Python zlib.compressobj方法代码示例

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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) 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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() 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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) 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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) 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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() 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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) 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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() 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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()) 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
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()) 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
def compress(body, compress_level):
    """Compress 'body' at the given compress_level."""
    import zlib

    # See http://www.gzip.org/zlib/rfc-gzip.html
    yield b'\x1f\x8b'       # ID1 and ID2: gzip marker
    yield b'\x08'           # CM: compression method
    yield b'\x00'           # FLG: none set
    # MTIME: 4 bytes
    yield struct.pack('<L', int(time.time()) & int('FFFFFFFF', 16))
    yield b'\x02'           # XFL: max compression, slowest algo
    yield b'\xff'           # OS: unknown

    crc = zlib.crc32(b'')
    size = 0
    zobj = zlib.compressobj(compress_level,
                            zlib.DEFLATED, -zlib.MAX_WBITS,
                            zlib.DEF_MEM_LEVEL, 0)
    for line in body:
        size += len(line)
        crc = zlib.crc32(line, crc)
        yield zobj.compress(line)
    yield zobj.flush()

    # CRC32: 4 bytes
    yield struct.pack('<L', crc & int('FFFFFFFF', 16))
    # ISIZE: 4 bytes
    yield struct.pack('<L', size & int('FFFFFFFF', 16)) 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
def _create_compressor(self):
        return zlib.compressobj(tornado.web.GZipContentEncoding.GZIP_LEVEL,
                                zlib.DEFLATED, -self._max_wbits) 

# 需要导入模块: import zlib [as 别名]
# 或者: from zlib import compressobj [as 别名]
def _write_block(self, block):
        """Write provided data to file as a single BGZF compressed block (PRIVATE)."""
        # print("Saving %i bytes" % len(block))
        start_offset = self._handle.tell()
        assert len(block) <= 65536
        # Giving a negative window bits means no gzip/zlib headers,
        # -15 used in samtools
        c = zlib.compressobj(self.compresslevel,
                             zlib.DEFLATED,
                             -15,
                             zlib.DEF_MEM_LEVEL,
                             0)
        compressed = c.compress(block) + c.flush()
        del c
        assert len(compressed) < 65536, \
            "TODO - Didn't compress enough, try less data in this block"
        crc = zlib.crc32(block)
        # Should cope with a mix of Python platforms...
        if crc < 0:
            crc = struct.pack("<i", crc)
        else:
            crc = struct.pack("<I", crc)
        bsize = struct.pack("<H", len(compressed) + 25)  # includes -1
        crc = struct.pack("<I", zlib.crc32(block) & 0xffffffff)
        uncompressed_length = struct.pack("<I", len(block))
        # Fixed 16 bytes,
        # gzip magic bytes (4) mod time (4),
        # gzip flag (1), os (1), extra length which is six (2),
        # sub field which is BC (2), sub field length of two (2),
        # Variable data,
        # 2 bytes: block length as BC sub field (2)
        # X bytes: the data
        # 8 bytes: crc (4), uncompressed data length (4)
        data = _bgzf_header + bsize + compressed + crc + uncompressed_length
        self._handle.write(data)