Python zlib.compressobj() Examples

def _newKeys(self):
        """
        Called back by a subclass once a I{MSG_NEWKEYS} message has been
        received.  This indicates key exchange has completed and new encryption
        and compression parameters should be adopted.  Any messages which were
        queued during key exchange will also be flushed.
        """
        log.msg('NEW KEYS')
        self.currentEncryptions = self.nextEncryptions
        if self.outgoingCompressionType == b'zlib':
            self.outgoingCompression = zlib.compressobj(6)
        if self.incomingCompressionType == b'zlib':
            self.incomingCompression = zlib.decompressobj()

        self._keyExchangeState = self._KEY_EXCHANGE_NONE
        messages = self._blockedByKeyExchange
        self._blockedByKeyExchange = None
        for (messageType, payload) in messages:
            self.sendPacket(messageType, payload) 

def get_compression_options(self) -> Optional[Dict[str, Any]]:
        """Override to return compression options for the connection.

        If this method returns None (the default), compression will
        be disabled.  If it returns a dict (even an empty one), it
        will be enabled.  The contents of the dict may be used to
        control the following compression options:

        ``compression_level`` specifies the compression level.

        ``mem_level`` specifies the amount of memory used for the internal compression state.

         These parameters are documented in details here:
         https://docs.python.org/3.6/library/zlib.html#zlib.compressobj

        .. versionadded:: 4.1

        .. versionchanged:: 4.5

           Added ``compression_level`` and ``mem_level``.
        """
        # TODO: Add wbits option.
        return None 

def test_send_message(self):
        compress = zlib.compressobj(
            zlib.Z_DEFAULT_COMPRESSION, zlib.DEFLATED, -zlib.MAX_WBITS)

        extension = common.ExtensionParameter(common.DEFLATE_FRAME_EXTENSION)
        request = _create_request_from_rawdata(
            '', deflate_frame_request=extension)
        msgutil.send_message(request, 'Hello')
        msgutil.send_message(request, 'World')

        expected = ''

        compressed_hello = compress.compress('Hello')
        compressed_hello += compress.flush(zlib.Z_SYNC_FLUSH)
        compressed_hello = compressed_hello[:-4]
        expected += '\xc1%c' % len(compressed_hello)
        expected += compressed_hello

        compressed_world = compress.compress('World')
        compressed_world += compress.flush(zlib.Z_SYNC_FLUSH)
        compressed_world = compressed_world[:-4]
        expected += '\xc1%c' % len(compressed_world)
        expected += compressed_world

        self.assertEqual(expected, request.connection.written_data()) 

def gzip_app_iter(app_iter):
    size = 0
    crc = zlib.crc32(b"") & 0xffffffff
    compress = zlib.compressobj(9, zlib.DEFLATED, -zlib.MAX_WBITS,
                                zlib.DEF_MEM_LEVEL, 0)

    yield _gzip_header
    for item in app_iter:
        size += len(item)
        crc = zlib.crc32(item, crc) & 0xffffffff

        # The compress function may return zero length bytes if the input is
        # small enough; it buffers the input for the next iteration or for a
        # flush.
        result = compress.compress(item)
        if result:
            yield result

    # Similarly, flush may also not yield a value.
    result = compress.flush()
    if result:
        yield result
    yield struct.pack("<2L", crc, size & 0xffffffff) 

def test_send_message_no_context_takeover_parameter(self):
        compress = zlib.compressobj(
            zlib.Z_DEFAULT_COMPRESSION, zlib.DEFLATED, -zlib.MAX_WBITS)

        extension = common.ExtensionParameter(common.DEFLATE_FRAME_EXTENSION)
        extension.add_parameter('no_context_takeover', None)
        request = _create_request_from_rawdata(
            '', deflate_frame_request=extension)
        for i in xrange(3):
            msgutil.send_message(request, 'Hello')

