def __loadBlock(self):
frame = self.__frames[self.__iFrame]
# Read block's size
raw = self.file.read(4)
if len(raw) != 4:
raise IOError('LZ4 block has been truncated')
sizeBlock = struct.unpack('<I', raw)[0]
sizeBlock &= 0x7fffffff
# EndMark reached
# - push end of mark block and content checksum in decompressor engine (maybe useless ...)
# - mark current frame as empty
if sizeBlock == 0:
res = lz4f.decompressFrame(raw, self.__ctx)
#print " next={0}".format(res['next'])
if len(res['decomp']) != 0:
raise IOError('Unexpected output')
# Read content checksum if enabled
if frame.bContentChecksum:
raw = self.file.read(4)
if len(raw) != 4:
raise IOError('Not enought data for content checksum')
# TODO check content checksum
res = lz4f.decompressFrame(raw, self.__ctx)
#print " next={0}".format(res['next'])
if len(res['decomp']) != 0:
raise IOError('Unexpected output')
frame.empty = True
# Another block to process, go back in file
else:
self.file.seek(-4, 1)
toRead = 4 + sizeBlock + (4 if frame.bBlockChecksum else 0)
raw = self.file.read(toRead)
if (len(raw) != toRead):
raise IOError('LZ4 block has been truncated')
res = lz4f.decompressFrame(raw, self.__ctx)
#print " next={0}".format(res['next'])
self.__blockdata = res['decomp']
self.__blockpos = 0
def __loadBlock(self):
frame = self.__frames[self.__iFrame]
# Read block's size
raw = self.file.read(4)
if len(raw) != 4:
raise IOError('LZ4 block has been truncated')
sizeBlock = struct.unpack('<I', raw)[0]
sizeBlock &= 0x7fffffff
# EndMark reached
# - push end of mark block and content checksum in decompressor engine (maybe useless ...)
# - mark current frame as empty
if sizeBlock == 0:
res = lz4f.decompressFrame(raw, self.__ctx)
#print " next={0}".format(res['next'])
if len(res['decomp']) != 0:
raise IOError('Unexpected output')
# Read content checksum if enabled
if frame.bContentChecksum:
raw = self.file.read(4)
if len(raw) != 4:
raise IOError('Not enought data for content checksum')
# TODO check content checksum
res = lz4f.decompressFrame(raw, self.__ctx)
#print " next={0}".format(res['next'])
if len(res['decomp']) != 0:
raise IOError('Unexpected output')
frame.empty = True
# Another block to process, go back in file
else:
self.file.seek(-4, 1)
toRead = 4 + sizeBlock + (4 if frame.bBlockChecksum else 0)
raw = self.file.read(toRead)
if(len(raw) != toRead):
raise IOError('LZ4 block has been truncated')
res = lz4f.decompressFrame(raw, self.__ctx)
#print " next={0}".format(res['next'])
self.__blockdata = res['decomp']
self.__blockpos = 0
def read_block(self, blkSize=None, blk=None, setCur=True):
"""
:type int: blkSize - returned from get_block_size()
:type dict: blk - entry from blkDict
:type bool: setCur - update current blk var
Reads the next block, unless provided a blk from blkDict. If provided
a blk, it will read that specific block.
"""
if blk:
self.fileObj.seek(blk.get('comp_begin'))
blkSize = blk.get('blkSize')
if not blkSize:
blkSize = self.get_block_size()
if blkSize == 0:
return ''
if setCur:
try:
iteritems = self.blkDict.iteritems
except AttributeError:
iteritems = self.blkDict.items
self.curBlk = [num for num, b in iteritems()
if self.fileObj.tell() == b.get('comp_begin')][0]
if (self.fileObj.tell() + blkSize + 8) == self.compEnd:
blkSize += 8
regen = True
compData = self.fileObj.read(blkSize)
#resultDict = lz4f.decompressFrame(compData, self.dCtx, self.blkSizeID)
resultDict = lz4f.decompressFrame(compData, self.dCtx)
if 'regen' in locals():
self._regenDCTX()
return resultDict.get('decomp')
def read_block(self, blkSize=None, blk=None, setCur=True):
"""
:type int: blkSize - returned from get_block_size()
:type dict: blk - entry from blkDict
:type bool: setCur - update current blk var
Reads the next block, unless provided a blk from blkDict. If provided
a blk, it will read that specific block.
