary_file, encoding, errors, newline)
      else:
          return binary_file
  
  def write32u(output, value):
      # The L format writes the bit pattern correctly whether signed
      # or unsigned.
      output.write(struct.pack("<L", value))
  
  class _PaddedFile:
      """Minimal read-only file object that prepends a string to the contents
      of an actual file. Shouldn't be used outside of gzip.py, as it lacks
      essential functionality."""
  
      def __init__(self, f, prepend=b''):
          self._buffer = prepend
          self._length = len(prepend)
          self.file = f
          self._read = 0
  
      def read(self, size):
          if self._read is None:
              return self.file.read(size)
          if self._read + size <= self._length:
              read = self._read
              self._read += size
              return self._buffer[read:self._read]
          else:
              read = self._read
              self._read = None
              return self._buffer[read:] + \
                     self.file.read(size-self._length+read)
  
      def prepend(self, prepend=b'', readprevious=False):
          if self._read is None:
              self._buffer = prepend
          elif readprevious and len(prepend) <= self._read:
              self._read -= len(prepend)
              return
          else:
              self._buffer = self._buffer[self._read:] + prepend
          self._length = len(self._buffer)
          self._read = 0
  
      def unused(self):
          if self._read is None:
              return b''
          return self._buffer[self._read:]
  
      def seek(self, offset, whence=0):
          # This is only ever called with offset=whence=0
          if whence == 1 and self._read is not None:
              if 0 <= offset + self._read <= self._length:
                  self._read += offset
                  return
              else:
                  offset += self._length - self._read
          self._read = None
          self._buffer = None
          return self.file.seek(offset, whence)
  
      def __getattr__(self, name):
          return getattr(self.file, name)
  
  
  class GzipFile(io.BufferedIOBase):
      """The GzipFile class simulates most of the methods of a file object with
      the exception of the readinto() and truncate() methods.
  
      This class only supports opening files in binary mode. If you need to open a
      compressed file in text mode, use the gzip.open() function.
  
      """
  
      myfileobj = None
      max_read_chunk = 10 * 1024 * 1024   # 10Mb
  
      def __init__(self, filename=None, mode=None,
                   compresslevel=9, fileobj=None, mtime=None):
          """Constructor for the GzipFile class.
  
          At least one of fileobj and filename must be given a
          non-trivial value.
  
          The new class instance is based on fileobj, which can be a regular
          file, an io.BytesIO object, or any other object which simulates a file.
          It defaults to None, in which case filename is opened to provide
          a file object.
  
          When fileobj is not None, the filename argument is only used to be
          included in the gzip file header, which may includes the original
          filename of the uncompressed file.  It defaults to the filename of
          fileobj, if discernible; otherwise, it defaults to the empty string,
          and in this case the original filename is not included in the header.
  
          The mode argument can be any of 'r', 'rb', 'a', 'ab', 'w', 'wb', 'x', or
          'xb' depending on whether the file will be read or written.  The default
          is the mode of fileobj if discernible; otherwise, the default is 'rb'.
          A mode of 'r' is equivalent to one of 'rb', and similarly for 'w' and
          'wb', 'a' and 'ab', and 'x' and 'xb'.
  
          The compresslevel argument is an integer from 0 to 9 controlling the
          level of compression; 1 is fastest and produces the least compression,
          and 9 is slowest and produces the most compression. 0 is no compression
          at all. The default is 9.
  
          The mtime argument is an optional numeric timestamp to be written
          to the stream when compressing.  All gzip compressed streams
          are required to contain a timestamp.  If omitted or None, the
          current time is used.  This module ignores the timestamp when
          decompressing; however, some programs, such as gunzip, make use
          of it.  The format of the timestamp is the same as that of the
          return value of time.time() and of the st_mtime member of the
          object returned by os.stat().
  