        compressed_message = compress.compress('Hello')
        compressed_message += compress.flush(zlib.Z_SYNC_FLUSH)
        compressed_message = compressed_message[:-4]
        expected = '\xc1%c' % len(compressed_message)
        expected += compressed_message

        self.assertEqual(
            expected + expected + expected, request.connection.written_data()) 

def _encode_packobj(type, content, compression_level=1):
    szout = ''
    sz = len(content)
    szbits = (sz & 0x0f) | (_typemap[type]<<4)
    sz >>= 4
    while 1:
        if sz: szbits |= 0x80
        szout += chr(szbits)
        if not sz:
            break
        szbits = sz & 0x7f
        sz >>= 7
    if compression_level > 9:
        compression_level = 9
    elif compression_level < 0:
        compression_level = 0
    z = zlib.compressobj(compression_level)
    yield szout
    yield z.compress(content)
    yield z.flush() 

def __init__(self, id, len, file, extra=None):
        """id: object id of stream; len: an unused Reference object for the
        length of the stream, or None (to use a memory buffer); file:
        a PdfFile; extra: a dictionary of extra key-value pairs to
        include in the stream header """
        self.id = id            # object id
        self.len = len          # id of length object
        self.pdfFile = file
        self.file = file.fh     # file to which the stream is written
        self.compressobj = None # compression object
        if extra is None: self.extra = dict()
        else: self.extra = extra

        self.pdfFile.recordXref(self.id)
        if rcParams['pdf.compression']:
            self.compressobj = zlib.compressobj(rcParams['pdf.compression'])
        if self.len is None:
            self.file = BytesIO()
        else:
            self._writeHeader()
            self.pos = self.file.tell() 

def __init__(self, id, len, file, extra=None):
        """id: object id of stream; len: an unused Reference object for the
        length of the stream, or None (to use a memory buffer); file:
        a PdfFile; extra: a dictionary of extra key-value pairs to
        include in the stream header """
        self.id = id            # object id
        self.len = len          # id of length object
        self.pdfFile = file
        self.file = file.fh     # file to which the stream is written
        self.compressobj = None # compression object
        if extra is None: self.extra = dict()
        else: self.extra = extra

        self.pdfFile.recordXref(self.id)
        if rcParams['pdf.compression']:
            self.compressobj = zlib.compressobj(rcParams['pdf.compression'])
        if self.len is None:
            self.file = BytesIO()
        else:
            self._writeHeader()
            self.pos = self.file.tell() 

def get_compression_options(self):
        """Override to return compression options for the connection.

        If this method returns None (the default), compression will
        be disabled.  If it returns a dict (even an empty one), it
        will be enabled.  The contents of the dict may be used to
        control the following compression options:

        ``compression_level`` specifies the compression level.

        ``mem_level`` specifies the amount of memory used for the internal compression state.

         These parameters are documented in details here:
         https://docs.python.org/3.6/library/zlib.html#zlib.compressobj

        .. versionadded:: 4.1

        .. versionchanged:: 4.5

           Added ``compression_level`` and ``mem_level``.
        """
        # TODO: Add wbits option.
        return None 

def _newKeys(self):
        """
        Called back by a subclass once a I{MSG_NEWKEYS} message has been
        received.  This indicates key exchange has completed and new encryption
        and compression parameters should be adopted.  Any messages which were
        queued during key exchange will also be flushed.
        """
        log.msg('NEW KEYS')
        self.currentEncryptions = self.nextEncryptions
        if self.outgoingCompressionType == b'zlib':
            self.outgoingCompression = zlib.compressobj(6)
        if self.incomingCompressionType == b'zlib':
            self.incomingCompression = zlib.decompressobj()

        self._keyExchangeState = self._KEY_EXCHANGE_NONE
        messages = self._blockedByKeyExchange
        self._blockedByKeyExchange = None
        for (messageType, payload) in messages:
            self.sendPacket(messageType, payload) 

def get_compression_options(self):
        """Override to return compression options for the connection.