"""
if blk:
self.fileObj.seek(blk.get('comp_begin'))
blkSize = blk.get('blkSize')
if not blkSize:
blkSize = self.get_block_size()
if blkSize == 0:
return ''
if setCur:
try:
iteritems = self.blkDict.iteritems
except AttributeError:
iteritems = self.blkDict.items
self.curBlk = [num for num, b in iteritems()
if self.fileObj.tell() == b.get('comp_begin')][0]
if (self.fileObj.tell() + blkSize + 8) == self.compEnd:
blkSize += 8
regen = True
compData = self.fileObj.read(blkSize)
resultDict = lz4f.decompressFrame(compData, self.dCtx, self.blkSizeID)
if 'regen' in locals():
self._regenDCTX()
return resultDict.get('decomp')
def __loadFrame(self):
self.__iFrame += 1
self.__blockdata = ''
self.__blockpos = 0
# if new index reaches the end of frame array, try to read new one
if self.__iFrame >= len(self.__frames):
frame = self.__readFrame()
# No more frame ?
if frame is None:
return False
self.__frames.append(frame)
# Use an already discovered frame
else:
frame = self.__frames[self.__iFrame]
# Init decompression context with this frame header
raw = self.file.read(frame.szHeader)
res = lz4f.decompressFrame(raw, self.__ctx)
if len(res['decomp']) != 0:
raise IOError('Unexpected output')
return True
def __loadFrame(self):
self.__iFrame += 1
self.__blockdata = ''
self.__blockpos = 0
# if new index reaches the end of frame array, try to read new one
if self.__iFrame >= len(self.__frames):
frame = self.__readFrame()
# No more frame ?
if frame is None:
return False
self.__frames.append(frame)
# Use an already discovered frame
else:
frame = self.__frames[self.__iFrame]
# Init decompression context with this frame header
raw = self.file.read(frame.szHeader)
res = lz4f.decompressFrame(raw, self.__ctx)
if len(res['decomp']) != 0:
raise IOError('Unexpected output')
return True
def lz4_decode(payload):
"""Decode payload using interoperable LZ4 framing. Requires Kafka >= 0.10"""
# pylint: disable-msg=no-member
ctx = lz4f.createDecompContext()
data = lz4f.decompressFrame(payload, ctx)
# lz4f python module does not expose how much of the payload was
# actually read if the decompression was only partial.
if data['next'] != 0:
raise RuntimeError('lz4f unable to decompress full payload')
return data['decomp']
def lz4_decode(payload):
# Kafka's LZ4 code has a bug in its header checksum implementation
header_size = 7
if isinstance(payload[4], int):
flg = payload[4]
else:
flg = ord(payload[4])
content_size_bit = ((flg >> 3) & 1)
if content_size_bit:
header_size += 8
# This should be the correct hc
hc = xxhash.xxh32(payload[4:header_size-1]).digest()[-2:-1] # pylint: disable-msg=no-member
munged_payload = b''.join([
payload[0:header_size-1],
hc,
payload[header_size:]
])
cCtx = lz4f.createCompContext() # pylint: disable-msg=no-member
data = lz4f.decompressFrame(munged_payload, cCtx) # pylint: disable-msg=no-member
return data['decomp']
def lz4_decode(payload):
# Kafka's LZ4 code has a bug in its header checksum implementation
header_size = 7
if isinstance(payload[4], int):
flg = payload[4]
else:
flg = ord(payload[4])
content_size_bit = ((flg >> 3) & 1)
if content_size_bit:
header_size += 8
# This should be the correct hc
hc = xxhash.xxh32(
payload[4:header_size -
1]).digest()[-2:-1] # pylint: disable-msg=no-member
munged_payload = b''.join(
[payload[0:header_size - 1], hc, payload[header_size:]])
cCtx = lz4f.createCompContext() # pylint: disable-msg=no-member
data = lz4f.decompressFrame(munged_payload,
cCtx) # pylint: disable-msg=no-member
return data['decomp']
def extract_slice_data(slison_zip, data_filename, value_type):
with slison_zip.open(data_filename) as slice_file:
data = lz4f.decompressFrame(slice_file.read(),
dCtx=lz4f.createDecompContext())
slice_data = np.frombuffer(data['decomp'], dtype=value_type)
return slice_data