          """
  
          if mode and ('t' in mode or 'U' in mode):
              raise ValueError("Invalid mode: {!r}".format(mode))
          if mode and 'b' not in mode:
              mode += 'b'
          if fileobj is None:
              fileobj = self.myfileobj = builtins.open(filename, mode or 'rb')
          if filename is None:
              filename = getattr(fileobj, 'name', '')
              if not isinstance(filename, (str, bytes)):
                  filename = ''
          if mode is None:
              mode = getattr(fileobj, 'mode', 'rb')
  
          if mode.startswith('r'):
              self.mode = READ
              # Set flag indicating start of a new member
              self._new_member = True
              # Buffer data read from gzip file. extrastart is offset in
              # stream where buffer starts. extrasize is number of
              # bytes remaining in buffer from current stream position.
              self.extrabuf = b""
              self.extrasize = 0
              self.extrastart = 0
              self.name = filename
              # Starts small, scales exponentially
              self.min_readsize = 100
              fileobj = _PaddedFile(fileobj)
  
          elif mode.startswith(('w', 'a', 'x')):
              self.mode = WRITE
              self._init_write(filename)
              self.compress = zlib.compressobj(compresslevel,
                                               zlib.DEFLATED,
                                               -zlib.MAX_WBITS,
                                               zlib.DEF_MEM_LEVEL,
                                               0)
          else:
              raise ValueError("Invalid mode: {!r}".format(mode))
  
          self.fileobj = fileobj
          self.offset = 0
          self.mtime = mtime
  
          if self.mode == WRITE:
              self._write_gzip_header()
  
      @property
      def filename(self):
          import warnings
          warnings.warn("use the name attribute", DeprecationWarning, 2)
          if self.mode == WRITE and self.name[-3:] != ".gz":
              return self.name + ".gz"
          return self.name
  
      def __repr__(self):
          fileobj = self.fileobj
          if isinstance(fileobj, _PaddedFile):
              fileobj = fileobj.file
          s = repr(fileobj)
          return '<gzip ' + s[1:-1] + ' ' + hex(id(self)) + '>'
  
      def _check_closed(self):
          """Raises a ValueError if the underlying file object has been closed.
  
          """
          if self.closed:
              raise ValueError('I/O operation on closed file.')
  
      def _init_write(self, filename):
          self.name = filename
          self.crc = zlib.crc32(b"") & 0xffffffff
          self.size = 0
          self.writebuf = []
          self.bufsize = 0
  
      def _write_gzip_header(self):
          self.fileobj.write(b'\037\213')             # magic header
          self.fileobj.write(b'\010')                 # compression method
          try:
              # RFC 1952 requires the FNAME field to be Latin-1. Do not
              # include filenames that cannot be represented that way.
              fname = os.path.basename(self.name)
              if not isinstance(fname, bytes):
                  fname = fname.encode('latin-1')
              if fname.endswith(b'.gz'):
                  fname = fname[:-3]
          except UnicodeEncodeError:
              fname = b''
          flags = 0
          if fname:
              flags = FNAME
          self.fileobj.write(chr(flags).encode('latin-1'))
          mtime = self.mtime
          if mtime is None:
              mtime = time.time()
          write32u(self.fileobj, int(mtime))
          self.fileobj.write(b'\002')
          self.fileobj.write(b'\377')
          if fname:
              self.fileobj.write(fname + b'\000')
  
      def _init_read(self):
          self.crc = zlib.crc32(b"") & 0xffffffff
          self.size = 0
  
      def _read_exact(self, n):
          data = self.fileobj.read(n)
          while len(data) < n:
              b = self.fileobj.read(n - len(data))
              if not b:
                  raise EOFError("Compressed file ended before the "
                                 "end-of-stream marker was reached")
              data += b
          return data
  
      def _read_gzip_header(self):
          magic = self.fileobj.read(2)
          if magic == b'':
              return False
  
          if magic != b'\037\213':
              raise OSError('Not a gzipped file')
  
          method, flag, self.mtime = struct.unpack("<BBIxx", self._read_exact(8))
          if method != 8:
              raise OSError('Unknown compression method')
  