        If this method returns None (the default), compression will
        be disabled.  If it returns a dict (even an empty one), it
        will be enabled.  The contents of the dict may be used to
        control the following compression options:

        ``compression_level`` specifies the compression level.

        ``mem_level`` specifies the amount of memory used for the internal compression state.

         These parameters are documented in details here:
         https://docs.python.org/3.6/library/zlib.html#zlib.compressobj

        .. versionadded:: 4.1

        .. versionchanged:: 4.5

           Added ``compression_level`` and ``mem_level``.
        """
        # TODO: Add wbits option.
        return None 

def get_compression_options(self) -> Optional[Dict[str, Any]]:
        """Override to return compression options for the connection.

        If this method returns None (the default), compression will
        be disabled.  If it returns a dict (even an empty one), it
        will be enabled.  The contents of the dict may be used to
        control the following compression options:

        ``compression_level`` specifies the compression level.

        ``mem_level`` specifies the amount of memory used for the internal compression state.

         These parameters are documented in details here:
         https://docs.python.org/3.6/library/zlib.html#zlib.compressobj

        .. versionadded:: 4.1

        .. versionchanged:: 4.5

           Added ``compression_level`` and ``mem_level``.
        """
        # TODO: Add wbits option.
        return None 

def get_compression_options(self) -> Optional[Dict[str, Any]]:
        """Override to return compression options for the connection.

        If this method returns None (the default), compression will
        be disabled.  If it returns a dict (even an empty one), it
        will be enabled.  The contents of the dict may be used to
        control the following compression options:

        ``compression_level`` specifies the compression level.

        ``mem_level`` specifies the amount of memory used for the internal compression state.

         These parameters are documented in details here:
         https://docs.python.org/3.6/library/zlib.html#zlib.compressobj

        .. versionadded:: 4.1

        .. versionchanged:: 4.5

           Added ``compression_level`` and ``mem_level``.
        """
        # TODO: Add wbits option.
        return None 

def _write_part(self):
        z = zlib.compressobj(6, zlib.DEFLATED, zlib.MAX_WBITS + 16)

        offset = self.gzip_temp.tell()

        buff = '\n'.join(self.curr_lines) + '\n'
        self.curr_lines = []

        buff = z.compress(buff)
        self.gzip_temp.write(buff)

        buff = z.flush()
        self.gzip_temp.write(buff)
        self.gzip_temp.flush()

        length = self.gzip_temp.tell() - offset

        partline = '{0}\t{1}\t{2}\t{3}'.format(self.curr_key, self.part_name, offset, length)

        return partline 

def enc(self, data, final):
        buf = []
        if not self.writeheader:
            h = header.new()
            h.mtime = int(time.time())
            h.fname = self.fname
            buf.append(header.tobytes(h))
            self.compobj = zlib.compressobj(self.level, zlib.DEFLATED, -zlib.MAX_WBITS, zlib.DEF_MEM_LEVEL)
            self.writeheader = True
        buf.append(self.compobj.compress(data))
        self.crc = zlib.crc32(data, self.crc) & 0xffffffff
        self.size += len(data)
        if final:
            buf.append(self.compobj.flush())
            t = tail.new()
            t.crc32 = self.crc
            t.isize = self.size
            buf.append(tail.tobytes(t))
        return b''.join(buf) 

def __init__(self, id, len, file, extra=None):
        """id: object id of stream; len: an unused Reference object for the
        length of the stream, or None (to use a memory buffer); file:
        a PdfFile; extra: a dictionary of extra key-value pairs to
        include in the stream header """
        self.id = id            # object id
        self.len = len          # id of length object
        self.pdfFile = file
        self.file = file.fh      # file to which the stream is written
        self.compressobj = None  # compression object
        if extra is None:
            self.extra = dict()
        else:
            self.extra = extra

        self.pdfFile.recordXref(self.id)
        if rcParams['pdf.compression']:
            self.compressobj = zlib.compressobj(rcParams['pdf.compression'])
        if self.len is None:
            self.file = BytesIO()
        else:
            self._writeHeader()
            self.pos = self.file.tell() 

