def _initialize(self, path, start, length):
self._stream = self.getStream(path)
if length == 0:
self._end = self._stream.getPos() + self._stream.length()
else:
self._end = self._stream.getPos() + length
# Parse Header
version_block = self._stream.read(len(VERSION))
self._version = version_block[len(VERSION_PREFIX)]
if not self._version.startswith(VERSION_PREFIX):
raise VersionPrefixException(VERSION_PREFIX,
self._version[0:len(VERSION_PREFIX)])
if self._version > VERSION[len(VERSION_PREFIX)]:
raise VersionMismatchException(VERSION[len(VERSION_PREFIX)],
self._version)
if self._version < BLOCK_COMPRESS_VERSION:
# Same as below, but with UTF8 Deprecated Class
raise NotImplementedError
else:
self._key_class_name = Text.readString(self._stream)
self._value_class_name = Text.readString(self._stream)
if ord(self._version) > 2:
self._decompress = self._stream.readBoolean()
else:
self._decompress = False
if self._version >= BLOCK_COMPRESS_VERSION:
self._block_compressed = self._stream.readBoolean()
else:
self._block_compressed = False
# setup compression codec
if self._decompress:
if self._version >= CUSTOM_COMPRESS_VERSION:
codec_class = Text.readString(self._stream)
self._codec = CodecPool().getDecompressor(codec_class)
else:
self._codec = CodecPool().getDecompressor()
self._metadata = Metadata()
if self._version >= VERSION_WITH_METADATA:
self._metadata.readFields(self._stream)
if self._version > 1:
self._sync = self._stream.read(SYNC_HASH_SIZE)
self._header_end = self._stream.getPos()
def __init__(self, path, key_class, value_class, metadata, compress=False, block_compress=False):
if os.path.exists(path):
raise IOError("File %s already exists." % path)
self._key_class = key_class
self._value_class = value_class
self._compress = compress
self._block_compress = block_compress
if not metadata:
metadata = Metadata()
self._metadata = metadata
if self._compress or self._block_compress:
self._codec = CodecPool().getCompressor()
else:
self._codec = None
self._last_sync = 0
self._block = None
self._stream = DataOutputStream(FileOutputStream(path))
# sync is 16 random bytes
self._sync = md5('%s@%d' % (uuid1().bytes, int(time() * 1000))).digest()
self._writeFileHeader()