          if flag & FEXTRA:
              # Read & discard the extra field, if present
              extra_len, = struct.unpack("<H", self._read_exact(2))
              self._read_exact(extra_len)
          if flag & FNAME:
              # Read and discard a null-terminated string containing the filename
              while True:
                  s = self.fileobj.read(1)
                  if not s or s==b'\000':
                      break
          if flag & FCOMMENT:
              # Read and discard a null-terminated string containing a comment
              while True:
                  s = self.fileobj.read(1)
                  if not s or s==b'\000':
                      break
          if flag & FHCRC:
              self._read_exact(2)     # Read & discard the 16-bit header CRC
  
          unused = self.fileobj.unused()
          if unused:
              uncompress = self.decompress.decompress(unused)
              self._add_read_data(uncompress)
          return True
  
      def write(self,data):
          self._check_closed()
          if self.mode != WRITE:
              import errno
              raise OSError(errno.EBADF, "write() on read-only GzipFile object")
  
          if self.fileobj is None:
              raise ValueError("write() on closed GzipFile object")
  
          # Convert data type if called by io.BufferedWriter.
          if isinstance(data, memoryview):
              data = data.tobytes()
  
          if len(data) > 0:
              self.fileobj.write(self.compress.compress(data))
              self.size += len(data)
              self.crc = zlib.crc32(data, self.crc) & 0xffffffff
              self.offset += len(data)
  
          return len(data)
  
      def read(self, size=-1):
          self._check_closed()
          if self.mode != READ:
              import errno
              raise OSError(errno.EBADF, "read() on write-only GzipFile object")
  
          if self.extrasize <= 0 and self.fileobj is None:
              return b''
  
          readsize = 1024
          if size < 0:        # get the whole thing
              while self._read(readsize):
                  readsize = min(self.max_read_chunk, readsize * 2)
              size = self.extrasize
          else:               # just get some more of it
              while size > self.extrasize:
                  if not self._read(readsize):
                      if size > self.extrasize:
                          size = self.extrasize
                      break
                  readsize = min(self.max_read_chunk, readsize * 2)
  
          offset = self.offset - self.extrastart
          chunk = self.extrabuf[offset: offset + size]
          self.extrasize = self.extrasize - size
  
          self.offset += size
          return chunk
  
      def read1(self, size=-1):
          self._check_closed()
          if self.mode != READ:
              import errno
              raise OSError(errno.EBADF, "read1() on write-only GzipFile object")
  
          if self.extrasize <= 0 and self.fileobj is None:
              return b''
  
          # For certain input data, a single call to _read() may not return
          # any data. In this case, retry until we get some data or reach EOF.
          while self.extrasize <= 0 and self._read():
              pass
          if size < 0 or size > self.extrasize:
              size = self.extrasize
  
          offset = self.offset - self.extrastart
          chunk = self.extrabuf[offset: offset + size]
          self.extrasize -= size
          self.offset += size
          return chunk
  
      def peek(self, n):
          if self.mode != READ:
              import errno
              raise OSError(errno.EBADF, "peek() on write-only GzipFile object")
  
          # Do not return ridiculously small buffers, for one common idiom
          # is to call peek(1) and expect more bytes in return.
          if n < 100:
              n = 100
          if self.extrasize == 0:
              if self.fileobj is None:
                  return b''
              # Ensure that we don't return b"" if we haven't reached EOF.
              # 1024 is the same buffering heuristic used in read()
              while self.extrasize == 0 and self._read(max(n, 1024)):
                  pass
          offset = self.offset - self.extrastart
          remaining = self.extrasize
          assert remaining == len(self.extrabuf) - offset
          return self.extrabuf[offset:offset + n]
  
      def _unread(self, buf):
          self.extrasize = len(buf) + self.extrasize
          self.offset -= len(buf)
  
      def _read(self, size=1024):
          if self.fileobj is None:
              return False
  
          if self._new_member:
              # If the _new_member flag is set, we have to
              # jump to the next member, if there is one.
              self._init_read()
              if not self._read_gzip_header():
                  return False
              self.decompress = zlib.decompressobj(-zlib.MAX_WBITS)
              self._new_member = False
  