def handle(self, connection):

        exported = self.createPlaylist(connection.headers['Host'], connection.reqtype, query_get(connection.query, 'fmt')).encode('utf-8')

        connection.send_response(200)
        connection.send_header('Content-Type', 'audio/mpegurl; charset=utf-8')
        connection.send_header('Access-Control-Allow-Origin', '*')
        try:
           h = connection.headers.get('Accept-Encoding').split(',')[0]
           compress_method = { 'zlib': zlib.compressobj(9, zlib.DEFLATED, zlib.MAX_WBITS),
                               'deflate': zlib.compressobj(9, zlib.DEFLATED, -zlib.MAX_WBITS),
                               'gzip': zlib.compressobj(9, zlib.DEFLATED, zlib.MAX_WBITS | 16) }
           exported = compress_method[h].compress(exported) + compress_method[h].flush()
           connection.send_header('Content-Encoding', h)
        except: pass
        connection.send_header('Content-Length', len(exported))
        connection.send_header('Connection', 'close')
        connection.end_headers()
        connection.wfile.write(exported) 

def _init_zlib(self):
        """Internal method for setting up the zlib compression and
        decompression objects.
        """
        self._zcomp_read = zlib.decompressobj()
        self._zcomp_write = zlib.compressobj(self.compresslevel) 

def write(self, data):
        """Write some data on the stream."""

        if self.compressobj is None:
            self.file.write(data)
        else:
            compressed = self.compressobj.compress(data)
            self.file.write(compressed) 

def enable_compression(self, encoding: str='deflate') -> None:
        zlib_mode = (16 + zlib.MAX_WBITS
                     if encoding == 'gzip' else -zlib.MAX_WBITS)
        self._compress = zlib.compressobj(wbits=zlib_mode) 

def __init__(self, id, len, file, extra=None, png=None):
        """id: object id of stream; len: an unused Reference object for the
        length of the stream, or None (to use a memory buffer); file:
        a PdfFile; extra: a dictionary of extra key-value pairs to
        include in the stream header; png: if the data is already
        png compressed, the decode parameters"""
        self.id = id            # object id
        self.len = len          # id of length object
        self.pdfFile = file
        self.file = file.fh      # file to which the stream is written
        self.compressobj = None  # compression object
        if extra is None:
            self.extra = dict()
        else:
            self.extra = extra.copy()
        if png is not None:
            self.extra.update({'Filter':      Name('FlateDecode'),
                               'DecodeParms': png})

        self.pdfFile.recordXref(self.id)
        if rcParams['pdf.compression'] and not png:
            self.compressobj = zlib.compressobj(rcParams['pdf.compression'])
        if self.len is None:
            self.file = BytesIO()
        else:
            self._writeHeader()
            self.pos = self.file.tell() 

def _flush(self):
        """Flush the compression object."""

        if self.compressobj is not None:
            compressed = self.compressobj.flush()
            self.file.write(compressed)
            self.compressobj = None 

def test_send_message_bfinal(self):
        extension = common.ExtensionParameter(common.DEFLATE_FRAME_EXTENSION)
        request = _create_request_from_rawdata(
            '', deflate_frame_request=extension)
        self.assertEquals(1, len(request.ws_extension_processors))
        deflate_frame_processor = request.ws_extension_processors[0]
        deflate_frame_processor.set_bfinal(True)
        msgutil.send_message(request, 'Hello')
        msgutil.send_message(request, 'World')

        expected = ''

        compress = zlib.compressobj(
            zlib.Z_DEFAULT_COMPRESSION, zlib.DEFLATED, -zlib.MAX_WBITS)
        compressed_hello = compress.compress('Hello')
        compressed_hello += compress.flush(zlib.Z_FINISH)
        compressed_hello = compressed_hello + chr(0)
        expected += '\xc1%c' % len(compressed_hello)
        expected += compressed_hello

        compress = zlib.compressobj(
            zlib.Z_DEFAULT_COMPRESSION, zlib.DEFLATED, -zlib.MAX_WBITS)
        compressed_world = compress.compress('World')
        compressed_world += compress.flush(zlib.Z_FINISH)
        compressed_world = compressed_world + chr(0)
        expected += '\xc1%c' % len(compressed_world)
        expected += compressed_world

        self.assertEqual(expected, request.connection.written_data()) 

def write(self, data):
        """Write some data on the stream."""

