53 lines
1.4 KiB
Python
53 lines
1.4 KiB
Python
import struct, warnings
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try:
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import lz4
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except:
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lz4 = None
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#old scheme for VERSION < 0.9 otherwise use lz4.block
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def decompress(data):
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(compression,) = struct.unpack(">L", data[4:8])
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scheme = compression >> 27
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size = compression & 0x07ffffff
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if scheme == 0:
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pass
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elif scheme == 1 and lz4:
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res = lz4.decompress(struct.pack("<L", size) + data[8:])
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if len(res) != size:
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warnings.warn("Table decompression failed.")
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else:
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data = res
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else:
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warnings.warn("Table is compressed with an unsupported compression scheme")
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return (data, scheme)
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def compress(scheme, data):
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hdr = data[:4] + struct.pack(">L", (scheme << 27) + (len(data) & 0x07ffffff))
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if scheme == 0 :
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return data
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elif scheme == 1 and lz4:
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res = lz4.compress(hdr + data)
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return res
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else:
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warnings.warn("Table failed to compress by unsupported compression scheme")
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return data
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def _entries(attrs, sameval):
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ak = 0
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vals = []
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lastv = 0
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for k,v in attrs:
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if len(vals) and (k != ak + 1 or (sameval and v != lastv)) :
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yield (ak - len(vals) + 1, len(vals), vals)
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vals = []
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ak = k
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vals.append(v)
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lastv = v
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yield (ak - len(vals) + 1, len(vals), vals)
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def entries(attributes, sameval = False):
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g = _entries(sorted(attributes.iteritems(), key=lambda x:int(x[0])), sameval)
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return g
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