          # Read a chunk of data from the file
          buf = self.fileobj.read(size)
  
          # If the EOF has been reached, flush the decompression object
          # and mark this object as finished.
  
          if buf == b"":
              uncompress = self.decompress.flush()
              # Prepend the already read bytes to the fileobj to they can be
              # seen by _read_eof()
              self.fileobj.prepend(self.decompress.unused_data, True)
              self._read_eof()
              self._add_read_data( uncompress )
              return False
  
          uncompress = self.decompress.decompress(buf)
          self._add_read_data( uncompress )
  
          if self.decompress.unused_data != b"":
              # Ending case: we've come to the end of a member in the file,
              # so seek back to the start of the unused data, finish up
              # this member, and read a new gzip header.
              # Prepend the already read bytes to the fileobj to they can be
              # seen by _read_eof() and _read_gzip_header()
              self.fileobj.prepend(self.decompress.unused_data, True)
              # Check the CRC and file size, and set the flag so we read
              # a new member on the next call
              self._read_eof()
              self._new_member = True
          return True
  
      def _add_read_data(self, data):
          self.crc = zlib.crc32(data, self.crc) & 0xffffffff
          offset = self.offset - self.extrastart
          self.extrabuf = self.extrabuf[offset:] + data
          self.extrasize = self.extrasize + len(data)
          self.extrastart = self.offset
          self.size = self.size + len(data)
  
      def _read_eof(self):
          # We've read to the end of the file
          # We check the that the computed CRC and size of the
          # uncompressed data matches the stored values.  Note that the size
          # stored is the true file size mod 2**32.
          crc32, isize = struct.unpack("<II", self._read_exact(8))
          if crc32 != self.crc:
              raise OSError("CRC check failed %s != %s" % (hex(crc32),
                                                           hex(self.crc)))
          elif isize != (self.size & 0xffffffff):
              raise OSError("Incorrect length of data produced")
  
          # Gzip files can be padded with zeroes and still have archives.
          # Consume all zero bytes and set the file position to the first
          # non-zero byte. See http://www.gzip.org/#faq8
          c = b"\x00"
          while c == b"\x00":
              c = self.fileobj.read(1)
          if c:
              self.fileobj.prepend(c, True)
  
      @property
      def closed(self):
          return self.fileobj is None
  
      def close(self):
          fileobj = self.fileobj
          if fileobj is None:
              return
          self.fileobj = None
          try:
              if self.mode == WRITE:
                  fileobj.write(self.compress.flush())
                  write32u(fileobj, self.crc)
                  # self.size may exceed 2GB, or even 4GB
                  write32u(fileobj, self.size & 0xffffffff)
          finally:
              myfileobj = self.myfileobj
              if myfileobj:
                  self.myfileobj = None
                  myfileobj.close()
  
      def flush(self,zlib_mode=zlib.Z_SYNC_FLUSH):
          self._check_closed()
          if self.mode == WRITE:
              # Ensure the compressor's buffer is flushed
              self.fileobj.write(self.compress.flush(zlib_mode))
              self.fileobj.flush()
  
      def fileno(self):
          """Invoke the underlying file object's fileno() method.
  