        if self.compressobj is None:
            self.file.write(data)
        else:
            compressed = self.compressobj.compress(data)
            self.file.write(compressed) 

def __init__(self, id, len, file, extra=None, png=None):
        """id: object id of stream; len: an unused Reference object for the
        length of the stream, or None (to use a memory buffer); file:
        a PdfFile; extra: a dictionary of extra key-value pairs to
        include in the stream header; png: if the data is already
        png compressed, the decode parameters"""
        self.id = id            # object id
        self.len = len          # id of length object
        self.pdfFile = file
        self.file = file.fh      # file to which the stream is written
        self.compressobj = None  # compression object
        if extra is None:
            self.extra = dict()
        else:
            self.extra = extra.copy()
        if png is not None:
            self.extra.update({'Filter':      Name('FlateDecode'),
                               'DecodeParms': png})

        self.pdfFile.recordXref(self.id)
        if rcParams['pdf.compression'] and not png:
            self.compressobj = zlib.compressobj(rcParams['pdf.compression'])
        if self.len is None:
            self.file = BytesIO()
        else:
            self._writeHeader()
            self.pos = self.file.tell() 

def _init_zlib(self):
        """Internal method for setting up the zlib compression and
        decompression objects.
        """
        self._zcomp_read = zlib.decompressobj()
        self._zcomp_write = zlib.compressobj(self.compresslevel) 

def test_send_message_comp_bit(self):
        compress = zlib.compressobj(
            zlib.Z_DEFAULT_COMPRESSION, zlib.DEFLATED, -zlib.MAX_WBITS)

        extension = common.ExtensionParameter(common.DEFLATE_FRAME_EXTENSION)
        request = _create_request_from_rawdata(
            '', deflate_frame_request=extension)
        self.assertEquals(1, len(request.ws_extension_processors))
        deflate_frame_processor = request.ws_extension_processors[0]
        msgutil.send_message(request, 'Hello')
        deflate_frame_processor.disable_outgoing_compression()
        msgutil.send_message(request, 'Hello')
        deflate_frame_processor.enable_outgoing_compression()
        msgutil.send_message(request, 'Hello')

        expected = ''

        compressed_hello = compress.compress('Hello')
        compressed_hello += compress.flush(zlib.Z_SYNC_FLUSH)
        compressed_hello = compressed_hello[:-4]
        expected += '\xc1%c' % len(compressed_hello)
        expected += compressed_hello

        expected += '\x81\x05Hello'

        compressed_2nd_hello = compress.compress('Hello')
        compressed_2nd_hello += compress.flush(zlib.Z_SYNC_FLUSH)
        compressed_2nd_hello = compressed_2nd_hello[:-4]
        expected += '\xc1%c' % len(compressed_2nd_hello)
        expected += compressed_2nd_hello

        self.assertEqual(expected, request.connection.written_data()) 

def write(self, data):
        """Write some data on the stream."""

        if self.compressobj is None:
            self.file.write(data)
        else:
            compressed = self.compressobj.compress(data)
            self.file.write(compressed) 

def _init_write(self, header):
        self.crc = zlib.crc32("")
        self.segsize = 0
        if not header:
            header = GzipHeader() # take default values
            header.set_name("<unknown>")
        header.write(self)
        self.header = header
        self.compress = zlib.compressobj(self.compresslevel) 

def _flush(self):
        """Flush the compression object."""

        if self.compressobj is not None:
            compressed = self.compressobj.flush()
            self.file.write(compressed)
            self.compressobj = None