          This will raise AttributeError if the underlying file object
          doesn't support fileno().
          """
          return self.fileobj.fileno()
  
      def rewind(self):
          '''Return the uncompressed stream file position indicator to the
          beginning of the file'''
          if self.mode != READ:
              raise OSError("Can't rewind in write mode")
          self.fileobj.seek(0)
          self._new_member = True
          self.extrabuf = b""
          self.extrasize = 0
          self.extrastart = 0
          self.offset = 0
  
      def readable(self):
          return self.mode == READ
  
      def writable(self):
          return self.mode == WRITE
  
      def seekable(self):
          return True
  
      def seek(self, offset, whence=0):
          if whence:
              if whence == 1:
                  offset = self.offset + offset
              else:
                  raise ValueError('Seek from end not supported')
          if self.mode == WRITE:
              if offset < self.offset:
                  raise OSError('Negative seek in write mode')
              count = offset - self.offset
              chunk = bytes(1024)
              for i in range(count // 1024):
                  self.write(chunk)
              self.write(bytes(count % 1024))
          elif self.mode == READ:
              if offset < self.offset:
                  # for negative seek, rewind and do positive seek
                  self.rewind()
              count = offset - self.offset
              for i in range(count // 1024):
                  self.read(1024)
              self.read(count % 1024)
  
          return self.offset
  
      def readline(self, size=-1):
          if size < 0:
              # Shortcut common case - newline found in buffer.
              offset = self.offset - self.extrastart
              i = self.extrabuf.find(b'\n', offset) + 1
              if i > 0:
                  self.extrasize -= i - offset
                  self.offset += i - offset
                  return self.extrabuf[offset: i]
  
              size = sys.maxsize
              readsize = self.min_readsize
          else:
              readsize = size
          bufs = []
          while size != 0:
              c = self.read(readsize)
              i = c.find(b'\n')
  
              # We set i=size to break out of the loop under two
              # conditions: 1) there's no newline, and the chunk is
              # larger than size, or 2) there is a newline, but the
              # resulting line would be longer than 'size'.
              if (size <= i) or (i == -1 and len(c) > size):
                  i = size - 1
  
              if i >= 0 or c == b'':
                  bufs.append(c[:i + 1])    # Add portion of last chunk
                  self._unread(c[i + 1:])   # Push back rest of chunk
                  break
  
              # Append chunk to list, decrease 'size',
              bufs.append(c)
              size = size - len(c)
              readsize = min(size, readsize * 2)
          if readsize > self.min_readsize:
              self.min_readsize = min(readsize, self.min_readsize * 2, 512)
          return b''.join(bufs) # Return resulting line
  
  
  def compress(data, compresslevel=9):
      """Compress data in one shot and return the compressed string.
      Optional argument is the compression level, in range of 0-9.
      """
      buf = io.BytesIO()
      with GzipFile(fileobj=buf, mode='wb', compresslevel=compresslevel) as f:
          f.write(data)
      return buf.getvalue()
  
  def decompress(data):
      """Decompress a gzip compressed string in one shot.
      Return the decompressed string.
      """
      with GzipFile(fileobj=io.BytesIO(data)) as f:
          return f.read()
  
  
  def _test():
      # Act like gzip; with -d, act like gunzip.
      # The input file is not deleted, however, nor are any other gzip
      # options or features supported.
      args = sys.argv[1:]
      decompress = args and args[0] == "-d"
      if decompress:
          args = args[1:]
      if not args:
          args = ["-"]
      for arg in args:
          if decompress:
              if arg == "-":
                  f = GzipFile(filename="", mode="rb", fileobj=sys.stdin.buffer)
                  g = sys.stdout.buffer
              else:
                  if arg[-3:] != ".gz":
                      print("filename doesn't end in .gz:", repr(arg))
                      continue
                  f = open(arg, "rb")
                  g = builtins.open(arg[:-3], "wb")
          else:
              if arg == "-":
                  f = sys.stdin.buffer
                  g = GzipFile(filename="", mode="wb", fileobj=sys.stdout.buffer)
              else:
                  f = builtins.open(arg, "rb")
                  g = open(arg + ".gz", "wb")
          while True:
              chunk = f.read(1024)
              if not chunk:
                  break
              g.write(chunk)
          if g is not sys.stdout.buffer:
              g.close()
          if f is not sys.stdin.buffer:
              f.close()
  
  if __name__ == '__main__':
      _test()
  